ffmpeg / libavcodec / wma.h @ 891bd2e5
History  View  Annotate  Download (6.21 KB)
1 
/*


2 
* WMA compatible codec

3 
* Copyright (c) 20022007 The FFmpeg Project

4 
*

5 
* This file is part of FFmpeg.

6 
*

7 
* FFmpeg is free software; you can redistribute it and/or

8 
* modify it under the terms of the GNU Lesser General Public

9 
* License as published by the Free Software Foundation; either

10 
* version 2.1 of the License, or (at your option) any later version.

11 
*

12 
* FFmpeg is distributed in the hope that it will be useful,

13 
* but WITHOUT ANY WARRANTY; without even the implied warranty of

14 
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

15 
* Lesser General Public License for more details.

16 
*

17 
* You should have received a copy of the GNU Lesser General Public

18 
* License along with FFmpeg; if not, write to the Free Software

19 
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 021101301 USA

20 
*/

21  
22 
#ifndef AVCODEC_WMA_H

23 
#define AVCODEC_WMA_H

24  
25 
#include "get_bits.h" 
26 
#include "put_bits.h" 
27 
#include "dsputil.h" 
28  
29 
/* size of blocks */

30 
#define BLOCK_MIN_BITS 7 
31 
#define BLOCK_MAX_BITS 11 
32 
#define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS) 
33  
34 
#define BLOCK_NB_SIZES (BLOCK_MAX_BITS  BLOCK_MIN_BITS + 1) 
35  
36 
/* XXX: find exact max size */

37 
#define HIGH_BAND_MAX_SIZE 16 
38  
39 
#define NB_LSP_COEFS 10 
40  
41 
/* XXX: is it a suitable value ? */

42 
#define MAX_CODED_SUPERFRAME_SIZE 16384 
43  
44 
#define MAX_CHANNELS 2 
45  
46 
#define NOISE_TAB_SIZE 8192 
47  
48 
#define LSP_POW_BITS 7 
49  
50 
//FIXME should be in wmadec

51 
#define VLCBITS 9 
52 
#define VLCMAX ((22+VLCBITS1)/VLCBITS) 
53  
54 
typedef float WMACoef; ///< type for decoded coefficients, int16_t would be enough for wma 1/2 
55  
56 
typedef struct CoefVLCTable { 
57 
int n; ///< total number of codes 
58 
int max_level;

59 
const uint32_t *huffcodes; ///< VLC bit values 
60 
const uint8_t *huffbits; ///< VLC bit size 
61 
const uint16_t *levels; ///< table to build run/level tables 
62 
} CoefVLCTable; 
63  
64 
typedef struct WMACodecContext { 
65 
AVCodecContext* avctx; 
66 
GetBitContext gb; 
67 
PutBitContext pb; 
68 
int sample_rate;

69 
int nb_channels;

70 
int bit_rate;

71 
int version; ///< 1 = 0x160 (WMAV1), 2 = 0x161 (WMAV2) 
72 
int block_align;

73 
int use_bit_reservoir;

74 
int use_variable_block_len;

75 
int use_exp_vlc; ///< exponent coding: 0 = lsp, 1 = vlc + delta 
76 
int use_noise_coding; ///< true if perceptual noise is added 
77 
int byte_offset_bits;

78 
VLC exp_vlc; 
79 
int exponent_sizes[BLOCK_NB_SIZES];

80 
uint16_t exponent_bands[BLOCK_NB_SIZES][25];

81 
int high_band_start[BLOCK_NB_SIZES]; ///< index of first coef in high band 
82 
int coefs_start; ///< first coded coef 
83 
int coefs_end[BLOCK_NB_SIZES]; ///< max number of coded coefficients 
84 
int exponent_high_sizes[BLOCK_NB_SIZES];

85 
int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];

86 
VLC hgain_vlc; 
87  
88 
/* coded values in high bands */

89 
int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];

90 
int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];

91  
92 
/* there are two possible tables for spectral coefficients */

93 
//FIXME the following 3 tables should be shared between decoders

94 
VLC coef_vlc[2];

95 
uint16_t *run_table[2];

96 
uint16_t *level_table[2];

97 
uint16_t *int_table[2];

98 
const CoefVLCTable *coef_vlcs[2]; 
99 
/* frame info */

100 
int frame_len; ///< frame length in samples 
101 
int frame_len_bits; ///< frame_len = 1 << frame_len_bits 
102 
int nb_block_sizes; ///< number of block sizes 
103 
/* block info */

104 
int reset_block_lengths;

105 
int block_len_bits; ///< log2 of current block length 
106 
int next_block_len_bits; ///< log2 of next block length 
107 
int prev_block_len_bits; ///< log2 of prev block length 
108 
int block_len; ///< block length in samples 
109 
int block_num; ///< block number in current frame 
110 
int block_pos; ///< current position in frame 
111 
uint8_t ms_stereo; ///< true if mid/side stereo mode

112 
uint8_t channel_coded[MAX_CHANNELS]; ///< true if channel is coded

113 
int exponents_bsize[MAX_CHANNELS]; ///< log2 ratio frame/exp. length 
114 
DECLARE_ALIGNED_16(float, exponents[MAX_CHANNELS][BLOCK_MAX_SIZE]);

115 
float max_exponent[MAX_CHANNELS];

116 
WMACoef coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE]; 
117 
DECLARE_ALIGNED_16(float, coefs[MAX_CHANNELS][BLOCK_MAX_SIZE]);

118 
DECLARE_ALIGNED_16(FFTSample, output[BLOCK_MAX_SIZE * 2]);

119 
MDCTContext mdct_ctx[BLOCK_NB_SIZES]; 
120 
float *windows[BLOCK_NB_SIZES];

121 
/* output buffer for one frame and the last for IMDCT windowing */

122 
DECLARE_ALIGNED_16(float, frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2]); 
123 
/* last frame info */

124 
uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */ 
125 
int last_bitoffset;

126 
int last_superframe_len;

127 
float noise_table[NOISE_TAB_SIZE];

128 
int noise_index;

129 
float noise_mult; /* XXX: suppress that and integrate it in the noise array */ 
130 
/* lsp_to_curve tables */

131 
float lsp_cos_table[BLOCK_MAX_SIZE];

132 
float lsp_pow_e_table[256]; 
133 
float lsp_pow_m_table1[(1 << LSP_POW_BITS)]; 
134 
float lsp_pow_m_table2[(1 << LSP_POW_BITS)]; 
135 
DSPContext dsp; 
136  
137 
#ifdef TRACE

138 
int frame_count;

139 
#endif

140 
} WMACodecContext; 
141  
142 
extern const uint16_t ff_wma_hgain_huffcodes[37]; 
143 
extern const uint8_t ff_wma_hgain_huffbits[37]; 
144 
extern const float ff_wma_lsp_codebook[NB_LSP_COEFS][16]; 
145 
extern const uint32_t ff_wma_scale_huffcodes[121]; 
146 
extern const uint8_t ff_wma_scale_huffbits[121]; 
147  
148 
int av_cold ff_wma_get_frame_len_bits(int sample_rate, int version, 
149 
unsigned int decode_flags); 
150 
int ff_wma_init(AVCodecContext * avctx, int flags2); 
151 
int ff_wma_total_gain_to_bits(int total_gain); 
152 
int ff_wma_end(AVCodecContext *avctx);

153 
unsigned int ff_wma_get_large_val(GetBitContext* gb); 
154 
int ff_wma_run_level_decode(AVCodecContext* avctx, GetBitContext* gb,

155 
VLC *vlc, 
156 
const uint16_t *level_table, const uint16_t *run_table, 
157 
int version, WMACoef *ptr, int offset, 
158 
int num_coefs, int block_len, int frame_len_bits, 
159 
int coef_nb_bits);

160  
161 
#endif /* AVCODEC_WMA_H */ 