ffmpeg / libavcodec / mpegaudiodec.c @ 191e8ca7
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/*


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* MPEG Audio decoder

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* Copyright (c) 2001, 2002 Fabrice Bellard.

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*

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* This library is free software; you can redistribute it and/or

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* modify it under the terms of the GNU Lesser General Public

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* License as published by the Free Software Foundation; either

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* version 2 of the License, or (at your option) any later version.

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*

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* This library is distributed in the hope that it will be useful,

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* but WITHOUT ANY WARRANTY; without even the implied warranty of

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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

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* Lesser General Public License for more details.

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*

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* You should have received a copy of the GNU Lesser General Public

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* License along with this library; if not, write to the Free Software

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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 021101301 USA

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*/

19  
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/**

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* @file mpegaudiodec.c

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* MPEG Audio decoder.

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*/

24  
25 
//#define DEBUG

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#include "avcodec.h" 
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#include "bitstream.h" 
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#include "dsputil.h" 
29  
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/*

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* TODO:

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*  in low precision mode, use more 16 bit multiplies in synth filter

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*  test lsf / mpeg25 extensively.

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*/

35  
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/* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg

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audio decoder */

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#ifdef CONFIG_MPEGAUDIO_HP

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# define USE_HIGHPRECISION

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#endif

41  
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#include "mpegaudio.h" 
43  
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#include "mathops.h" 
45  
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#define FRAC_ONE (1 << FRAC_BITS) 
47  
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#define FIX(a) ((int)((a) * FRAC_ONE)) 
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/* WARNING: only correct for posititive numbers */

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#define FIXR(a) ((int)((a) * FRAC_ONE + 0.5)) 
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#define FRAC_RND(a) (((a) + (FRAC_ONE/2)) >> FRAC_BITS) 
52  
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#define FIXHR(a) ((int)((a) * (1LL<<32) + 0.5)) 
54  
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/****************/

56  
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#define HEADER_SIZE 4 
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#define BACKSTEP_SIZE 512 
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#define EXTRABYTES 24 
60  
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struct GranuleDef;

62  
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typedef struct MPADecodeContext { 
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DECLARE_ALIGNED_8(uint8_t, last_buf[2*BACKSTEP_SIZE + EXTRABYTES]);

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int last_buf_size;

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int frame_size;

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/* next header (used in free format parsing) */

68 
uint32_t free_format_next_header; 
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int error_protection;

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int layer;

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int sample_rate;

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int sample_rate_index; /* between 0 and 8 */ 
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int bit_rate;

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GetBitContext gb; 
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GetBitContext in_gb; 
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int nb_channels;

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int mode;

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int mode_ext;

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int lsf;

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MPA_INT synth_buf[MPA_MAX_CHANNELS][512 * 2] __attribute__((aligned(16))); 
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int synth_buf_offset[MPA_MAX_CHANNELS];

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int32_t sb_samples[MPA_MAX_CHANNELS][36][SBLIMIT] __attribute__((aligned(16))); 
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int32_t mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */ 
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#ifdef DEBUG

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int frame_count;

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#endif

87 
void (*compute_antialias)(struct MPADecodeContext *s, struct GranuleDef *g); 
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int adu_mode; ///< 0 for standard mp3, 1 for adu formatted mp3 
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int dither_state;

90 
} MPADecodeContext; 
91  
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/**

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* Context for MP3On4 decoder

94 
*/

95 
typedef struct MP3On4DecodeContext { 
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int frames; ///< number of mp3 frames per block (number of mp3 decoder instances) 
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int chan_cfg; ///< channel config number 
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MPADecodeContext *mp3decctx[5]; ///< MPADecodeContext for every decoder instance 
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} MP3On4DecodeContext; 
100  
101 
/* layer 3 "granule" */

102 
typedef struct GranuleDef { 
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uint8_t scfsi; 
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int part2_3_length;

105 
int big_values;

106 
int global_gain;

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int scalefac_compress;

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uint8_t block_type; 
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uint8_t switch_point; 
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int table_select[3]; 
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int subblock_gain[3]; 
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uint8_t scalefac_scale; 
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uint8_t count1table_select; 
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int region_size[3]; /* number of huffman codes in each region */ 
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int preflag;

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int short_start, long_end; /* long/short band indexes */ 
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uint8_t scale_factors[40];

118 
int32_t sb_hybrid[SBLIMIT * 18]; /* 576 samples */ 
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} GranuleDef; 
120  
121 
#define MODE_EXT_MS_STEREO 2 
122 
#define MODE_EXT_I_STEREO 1 
123  
124 
/* layer 3 huffman tables */

125 
typedef struct HuffTable { 
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int xsize;

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const uint8_t *bits;

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const uint16_t *codes;

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} HuffTable; 
130  
131 
#include "mpegaudiodectab.h" 
132  
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static void compute_antialias_integer(MPADecodeContext *s, GranuleDef *g); 
134 
static void compute_antialias_float(MPADecodeContext *s, GranuleDef *g); 
135  
136 
/* vlc structure for decoding layer 3 huffman tables */

137 
static VLC huff_vlc[16]; 
138 
static VLC huff_quad_vlc[2]; 
139 
/* computed from band_size_long */

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static uint16_t band_index_long[9][23]; 
141 
/* XXX: free when all decoders are closed */

142 
#define TABLE_4_3_SIZE (8191 + 16)*4 
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static int8_t *table_4_3_exp;

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static uint32_t *table_4_3_value;

145 
static uint32_t exp_table[512]; 
146 
static uint32_t expval_table[512][16]; 
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/* intensity stereo coef table */

148 
static int32_t is_table[2][16]; 
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static int32_t is_table_lsf[2][2][16]; 
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static int32_t csa_table[8][4]; 
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static float csa_table_float[8][4]; 
152 
static int32_t mdct_win[8][36]; 
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154 
/* lower 2 bits: modulo 3, higher bits: shift */

155 
static uint16_t scale_factor_modshift[64]; 
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/* [i][j]: 2^(j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2)  1) */

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static int32_t scale_factor_mult[15][3]; 
158 
/* mult table for layer 2 group quantization */

159  
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#define SCALE_GEN(v) \

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{ FIXR(1.0 * (v)), FIXR(0.7937005259 * (v)), FIXR(0.6299605249 * (v)) } 
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static const int32_t scale_factor_mult2[3][3] = { 
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SCALE_GEN(4.0 / 3.0), /* 3 steps */ 
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SCALE_GEN(4.0 / 5.0), /* 5 steps */ 
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SCALE_GEN(4.0 / 9.0), /* 9 steps */ 
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}; 
168  
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static MPA_INT window[512] __attribute__((aligned(16))); 
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/* layer 1 unscaling */

172 
/* n = number of bits of the mantissa minus 1 */

173 
static inline int l1_unscale(int n, int mant, int scale_factor) 
174 
{ 
175 
int shift, mod;

176 
int64_t val; 
177  
178 
shift = scale_factor_modshift[scale_factor]; 
179 
mod = shift & 3;

180 
shift >>= 2;

181 
val = MUL64(mant + (1 << n) + 1, scale_factor_mult[n1][mod]); 
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shift += n; 
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/* NOTE: at this point, 1 <= shift >= 21 + 15 */

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return (int)((val + (1LL << (shift  1))) >> shift); 
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} 
186  
187 
static inline int l2_unscale_group(int steps, int mant, int scale_factor) 
188 
{ 
189 
int shift, mod, val;

190  
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shift = scale_factor_modshift[scale_factor]; 
192 
mod = shift & 3;

193 
shift >>= 2;

194  
195 
val = (mant  (steps >> 1)) * scale_factor_mult2[steps >> 2][mod]; 
196 
/* NOTE: at this point, 0 <= shift <= 21 */

197 
if (shift > 0) 
198 
val = (val + (1 << (shift  1))) >> shift; 
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return val;

200 
} 
201  
202 
/* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */

203 
static inline int l3_unscale(int value, int exponent) 
204 
{ 
205 
unsigned int m; 
206 
int e;

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208 
e = table_4_3_exp [4*value + (exponent&3)]; 
209 
m = table_4_3_value[4*value + (exponent&3)]; 
210 
e = (exponent >> 2);

211 
assert(e>=1);

212 
if (e > 31) 
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return 0; 
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m = (m + (1 << (e1))) >> e; 
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return m;

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} 
218  
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/* all integer n^(4/3) computation code */

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#define DEV_ORDER 13 
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#define POW_FRAC_BITS 24 
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#define POW_FRAC_ONE (1 << POW_FRAC_BITS) 
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#define POW_FIX(a) ((int)((a) * POW_FRAC_ONE)) 
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#define POW_MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> POW_FRAC_BITS)

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static int dev_4_3_coefs[DEV_ORDER]; 
228  
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#if 0 /* unused */

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static int pow_mult3[3] = {

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POW_FIX(1.0),

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POW_FIX(1.25992104989487316476),

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POW_FIX(1.58740105196819947474),

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};

235 
#endif

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static void int_pow_init(void) 
238 
{ 
239 
int i, a;

240  
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a = POW_FIX(1.0); 
242 
for(i=0;i<DEV_ORDER;i++) { 
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a = POW_MULL(a, POW_FIX(4.0 / 3.0)  i * POW_FIX(1.0)) / (i + 1); 
244 
dev_4_3_coefs[i] = a; 
245 
} 
246 
} 
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248 
#if 0 /* unused, remove? */

249 
/* return the mantissa and the binary exponent */

250 
static int int_pow(int i, int *exp_ptr)

251 
{

252 
int e, er, eq, j;

253 
int a, a1;

254 

255 
/* renormalize */

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a = i;

257 
e = POW_FRAC_BITS;

258 
while (a < (1 << (POW_FRAC_BITS  1))) {

259 
a = a << 1;

260 
e;

261 
}

262 
a = (1 << POW_FRAC_BITS);

263 
a1 = 0;

264 
for(j = DEV_ORDER  1; j >= 0; j)

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a1 = POW_MULL(a, dev_4_3_coefs[j] + a1);

266 
a = (1 << POW_FRAC_BITS) + a1;

267 
/* exponent compute (exact) */

268 
e = e * 4;

269 
er = e % 3;

270 
eq = e / 3;

271 
a = POW_MULL(a, pow_mult3[er]);

272 
while (a >= 2 * POW_FRAC_ONE) {

273 
a = a >> 1;

274 
eq++;

275 
}

276 
/* convert to float */

277 
while (a < POW_FRAC_ONE) {

278 
a = a << 1;

279 
eq;

280 
}

281 
/* now POW_FRAC_ONE <= a < 2 * POW_FRAC_ONE */

282 
#if POW_FRAC_BITS > FRAC_BITS

283 
a = (a + (1 << (POW_FRAC_BITS  FRAC_BITS  1))) >> (POW_FRAC_BITS  FRAC_BITS);

284 
/* correct overflow */

285 
if (a >= 2 * (1 << FRAC_BITS)) {

286 
a = a >> 1;

287 
eq++;

288 
}

289 
#endif

290 
*exp_ptr = eq; 
291 
return a;

292 
} 
293 
#endif

294  
295 
static int decode_init(AVCodecContext * avctx) 
296 
{ 
297 
MPADecodeContext *s = avctx>priv_data; 
298 
static int init=0; 
299 
int i, j, k;

300  
301 
#if defined(USE_HIGHPRECISION) && defined(CONFIG_AUDIO_NONSHORT)

302 
avctx>sample_fmt= SAMPLE_FMT_S32; 
303 
#else

304 
avctx>sample_fmt= SAMPLE_FMT_S16; 
305 
#endif

306  
307 
if(avctx>antialias_algo != FF_AA_FLOAT)

308 
s>compute_antialias= compute_antialias_integer; 
309 
else

310 
s>compute_antialias= compute_antialias_float; 
311  
312 
if (!init && !avctx>parse_only) {

313 
/* scale factors table for layer 1/2 */

314 
for(i=0;i<64;i++) { 
315 
int shift, mod;

316 
/* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */

317 
shift = (i / 3);

318 
mod = i % 3;

319 
scale_factor_modshift[i] = mod  (shift << 2);

320 
} 
321  
322 
/* scale factor multiply for layer 1 */

323 
for(i=0;i<15;i++) { 
324 
int n, norm;

325 
n = i + 2;

326 
norm = ((int64_t_C(1) << n) * FRAC_ONE) / ((1 << n)  1); 
327 
scale_factor_mult[i][0] = MULL(FIXR(1.0 * 2.0), norm); 
328 
scale_factor_mult[i][1] = MULL(FIXR(0.7937005259 * 2.0), norm); 
329 
scale_factor_mult[i][2] = MULL(FIXR(0.6299605249 * 2.0), norm); 
330 
dprintf("%d: norm=%x s=%x %x %x\n",

331 
i, norm, 
332 
scale_factor_mult[i][0],

333 
scale_factor_mult[i][1],

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scale_factor_mult[i][2]);

335 
} 
336  
337 
ff_mpa_synth_init(window); 
338  
339 
/* huffman decode tables */

340 
for(i=1;i<16;i++) { 
341 
const HuffTable *h = &mpa_huff_tables[i];

342 
int xsize, x, y;

343 
unsigned int n; 
344 
uint8_t tmp_bits [512];

345 
uint16_t tmp_codes[512];

346  
347 
memset(tmp_bits , 0, sizeof(tmp_bits )); 
348 
memset(tmp_codes, 0, sizeof(tmp_codes)); 
349  
350 
xsize = h>xsize; 
351 
n = xsize * xsize; 
352  
353 
j = 0;

354 
for(x=0;x<xsize;x++) { 
355 
for(y=0;y<xsize;y++){ 
356 
tmp_bits [(x << 5)  y  ((x&&y)<<4)]= h>bits [j ]; 
357 
tmp_codes[(x << 5)  y  ((x&&y)<<4)]= h>codes[j++]; 
358 
} 
359 
} 
360  
361 
/* XXX: fail test */

362 
init_vlc(&huff_vlc[i], 7, 512, 
363 
tmp_bits, 1, 1, tmp_codes, 2, 2, 1); 
364 
} 
365 
for(i=0;i<2;i++) { 
366 
init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16, 
367 
mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1, 1); 
368 
} 
369  
370 
for(i=0;i<9;i++) { 
371 
k = 0;

372 
for(j=0;j<22;j++) { 
373 
band_index_long[i][j] = k; 
374 
k += band_size_long[i][j]; 
375 
} 
376 
band_index_long[i][22] = k;

377 
} 
378  
379 
/* compute n ^ (4/3) and store it in mantissa/exp format */

380 
table_4_3_exp= av_mallocz_static(TABLE_4_3_SIZE * sizeof(table_4_3_exp[0])); 
381 
if(!table_4_3_exp)

382 
return 1; 
383 
table_4_3_value= av_mallocz_static(TABLE_4_3_SIZE * sizeof(table_4_3_value[0])); 
384 
if(!table_4_3_value)

385 
return 1; 
386  
387 
int_pow_init(); 
388 
for(i=1;i<TABLE_4_3_SIZE;i++) { 
389 
double f, fm;

390 
int e, m;

391 
f = pow((double)(i/4), 4.0 / 3.0) * pow(2, (i&3)*0.25); 
392 
fm = frexp(f, &e); 
393 
m = (uint32_t)(fm*(1LL<<31) + 0.5); 
394 
e+= FRAC_BITS  31 + 5  100; 
395  
396 
/* normalized to FRAC_BITS */

397 
table_4_3_value[i] = m; 
398 
// av_log(NULL, AV_LOG_DEBUG, "%d %d %f\n", i, m, pow((double)i, 4.0 / 3.0));

399 
table_4_3_exp[i] = e; 
400 
} 
401 
for(i=0; i<512*16; i++){ 
402 
int exponent= (i>>4); 
403 
double f= pow(i&15, 4.0 / 3.0) * pow(2, (exponent400)*0.25 + FRAC_BITS + 5); 
404 
expval_table[exponent][i&15]= llrint(f);

405 
if((i&15)==1) 
406 
exp_table[exponent]= llrint(f); 
407 
} 
408  
409 
for(i=0;i<7;i++) { 
410 
float f;

411 
int v;

412 
if (i != 6) { 
413 
f = tan((double)i * M_PI / 12.0); 
414 
v = FIXR(f / (1.0 + f)); 
415 
} else {

416 
v = FIXR(1.0); 
417 
} 
418 
is_table[0][i] = v;

419 
is_table[1][6  i] = v; 
420 
} 
421 
/* invalid values */

422 
for(i=7;i<16;i++) 
423 
is_table[0][i] = is_table[1][i] = 0.0; 
424  
425 
for(i=0;i<16;i++) { 
426 
double f;

427 
int e, k;

428  
429 
for(j=0;j<2;j++) { 
430 
e = (j + 1) * ((i + 1) >> 1); 
431 
f = pow(2.0, e / 4.0); 
432 
k = i & 1;

433 
is_table_lsf[j][k ^ 1][i] = FIXR(f);

434 
is_table_lsf[j][k][i] = FIXR(1.0); 
435 
dprintf("is_table_lsf %d %d: %x %x\n",

436 
i, j, is_table_lsf[j][0][i], is_table_lsf[j][1][i]); 
437 
} 
438 
} 
439  
440 
for(i=0;i<8;i++) { 
441 
float ci, cs, ca;

442 
ci = ci_table[i]; 
443 
cs = 1.0 / sqrt(1.0 + ci * ci); 
444 
ca = cs * ci; 
445 
csa_table[i][0] = FIXHR(cs/4); 
446 
csa_table[i][1] = FIXHR(ca/4); 
447 
csa_table[i][2] = FIXHR(ca/4) + FIXHR(cs/4); 
448 
csa_table[i][3] = FIXHR(ca/4)  FIXHR(cs/4); 
449 
csa_table_float[i][0] = cs;

450 
csa_table_float[i][1] = ca;

451 
csa_table_float[i][2] = ca + cs;

452 
csa_table_float[i][3] = ca  cs;

453 
// printf("%d %d %d %d\n", FIX(cs), FIX(cs1), FIX(ca), FIX(cs)FIX(ca));

454 
// av_log(NULL, AV_LOG_DEBUG,"%f %f %f %f\n", cs, ca, ca+cs, cacs);

455 
} 
456  
457 
/* compute mdct windows */

458 
for(i=0;i<36;i++) { 
459 
for(j=0; j<4; j++){ 
460 
double d;

461  
462 
if(j==2 && i%3 != 1) 
463 
continue;

464  
465 
d= sin(M_PI * (i + 0.5) / 36.0); 
466 
if(j==1){ 
467 
if (i>=30) d= 0; 
468 
else if(i>=24) d= sin(M_PI * (i  18 + 0.5) / 12.0); 
469 
else if(i>=18) d= 1; 
470 
}else if(j==3){ 
471 
if (i< 6) d= 0; 
472 
else if(i< 12) d= sin(M_PI * (i  6 + 0.5) / 12.0); 
473 
else if(i< 18) d= 1; 
474 
} 
475 
//merge last stage of imdct into the window coefficients

476 
d*= 0.5 / cos(M_PI*(2*i + 19)/72); 
477  
478 
if(j==2) 
479 
mdct_win[j][i/3] = FIXHR((d / (1<<5))); 
480 
else

481 
mdct_win[j][i ] = FIXHR((d / (1<<5))); 
482 
// av_log(NULL, AV_LOG_DEBUG, "%2d %d %f\n", i,j,d / (1<<5));

483 
} 
484 
} 
485  
486 
/* NOTE: we do frequency inversion adter the MDCT by changing

487 
the sign of the right window coefs */

488 
for(j=0;j<4;j++) { 
489 
for(i=0;i<36;i+=2) { 
490 
mdct_win[j + 4][i] = mdct_win[j][i];

491 
mdct_win[j + 4][i + 1] = mdct_win[j][i + 1]; 
492 
} 
493 
} 
494  
495 
#if defined(DEBUG)

496 
for(j=0;j<8;j++) { 
497 
av_log(avctx, AV_LOG_DEBUG, "win%d=\n", j);

498 
for(i=0;i<36;i++) 
499 
av_log(avctx, AV_LOG_DEBUG, "%f, ", (double)mdct_win[j][i] / FRAC_ONE); 
500 
av_log(avctx, AV_LOG_DEBUG, "\n");

501 
} 
502 
#endif

503 
init = 1;

504 
} 
505  
506 
#ifdef DEBUG

507 
s>frame_count = 0;

508 
#endif

509 
if (avctx>codec_id == CODEC_ID_MP3ADU)

510 
s>adu_mode = 1;

511 
return 0; 
512 
} 
513  
514 
/* tab[i][j] = 1.0 / (2.0 * cos(pi*(2*k+1) / 2^(6  j))) */

515  
516 
/* cos(i*pi/64) */

517  
518 
#define COS0_0 FIXHR(0.50060299823519630134/2) 
519 
#define COS0_1 FIXHR(0.50547095989754365998/2) 
520 
#define COS0_2 FIXHR(0.51544730992262454697/2) 
521 
#define COS0_3 FIXHR(0.53104259108978417447/2) 
522 
#define COS0_4 FIXHR(0.55310389603444452782/2) 
523 
#define COS0_5 FIXHR(0.58293496820613387367/2) 
524 
#define COS0_6 FIXHR(0.62250412303566481615/2) 
525 
#define COS0_7 FIXHR(0.67480834145500574602/2) 
526 
#define COS0_8 FIXHR(0.74453627100229844977/2) 
527 
#define COS0_9 FIXHR(0.83934964541552703873/2) 
528 
#define COS0_10 FIXHR(0.97256823786196069369/2) 
529 
#define COS0_11 FIXHR(1.16943993343288495515/4) 
530 
#define COS0_12 FIXHR(1.48416461631416627724/4) 
531 
#define COS0_13 FIXHR(2.05778100995341155085/8) 
532 
#define COS0_14 FIXHR(3.40760841846871878570/8) 
533 
#define COS0_15 FIXHR(10.19000812354805681150/32) 
534  
535 
#define COS1_0 FIXHR(0.50241928618815570551/2) 
536 
#define COS1_1 FIXHR(0.52249861493968888062/2) 
537 
#define COS1_2 FIXHR(0.56694403481635770368/2) 
538 
#define COS1_3 FIXHR(0.64682178335999012954/2) 
539 
#define COS1_4 FIXHR(0.78815462345125022473/2) 
540 
#define COS1_5 FIXHR(1.06067768599034747134/4) 
541 
#define COS1_6 FIXHR(1.72244709823833392782/4) 
542 
#define COS1_7 FIXHR(5.10114861868916385802/16) 
543  
544 
#define COS2_0 FIXHR(0.50979557910415916894/2) 
545 
#define COS2_1 FIXHR(0.60134488693504528054/2) 
546 
#define COS2_2 FIXHR(0.89997622313641570463/2) 
547 
#define COS2_3 FIXHR(2.56291544774150617881/8) 
548  
549 
#define COS3_0 FIXHR(0.54119610014619698439/2) 
550 
#define COS3_1 FIXHR(1.30656296487637652785/4) 
551  
552 
#define COS4_0 FIXHR(0.70710678118654752439/2) 
553  
554 
/* butterfly operator */

555 
#define BF(a, b, c, s)\

556 
{\ 
557 
tmp0 = tab[a] + tab[b];\ 
558 
tmp1 = tab[a]  tab[b];\ 
559 
tab[a] = tmp0;\ 
560 
tab[b] = MULH(tmp1<<(s), c);\ 
561 
} 
562  
563 
#define BF1(a, b, c, d)\

564 
{\ 
565 
BF(a, b, COS4_0, 1);\

566 
BF(c, d,COS4_0, 1);\

567 
tab[c] += tab[d];\ 
568 
} 
569  
570 
#define BF2(a, b, c, d)\

571 
{\ 
572 
BF(a, b, COS4_0, 1);\

573 
BF(c, d,COS4_0, 1);\

574 
tab[c] += tab[d];\ 
575 
tab[a] += tab[c];\ 
576 
tab[c] += tab[b];\ 
577 
tab[b] += tab[d];\ 
578 
} 
579  
580 
#define ADD(a, b) tab[a] += tab[b]

581  
582 
/* DCT32 without 1/sqrt(2) coef zero scaling. */

583 
static void dct32(int32_t *out, int32_t *tab) 
584 
{ 
585 
int tmp0, tmp1;

586  
587 
/* pass 1 */

588 
BF( 0, 31, COS0_0 , 1); 
589 
BF(15, 16, COS0_15, 5); 
590 
/* pass 2 */

591 
BF( 0, 15, COS1_0 , 1); 
592 
BF(16, 31,COS1_0 , 1); 
593 
/* pass 1 */

594 
BF( 7, 24, COS0_7 , 1); 
595 
BF( 8, 23, COS0_8 , 1); 
596 
/* pass 2 */

597 
BF( 7, 8, COS1_7 , 4); 
598 
BF(23, 24,COS1_7 , 4); 
599 
/* pass 3 */

600 
BF( 0, 7, COS2_0 , 1); 
601 
BF( 8, 15,COS2_0 , 1); 
602 
BF(16, 23, COS2_0 , 1); 
603 
BF(24, 31,COS2_0 , 1); 
604 
/* pass 1 */

605 
BF( 3, 28, COS0_3 , 1); 
606 
BF(12, 19, COS0_12, 2); 
607 
/* pass 2 */

608 
BF( 3, 12, COS1_3 , 1); 
609 
BF(19, 28,COS1_3 , 1); 
610 
/* pass 1 */

611 
BF( 4, 27, COS0_4 , 1); 
612 
BF(11, 20, COS0_11, 2); 
613 
/* pass 2 */

614 
BF( 4, 11, COS1_4 , 1); 
615 
BF(20, 27,COS1_4 , 1); 
616 
/* pass 3 */

617 
BF( 3, 4, COS2_3 , 3); 
618 
BF(11, 12,COS2_3 , 3); 
619 
BF(19, 20, COS2_3 , 3); 
620 
BF(27, 28,COS2_3 , 3); 
621 
/* pass 4 */

622 
BF( 0, 3, COS3_0 , 1); 
623 
BF( 4, 7,COS3_0 , 1); 
624 
BF( 8, 11, COS3_0 , 1); 
625 
BF(12, 15,COS3_0 , 1); 
626 
BF(16, 19, COS3_0 , 1); 
627 
BF(20, 23,COS3_0 , 1); 
628 
BF(24, 27, COS3_0 , 1); 
629 
BF(28, 31,COS3_0 , 1); 
630  
631  
632  
633 
/* pass 1 */

634 
BF( 1, 30, COS0_1 , 1); 
635 
BF(14, 17, COS0_14, 3); 
636 
/* pass 2 */

637 
BF( 1, 14, COS1_1 , 1); 
638 
BF(17, 30,COS1_1 , 1); 
639 
/* pass 1 */

640 
BF( 6, 25, COS0_6 , 1); 
641 
BF( 9, 22, COS0_9 , 1); 
642 
/* pass 2 */

643 
BF( 6, 9, COS1_6 , 2); 
644 
BF(22, 25,COS1_6 , 2); 
645 
/* pass 3 */

646 
BF( 1, 6, COS2_1 , 1); 
647 
BF( 9, 14,COS2_1 , 1); 
648 
BF(17, 22, COS2_1 , 1); 
649 
BF(25, 30,COS2_1 , 1); 
650  
651 
/* pass 1 */

652 
BF( 2, 29, COS0_2 , 1); 
653 
BF(13, 18, COS0_13, 3); 
654 
/* pass 2 */

655 
BF( 2, 13, COS1_2 , 1); 
656 
BF(18, 29,COS1_2 , 1); 
657 
/* pass 1 */

658 
BF( 5, 26, COS0_5 , 1); 
659 
BF(10, 21, COS0_10, 1); 
660 
/* pass 2 */

661 
BF( 5, 10, COS1_5 , 2); 
662 
BF(21, 26,COS1_5 , 2); 
663 
/* pass 3 */

664 
BF( 2, 5, COS2_2 , 1); 
665 
BF(10, 13,COS2_2 , 1); 
666 
BF(18, 21, COS2_2 , 1); 
667 
BF(26, 29,COS2_2 , 1); 
668 
/* pass 4 */

669 
BF( 1, 2, COS3_1 , 2); 
670 
BF( 5, 6,COS3_1 , 2); 
671 
BF( 9, 10, COS3_1 , 2); 
672 
BF(13, 14,COS3_1 , 2); 
673 
BF(17, 18, COS3_1 , 2); 
674 
BF(21, 22,COS3_1 , 2); 
675 
BF(25, 26, COS3_1 , 2); 
676 
BF(29, 30,COS3_1 , 2); 
677  
678 
/* pass 5 */

679 
BF1( 0, 1, 2, 3); 
680 
BF2( 4, 5, 6, 7); 
681 
BF1( 8, 9, 10, 11); 
682 
BF2(12, 13, 14, 15); 
683 
BF1(16, 17, 18, 19); 
684 
BF2(20, 21, 22, 23); 
685 
BF1(24, 25, 26, 27); 
686 
BF2(28, 29, 30, 31); 
687  
688 
/* pass 6 */

689  
690 
ADD( 8, 12); 
691 
ADD(12, 10); 
692 
ADD(10, 14); 
693 
ADD(14, 9); 
694 
ADD( 9, 13); 
695 
ADD(13, 11); 
696 
ADD(11, 15); 
697  
698 
out[ 0] = tab[0]; 
699 
out[16] = tab[1]; 
700 
out[ 8] = tab[2]; 
701 
out[24] = tab[3]; 
702 
out[ 4] = tab[4]; 
703 
out[20] = tab[5]; 
704 
out[12] = tab[6]; 
705 
out[28] = tab[7]; 
706 
out[ 2] = tab[8]; 
707 
out[18] = tab[9]; 
708 
out[10] = tab[10]; 
709 
out[26] = tab[11]; 
710 
out[ 6] = tab[12]; 
711 
out[22] = tab[13]; 
712 
out[14] = tab[14]; 
713 
out[30] = tab[15]; 
714  
715 
ADD(24, 28); 
716 
ADD(28, 26); 
717 
ADD(26, 30); 
718 
ADD(30, 25); 
719 
ADD(25, 29); 
720 
ADD(29, 27); 
721 
ADD(27, 31); 
722  
723 
out[ 1] = tab[16] + tab[24]; 
724 
out[17] = tab[17] + tab[25]; 
725 
out[ 9] = tab[18] + tab[26]; 
726 
out[25] = tab[19] + tab[27]; 
727 
out[ 5] = tab[20] + tab[28]; 
728 
out[21] = tab[21] + tab[29]; 
729 
out[13] = tab[22] + tab[30]; 
730 
out[29] = tab[23] + tab[31]; 
731 
out[ 3] = tab[24] + tab[20]; 
732 
out[19] = tab[25] + tab[21]; 
733 
out[11] = tab[26] + tab[22]; 
734 
out[27] = tab[27] + tab[23]; 
735 
out[ 7] = tab[28] + tab[18]; 
736 
out[23] = tab[29] + tab[19]; 
737 
out[15] = tab[30] + tab[17]; 
738 
out[31] = tab[31]; 
739 
} 
740  
741 
#if FRAC_BITS <= 15 
742  
743 
static inline int round_sample(int *sum) 
744 
{ 
745 
int sum1;

746 
sum1 = (*sum) >> OUT_SHIFT; 
747 
*sum &= (1<<OUT_SHIFT)1; 
748 
if (sum1 < OUT_MIN)

749 
sum1 = OUT_MIN; 
750 
else if (sum1 > OUT_MAX) 
751 
sum1 = OUT_MAX; 
752 
return sum1;

753 
} 
754  
755 
/* signed 16x16 > 32 multiply add accumulate */

756 
#define MACS(rt, ra, rb) MAC16(rt, ra, rb)

757  
758 
/* signed 16x16 > 32 multiply */

759 
#define MULS(ra, rb) MUL16(ra, rb)

760  
761 
#else

762  
763 
static inline int round_sample(int64_t *sum) 
764 
{ 
765 
int sum1;

766 
sum1 = (int)((*sum) >> OUT_SHIFT);

767 
*sum &= (1<<OUT_SHIFT)1; 
768 
if (sum1 < OUT_MIN)

769 
sum1 = OUT_MIN; 
770 
else if (sum1 > OUT_MAX) 
771 
sum1 = OUT_MAX; 
772 
return sum1;

773 
} 
774  
775 
# define MULS(ra, rb) MUL64(ra, rb)

776 
#endif

777  
778 
#define SUM8(sum, op, w, p) \

779 
{ \ 
780 
sum op MULS((w)[0 * 64], p[0 * 64]);\ 
781 
sum op MULS((w)[1 * 64], p[1 * 64]);\ 
782 
sum op MULS((w)[2 * 64], p[2 * 64]);\ 
783 
sum op MULS((w)[3 * 64], p[3 * 64]);\ 
784 
sum op MULS((w)[4 * 64], p[4 * 64]);\ 
785 
sum op MULS((w)[5 * 64], p[5 * 64]);\ 
786 
sum op MULS((w)[6 * 64], p[6 * 64]);\ 
787 
sum op MULS((w)[7 * 64], p[7 * 64]);\ 
788 
} 
789  
790 
#define SUM8P2(sum1, op1, sum2, op2, w1, w2, p) \

791 
{ \ 
792 
int tmp;\

793 
tmp = p[0 * 64];\ 
794 
sum1 op1 MULS((w1)[0 * 64], tmp);\ 
795 
sum2 op2 MULS((w2)[0 * 64], tmp);\ 
796 
tmp = p[1 * 64];\ 
797 
sum1 op1 MULS((w1)[1 * 64], tmp);\ 
798 
sum2 op2 MULS((w2)[1 * 64], tmp);\ 
799 
tmp = p[2 * 64];\ 
800 
sum1 op1 MULS((w1)[2 * 64], tmp);\ 
801 
sum2 op2 MULS((w2)[2 * 64], tmp);\ 
802 
tmp = p[3 * 64];\ 
803 
sum1 op1 MULS((w1)[3 * 64], tmp);\ 
804 
sum2 op2 MULS((w2)[3 * 64], tmp);\ 
805 
tmp = p[4 * 64];\ 
806 
sum1 op1 MULS((w1)[4 * 64], tmp);\ 
807 
sum2 op2 MULS((w2)[4 * 64], tmp);\ 
808 
tmp = p[5 * 64];\ 
809 
sum1 op1 MULS((w1)[5 * 64], tmp);\ 
810 
sum2 op2 MULS((w2)[5 * 64], tmp);\ 
811 
tmp = p[6 * 64];\ 
812 
sum1 op1 MULS((w1)[6 * 64], tmp);\ 
813 
sum2 op2 MULS((w2)[6 * 64], tmp);\ 
814 
tmp = p[7 * 64];\ 
815 
sum1 op1 MULS((w1)[7 * 64], tmp);\ 
816 
sum2 op2 MULS((w2)[7 * 64], tmp);\ 
817 
} 
818  
819 
void ff_mpa_synth_init(MPA_INT *window)

820 
{ 
821 
int i;

822  
823 
/* max = 18760, max sum over all 16 coefs : 44736 */

824 
for(i=0;i<257;i++) { 
825 
int v;

826 
v = mpa_enwindow[i]; 
827 
#if WFRAC_BITS < 16 
828 
v = (v + (1 << (16  WFRAC_BITS  1))) >> (16  WFRAC_BITS); 
829 
#endif

830 
window[i] = v; 
831 
if ((i & 63) != 0) 
832 
v = v; 
833 
if (i != 0) 
834 
window[512  i] = v;

835 
} 
836 
} 
837  
838 
/* 32 sub band synthesis filter. Input: 32 sub band samples, Output:

839 
32 samples. */

840 
/* XXX: optimize by avoiding ring buffer usage */

841 
void ff_mpa_synth_filter(MPA_INT *synth_buf_ptr, int *synth_buf_offset, 
842 
MPA_INT *window, int *dither_state,

843 
OUT_INT *samples, int incr,

844 
int32_t sb_samples[SBLIMIT]) 
845 
{ 
846 
int32_t tmp[32];

847 
register MPA_INT *synth_buf;

848 
register const MPA_INT *w, *w2, *p; 
849 
int j, offset, v;

850 
OUT_INT *samples2; 
851 
#if FRAC_BITS <= 15 
852 
int sum, sum2;

853 
#else

854 
int64_t sum, sum2; 
855 
#endif

856  
857 
dct32(tmp, sb_samples); 
858  
859 
offset = *synth_buf_offset; 
860 
synth_buf = synth_buf_ptr + offset; 
861  
862 
for(j=0;j<32;j++) { 
863 
v = tmp[j]; 
864 
#if FRAC_BITS <= 15 
865 
/* NOTE: can cause a loss in precision if very high amplitude

866 
sound */

867 
if (v > 32767) 
868 
v = 32767;

869 
else if (v < 32768) 
870 
v = 32768;

871 
#endif

872 
synth_buf[j] = v; 
873 
} 
874 
/* copy to avoid wrap */

875 
memcpy(synth_buf + 512, synth_buf, 32 * sizeof(MPA_INT)); 
876  
877 
samples2 = samples + 31 * incr;

878 
w = window; 
879 
w2 = window + 31;

880  
881 
sum = *dither_state; 
882 
p = synth_buf + 16;

883 
SUM8(sum, +=, w, p); 
884 
p = synth_buf + 48;

885 
SUM8(sum, =, w + 32, p);

886 
*samples = round_sample(&sum); 
887 
samples += incr; 
888 
w++; 
889  
890 
/* we calculate two samples at the same time to avoid one memory

891 
access per two sample */

892 
for(j=1;j<16;j++) { 
893 
sum2 = 0;

894 
p = synth_buf + 16 + j;

895 
SUM8P2(sum, +=, sum2, =, w, w2, p); 
896 
p = synth_buf + 48  j;

897 
SUM8P2(sum, =, sum2, =, w + 32, w2 + 32, p); 
898  
899 
*samples = round_sample(&sum); 
900 
samples += incr; 
901 
sum += sum2; 
902 
*samples2 = round_sample(&sum); 
903 
samples2 = incr; 
904 
w++; 
905 
w2; 
906 
} 
907  
908 
p = synth_buf + 32;

909 
SUM8(sum, =, w + 32, p);

910 
*samples = round_sample(&sum); 
911 
*dither_state= sum; 
912  
913 
offset = (offset  32) & 511; 
914 
*synth_buf_offset = offset; 
915 
} 
916  
917 
#define C3 FIXHR(0.86602540378443864676/2) 
918  
919 
/* 0.5 / cos(pi*(2*i+1)/36) */

920 
static const int icos36[9] = { 
921 
FIXR(0.50190991877167369479), 
922 
FIXR(0.51763809020504152469), //0 
923 
FIXR(0.55168895948124587824), 
924 
FIXR(0.61038729438072803416), 
925 
FIXR(0.70710678118654752439), //1 
926 
FIXR(0.87172339781054900991), 
927 
FIXR(1.18310079157624925896), 
928 
FIXR(1.93185165257813657349), //2 
929 
FIXR(5.73685662283492756461), 
930 
}; 
931  
932 
/* 0.5 / cos(pi*(2*i+1)/36) */

933 
static const int icos36h[9] = { 
934 
FIXHR(0.50190991877167369479/2), 
935 
FIXHR(0.51763809020504152469/2), //0 
936 
FIXHR(0.55168895948124587824/2), 
937 
FIXHR(0.61038729438072803416/2), 
938 
FIXHR(0.70710678118654752439/2), //1 
939 
FIXHR(0.87172339781054900991/2), 
940 
FIXHR(1.18310079157624925896/4), 
941 
FIXHR(1.93185165257813657349/4), //2 
942 
// FIXHR(5.73685662283492756461),

943 
}; 
944  
945 
/* 12 points IMDCT. We compute it "by hand" by factorizing obvious

946 
cases. */

947 
static void imdct12(int *out, int *in) 
948 
{ 
949 
int in0, in1, in2, in3, in4, in5, t1, t2;

950  
951 
in0= in[0*3]; 
952 
in1= in[1*3] + in[0*3]; 
953 
in2= in[2*3] + in[1*3]; 
954 
in3= in[3*3] + in[2*3]; 
955 
in4= in[4*3] + in[3*3]; 
956 
in5= in[5*3] + in[4*3]; 
957 
in5 += in3; 
958 
in3 += in1; 
959  
960 
in2= MULH(2*in2, C3);

961 
in3= MULH(4*in3, C3);

962  
963 
t1 = in0  in4; 
964 
t2 = MULH(2*(in1  in5), icos36h[4]); 
965  
966 
out[ 7]=

967 
out[10]= t1 + t2;

968 
out[ 1]=

969 
out[ 4]= t1  t2;

970  
971 
in0 += in4>>1;

972 
in4 = in0 + in2; 
973 
in5 += 2*in1;

974 
in1 = MULH(in5 + in3, icos36h[1]);

975 
out[ 8]=

976 
out[ 9]= in4 + in1;

977 
out[ 2]=

978 
out[ 3]= in4  in1;

979  
980 
in0 = in2; 
981 
in5 = MULH(2*(in5  in3), icos36h[7]); 
982 
out[ 0]=

983 
out[ 5]= in0  in5;

984 
out[ 6]=

985 
out[11]= in0 + in5;

986 
} 
987  
988 
/* cos(pi*i/18) */

989 
#define C1 FIXHR(0.98480775301220805936/2) 
990 
#define C2 FIXHR(0.93969262078590838405/2) 
991 
#define C3 FIXHR(0.86602540378443864676/2) 
992 
#define C4 FIXHR(0.76604444311897803520/2) 
993 
#define C5 FIXHR(0.64278760968653932632/2) 
994 
#define C6 FIXHR(0.5/2) 
995 
#define C7 FIXHR(0.34202014332566873304/2) 
996 
#define C8 FIXHR(0.17364817766693034885/2) 
997  
998  
999 
/* using Lee like decomposition followed by hand coded 9 points DCT */

1000 
static void imdct36(int *out, int *buf, int *in, int *win) 
1001 
{ 
1002 
int i, j, t0, t1, t2, t3, s0, s1, s2, s3;

1003 
int tmp[18], *tmp1, *in1; 
1004  
1005 
for(i=17;i>=1;i) 
1006 
in[i] += in[i1];

1007 
for(i=17;i>=3;i=2) 
1008 
in[i] += in[i2];

1009  
1010 
for(j=0;j<2;j++) { 
1011 
tmp1 = tmp + j; 
1012 
in1 = in + j; 
1013 
#if 0

1014 
//more accurate but slower

1015 
int64_t t0, t1, t2, t3;

1016 
t2 = in1[2*4] + in1[2*8]  in1[2*2];

1017 

1018 
t3 = (in1[2*0] + (int64_t)(in1[2*6]>>1))<<32;

1019 
t1 = in1[2*0]  in1[2*6];

1020 
tmp1[ 6] = t1  (t2>>1);

1021 
tmp1[16] = t1 + t2;

1022 

1023 
t0 = MUL64(2*(in1[2*2] + in1[2*4]), C2);

1024 
t1 = MUL64( in1[2*4]  in1[2*8] , 2*C8);

1025 
t2 = MUL64(2*(in1[2*2] + in1[2*8]), C4);

1026 

1027 
tmp1[10] = (t3  t0  t2) >> 32;

1028 
tmp1[ 2] = (t3 + t0 + t1) >> 32;

1029 
tmp1[14] = (t3 + t2  t1) >> 32;

1030 

1031 
tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7]  in1[2*1]), C3);

1032 
t2 = MUL64(2*(in1[2*1] + in1[2*5]), C1);

1033 
t3 = MUL64( in1[2*5]  in1[2*7] , 2*C7);

1034 
t0 = MUL64(2*in1[2*3], C3);

1035 

1036 
t1 = MUL64(2*(in1[2*1] + in1[2*7]), C5);

1037 

1038 
tmp1[ 0] = (t2 + t3 + t0) >> 32;

1039 
tmp1[12] = (t2 + t1  t0) >> 32;

1040 
tmp1[ 8] = (t3  t1  t0) >> 32;

1041 
#else

1042 
t2 = in1[2*4] + in1[2*8]  in1[2*2]; 
1043  
1044 
t3 = in1[2*0] + (in1[2*6]>>1); 
1045 
t1 = in1[2*0]  in1[2*6]; 
1046 
tmp1[ 6] = t1  (t2>>1); 
1047 
tmp1[16] = t1 + t2;

1048  
1049 
t0 = MULH(2*(in1[2*2] + in1[2*4]), C2); 
1050 
t1 = MULH( in1[2*4]  in1[2*8] , 2*C8); 
1051 
t2 = MULH(2*(in1[2*2] + in1[2*8]), C4); 
1052  
1053 
tmp1[10] = t3  t0  t2;

1054 
tmp1[ 2] = t3 + t0 + t1;

1055 
tmp1[14] = t3 + t2  t1;

1056  
1057 
tmp1[ 4] = MULH(2*(in1[2*5] + in1[2*7]  in1[2*1]), C3); 
1058 
t2 = MULH(2*(in1[2*1] + in1[2*5]), C1); 
1059 
t3 = MULH( in1[2*5]  in1[2*7] , 2*C7); 
1060 
t0 = MULH(2*in1[2*3], C3); 
1061  
1062 
t1 = MULH(2*(in1[2*1] + in1[2*7]), C5); 
1063  
1064 
tmp1[ 0] = t2 + t3 + t0;

1065 
tmp1[12] = t2 + t1  t0;

1066 
tmp1[ 8] = t3  t1  t0;

1067 
#endif

1068 
} 
1069  
1070 
i = 0;

1071 
for(j=0;j<4;j++) { 
1072 
t0 = tmp[i]; 
1073 
t1 = tmp[i + 2];

1074 
s0 = t1 + t0; 
1075 
s2 = t1  t0; 
1076  
1077 
t2 = tmp[i + 1];

1078 
t3 = tmp[i + 3];

1079 
s1 = MULH(2*(t3 + t2), icos36h[j]);

1080 
s3 = MULL(t3  t2, icos36[8  j]);

1081  
1082 
t0 = s0 + s1; 
1083 
t1 = s0  s1; 
1084 
out[(9 + j)*SBLIMIT] = MULH(t1, win[9 + j]) + buf[9 + j]; 
1085 
out[(8  j)*SBLIMIT] = MULH(t1, win[8  j]) + buf[8  j]; 
1086 
buf[9 + j] = MULH(t0, win[18 + 9 + j]); 
1087 
buf[8  j] = MULH(t0, win[18 + 8  j]); 
1088  
1089 
t0 = s2 + s3; 
1090 
t1 = s2  s3; 
1091 
out[(9 + 8  j)*SBLIMIT] = MULH(t1, win[9 + 8  j]) + buf[9 + 8  j]; 
1092 
out[( j)*SBLIMIT] = MULH(t1, win[ j]) + buf[ j]; 
1093 
buf[9 + 8  j] = MULH(t0, win[18 + 9 + 8  j]); 
1094 
buf[ + j] = MULH(t0, win[18 + j]);

1095 
i += 4;

1096 
} 
1097  
1098 
s0 = tmp[16];

1099 
s1 = MULH(2*tmp[17], icos36h[4]); 
1100 
t0 = s0 + s1; 
1101 
t1 = s0  s1; 
1102 
out[(9 + 4)*SBLIMIT] = MULH(t1, win[9 + 4]) + buf[9 + 4]; 
1103 
out[(8  4)*SBLIMIT] = MULH(t1, win[8  4]) + buf[8  4]; 
1104 
buf[9 + 4] = MULH(t0, win[18 + 9 + 4]); 
1105 
buf[8  4] = MULH(t0, win[18 + 8  4]); 
1106 
} 
1107  
1108 
/* header decoding. MUST check the header before because no

1109 
consistency check is done there. Return 1 if free format found and

1110 
that the frame size must be computed externally */

1111 
static int decode_header(MPADecodeContext *s, uint32_t header) 
1112 
{ 
1113 
int sample_rate, frame_size, mpeg25, padding;

1114 
int sample_rate_index, bitrate_index;

1115 
if (header & (1<<20)) { 
1116 
s>lsf = (header & (1<<19)) ? 0 : 1; 
1117 
mpeg25 = 0;

1118 
} else {

1119 
s>lsf = 1;

1120 
mpeg25 = 1;

1121 
} 
1122  
1123 
s>layer = 4  ((header >> 17) & 3); 
1124 
/* extract frequency */

1125 
sample_rate_index = (header >> 10) & 3; 
1126 
sample_rate = mpa_freq_tab[sample_rate_index] >> (s>lsf + mpeg25); 
1127 
sample_rate_index += 3 * (s>lsf + mpeg25);

1128 
s>sample_rate_index = sample_rate_index; 
1129 
s>error_protection = ((header >> 16) & 1) ^ 1; 
1130 
s>sample_rate = sample_rate; 
1131  
1132 
bitrate_index = (header >> 12) & 0xf; 
1133 
padding = (header >> 9) & 1; 
1134 
//extension = (header >> 8) & 1;

1135 
s>mode = (header >> 6) & 3; 
1136 
s>mode_ext = (header >> 4) & 3; 
1137 
//copyright = (header >> 3) & 1;

1138 
//original = (header >> 2) & 1;

1139 
//emphasis = header & 3;

1140  
1141 
if (s>mode == MPA_MONO)

1142 
s>nb_channels = 1;

1143 
else

1144 
s>nb_channels = 2;

1145  
1146 
if (bitrate_index != 0) { 
1147 
frame_size = mpa_bitrate_tab[s>lsf][s>layer  1][bitrate_index];

1148 
s>bit_rate = frame_size * 1000;

1149 
switch(s>layer) {

1150 
case 1: 
1151 
frame_size = (frame_size * 12000) / sample_rate;

1152 
frame_size = (frame_size + padding) * 4;

1153 
break;

1154 
case 2: 
1155 
frame_size = (frame_size * 144000) / sample_rate;

1156 
frame_size += padding; 
1157 
break;

1158 
default:

1159 
case 3: 
1160 
frame_size = (frame_size * 144000) / (sample_rate << s>lsf);

1161 
frame_size += padding; 
1162 
break;

1163 
} 
1164 
s>frame_size = frame_size; 
1165 
} else {

1166 
/* if no frame size computed, signal it */

1167 
return 1; 
1168 
} 
1169  
1170 
#if defined(DEBUG)

1171 
dprintf("layer%d, %d Hz, %d kbits/s, ",

1172 
s>layer, s>sample_rate, s>bit_rate); 
1173 
if (s>nb_channels == 2) { 
1174 
if (s>layer == 3) { 
1175 
if (s>mode_ext & MODE_EXT_MS_STEREO)

1176 
dprintf("ms");

1177 
if (s>mode_ext & MODE_EXT_I_STEREO)

1178 
dprintf("i");

1179 
} 
1180 
dprintf("stereo");

1181 
} else {

1182 
dprintf("mono");

1183 
} 
1184 
dprintf("\n");

1185 
#endif

1186 
return 0; 
1187 
} 
1188  
1189 
/* useful helper to get mpeg audio stream infos. Return 1 if error in

1190 
header, otherwise the coded frame size in bytes */

1191 
int mpa_decode_header(AVCodecContext *avctx, uint32_t head)

1192 
{ 
1193 
MPADecodeContext s1, *s = &s1; 
1194  
1195 
if (ff_mpa_check_header(head) != 0) 
1196 
return 1; 
1197  
1198 
if (decode_header(s, head) != 0) { 
1199 
return 1; 
1200 
} 
1201  
1202 
switch(s>layer) {

1203 
case 1: 
1204 
avctx>frame_size = 384;

1205 
break;

1206 
case 2: 
1207 
avctx>frame_size = 1152;

1208 
break;

1209 
default:

1210 
case 3: 
1211 
if (s>lsf)

1212 
avctx>frame_size = 576;

1213 
else

1214 
avctx>frame_size = 1152;

1215 
break;

1216 
} 
1217  
1218 
avctx>sample_rate = s>sample_rate; 
1219 
avctx>channels = s>nb_channels; 
1220 
avctx>bit_rate = s>bit_rate; 
1221 
avctx>sub_id = s>layer; 
1222 
return s>frame_size;

1223 
} 
1224  
1225 
/* return the number of decoded frames */

1226 
static int mp_decode_layer1(MPADecodeContext *s) 
1227 
{ 
1228 
int bound, i, v, n, ch, j, mant;

1229 
uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT]; 
1230 
uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT]; 
1231  
1232 
if (s>mode == MPA_JSTEREO)

1233 
bound = (s>mode_ext + 1) * 4; 
1234 
else

1235 
bound = SBLIMIT; 
1236  
1237 
/* allocation bits */

1238 
for(i=0;i<bound;i++) { 
1239 
for(ch=0;ch<s>nb_channels;ch++) { 
1240 
allocation[ch][i] = get_bits(&s>gb, 4);

1241 
} 
1242 
} 
1243 
for(i=bound;i<SBLIMIT;i++) {

1244 
allocation[0][i] = get_bits(&s>gb, 4); 
1245 
} 
1246  
1247 
/* scale factors */

1248 
for(i=0;i<bound;i++) { 
1249 
for(ch=0;ch<s>nb_channels;ch++) { 
1250 
if (allocation[ch][i])

1251 
scale_factors[ch][i] = get_bits(&s>gb, 6);

1252 
} 
1253 
} 
1254 
for(i=bound;i<SBLIMIT;i++) {

1255 
if (allocation[0][i]) { 
1256 
scale_factors[0][i] = get_bits(&s>gb, 6); 
1257 
scale_factors[1][i] = get_bits(&s>gb, 6); 
1258 
} 
1259 
} 
1260  
1261 
/* compute samples */

1262 
for(j=0;j<12;j++) { 
1263 
for(i=0;i<bound;i++) { 
1264 
for(ch=0;ch<s>nb_channels;ch++) { 
1265 
n = allocation[ch][i]; 
1266 
if (n) {

1267 
mant = get_bits(&s>gb, n + 1);

1268 
v = l1_unscale(n, mant, scale_factors[ch][i]); 
1269 
} else {

1270 
v = 0;

1271 
} 
1272 
s>sb_samples[ch][j][i] = v; 
1273 
} 
1274 
} 
1275 
for(i=bound;i<SBLIMIT;i++) {

1276 
n = allocation[0][i];

1277 
if (n) {

1278 
mant = get_bits(&s>gb, n + 1);

1279 
v = l1_unscale(n, mant, scale_factors[0][i]);

1280 
s>sb_samples[0][j][i] = v;

1281 
v = l1_unscale(n, mant, scale_factors[1][i]);

1282 
s>sb_samples[1][j][i] = v;

1283 
} else {

1284 
s>sb_samples[0][j][i] = 0; 
1285 
s>sb_samples[1][j][i] = 0; 
1286 
} 
1287 
} 
1288 
} 
1289 
return 12; 
1290 
} 
1291  
1292 
/* bitrate is in kb/s */

1293 
int l2_select_table(int bitrate, int nb_channels, int freq, int lsf) 
1294 
{ 
1295 
int ch_bitrate, table;

1296  
1297 
ch_bitrate = bitrate / nb_channels; 
1298 
if (!lsf) {

1299 
if ((freq == 48000 && ch_bitrate >= 56)  
1300 
(ch_bitrate >= 56 && ch_bitrate <= 80)) 
1301 
table = 0;

1302 
else if (freq != 48000 && ch_bitrate >= 96) 
1303 
table = 1;

1304 
else if (freq != 32000 && ch_bitrate <= 48) 
1305 
table = 2;

1306 
else

1307 
table = 3;

1308 
} else {

1309 
table = 4;

1310 
} 
1311 
return table;

1312 
} 
1313  
1314 
static int mp_decode_layer2(MPADecodeContext *s) 
1315 
{ 
1316 
int sblimit; /* number of used subbands */ 
1317 
const unsigned char *alloc_table; 
1318 
int table, bit_alloc_bits, i, j, ch, bound, v;

1319 
unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT]; 
1320 
unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT]; 
1321 
unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf; 
1322 
int scale, qindex, bits, steps, k, l, m, b;

1323  
1324 
/* select decoding table */

1325 
table = l2_select_table(s>bit_rate / 1000, s>nb_channels,

1326 
s>sample_rate, s>lsf); 
1327 
sblimit = sblimit_table[table]; 
1328 
alloc_table = alloc_tables[table]; 
1329  
1330 
if (s>mode == MPA_JSTEREO)

1331 
bound = (s>mode_ext + 1) * 4; 
1332 
else

1333 
bound = sblimit; 
1334  
1335 
dprintf("bound=%d sblimit=%d\n", bound, sblimit);

1336  
1337 
/* sanity check */

1338 
if( bound > sblimit ) bound = sblimit;

1339  
1340 
/* parse bit allocation */

1341 
j = 0;

1342 
for(i=0;i<bound;i++) { 
1343 
bit_alloc_bits = alloc_table[j]; 
1344 
for(ch=0;ch<s>nb_channels;ch++) { 
1345 
bit_alloc[ch][i] = get_bits(&s>gb, bit_alloc_bits); 
1346 
} 
1347 
j += 1 << bit_alloc_bits;

1348 
} 
1349 
for(i=bound;i<sblimit;i++) {

1350 
bit_alloc_bits = alloc_table[j]; 
1351 
v = get_bits(&s>gb, bit_alloc_bits); 
1352 
bit_alloc[0][i] = v;

1353 
bit_alloc[1][i] = v;

1354 
j += 1 << bit_alloc_bits;

1355 
} 
1356  
1357 
#ifdef DEBUG

1358 
{ 
1359 
for(ch=0;ch<s>nb_channels;ch++) { 
1360 
for(i=0;i<sblimit;i++) 
1361 
dprintf(" %d", bit_alloc[ch][i]);

1362 
dprintf("\n");

1363 
} 
1364 
} 
1365 
#endif

1366  
1367 
/* scale codes */

1368 
for(i=0;i<sblimit;i++) { 
1369 
for(ch=0;ch<s>nb_channels;ch++) { 
1370 
if (bit_alloc[ch][i])

1371 
scale_code[ch][i] = get_bits(&s>gb, 2);

1372 
} 
1373 
} 
1374  
1375 
/* scale factors */

1376 
for(i=0;i<sblimit;i++) { 
1377 
for(ch=0;ch<s>nb_channels;ch++) { 
1378 
if (bit_alloc[ch][i]) {

1379 
sf = scale_factors[ch][i]; 
1380 
switch(scale_code[ch][i]) {

1381 
default:

1382 
case 0: 
1383 
sf[0] = get_bits(&s>gb, 6); 
1384 
sf[1] = get_bits(&s>gb, 6); 
1385 
sf[2] = get_bits(&s>gb, 6); 
1386 
break;

1387 
case 2: 
1388 
sf[0] = get_bits(&s>gb, 6); 
1389 
sf[1] = sf[0]; 
1390 
sf[2] = sf[0]; 
1391 
break;

1392 
case 1: 
1393 
sf[0] = get_bits(&s>gb, 6); 
1394 
sf[2] = get_bits(&s>gb, 6); 
1395 
sf[1] = sf[0]; 
1396 
break;

1397 
case 3: 
1398 
sf[0] = get_bits(&s>gb, 6); 
1399 
sf[2] = get_bits(&s>gb, 6); 
1400 
sf[1] = sf[2]; 
1401 
break;

1402 
} 
1403 
} 
1404 
} 
1405 
} 
1406  
1407 
#ifdef DEBUG

1408 
for(ch=0;ch<s>nb_channels;ch++) { 
1409 
for(i=0;i<sblimit;i++) { 
1410 
if (bit_alloc[ch][i]) {

1411 
sf = scale_factors[ch][i]; 
1412 
dprintf(" %d %d %d", sf[0], sf[1], sf[2]); 
1413 
} else {

1414 
dprintf(" ");

1415 
} 
1416 
} 
1417 
dprintf("\n");

1418 
} 
1419 
#endif

1420  
1421 
/* samples */

1422 
for(k=0;k<3;k++) { 
1423 
for(l=0;l<12;l+=3) { 
1424 
j = 0;

1425 
for(i=0;i<bound;i++) { 
1426 
bit_alloc_bits = alloc_table[j]; 
1427 
for(ch=0;ch<s>nb_channels;ch++) { 
1428 
b = bit_alloc[ch][i]; 
1429 
if (b) {

1430 
scale = scale_factors[ch][i][k]; 
1431 
qindex = alloc_table[j+b]; 
1432 
bits = quant_bits[qindex]; 
1433 
if (bits < 0) { 
1434 
/* 3 values at the same time */

1435 
v = get_bits(&s>gb, bits); 
1436 
steps = quant_steps[qindex]; 
1437 
s>sb_samples[ch][k * 12 + l + 0][i] = 
1438 
l2_unscale_group(steps, v % steps, scale); 
1439 
v = v / steps; 
1440 
s>sb_samples[ch][k * 12 + l + 1][i] = 
1441 
l2_unscale_group(steps, v % steps, scale); 
1442 
v = v / steps; 
1443 
s>sb_samples[ch][k * 12 + l + 2][i] = 
1444 
l2_unscale_group(steps, v, scale); 
1445 
} else {

1446 
for(m=0;m<3;m++) { 
1447 
v = get_bits(&s>gb, bits); 
1448 
v = l1_unscale(bits  1, v, scale);

1449 
s>sb_samples[ch][k * 12 + l + m][i] = v;

1450 
} 
1451 
} 
1452 
} else {

1453 
s>sb_samples[ch][k * 12 + l + 0][i] = 0; 
1454 
s>sb_samples[ch][k * 12 + l + 1][i] = 0; 
1455 
s>sb_samples[ch][k * 12 + l + 2][i] = 0; 
1456 
} 
1457 
} 
1458 
/* next subband in alloc table */

1459 
j += 1 << bit_alloc_bits;

1460 
} 
1461 
/* XXX: find a way to avoid this duplication of code */

1462 
for(i=bound;i<sblimit;i++) {

1463 
bit_alloc_bits = alloc_table[j]; 
1464 
b = bit_alloc[0][i];

1465 
if (b) {

1466 
int mant, scale0, scale1;

1467 
scale0 = scale_factors[0][i][k];

1468 
scale1 = scale_factors[1][i][k];

1469 
qindex = alloc_table[j+b]; 
1470 
bits = quant_bits[qindex]; 
1471 
if (bits < 0) { 
1472 
/* 3 values at the same time */

1473 
v = get_bits(&s>gb, bits); 
1474 
steps = quant_steps[qindex]; 
1475 
mant = v % steps; 
1476 
v = v / steps; 
1477 
s>sb_samples[0][k * 12 + l + 0][i] = 
1478 
l2_unscale_group(steps, mant, scale0); 
1479 
s>sb_samples[1][k * 12 + l + 0][i] = 
1480 
l2_unscale_group(steps, mant, scale1); 
1481 
mant = v % steps; 
1482 
v = v / steps; 
1483 
s>sb_samples[0][k * 12 + l + 1][i] = 
1484 
l2_unscale_group(steps, mant, scale0); 
1485 
s>sb_samples[1][k * 12 + l + 1][i] = 
1486 
l2_unscale_group(steps, mant, scale1); 
1487 
s>sb_samples[0][k * 12 + l + 2][i] = 
1488 
l2_unscale_group(steps, v, scale0); 
1489 
s>sb_samples[1][k * 12 + l + 2][i] = 
1490 
l2_unscale_group(steps, v, scale1); 
1491 
} else {

1492 
for(m=0;m<3;m++) { 
1493 
mant = get_bits(&s>gb, bits); 
1494 
s>sb_samples[0][k * 12 + l + m][i] = 
1495 
l1_unscale(bits  1, mant, scale0);

1496 
s>sb_samples[1][k * 12 + l + m][i] = 
1497 
l1_unscale(bits  1, mant, scale1);

1498 
} 
1499 
} 
1500 
} else {

1501 
s>sb_samples[0][k * 12 + l + 0][i] = 0; 
1502 
s>sb_samples[0][k * 12 + l + 1][i] = 0; 
1503 
s>sb_samples[0][k * 12 + l + 2][i] = 0; 
1504 
s>sb_samples[1][k * 12 + l + 0][i] = 0; 
1505 
s>sb_samples[1][k * 12 + l + 1][i] = 0; 
1506 
s>sb_samples[1][k * 12 + l + 2][i] = 0; 
1507 
} 
1508 
/* next subband in alloc table */

1509 
j += 1 << bit_alloc_bits;

1510 
} 
1511 
/* fill remaining samples to zero */

1512 
for(i=sblimit;i<SBLIMIT;i++) {

1513 
for(ch=0;ch<s>nb_channels;ch++) { 
1514 
s>sb_samples[ch][k * 12 + l + 0][i] = 0; 
1515 
s>sb_samples[ch][k * 12 + l + 1][i] = 0; 
1516 
s>sb_samples[ch][k * 12 + l + 2][i] = 0; 
1517 
} 
1518 
} 
1519 
} 
1520 
} 
1521 
return 3 * 12; 
1522 
} 
1523  
1524 
static inline void lsf_sf_expand(int *slen, 
1525 
int sf, int n1, int n2, int n3) 
1526 
{ 
1527 
if (n3) {

1528 
slen[3] = sf % n3;

1529 
sf /= n3; 
1530 
} else {

1531 
slen[3] = 0; 
1532 
} 
1533 
if (n2) {

1534 
slen[2] = sf % n2;

1535 
sf /= n2; 
1536 
} else {

1537 
slen[2] = 0; 
1538 
} 
1539 
slen[1] = sf % n1;

1540 
sf /= n1; 
1541 
slen[0] = sf;

1542 
} 
1543  
1544 
static void exponents_from_scale_factors(MPADecodeContext *s, 
1545 
GranuleDef *g, 
1546 
int16_t *exponents) 
1547 
{ 
1548 
const uint8_t *bstab, *pretab;

1549 
int len, i, j, k, l, v0, shift, gain, gains[3]; 
1550 
int16_t *exp_ptr; 
1551  
1552 
exp_ptr = exponents; 
1553 
gain = g>global_gain  210;

1554 
shift = g>scalefac_scale + 1;

1555  
1556 
bstab = band_size_long[s>sample_rate_index]; 
1557 
pretab = mpa_pretab[g>preflag]; 
1558 
for(i=0;i<g>long_end;i++) { 
1559 
v0 = gain  ((g>scale_factors[i] + pretab[i]) << shift) + 400;

1560 
len = bstab[i]; 
1561 
for(j=len;j>0;j) 
1562 
*exp_ptr++ = v0; 
1563 
} 
1564  
1565 
if (g>short_start < 13) { 
1566 
bstab = band_size_short[s>sample_rate_index]; 
1567 
gains[0] = gain  (g>subblock_gain[0] << 3); 
1568 
gains[1] = gain  (g>subblock_gain[1] << 3); 
1569 
gains[2] = gain  (g>subblock_gain[2] << 3); 
1570 
k = g>long_end; 
1571 
for(i=g>short_start;i<13;i++) { 
1572 
len = bstab[i]; 
1573 
for(l=0;l<3;l++) { 
1574 
v0 = gains[l]  (g>scale_factors[k++] << shift) + 400;

1575 
for(j=len;j>0;j) 
1576 
*exp_ptr++ = v0; 
1577 
} 
1578 
} 
1579 
} 
1580 
} 
1581  
1582 
/* handle n = 0 too */

1583 
static inline int get_bitsz(GetBitContext *s, int n) 
1584 
{ 
1585 
if (n == 0) 
1586 
return 0; 
1587 
else

1588 
return get_bits(s, n);

1589 
} 
1590  
1591 
static int huffman_decode(MPADecodeContext *s, GranuleDef *g, 
1592 
int16_t *exponents, int end_pos2)

1593 
{ 
1594 
int s_index;

1595 
int i;

1596 
int last_pos, bits_left;

1597 
VLC *vlc; 
1598 
int end_pos= FFMIN(end_pos2, s>gb.size_in_bits);

1599  
1600 
/* low frequencies (called big values) */

1601 
s_index = 0;

1602 
for(i=0;i<3;i++) { 
1603 
int j, k, l, linbits;

1604 
j = g>region_size[i]; 
1605 
if (j == 0) 
1606 
continue;

1607 
/* select vlc table */

1608 
k = g>table_select[i]; 
1609 
l = mpa_huff_data[k][0];

1610 
linbits = mpa_huff_data[k][1];

1611 
vlc = &huff_vlc[l]; 
1612  
1613 
if(!l){

1614 
memset(&g>sb_hybrid[s_index], 0, sizeof(*g>sb_hybrid)*2*j); 
1615 
s_index += 2*j;

1616 
continue;

1617 
} 
1618  
1619 
/* read huffcode and compute each couple */

1620 
for(;j>0;j) { 
1621 
int exponent, x, y, v;

1622 
int pos= get_bits_count(&s>gb);

1623  
1624 
if (pos >= end_pos){

1625 
// av_log(NULL, AV_LOG_ERROR, "pos: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

1626 
if(s>in_gb.buffer && pos >= s>gb.size_in_bits){

1627 
s>gb= s>in_gb; 
1628 
s>in_gb.buffer=NULL;

1629 
assert((get_bits_count(&s>gb) & 7) == 0); 
1630 
skip_bits_long(&s>gb, pos  end_pos); 
1631 
end_pos2= 
1632 
end_pos= end_pos2 + get_bits_count(&s>gb)  pos; 
1633 
pos= get_bits_count(&s>gb); 
1634 
} 
1635 
// av_log(NULL, AV_LOG_ERROR, "new pos: %d %d\n", pos, end_pos);

1636 
if(pos >= end_pos)

1637 
break;

1638 
} 
1639 
y = get_vlc2(&s>gb, vlc>table, 7, 3); 
1640  
1641 
if(!y){

1642 
g>sb_hybrid[s_index ] = 
1643 
g>sb_hybrid[s_index+1] = 0; 
1644 
s_index += 2;

1645 
continue;

1646 
} 
1647  
1648 
exponent= exponents[s_index]; 
1649  
1650 
dprintf("region=%d n=%d x=%d y=%d exp=%d\n",

1651 
i, g>region_size[i]  j, x, y, exponent); 
1652 
if(y&16){ 
1653 
x = y >> 5;

1654 
y = y & 0x0f;

1655 
if (x < 15){ 
1656 
v = expval_table[ exponent ][ x ]; 
1657 
// v = expval_table[ (exponent&3) ][ x ] >> FFMIN(0  (exponent>>2), 31);

1658 
}else{

1659 
x += get_bitsz(&s>gb, linbits); 
1660 
v = l3_unscale(x, exponent); 
1661 
} 
1662 
if (get_bits1(&s>gb))

1663 
v = v; 
1664 
g>sb_hybrid[s_index] = v; 
1665 
if (y < 15){ 
1666 
v = expval_table[ exponent ][ y ]; 
1667 
}else{

1668 
y += get_bitsz(&s>gb, linbits); 
1669 
v = l3_unscale(y, exponent); 
1670 
} 
1671 
if (get_bits1(&s>gb))

1672 
v = v; 
1673 
g>sb_hybrid[s_index+1] = v;

1674 
}else{

1675 
x = y >> 5;

1676 
y = y & 0x0f;

1677 
x += y; 
1678 
if (x < 15){ 
1679 
v = expval_table[ exponent ][ x ]; 
1680 
}else{

1681 
x += get_bitsz(&s>gb, linbits); 
1682 
v = l3_unscale(x, exponent); 
1683 
} 
1684 
if (get_bits1(&s>gb))

1685 
v = v; 
1686 
g>sb_hybrid[s_index+!!y] = v; 
1687 
g>sb_hybrid[s_index+ !y] = 0;

1688 
} 
1689 
s_index+=2;

1690 
} 
1691 
} 
1692  
1693 
/* high frequencies */

1694 
vlc = &huff_quad_vlc[g>count1table_select]; 
1695 
last_pos=0;

1696 
while (s_index <= 572) { 
1697 
int pos, code;

1698 
pos = get_bits_count(&s>gb); 
1699 
if (pos >= end_pos) {

1700 
if (pos > end_pos2 && last_pos){

1701 
/* some encoders generate an incorrect size for this

1702 
part. We must go back into the data */

1703 
s_index = 4;

1704 
skip_bits_long(&s>gb, last_pos  pos); 
1705 
av_log(NULL, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos  pos, end_pospos, end_pos2pos); 
1706 
break;

1707 
} 
1708 
// av_log(NULL, AV_LOG_ERROR, "pos2: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);

1709 
if(s>in_gb.buffer && pos >= s>gb.size_in_bits){

1710 
s>gb= s>in_gb; 
1711 
s>in_gb.buffer=NULL;

1712 
assert((get_bits_count(&s>gb) & 7) == 0); 
1713 
skip_bits_long(&s>gb, pos  end_pos); 
1714 
end_pos2= 
1715 
end_pos= end_pos2 + get_bits_count(&s>gb)  pos; 
1716 
pos= get_bits_count(&s>gb); 
1717 
} 
1718 
// av_log(NULL, AV_LOG_ERROR, "new pos2: %d %d %d\n", pos, end_pos, s_index);

1719 
if(pos >= end_pos)

1720 
break;

1721 
} 
1722 
last_pos= pos; 
1723  
1724 
code = get_vlc2(&s>gb, vlc>table, vlc>bits, 1);

1725 
dprintf("t=%d code=%d\n", g>count1table_select, code);

1726 
g>sb_hybrid[s_index+0]=

1727 
g>sb_hybrid[s_index+1]=

1728 
g>sb_hybrid[s_index+2]=

1729 
g>sb_hybrid[s_index+3]= 0; 
1730 
while(code){

1731 
const static int idxtab[16]={3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0}; 
1732 
int v;

1733 
int pos= s_index+idxtab[code];

1734 
code ^= 8>>idxtab[code];

1735 
v = exp_table[ exponents[pos] ]; 
1736 
// v = exp_table[ (exponents[pos]&3) ] >> FFMIN(0  (exponents[pos]>>2), 31);

1737 
if(get_bits1(&s>gb))

1738 
v = v; 
1739 
g>sb_hybrid[pos] = v; 
1740 
} 
1741 
s_index+=4;

1742 
} 
1743 
memset(&g>sb_hybrid[s_index], 0, sizeof(*g>sb_hybrid)*(576  s_index)); 
1744  
1745 
/* skip extension bits */

1746 
bits_left = end_pos  get_bits_count(&s>gb); 
1747 
//av_log(NULL, AV_LOG_ERROR, "left:%d buf:%p\n", bits_left, s>in_gb.buffer);

1748 
if (bits_left < 0) { 
1749 
dprintf("bits_left=%d\n", bits_left);

1750 
return 1; 
1751 
} 
1752 
skip_bits_long(&s>gb, bits_left); 
1753  
1754 
return 0; 
1755 
} 
1756  
1757 
/* Reorder short blocks from bitstream order to interleaved order. It

1758 
would be faster to do it in parsing, but the code would be far more

1759 
complicated */

1760 
static void reorder_block(MPADecodeContext *s, GranuleDef *g) 
1761 
{ 
1762 
int i, j, len;

1763 
int32_t *ptr, *dst, *ptr1; 
1764 
int32_t tmp[576];

1765  
1766 
if (g>block_type != 2) 
1767 
return;

1768  
1769 
if (g>switch_point) {

1770 
if (s>sample_rate_index != 8) { 
1771 
ptr = g>sb_hybrid + 36;

1772 
} else {

1773 
ptr = g>sb_hybrid + 48;

1774 
} 
1775 
} else {

1776 
ptr = g>sb_hybrid; 
1777 
} 
1778  
1779 
for(i=g>short_start;i<13;i++) { 
1780 
len = band_size_short[s>sample_rate_index][i]; 
1781 
ptr1 = ptr; 
1782 
dst = tmp; 
1783 
for(j=len;j>0;j) { 
1784 
*dst++ = ptr[0*len];

1785 
*dst++ = ptr[1*len];

1786 
*dst++ = ptr[2*len];

1787 
ptr++; 
1788 
} 
1789 
ptr+=2*len;

1790 
memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1)); 
1791 
} 
1792 
} 
1793  
1794 
#define ISQRT2 FIXR(0.70710678118654752440) 
1795  
1796 
static void compute_stereo(MPADecodeContext *s, 
1797 
GranuleDef *g0, GranuleDef *g1) 
1798 
{ 
1799 
int i, j, k, l;

1800 
int32_t v1, v2; 
1801 
int sf_max, tmp0, tmp1, sf, len, non_zero_found;

1802 
int32_t (*is_tab)[16];

1803 
int32_t *tab0, *tab1; 
1804 
int non_zero_found_short[3]; 
1805  
1806 
/* intensity stereo */

1807 
if (s>mode_ext & MODE_EXT_I_STEREO) {

1808 
if (!s>lsf) {

1809 
is_tab = is_table; 
1810 
sf_max = 7;

1811 
} else {

1812 
is_tab = is_table_lsf[g1>scalefac_compress & 1];

1813 
sf_max = 16;

1814 
} 
1815  
1816 
tab0 = g0>sb_hybrid + 576;

1817 
tab1 = g1>sb_hybrid + 576;

1818  
1819 
non_zero_found_short[0] = 0; 
1820 
non_zero_found_short[1] = 0; 
1821 
non_zero_found_short[2] = 0; 
1822 
k = (13  g1>short_start) * 3 + g1>long_end  3; 
1823 
for(i = 12;i >= g1>short_start;i) { 
1824 
/* for last band, use previous scale factor */

1825 
if (i != 11) 
1826 
k = 3;

1827 
len = band_size_short[s>sample_rate_index][i]; 
1828 
for(l=2;l>=0;l) { 
1829 
tab0 = len; 
1830 
tab1 = len; 
1831 
if (!non_zero_found_short[l]) {

1832 
/* test if non zero band. if so, stop doing istereo */

1833 
for(j=0;j<len;j++) { 
1834 
if (tab1[j] != 0) { 
1835 
non_zero_found_short[l] = 1;

1836 
goto found1;

1837 
} 
1838 
} 
1839 
sf = g1>scale_factors[k + l]; 
1840 
if (sf >= sf_max)

1841 
goto found1;

1842  
1843 
v1 = is_tab[0][sf];

1844 
v2 = is_tab[1][sf];

1845 
for(j=0;j<len;j++) { 
1846 
tmp0 = tab0[j]; 
1847 
tab0[j] = MULL(tmp0, v1); 
1848 
tab1[j] = MULL(tmp0, v2); 
1849 
} 
1850 
} else {

1851 
found1:

1852 
if (s>mode_ext & MODE_EXT_MS_STEREO) {

1853 
/* lower part of the spectrum : do ms stereo

1854 
if enabled */

1855 
for(j=0;j<len;j++) { 
1856 
tmp0 = tab0[j]; 
1857 
tmp1 = tab1[j]; 
1858 
tab0[j] = MULL(tmp0 + tmp1, ISQRT2); 
1859 
tab1[j] = MULL(tmp0  tmp1, ISQRT2); 
1860 
} 
1861 
} 
1862 
} 
1863 
} 
1864 
} 
1865  
1866 
non_zero_found = non_zero_found_short[0] 

1867 
non_zero_found_short[1] 

1868 
non_zero_found_short[2];

1869  
1870 
for(i = g1>long_end  1;i >= 0;i) { 
1871 
len = band_size_long[s>sample_rate_index][i]; 
1872 
tab0 = len; 
1873 
tab1 = len; 
1874 
/* test if non zero band. if so, stop doing istereo */

1875 
if (!non_zero_found) {

1876 
for(j=0;j<len;j++) { 
1877 
if (tab1[j] != 0) { 
1878 
non_zero_found = 1;

1879 
goto found2;

1880 
} 
1881 
} 
1882 
/* for last band, use previous scale factor */

1883 
k = (i == 21) ? 20 : i; 
1884 
sf = g1>scale_factors[k]; 
1885 
if (sf >= sf_max)

1886 
goto found2;

1887 
v1 = is_tab[0][sf];

1888 
v2 = is_tab[1][sf];

1889 
for(j=0;j<len;j++) { 
1890 
tmp0 = tab0[j]; 
1891 
tab0[j] = MULL(tmp0, v1); 
1892 
tab1[j] = MULL(tmp0, v2); 
1893 
} 
1894 
} else {

1895 
found2:

1896 
if (s>mode_ext & MODE_EXT_MS_STEREO) {

1897 
/* lower part of the spectrum : do ms stereo

1898 
if enabled */

1899 
for(j=0;j<len;j++) { 
1900 
tmp0 = tab0[j]; 
1901 
tmp1 = tab1[j]; 
1902 
tab0[j] = MULL(tmp0 + tmp1, ISQRT2); 
1903 
tab1[j] = MULL(tmp0  tmp1, ISQRT2); 
1904 
} 
1905 
} 
1906 
} 
1907 
} 
1908 
} else if (s>mode_ext & MODE_EXT_MS_STEREO) { 
1909 
/* ms stereo ONLY */

1910 
/* NOTE: the 1/sqrt(2) normalization factor is included in the

1911 
global gain */

1912 
tab0 = g0>sb_hybrid; 
1913 
tab1 = g1>sb_hybrid; 
1914 
for(i=0;i<576;i++) { 
1915 
tmp0 = tab0[i]; 
1916 
tmp1 = tab1[i]; 
1917 
tab0[i] = tmp0 + tmp1; 
1918 
tab1[i] = tmp0  tmp1; 
1919 
} 
1920 
} 
1921 
} 
1922  
1923 
static void compute_antialias_integer(MPADecodeContext *s, 
1924 
GranuleDef *g) 
1925 
{ 
1926 
int32_t *ptr, *csa; 
1927 
int n, i;

1928  
1929 
/* we antialias only "long" bands */

1930 
if (g>block_type == 2) { 
1931 
if (!g>switch_point)

1932 
return;

1933 
/* XXX: check this for 8000Hz case */

1934 
n = 1;

1935 
} else {

1936 
n = SBLIMIT  1;

1937 
} 
1938  
1939 
ptr = g>sb_hybrid + 18;

1940 
for(i = n;i > 0;i) { 
1941 
int tmp0, tmp1, tmp2;

1942 
csa = &csa_table[0][0]; 
1943 
#define INT_AA(j) \

1944 
tmp0 = ptr[1j];\

1945 
tmp1 = ptr[ j];\ 
1946 
tmp2= MULH(tmp0 + tmp1, csa[0+4*j]);\ 
1947 
ptr[1j] = 4*(tmp2  MULH(tmp1, csa[2+4*j]));\ 
1948 
ptr[ j] = 4*(tmp2 + MULH(tmp0, csa[3+4*j])); 
1949  
1950 
INT_AA(0)

1951 
INT_AA(1)

1952 
INT_AA(2)

1953 
INT_AA(3)

1954 
INT_AA(4)

1955 
INT_AA(5)

1956 
INT_AA(6)

1957 
INT_AA(7)

1958  
1959 
ptr += 18;

1960 
} 
1961 
} 
1962  
1963 
static void compute_antialias_float(MPADecodeContext *s, 
1964 
GranuleDef *g) 
1965 
{ 
1966 
int32_t *ptr; 
1967 
int n, i;

1968  
1969 
/* we antialias only "long" bands */

1970 
if (g>block_type == 2) { 
1971 
if (!g>switch_point)

1972 
return;

1973 
/* XXX: check this for 8000Hz case */

1974 
n = 1;

1975 
} else {

1976 
n = SBLIMIT  1;

1977 
} 
1978  
1979 
ptr = g>sb_hybrid + 18;

1980 
for(i = n;i > 0;i) { 
1981 
float tmp0, tmp1;

1982 
float *csa = &csa_table_float[0][0]; 
1983 
#define FLOAT_AA(j)\

1984 
tmp0= ptr[1j];\

1985 
tmp1= ptr[ j];\ 
1986 
ptr[1j] = lrintf(tmp0 * csa[0+4*j]  tmp1 * csa[1+4*j]);\ 
1987 
ptr[ j] = lrintf(tmp0 * csa[1+4*j] + tmp1 * csa[0+4*j]); 
1988  
1989 
FLOAT_AA(0)

1990 
FLOAT_AA(1)

1991 
FLOAT_AA(2)

1992 
FLOAT_AA(3)

1993 
FLOAT_AA(4)

1994 
FLOAT_AA(5)

1995 
FLOAT_AA(6)

1996 
FLOAT_AA(7)

1997  
1998 
ptr += 18;

1999 
} 
2000 
} 
2001  
2002 
static void compute_imdct(MPADecodeContext *s, 
2003 
GranuleDef *g, 
2004 
int32_t *sb_samples, 
2005 
int32_t *mdct_buf) 
2006 
{ 
2007 
int32_t *ptr, *win, *win1, *buf, *out_ptr, *ptr1; 
2008 
int32_t out2[12];

2009 
int i, j, mdct_long_end, v, sblimit;

2010  
2011 
/* find last non zero block */

2012 
ptr = g>sb_hybrid + 576;

2013 
ptr1 = g>sb_hybrid + 2 * 18; 
2014 
while (ptr >= ptr1) {

2015 
ptr = 6;

2016 
v = ptr[0]  ptr[1]  ptr[2]  ptr[3]  ptr[4]  ptr[5]; 
2017 
if (v != 0) 
2018 
break;

2019 
} 
2020 
sblimit = ((ptr  g>sb_hybrid) / 18) + 1; 
2021  
2022 
if (g>block_type == 2) { 
2023 
/* XXX: check for 8000 Hz */

2024 
if (g>switch_point)

2025 
mdct_long_end = 2;

2026 
else

2027 
mdct_long_end = 0;

2028 
} else {

2029 
mdct_long_end = sblimit; 
2030 
} 
2031  
2032 
buf = mdct_buf; 
2033 
ptr = g>sb_hybrid; 
2034 
for(j=0;j<mdct_long_end;j++) { 
2035 
/* apply window & overlap with previous buffer */

2036 
out_ptr = sb_samples + j; 
2037 
/* select window */

2038 
if (g>switch_point && j < 2) 
2039 
win1 = mdct_win[0];

2040 
else

2041 
win1 = mdct_win[g>block_type]; 
2042 
/* select frequency inversion */

2043 
win = win1 + ((4 * 36) & (j & 1)); 
2044 
imdct36(out_ptr, buf, ptr, win); 
2045 
out_ptr += 18*SBLIMIT;

2046 
ptr += 18;

2047 
buf += 18;

2048 
} 
2049 
for(j=mdct_long_end;j<sblimit;j++) {

2050 
/* select frequency inversion */

2051 
win = mdct_win[2] + ((4 * 36) & (j & 1)); 
2052 
out_ptr = sb_samples + j; 
2053  
2054 
for(i=0; i<6; i++){ 
2055 
*out_ptr = buf[i]; 
2056 
out_ptr += SBLIMIT; 
2057 
} 
2058 
imdct12(out2, ptr + 0);

2059 
for(i=0;i<6;i++) { 
2060 
*out_ptr = MULH(out2[i], win[i]) + buf[i + 6*1]; 
2061 
buf[i + 6*2] = MULH(out2[i + 6], win[i + 6]); 
2062 
out_ptr += SBLIMIT; 
2063 
} 
2064 
imdct12(out2, ptr + 1);

2065 
for(i=0;i<6;i++) { 
2066 
*out_ptr = MULH(out2[i], win[i]) + buf[i + 6*2]; 
2067 
buf[i + 6*0] = MULH(out2[i + 6], win[i + 6]); 
2068 
out_ptr += SBLIMIT; 
2069 
} 
2070 
imdct12(out2, ptr + 2);

2071 
for(i=0;i<6;i++) { 
2072 
buf[i + 6*0] = MULH(out2[i], win[i]) + buf[i + 6*0]; 
2073 
buf[i + 6*1] = MULH(out2[i + 6], win[i + 6]); 
2074 
buf[i + 6*2] = 0; 
2075 
} 
2076 
ptr += 18;

2077 
buf += 18;

2078 
} 
2079 
/* zero bands */

2080 
for(j=sblimit;j<SBLIMIT;j++) {

2081 
/* overlap */

2082 
out_ptr = sb_samples + j; 
2083 
for(i=0;i<18;i++) { 
2084 
*out_ptr = buf[i]; 
2085 
buf[i] = 0;

2086 
out_ptr += SBLIMIT; 
2087 
} 
2088 
buf += 18;

2089 
} 
2090 
} 
2091  
2092 
#if defined(DEBUG)

2093 
void sample_dump(int fnum, int32_t *tab, int n) 
2094 
{ 
2095 
static FILE *files[16], *f; 
2096 
char buf[512]; 
2097 
int i;

2098 
int32_t v; 
2099  
2100 
f = files[fnum]; 
2101 
if (!f) {

2102 
snprintf(buf, sizeof(buf), "/tmp/out%d.%s.pcm", 
2103 
fnum, 
2104 
#ifdef USE_HIGHPRECISION

2105 
"hp"

2106 
#else

2107 
"lp"

2108 
#endif

2109 
); 
2110 
f = fopen(buf, "w");

2111 
if (!f)

2112 
return;

2113 
files[fnum] = f; 
2114 
} 
2115  
2116 
if (fnum == 0) { 
2117 
static int pos = 0; 
2118 
av_log(NULL, AV_LOG_DEBUG, "pos=%d\n", pos); 
2119 
for(i=0;i<n;i++) { 
2120 
av_log(NULL, AV_LOG_DEBUG, " %0.4f", (double)tab[i] / FRAC_ONE); 
2121 
if ((i % 18) == 17) 
2122 
av_log(NULL, AV_LOG_DEBUG, "\n"); 
2123 
} 
2124 
pos += n; 
2125 
} 
2126 
for(i=0;i<n;i++) { 
2127 
/* normalize to 23 frac bits */

2128 
v = tab[i] << (23  FRAC_BITS);

2129 
fwrite(&v, 1, sizeof(int32_t), f); 
2130 
} 
2131 
} 
2132 
#endif

2133  
2134  
2135 
/* main layer3 decoding function */

2136 
static int mp_decode_layer3(MPADecodeContext *s) 
2137 
{ 
2138 
int nb_granules, main_data_begin, private_bits;

2139 
int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;

2140 
GranuleDef granules[2][2], *g; 
2141 
int16_t exponents[576];

2142  
2143 
/* read side info */

2144 
if (s>lsf) {

2145 
main_data_begin = get_bits(&s>gb, 8);

2146 
private_bits = get_bits(&s>gb, s>nb_channels); 
2147 
nb_granules = 1;

2148 
} else {

2149 
main_data_begin = get_bits(&s>gb, 9);

2150 
if (s>nb_channels == 2) 
2151 
private_bits = get_bits(&s>gb, 3);

2152 
else

2153 
private_bits = get_bits(&s>gb, 5);

2154 
nb_granules = 2;

2155 
for(ch=0;ch<s>nb_channels;ch++) { 
2156 
granules[ch][0].scfsi = 0; /* all scale factors are transmitted */ 
2157 
granules[ch][1].scfsi = get_bits(&s>gb, 4); 
2158 
} 
2159 
} 
2160  
2161 
for(gr=0;gr<nb_granules;gr++) { 
2162 
for(ch=0;ch<s>nb_channels;ch++) { 
2163 
dprintf("gr=%d ch=%d: side_info\n", gr, ch);

2164 
g = &granules[ch][gr]; 
2165 
g>part2_3_length = get_bits(&s>gb, 12);

2166 
g>big_values = get_bits(&s>gb, 9);

2167 
g>global_gain = get_bits(&s>gb, 8);

2168 
/* if MS stereo only is selected, we precompute the

2169 
1/sqrt(2) renormalization factor */

2170 
if ((s>mode_ext & (MODE_EXT_MS_STEREO  MODE_EXT_I_STEREO)) ==

2171 
MODE_EXT_MS_STEREO) 
2172 
g>global_gain = 2;

2173 
if (s>lsf)

2174 
g>scalefac_compress = get_bits(&s>gb, 9);

2175 
else

2176 
g>scalefac_compress = get_bits(&s>gb, 4);

2177 
blocksplit_flag = get_bits(&s>gb, 1);

2178 
if (blocksplit_flag) {

2179 
g>block_type = get_bits(&s>gb, 2);

2180 
if (g>block_type == 0) 
2181 
return 1; 
2182 
g>switch_point = get_bits(&s>gb, 1);

2183 
for(i=0;i<2;i++) 
2184 
g>table_select[i] = get_bits(&s>gb, 5);

2185 
for(i=0;i<3;i++) 
2186 
g>subblock_gain[i] = get_bits(&s>gb, 3);

2187 
/* compute huffman coded region sizes */

2188 
if (g>block_type == 2) 
2189 
g>region_size[0] = (36 / 2); 
2190 
else {

2191 
if (s>sample_rate_index <= 2) 
2192 
g>region_size[0] = (36 / 2); 
2193 
else if (s>sample_rate_index != 8) 
2194 
g>region_size[0] = (54 / 2); 
2195 
else

2196 
g>region_size[0] = (108 / 2); 
2197 
} 
2198 
g>region_size[1] = (576 / 2); 
2199 
} else {

2200 
int region_address1, region_address2, l;

2201 
g>block_type = 0;

2202 
g>switch_point = 0;

2203 
for(i=0;i<3;i++) 
2204 
g>table_select[i] = get_bits(&s>gb, 5);

2205 
/* compute huffman coded region sizes */

2206 
region_address1 = get_bits(&s>gb, 4);

2207 
region_address2 = get_bits(&s>gb, 3);

2208 
dprintf("region1=%d region2=%d\n",

2209 
region_address1, region_address2); 
2210 
g>region_size[0] =

2211 
band_index_long[s>sample_rate_index][region_address1 + 1] >> 1; 
2212 
l = region_address1 + region_address2 + 2;

2213 
/* should not overflow */

2214 
if (l > 22) 
2215 
l = 22;

2216 
g>region_size[1] =

2217 
band_index_long[s>sample_rate_index][l] >> 1;

2218 
} 
2219 
/* convert region offsets to region sizes and truncate

2220 
size to big_values */

2221 
g>region_size[2] = (576 / 2); 
2222 
j = 0;

2223 
for(i=0;i<3;i++) { 
2224 
k = FFMIN(g>region_size[i], g>big_values); 
2225 
g>region_size[i] = k  j; 
2226 
j = k; 
2227 
} 
2228  
2229 
/* compute band indexes */

2230 
if (g>block_type == 2) { 
2231 
if (g>switch_point) {

2232 
/* if switched mode, we handle the 36 first samples as

2233 
long blocks. For 8000Hz, we handle the 48 first

2234 
exponents as long blocks (XXX: check this!) */

2235 
if (s>sample_rate_index <= 2) 
2236 
g>long_end = 8;

2237 
else if (s>sample_rate_index != 8) 
2238 
g>long_end = 6;

2239 
else

2240 
g>long_end = 4; /* 8000 Hz */ 
2241  
2242 
g>short_start = 2 + (s>sample_rate_index != 8); 
2243 
} else {

2244 
g>long_end = 0;

2245 
g>short_start = 0;

2246 
} 
2247 
} else {

2248 
g>short_start = 13;

2249 
g>long_end = 22;

2250 
} 
2251  
2252 
g>preflag = 0;

2253 
if (!s>lsf)

2254 
g>preflag = get_bits(&s>gb, 1);

2255 
g>scalefac_scale = get_bits(&s>gb, 1);

2256 
g>count1table_select = get_bits(&s>gb, 1);

2257 
dprintf("block_type=%d switch_point=%d\n",

2258 
g>block_type, g>switch_point); 
2259 
} 
2260 
} 
2261  
2262 
if (!s>adu_mode) {

2263 
const uint8_t *ptr = s>gb.buffer + (get_bits_count(&s>gb)>>3); 
2264 
assert((get_bits_count(&s>gb) & 7) == 0); 
2265 
/* now we get bits from the main_data_begin offset */

2266 
dprintf("seekback: %d\n", main_data_begin);

2267 
//av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s>last_buf_size);

2268 
if(main_data_begin > s>last_buf_size){

2269 
av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s>last_buf_size); 
2270 
s>last_buf_size= main_data_begin; 
2271 
} 
2272  
2273 
memcpy(s>last_buf + s>last_buf_size, ptr, EXTRABYTES); 
2274 
s>in_gb= s>gb; 
2275 
init_get_bits(&s>gb, s>last_buf + s>last_buf_size  main_data_begin, main_data_begin*8);

2276 
} 
2277  
2278 
for(gr=0;gr<nb_granules;gr++) { 
2279 
for(ch=0;ch<s>nb_channels;ch++) { 
2280 
g = &granules[ch][gr]; 
2281  
2282 
bits_pos = get_bits_count(&s>gb); 
2283  
2284 
if (!s>lsf) {

2285 
uint8_t *sc; 
2286 
int slen, slen1, slen2;

2287  
2288 
/* MPEG1 scale factors */

2289 
slen1 = slen_table[0][g>scalefac_compress];

2290 
slen2 = slen_table[1][g>scalefac_compress];

2291 
dprintf("slen1=%d slen2=%d\n", slen1, slen2);

2292 
if (g>block_type == 2) { 
2293 
n = g>switch_point ? 17 : 18; 
2294 
j = 0;

2295 
if(slen1){

2296 
for(i=0;i<n;i++) 
2297 
g>scale_factors[j++] = get_bits(&s>gb, slen1); 
2298 
}else{

2299 
for(i=0;i<n;i++) 
2300 
g>scale_factors[j++] = 0;

2301 
} 
2302 
if(slen2){

2303 
for(i=0;i<18;i++) 
2304 
g>scale_factors[j++] = get_bits(&s>gb, slen2); 
2305 
for(i=0;i<3;i++) 
2306 
g>scale_factors[j++] = 0;

2307 
}else{

2308 
for(i=0;i<21;i++) 
2309 
g>scale_factors[j++] = 0;

2310 
} 
2311 
} else {

2312 
sc = granules[ch][0].scale_factors;

2313 
j = 0;

2314 
for(k=0;k<4;k++) { 
2315 
n = (k == 0 ? 6 : 5); 
2316 
if ((g>scfsi & (0x8 >> k)) == 0) { 
2317 
slen = (k < 2) ? slen1 : slen2;

2318 
if(slen){

2319 
for(i=0;i<n;i++) 
2320 
g>scale_factors[j++] = get_bits(&s>gb, slen); 
2321 
}else{

2322 
for(i=0;i<n;i++) 
2323 
g>scale_factors[j++] = 0;

2324 
} 
2325 
} else {

2326 
/* simply copy from last granule */

2327 
for(i=0;i<n;i++) { 
2328 
g>scale_factors[j] = sc[j]; 
2329 
j++; 
2330 
} 
2331 
} 
2332 
} 
2333 
g>scale_factors[j++] = 0;

2334 
} 
2335 
#if defined(DEBUG)

2336 
{ 
2337 
dprintf("scfsi=%x gr=%d ch=%d scale_factors:\n",

2338 
g>scfsi, gr, ch); 
2339 
for(i=0;i<j;i++) 
2340 
dprintf(" %d", g>scale_factors[i]);

2341 
dprintf("\n");

2342 
} 
2343 
#endif

2344 
} else {

2345 
int tindex, tindex2, slen[4], sl, sf; 
2346  
2347 
/* LSF scale factors */

2348 
if (g>block_type == 2) { 
2349 
tindex = g>switch_point ? 2 : 1; 
2350 
} else {

2351 
tindex = 0;

2352 
} 
2353 
sf = g>scalefac_compress; 
2354 
if ((s>mode_ext & MODE_EXT_I_STEREO) && ch == 1) { 
2355 
/* intensity stereo case */

2356 
sf >>= 1;

2357 
if (sf < 180) { 
2358 
lsf_sf_expand(slen, sf, 6, 6, 0); 
2359 
tindex2 = 3;

2360 
} else if (sf < 244) { 
2361 
lsf_sf_expand(slen, sf  180, 4, 4, 0); 
2362 
tindex2 = 4;

2363 
} else {

2364 
lsf_sf_expand(slen, sf  244, 3, 0, 0); 
2365 
tindex2 = 5;

2366 
} 
2367 
} else {

2368 
/* normal case */

2369 
if (sf < 400) { 
2370 
lsf_sf_expand(slen, sf, 5, 4, 4); 
2371 
tindex2 = 0;

2372 
} else if (sf < 500) { 
2373 
lsf_sf_expand(slen, sf  400, 5, 4, 0); 
2374 
tindex2 = 1;

2375 
} else {

2376 
lsf_sf_expand(slen, sf  500, 3, 0, 0); 
2377 
tindex2 = 2;

2378 
g>preflag = 1;

2379 
} 
2380 
} 
2381  
2382 
j = 0;

2383 
for(k=0;k<4;k++) { 
2384 
n = lsf_nsf_table[tindex2][tindex][k]; 
2385 
sl = slen[k]; 
2386 
if(sl){

2387 
for(i=0;i<n;i++) 
2388 
g>scale_factors[j++] = get_bits(&s>gb, sl); 
2389 
}else{

2390 
for(i=0;i<n;i++) 
2391 
g>scale_factors[j++] = 0;

2392 
} 
2393 
} 
2394 
/* XXX: should compute exact size */

2395 
for(;j<40;j++) 
2396 
g>scale_factors[j] = 0;

2397 
#if defined(DEBUG)

2398 
{ 
2399 
dprintf("gr=%d ch=%d scale_factors:\n",

2400 
gr, ch); 
2401 
for(i=0;i<40;i++) 
2402 
dprintf(" %d", g>scale_factors[i]);

2403 
dprintf("\n");

2404 
} 
2405 
#endif

2406 
} 
2407  
2408 
exponents_from_scale_factors(s, g, exponents); 
2409  
2410 
/* read Huffman coded residue */

2411 
if (huffman_decode(s, g, exponents,

2412 
bits_pos + g>part2_3_length) < 0)

2413 
return 1; 
2414 
#if defined(DEBUG)

2415 
sample_dump(0, g>sb_hybrid, 576); 
2416 
#endif

2417 
} /* ch */

2418  
2419 
if (s>nb_channels == 2) 
2420 
compute_stereo(s, &granules[0][gr], &granules[1][gr]); 
2421  
2422 
for(ch=0;ch<s>nb_channels;ch++) { 
2423 
g = &granules[ch][gr]; 
2424  
2425 
reorder_block(s, g); 
2426 
#if defined(DEBUG)

2427 
sample_dump(0, g>sb_hybrid, 576); 
2428 
#endif

2429 
s>compute_antialias(s, g); 
2430 
#if defined(DEBUG)

2431 
sample_dump(1, g>sb_hybrid, 576); 
2432 
#endif

2433 
compute_imdct(s, g, &s>sb_samples[ch][18 * gr][0], s>mdct_buf[ch]); 
2434 
#if defined(DEBUG)

2435 
sample_dump(2, &s>sb_samples[ch][18 * gr][0], 576); 
2436 
#endif

2437 
} 
2438 
} /* gr */

2439 
return nb_granules * 18; 
2440 
} 
2441  
2442 
static int mp_decode_frame(MPADecodeContext *s, 
2443 
OUT_INT *samples, const uint8_t *buf, int buf_size) 
2444 
{ 
2445 
int i, nb_frames, ch;

2446 
OUT_INT *samples_ptr; 
2447  
2448 
init_get_bits(&s>gb, buf + HEADER_SIZE, (buf_size  HEADER_SIZE)*8);

2449  
2450 
/* skip error protection field */

2451 
if (s>error_protection)

2452 
get_bits(&s>gb, 16);

2453  
2454 
dprintf("frame %d:\n", s>frame_count);

2455 
switch(s>layer) {

2456 
case 1: 
2457 
nb_frames = mp_decode_layer1(s); 
2458 
break;

2459 
case 2: 
2460 
nb_frames = mp_decode_layer2(s); 
2461 
break;

2462 
case 3: 
2463 
default:

2464 
nb_frames = mp_decode_layer3(s); 
2465  
2466 
s>last_buf_size=0;

2467 
if(s>in_gb.buffer){

2468 
align_get_bits(&s>gb); 
2469 
i= (s>gb.size_in_bits  get_bits_count(&s>gb))>>3;

2470 
if(i >= 0 && i <= BACKSTEP_SIZE){ 
2471 
memmove(s>last_buf, s>gb.buffer + (get_bits_count(&s>gb)>>3), i);

2472 
s>last_buf_size=i; 
2473 
}else

2474 
av_log(NULL, AV_LOG_ERROR, "invalid old backstep %d\n", i); 
2475 
s>gb= s>in_gb; 
2476 
} 
2477  
2478 
align_get_bits(&s>gb); 
2479 
assert((get_bits_count(&s>gb) & 7) == 0); 
2480 
i= (s>gb.size_in_bits  get_bits_count(&s>gb))>>3;

2481  
2482 
if(i<0  i > BACKSTEP_SIZE  nb_frames<0){ 
2483 
av_log(NULL, AV_LOG_ERROR, "invalid new backstep %d\n", i); 
2484 
i= FFMIN(BACKSTEP_SIZE, buf_size  HEADER_SIZE); 
2485 
} 
2486 
assert(i <= buf_size  HEADER_SIZE && i>= 0);

2487 
memcpy(s>last_buf + s>last_buf_size, s>gb.buffer + buf_size  HEADER_SIZE  i, i); 
2488 
s>last_buf_size += i; 
2489  
2490 
break;

2491 
} 
2492 
#if defined(DEBUG)

2493 
for(i=0;i<nb_frames;i++) { 
2494 
for(ch=0;ch<s>nb_channels;ch++) { 
2495 
int j;

2496 
dprintf("%d%d:", i, ch);

2497 
for(j=0;j<SBLIMIT;j++) 
2498 
dprintf(" %0.6f", (double)s>sb_samples[ch][i][j] / FRAC_ONE); 
2499 
dprintf("\n");

2500 
} 
2501 
} 
2502 
#endif

2503 
/* apply the synthesis filter */

2504 
for(ch=0;ch<s>nb_channels;ch++) { 
2505 
samples_ptr = samples + ch; 
2506 
for(i=0;i<nb_frames;i++) { 
2507 
ff_mpa_synth_filter(s>synth_buf[ch], &(s>synth_buf_offset[ch]), 
2508 
window, &s>dither_state, 
2509 
samples_ptr, s>nb_channels, 
2510 
s>sb_samples[ch][i]); 
2511 
samples_ptr += 32 * s>nb_channels;

2512 
} 
2513 
} 
2514 
#ifdef DEBUG

2515 
s>frame_count++; 
2516 
#endif

2517 
return nb_frames * 32 * sizeof(OUT_INT) * s>nb_channels; 
2518 
} 
2519  
2520 
static int decode_frame(AVCodecContext * avctx, 
2521 
void *data, int *data_size, 
2522 
uint8_t * buf, int buf_size)

2523 
{ 
2524 
MPADecodeContext *s = avctx>priv_data; 
2525 
uint32_t header; 
2526 
int out_size;

2527 
OUT_INT *out_samples = data; 
2528  
2529 
retry:

2530 
if(buf_size < HEADER_SIZE)

2531 
return 1; 
2532  
2533 
header = (buf[0] << 24)  (buf[1] << 16)  (buf[2] << 8)  buf[3]; 
2534 
if(ff_mpa_check_header(header) < 0){ 
2535 
buf++; 
2536 
// buf_size;

2537 
av_log(avctx, AV_LOG_ERROR, "header missing skiping one byte\n");

2538 
goto retry;

2539 
} 
2540  
2541 
if (decode_header(s, header) == 1) { 
2542 
/* free format: prepare to compute frame size */

2543 
s>frame_size = 1;

2544 
return 1; 
2545 
} 
2546 
/* update codec info */

2547 
avctx>sample_rate = s>sample_rate; 
2548 
avctx>channels = s>nb_channels; 
2549 
avctx>bit_rate = s>bit_rate; 
2550 
avctx>sub_id = s>layer; 
2551 
switch(s>layer) {

2552 
case 1: 
2553 
avctx>frame_size = 384;

2554 
break;

2555 
case 2: 
2556 
avctx>frame_size = 1152;

2557 
break;

2558 
case 3: 
2559 
if (s>lsf)

2560 
avctx>frame_size = 576;

2561 
else

2562 
avctx>frame_size = 1152;

2563 
break;

2564 
} 
2565  
2566 
if(s>frame_size<=0  s>frame_size > buf_size){ 
2567 
av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");

2568 
return 1; 
2569 
}else if(s>frame_size < buf_size){ 
2570 
av_log(avctx, AV_LOG_ERROR, "incorrect frame size\n");

2571 
} 
2572  
2573 
out_size = mp_decode_frame(s, out_samples, buf, buf_size); 
2574 
if(out_size>=0) 
2575 
*data_size = out_size; 
2576 
else

2577 
av_log(avctx, AV_LOG_DEBUG, "Error while decoding mpeg audio frame\n"); //FIXME return 1 / but also return the number of bytes consumed 
2578 
s>frame_size = 0;

2579 
return buf_size;

2580 
} 
2581  
2582  
2583 
static int decode_frame_adu(AVCodecContext * avctx, 
2584 
void *data, int *data_size, 
2585 
uint8_t * buf, int buf_size)

2586 
{ 
2587 
MPADecodeContext *s = avctx>priv_data; 
2588 
uint32_t header; 
2589 
int len, out_size;

2590 
OUT_INT *out_samples = data; 
2591  
2592 
len = buf_size; 
2593  
2594 
// Discard too short frames

2595 
if (buf_size < HEADER_SIZE) {

2596 
*data_size = 0;

2597 
return buf_size;

2598 
} 
2599  
2600  
2601 
if (len > MPA_MAX_CODED_FRAME_SIZE)

2602 
len = MPA_MAX_CODED_FRAME_SIZE; 
2603  
2604 
// Get header and restore sync word

2605 
header = (buf[0] << 24)  (buf[1] << 16)  (buf[2] << 8)  buf[3]  0xffe00000; 
2606  
2607 
if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame 
2608 
*data_size = 0;

2609 
return buf_size;

2610 
} 
2611  
2612 
decode_header(s, header); 
2613 
/* update codec info */

2614 
avctx>sample_rate = s>sample_rate; 
2615 
avctx>channels = s>nb_channels; 
2616 
avctx>bit_rate = s>bit_rate; 
2617 
avctx>sub_id = s>layer; 
2618  
2619 
avctx>frame_size=s>frame_size = len; 
2620  
2621 
if (avctx>parse_only) {

2622 
out_size = buf_size; 
2623 
} else {

2624 
out_size = mp_decode_frame(s, out_samples, buf, buf_size); 
2625 
} 
2626  
2627 
*data_size = out_size; 
2628 
return buf_size;

2629 
} 
2630  
2631  
2632 
/* Next 3 arrays are indexed by channel config number (passed via codecdata) */

2633 
static int mp3Frames[16] = {0,1,1,2,3,3,4,5,2}; /* number of mp3 decoder instances */ 
2634 
static int mp3Channels[16] = {0,1,2,3,4,5,6,8,4}; /* total output channels */ 
2635 
/* offsets into output buffer, assume output order is FL FR BL BR C LFE */

2636 
static int chan_offset[9][5] = { 
2637 
{0},

2638 
{0}, // C 
2639 
{0}, // FLR 
2640 
{2,0}, // C FLR 
2641 
{2,0,3}, // C FLR BS 
2642 
{4,0,2}, // C FLR BLRS 
2643 
{4,0,2,5}, // C FLR BLRS LFE 
2644 
{4,0,2,6,5}, // C FLR BLRS BLR LFE 
2645 
{0,2} // FLR BLRS 
2646 
}; 
2647  
2648  
2649 
static int decode_init_mp3on4(AVCodecContext * avctx) 
2650 
{ 
2651 
MP3On4DecodeContext *s = avctx>priv_data; 
2652 
int i;

2653  
2654 
if ((avctx>extradata_size < 2)  (avctx>extradata == NULL)) { 
2655 
av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");

2656 
return 1; 
2657 
} 
2658  
2659 
s>chan_cfg = (((unsigned char *)avctx>extradata)[1] >> 3) & 0x0f; 
2660 
s>frames = mp3Frames[s>chan_cfg]; 
2661 
if(!s>frames) {

2662 
av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");

2663 
return 1; 
2664 
} 
2665 
avctx>channels = mp3Channels[s>chan_cfg]; 
2666  
2667 
/* Init the first mp3 decoder in standard way, so that all tables get builded

2668 
* We replace avctx>priv_data with the context of the first decoder so that

2669 
* decode_init() does not have to be changed.

2670 
* Other decoders will be inited here copying data from the first context

2671 
*/

2672 
// Allocate zeroed memory for the first decoder context

2673 
s>mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext)); 
2674 
// Put decoder context in place to make init_decode() happy

2675 
avctx>priv_data = s>mp3decctx[0];

2676 
decode_init(avctx); 
2677 
// Restore mp3on4 context pointer

2678 
avctx>priv_data = s; 
2679 
s>mp3decctx[0]>adu_mode = 1; // Set adu mode 
2680  
2681 
/* Create a separate codec/context for each frame (first is already ok).

2682 
* Each frame is 1 or 2 channels  up to 5 frames allowed

2683 
*/

2684 
for (i = 1; i < s>frames; i++) { 
2685 
s>mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));

2686 
s>mp3decctx[i]>compute_antialias = s>mp3decctx[0]>compute_antialias;

2687 
s>mp3decctx[i]>adu_mode = 1;

2688 
} 
2689  
2690 
return 0; 
2691 
} 
2692  
2693  
2694 
static int decode_close_mp3on4(AVCodecContext * avctx) 
2695 
{ 
2696 
MP3On4DecodeContext *s = avctx>priv_data; 
2697 
int i;

2698  
2699 
for (i = 0; i < s>frames; i++) 
2700 
if (s>mp3decctx[i])

2701 
av_free(s>mp3decctx[i]); 
2702  
2703 
return 0; 
2704 
} 
2705  
2706  
2707 
static int decode_frame_mp3on4(AVCodecContext * avctx, 
2708 
void *data, int *data_size, 
2709 
uint8_t * buf, int buf_size)

2710 
{ 
2711 
MP3On4DecodeContext *s = avctx>priv_data; 
2712 
MPADecodeContext *m; 
2713 
int len, out_size = 0; 
2714 
uint32_t header; 
2715 
OUT_INT *out_samples = data; 
2716 
OUT_INT decoded_buf[MPA_FRAME_SIZE * MPA_MAX_CHANNELS]; 
2717 
OUT_INT *outptr, *bp; 
2718 
int fsize;

2719 
unsigned char *start2 = buf, *start; 
2720 
int fr, i, j, n;

2721 
int off = avctx>channels;

2722 
int *coff = chan_offset[s>chan_cfg];

2723  
2724 
len = buf_size; 
2725  
2726 
// Discard too short frames

2727 
if (buf_size < HEADER_SIZE) {

2728 
*data_size = 0;

2729 
return buf_size;

2730 
} 
2731  
2732 
// If only one decoder interleave is not needed

2733 
outptr = s>frames == 1 ? out_samples : decoded_buf;

2734  
2735 
for (fr = 0; fr < s>frames; fr++) { 
2736 
start = start2; 
2737 
fsize = (start[0] << 4)  (start[1] >> 4); 
2738 
start2 += fsize; 
2739 
if (fsize > len)

2740 
fsize = len; 
2741 
len = fsize; 
2742 
if (fsize > MPA_MAX_CODED_FRAME_SIZE)

2743 
fsize = MPA_MAX_CODED_FRAME_SIZE; 
2744 
m = s>mp3decctx[fr]; 
2745 
assert (m != NULL);

2746  
2747 
// Get header

2748 
header = (start[0] << 24)  (start[1] << 16)  (start[2] << 8)  start[3]  0xfff00000; 
2749  
2750 
if (ff_mpa_check_header(header) < 0) { // Bad header, discard block 
2751 
*data_size = 0;

2752 
return buf_size;

2753 
} 
2754  
2755 
decode_header(m, header); 
2756 
mp_decode_frame(m, decoded_buf, start, fsize); 
2757  
2758 
n = MPA_FRAME_SIZE * m>nb_channels; 
2759 
out_size += n * sizeof(OUT_INT);

2760 
if(s>frames > 1) { 
2761 
/* interleave output data */

2762 
bp = out_samples + coff[fr]; 
2763 
if(m>nb_channels == 1) { 
2764 
for(j = 0; j < n; j++) { 
2765 
*bp = decoded_buf[j]; 
2766 
bp += off; 
2767 
} 
2768 
} else {

2769 
for(j = 0; j < n; j++) { 
2770 
bp[0] = decoded_buf[j++];

2771 
bp[1] = decoded_buf[j];

2772 
bp += off; 
2773 
} 
2774 
} 
2775 
} 
2776 
} 
2777  
2778 
/* update codec info */

2779 
avctx>sample_rate = s>mp3decctx[0]>sample_rate;

2780 
avctx>frame_size= buf_size; 
2781 
avctx>bit_rate = 0;

2782 
for (i = 0; i < s>frames; i++) 
2783 
avctx>bit_rate += s>mp3decctx[i]>bit_rate; 
2784  
2785 
*data_size = out_size; 
2786 
return buf_size;

2787 
} 
2788  
2789  
2790 
AVCodec mp2_decoder = 
2791 
{ 
2792 
"mp2",

2793 
CODEC_TYPE_AUDIO, 
2794 
CODEC_ID_MP2, 
2795 
sizeof(MPADecodeContext),

2796 
decode_init, 
2797 
NULL,

2798 
NULL,

2799 
decode_frame, 
2800 
CODEC_CAP_PARSE_ONLY, 
2801 
}; 
2802  
2803 
AVCodec mp3_decoder = 
2804 
{ 
2805 
"mp3",

2806 
CODEC_TYPE_AUDIO, 
2807 
CODEC_ID_MP3, 
2808 
sizeof(MPADecodeContext),

2809 
decode_init, 
2810 
NULL,

2811 
NULL,

2812 
decode_frame, 
2813 
CODEC_CAP_PARSE_ONLY, 
2814 
}; 
2815  
2816 
AVCodec mp3adu_decoder = 
2817 
{ 
2818 
"mp3adu",

2819 
CODEC_TYPE_AUDIO, 
2820 
CODEC_ID_MP3ADU, 
2821 
sizeof(MPADecodeContext),

2822 
decode_init, 
2823 
NULL,

2824 
NULL,

2825 
decode_frame_adu, 
2826 
CODEC_CAP_PARSE_ONLY, 
2827 
}; 
2828  
2829 
AVCodec mp3on4_decoder = 
2830 
{ 
2831 
"mp3on4",

2832 
CODEC_TYPE_AUDIO, 
2833 
CODEC_ID_MP3ON4, 
2834 
sizeof(MP3On4DecodeContext),

2835 
decode_init_mp3on4, 
2836 
NULL,

2837 
decode_close_mp3on4, 
2838 
decode_frame_mp3on4, 
2839 
0

2840 
}; 