## ffmpeg / libavcodec / mlpdec.c @ 72415b2a

History | View | Annotate | Download (38.1 KB)

1 | b517af05 | Ramiro Polla | ```
/*
``` |
---|---|---|---|

2 | ```
* MLP decoder
``` |
||

3 | ```
* Copyright (c) 2007-2008 Ian Caulfield
``` |
||

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 02110-1301 USA
``` |
||

20 | ```
*/
``` |
||

21 | |||

22 | ```
/**
``` |
||

23 | bad5537e | Diego Biurrun | ```
* @file libavcodec/mlpdec.c
``` |

24 | b517af05 | Ramiro Polla | ```
* MLP decoder
``` |

25 | ```
*/
``` |
||

26 | |||

27 | 0e74e1ff | Diego Biurrun | #include <stdint.h> |

28 | |||

29 | b517af05 | Ramiro Polla | #include "avcodec.h" |

30 | bf4f19dc | Ramiro Polla | #include "dsputil.h" |

31 | b517af05 | Ramiro Polla | #include "libavutil/intreadwrite.h" |

32 | 9106a698 | Stefano Sabatini | #include "get_bits.h" |

33 | b517af05 | Ramiro Polla | #include "libavutil/crc.h" |

34 | #include "parser.h" |
||

35 | #include "mlp_parser.h" |
||

36 | ce15710f | Ramiro Polla | #include "mlp.h" |

37 | b517af05 | Ramiro Polla | |

38 | 9906a2be | Diego Biurrun | ```
/** number of bits used for VLC lookup - longest Huffman code is 9 */
``` |

39 | b517af05 | Ramiro Polla | #define VLC_BITS 9 |

40 | |||

41 | |||

42 | static const char* sample_message = |
||

43 | ```
"Please file a bug report following the instructions at "
``` |
||

44 | 0fa5f24c | Diego Biurrun | ```
"http://ffmpeg.org/bugreports.html and include "
``` |

45 | b517af05 | Ramiro Polla | ```
"a sample of this file.";
``` |

46 | |||

47 | typedef struct SubStream { |
||

48 | 9906a2be | Diego Biurrun | ```
//! Set if a valid restart header has been read. Otherwise the substream cannot be decoded.
``` |

49 | b517af05 | Ramiro Polla | uint8_t restart_seen; |

50 | |||

51 | ```
//@{
``` |
||

52 | ```
/** restart header data */
``` |
||

53 | ```
//! The type of noise to be used in the rematrix stage.
``` |
||

54 | uint16_t noise_type; |
||

55 | |||

56 | ```
//! The index of the first channel coded in this substream.
``` |
||

57 | uint8_t min_channel; |
||

58 | ```
//! The index of the last channel coded in this substream.
``` |
||

59 | uint8_t max_channel; |
||

60 | ```
//! The number of channels input into the rematrix stage.
``` |
||

61 | uint8_t max_matrix_channel; |
||

62 | 9731e7f1 | Ramiro Polla | ```
//! For each channel output by the matrix, the output channel to map it to
``` |

63 | uint8_t ch_assign[MAX_CHANNELS]; |
||

64 | b517af05 | Ramiro Polla | |

65 | ```
//! The left shift applied to random noise in 0x31ea substreams.
``` |
||

66 | uint8_t noise_shift; |
||

67 | ```
//! The current seed value for the pseudorandom noise generator(s).
``` |
||

68 | uint32_t noisegen_seed; |
||

69 | |||

70 | ```
//! Set if the substream contains extra info to check the size of VLC blocks.
``` |
||

71 | uint8_t data_check_present; |
||

72 | |||

73 | ```
//! Bitmask of which parameter sets are conveyed in a decoding parameter block.
``` |
||

74 | uint8_t param_presence_flags; |
||

75 | #define PARAM_BLOCKSIZE (1 << 7) |
||

76 | #define PARAM_MATRIX (1 << 6) |
||

77 | #define PARAM_OUTSHIFT (1 << 5) |
||

78 | #define PARAM_QUANTSTEP (1 << 4) |
||

79 | #define PARAM_FIR (1 << 3) |
||

80 | #define PARAM_IIR (1 << 2) |
||

81 | #define PARAM_HUFFOFFSET (1 << 1) |
||

82 | cbf3cf19 | Ramiro Polla | #define PARAM_PRESENCE (1 << 0) |

83 | b517af05 | Ramiro Polla | ```
//@}
``` |

84 | |||

85 | ```
//@{
``` |
||

86 | ```
/** matrix data */
``` |
||

87 | |||

88 | ```
//! Number of matrices to be applied.
``` |
||

89 | uint8_t num_primitive_matrices; |
||

90 | |||

91 | ```
//! matrix output channel
``` |
||

92 | uint8_t matrix_out_ch[MAX_MATRICES]; |
||

93 | |||

94 | ```
//! Whether the LSBs of the matrix output are encoded in the bitstream.
``` |
||

95 | uint8_t lsb_bypass[MAX_MATRICES]; |
||

96 | ```
//! Matrix coefficients, stored as 2.14 fixed point.
``` |
||

97 | 420df930 | Ramiro Polla | int32_t matrix_coeff[MAX_MATRICES][MAX_CHANNELS]; |

98 | b517af05 | Ramiro Polla | ```
//! Left shift to apply to noise values in 0x31eb substreams.
``` |

99 | uint8_t matrix_noise_shift[MAX_MATRICES]; |
||

100 | ```
//@}
``` |
||

101 | |||

102 | 9906a2be | Diego Biurrun | ```
//! Left shift to apply to Huffman-decoded residuals.
``` |

103 | b517af05 | Ramiro Polla | uint8_t quant_step_size[MAX_CHANNELS]; |

104 | |||

105 | 9906a2be | Diego Biurrun | ```
//! number of PCM samples in current audio block
``` |

106 | b517af05 | Ramiro Polla | uint16_t blocksize; |

107 | ```
//! Number of PCM samples decoded so far in this frame.
``` |
||

108 | uint16_t blockpos; |
||

109 | |||

110 | ```
//! Left shift to apply to decoded PCM values to get final 24-bit output.
``` |
||

111 | int8_t output_shift[MAX_CHANNELS]; |
||

112 | |||

113 | ```
//! Running XOR of all output samples.
``` |
||

114 | int32_t lossless_check_data; |
||

115 | |||

116 | } SubStream; |
||

117 | |||

118 | typedef struct MLPDecodeContext { |
||

119 | AVCodecContext *avctx; |
||

120 | |||

121 | cc9c5126 | Ramiro Polla | ```
//! Current access unit being read has a major sync.
``` |

122 | ```
int is_major_sync_unit;
``` |
||

123 | |||

124 | b517af05 | Ramiro Polla | ```
//! Set if a valid major sync block has been read. Otherwise no decoding is possible.
``` |

125 | uint8_t params_valid; |
||

126 | |||

127 | ```
//! Number of substreams contained within this stream.
``` |
||

128 | uint8_t num_substreams; |
||

129 | |||

130 | ```
//! Index of the last substream to decode - further substreams are skipped.
``` |
||

131 | uint8_t max_decoded_substream; |
||

132 | |||

133 | 9906a2be | Diego Biurrun | ```
//! number of PCM samples contained in each frame
``` |

134 | b517af05 | Ramiro Polla | ```
int access_unit_size;
``` |

135 | 9906a2be | Diego Biurrun | ```
//! next power of two above the number of samples in each frame
``` |

136 | b517af05 | Ramiro Polla | ```
int access_unit_size_pow2;
``` |

137 | |||

138 | SubStream substream[MAX_SUBSTREAMS]; |
||

139 | |||

140 | f53acb7b | Ramiro Polla | ChannelParams channel_params[MAX_CHANNELS]; |

141 | b517af05 | Ramiro Polla | |

142 | 75428fa4 | Ramiro Polla | ```
int matrix_changed;
``` |

143 | ```
int filter_changed[MAX_CHANNELS][NUM_FILTERS];
``` |
||

144 | |||

145 | b517af05 | Ramiro Polla | int8_t noise_buffer[MAX_BLOCKSIZE_POW2]; |

146 | int8_t bypassed_lsbs[MAX_BLOCKSIZE][MAX_CHANNELS]; |
||

147 | 420df930 | Ramiro Polla | int32_t sample_buffer[MAX_BLOCKSIZE][MAX_CHANNELS]; |

148 | bf4f19dc | Ramiro Polla | |

149 | DSPContext dsp; |
||

150 | b517af05 | Ramiro Polla | } MLPDecodeContext; |

151 | |||

152 | static VLC huff_vlc[3]; |
||

153 | |||

154 | ```
/** Initialize static data, constant between all invocations of the codec. */
``` |
||

155 | |||

156 | dc8a7c93 | Diego Biurrun | static av_cold void init_static(void) |

157 | b517af05 | Ramiro Polla | { |

158 | 7fd88069 | Ramiro Polla | if (!huff_vlc[0].bits) { |

159 | 52ae1e86 | Ramiro Polla | INIT_VLC_STATIC(&huff_vlc[0], VLC_BITS, 18, |

160 | &ff_mlp_huffman_tables[0][0][1], 2, 1, |
||

161 | &ff_mlp_huffman_tables[0][0][0], 2, 1, 512); |
||

162 | INIT_VLC_STATIC(&huff_vlc[1], VLC_BITS, 16, |
||

163 | &ff_mlp_huffman_tables[1][0][1], 2, 1, |
||

164 | &ff_mlp_huffman_tables[1][0][0], 2, 1, 512); |
||

165 | INIT_VLC_STATIC(&huff_vlc[2], VLC_BITS, 15, |
||

166 | &ff_mlp_huffman_tables[2][0][1], 2, 1, |
||

167 | &ff_mlp_huffman_tables[2][0][0], 2, 1, 512); |
||

168 | 7fd88069 | Ramiro Polla | } |

169 | b517af05 | Ramiro Polla | |

170 | ce15710f | Ramiro Polla | ff_mlp_init_crc(); |

171 | b517af05 | Ramiro Polla | } |

172 | |||

173 | static inline int32_t calculate_sign_huff(MLPDecodeContext *m, |
||

174 | unsigned int substr, unsigned int ch) |
||

175 | { |
||

176 | f53acb7b | Ramiro Polla | ChannelParams *cp = &m->channel_params[ch]; |

177 | b517af05 | Ramiro Polla | SubStream *s = &m->substream[substr]; |

178 | f53acb7b | Ramiro Polla | ```
int lsb_bits = cp->huff_lsbs - s->quant_step_size[ch];
``` |

179 | int sign_shift = lsb_bits + (cp->codebook ? 2 - cp->codebook : -1); |
||

180 | int32_t sign_huff_offset = cp->huff_offset; |
||

181 | b517af05 | Ramiro Polla | |

182 | f53acb7b | Ramiro Polla | if (cp->codebook > 0) |

183 | b517af05 | Ramiro Polla | ```
sign_huff_offset -= 7 << lsb_bits;
``` |

184 | |||

185 | if (sign_shift >= 0) |
||

186 | ```
sign_huff_offset -= 1 << sign_shift;
``` |
||

187 | |||

188 | ```
return sign_huff_offset;
``` |
||

189 | } |
||

190 | |||

191 | ```
/** Read a sample, consisting of either, both or neither of entropy-coded MSBs
``` |
||

192 | ```
* and plain LSBs. */
``` |
||

193 | |||

194 | static inline int read_huff_channels(MLPDecodeContext *m, GetBitContext *gbp, |
||

195 | unsigned int substr, unsigned int pos) |
||

196 | { |
||

197 | SubStream *s = &m->substream[substr]; |
||

198 | unsigned int mat, channel; |
||

199 | |||

200 | for (mat = 0; mat < s->num_primitive_matrices; mat++) |
||

201 | ```
if (s->lsb_bypass[mat])
``` |
||

202 | m->bypassed_lsbs[pos + s->blockpos][mat] = get_bits1(gbp); |
||

203 | |||

204 | ```
for (channel = s->min_channel; channel <= s->max_channel; channel++) {
``` |
||

205 | f53acb7b | Ramiro Polla | ChannelParams *cp = &m->channel_params[channel]; |

206 | ```
int codebook = cp->codebook;
``` |
||

207 | b517af05 | Ramiro Polla | ```
int quant_step_size = s->quant_step_size[channel];
``` |

208 | f53acb7b | Ramiro Polla | ```
int lsb_bits = cp->huff_lsbs - quant_step_size;
``` |

209 | b517af05 | Ramiro Polla | int result = 0; |

210 | |||

211 | if (codebook > 0) |
||

212 | ```
result = get_vlc2(gbp, huff_vlc[codebook-1].table,
``` |
||

213 | VLC_BITS, (9 + VLC_BITS - 1) / VLC_BITS); |
||

214 | |||

215 | if (result < 0) |
||

216 | return -1; |
||

217 | |||

218 | if (lsb_bits > 0) |
||

219 | result = (result << lsb_bits) + get_bits(gbp, lsb_bits); |
||

220 | |||

221 | f53acb7b | Ramiro Polla | result += cp->sign_huff_offset; |

222 | b517af05 | Ramiro Polla | result <<= quant_step_size; |

223 | |||

224 | m->sample_buffer[pos + s->blockpos][channel] = result; |
||

225 | } |
||

226 | |||

227 | return 0; |
||

228 | } |
||

229 | |||

230 | static av_cold int mlp_decode_init(AVCodecContext *avctx) |
||

231 | { |
||

232 | MLPDecodeContext *m = avctx->priv_data; |
||

233 | ```
int substr;
``` |
||

234 | |||

235 | init_static(); |
||

236 | m->avctx = avctx; |
||

237 | for (substr = 0; substr < MAX_SUBSTREAMS; substr++) |
||

238 | ```
m->substream[substr].lossless_check_data = 0xffffffff;
``` |
||

239 | bf4f19dc | Ramiro Polla | dsputil_init(&m->dsp, avctx); |

240 | ee1a8f62 | Ramiro Polla | |

241 | b517af05 | Ramiro Polla | return 0; |

242 | } |
||

243 | |||

244 | ```
/** Read a major sync info header - contains high level information about
``` |
||

245 | ```
* the stream - sample rate, channel arrangement etc. Most of this
``` |
||

246 | ```
* information is not actually necessary for decoding, only for playback.
``` |
||

247 | ```
*/
``` |
||

248 | |||

249 | static int read_major_sync(MLPDecodeContext *m, GetBitContext *gb) |
||

250 | { |
||

251 | MLPHeaderInfo mh; |
||

252 | ```
int substr;
``` |
||

253 | |||

254 | if (ff_mlp_read_major_sync(m->avctx, &mh, gb) != 0) |
||

255 | return -1; |
||

256 | |||

257 | if (mh.group1_bits == 0) { |
||

258 | 9906a2be | Diego Biurrun | ```
av_log(m->avctx, AV_LOG_ERROR, "invalid/unknown bits per sample\n");
``` |

259 | b517af05 | Ramiro Polla | return -1; |

260 | } |
||

261 | ```
if (mh.group2_bits > mh.group1_bits) {
``` |
||

262 | av_log(m->avctx, AV_LOG_ERROR, |
||

263 | 9906a2be | Diego Biurrun | ```
"Channel group 2 cannot have more bits per sample than group 1.\n");
``` |

264 | b517af05 | Ramiro Polla | return -1; |

265 | } |
||

266 | |||

267 | ```
if (mh.group2_samplerate && mh.group2_samplerate != mh.group1_samplerate) {
``` |
||

268 | av_log(m->avctx, AV_LOG_ERROR, |
||

269 | 9906a2be | Diego Biurrun | ```
"Channel groups with differing sample rates are not currently supported.\n");
``` |

270 | b517af05 | Ramiro Polla | return -1; |

271 | } |
||

272 | |||

273 | if (mh.group1_samplerate == 0) { |
||

274 | 9906a2be | Diego Biurrun | ```
av_log(m->avctx, AV_LOG_ERROR, "invalid/unknown sampling rate\n");
``` |

275 | b517af05 | Ramiro Polla | return -1; |

276 | } |
||

277 | ```
if (mh.group1_samplerate > MAX_SAMPLERATE) {
``` |
||

278 | av_log(m->avctx, AV_LOG_ERROR, |
||

279 | 9906a2be | Diego Biurrun | ```
"Sampling rate %d is greater than the supported maximum (%d).\n",
``` |

280 | b517af05 | Ramiro Polla | mh.group1_samplerate, MAX_SAMPLERATE); |

281 | return -1; |
||

282 | } |
||

283 | ```
if (mh.access_unit_size > MAX_BLOCKSIZE) {
``` |
||

284 | av_log(m->avctx, AV_LOG_ERROR, |
||

285 | 9906a2be | Diego Biurrun | ```
"Block size %d is greater than the supported maximum (%d).\n",
``` |

286 | b517af05 | Ramiro Polla | mh.access_unit_size, MAX_BLOCKSIZE); |

287 | return -1; |
||

288 | } |
||

289 | ```
if (mh.access_unit_size_pow2 > MAX_BLOCKSIZE_POW2) {
``` |
||

290 | av_log(m->avctx, AV_LOG_ERROR, |
||

291 | 9906a2be | Diego Biurrun | ```
"Block size pow2 %d is greater than the supported maximum (%d).\n",
``` |

292 | b517af05 | Ramiro Polla | mh.access_unit_size_pow2, MAX_BLOCKSIZE_POW2); |

293 | return -1; |
||

294 | } |
||

295 | |||

296 | if (mh.num_substreams == 0) |
||

297 | return -1; |
||

298 | 932cee5d | Ramiro Polla | if (m->avctx->codec_id == CODEC_ID_MLP && mh.num_substreams > 2) { |

299 | ```
av_log(m->avctx, AV_LOG_ERROR, "MLP only supports up to 2 substreams.\n");
``` |
||

300 | return -1; |
||

301 | } |
||

302 | b517af05 | Ramiro Polla | ```
if (mh.num_substreams > MAX_SUBSTREAMS) {
``` |

303 | av_log(m->avctx, AV_LOG_ERROR, |
||

304 | 9906a2be | Diego Biurrun | ```
"Number of substreams %d is larger than the maximum supported "
``` |

305 | ```
"by the decoder. %s\n", mh.num_substreams, sample_message);
``` |
||

306 | b517af05 | Ramiro Polla | return -1; |

307 | } |
||

308 | |||

309 | m->access_unit_size = mh.access_unit_size; |
||

310 | m->access_unit_size_pow2 = mh.access_unit_size_pow2; |
||

311 | |||

312 | m->num_substreams = mh.num_substreams; |
||

313 | ```
m->max_decoded_substream = m->num_substreams - 1;
``` |
||

314 | |||

315 | m->avctx->sample_rate = mh.group1_samplerate; |
||

316 | m->avctx->frame_size = mh.access_unit_size; |
||

317 | |||

318 | 97679e6e | Mathieu Velten | m->avctx->bits_per_raw_sample = mh.group1_bits; |

319 | c687643c | Ramiro Polla | if (mh.group1_bits > 16) |

320 | b517af05 | Ramiro Polla | m->avctx->sample_fmt = SAMPLE_FMT_S32; |

321 | ee1a8f62 | Ramiro Polla | ```
else
``` |

322 | m->avctx->sample_fmt = SAMPLE_FMT_S16; |
||

323 | b517af05 | Ramiro Polla | |

324 | ```
m->params_valid = 1;
``` |
||

325 | for (substr = 0; substr < MAX_SUBSTREAMS; substr++) |
||

326 | ```
m->substream[substr].restart_seen = 0;
``` |
||

327 | |||

328 | return 0; |
||

329 | } |
||

330 | |||

331 | ```
/** Read a restart header from a block in a substream. This contains parameters
``` |
||

332 | ```
* required to decode the audio that do not change very often. Generally
``` |
||

333 | ```
* (always) present only in blocks following a major sync. */
``` |
||

334 | |||

335 | static int read_restart_header(MLPDecodeContext *m, GetBitContext *gbp, |
||

336 | const uint8_t *buf, unsigned int substr) |
||

337 | { |
||

338 | SubStream *s = &m->substream[substr]; |
||

339 | unsigned int ch; |
||

340 | ```
int sync_word, tmp;
``` |
||

341 | uint8_t checksum; |
||

342 | uint8_t lossless_check; |
||

343 | ```
int start_count = get_bits_count(gbp);
``` |
||

344 | 868170c4 | Ramiro Polla | const int max_matrix_channel = m->avctx->codec_id == CODEC_ID_MLP |

345 | ? MAX_MATRIX_CHANNEL_MLP |
||

346 | : MAX_MATRIX_CHANNEL_TRUEHD; |
||

347 | b517af05 | Ramiro Polla | |

348 | ```
sync_word = get_bits(gbp, 13);
``` |
||

349 | |||

350 | e8d341ce | Ramiro Polla | if (sync_word != 0x31ea >> 1) { |

351 | b517af05 | Ramiro Polla | av_log(m->avctx, AV_LOG_ERROR, |

352 | 9906a2be | Diego Biurrun | ```
"restart header sync incorrect (got 0x%04x)\n", sync_word);
``` |

353 | b517af05 | Ramiro Polla | return -1; |

354 | } |
||

355 | |||

356 | e8d341ce | Ramiro Polla | s->noise_type = get_bits1(gbp); |

357 | |||

358 | ```
if (m->avctx->codec_id == CODEC_ID_MLP && s->noise_type) {
``` |
||

359 | ```
av_log(m->avctx, AV_LOG_ERROR, "MLP must have 0x31ea sync word.\n");
``` |
||

360 | return -1; |
||

361 | } |
||

362 | |||

363 | b517af05 | Ramiro Polla | skip_bits(gbp, 16); /* Output timestamp */ |

364 | |||

365 | ```
s->min_channel = get_bits(gbp, 4);
``` |
||

366 | ```
s->max_channel = get_bits(gbp, 4);
``` |
||

367 | ```
s->max_matrix_channel = get_bits(gbp, 4);
``` |
||

368 | |||

369 | 868170c4 | Ramiro Polla | ```
if (s->max_matrix_channel > max_matrix_channel) {
``` |

370 | av_log(m->avctx, AV_LOG_ERROR, |
||

371 | ```
"Max matrix channel cannot be greater than %d.\n",
``` |
||

372 | max_matrix_channel); |
||

373 | return -1; |
||

374 | } |
||

375 | |||

376 | ```
if (s->max_channel != s->max_matrix_channel) {
``` |
||

377 | av_log(m->avctx, AV_LOG_ERROR, |
||

378 | ```
"Max channel must be equal max matrix channel.\n");
``` |
||

379 | return -1; |
||

380 | } |
||

381 | |||

382 | e2822726 | Ramiro Polla | ```
/* This should happen for TrueHD streams with >6 channels and MLP's noise
``` |

383 | ```
* type. It is not yet known if this is allowed. */
``` |
||

384 | ```
if (s->max_channel > MAX_MATRIX_CHANNEL_MLP && !s->noise_type) {
``` |
||

385 | av_log(m->avctx, AV_LOG_ERROR, |
||

386 | ```
"Number of channels %d is larger than the maximum supported "
``` |
||

387 | "by the decoder. %s\n", s->max_channel+2, sample_message); |
||

388 | return -1; |
||

389 | } |
||

390 | |||

391 | b517af05 | Ramiro Polla | ```
if (s->min_channel > s->max_channel) {
``` |

392 | av_log(m->avctx, AV_LOG_ERROR, |
||

393 | ```
"Substream min channel cannot be greater than max channel.\n");
``` |
||

394 | return -1; |
||

395 | } |
||

396 | |||

397 | if (m->avctx->request_channels > 0 |
||

398 | ```
&& s->max_channel + 1 >= m->avctx->request_channels
``` |
||

399 | && substr < m->max_decoded_substream) { |
||

400 | d780511b | Reimar DÃ¶ffinger | av_log(m->avctx, AV_LOG_DEBUG, |

401 | b517af05 | Ramiro Polla | ```
"Extracting %d channel downmix from substream %d. "
``` |

402 | ```
"Further substreams will be skipped.\n",
``` |
||

403 | ```
s->max_channel + 1, substr);
``` |
||

404 | m->max_decoded_substream = substr; |
||

405 | } |
||

406 | |||

407 | ```
s->noise_shift = get_bits(gbp, 4);
``` |
||

408 | ```
s->noisegen_seed = get_bits(gbp, 23);
``` |
||

409 | |||

410 | ```
skip_bits(gbp, 19);
``` |
||

411 | |||

412 | s->data_check_present = get_bits1(gbp); |
||

413 | ```
lossless_check = get_bits(gbp, 8);
``` |
||

414 | ```
if (substr == m->max_decoded_substream
``` |
||

415 | ```
&& s->lossless_check_data != 0xffffffff) {
``` |
||

416 | a7cc783d | Ramiro Polla | tmp = xor_32_to_8(s->lossless_check_data); |

417 | b517af05 | Ramiro Polla | ```
if (tmp != lossless_check)
``` |

418 | av_log(m->avctx, AV_LOG_WARNING, |
||

419 | 9906a2be | Diego Biurrun | ```
"Lossless check failed - expected %02x, calculated %02x.\n",
``` |

420 | b517af05 | Ramiro Polla | lossless_check, tmp); |

421 | } |
||

422 | |||

423 | ```
skip_bits(gbp, 16);
``` |
||

424 | |||

425 | 9731e7f1 | Ramiro Polla | memset(s->ch_assign, 0, sizeof(s->ch_assign)); |

426 | |||

427 | b517af05 | Ramiro Polla | for (ch = 0; ch <= s->max_matrix_channel; ch++) { |

428 | int ch_assign = get_bits(gbp, 6); |
||

429 | 9731e7f1 | Ramiro Polla | ```
if (ch_assign > s->max_matrix_channel) {
``` |

430 | b517af05 | Ramiro Polla | av_log(m->avctx, AV_LOG_ERROR, |

431 | 9731e7f1 | Ramiro Polla | ```
"Assignment of matrix channel %d to invalid output channel %d. %s\n",
``` |

432 | ch, ch_assign, sample_message); |
||

433 | b517af05 | Ramiro Polla | return -1; |

434 | } |
||

435 | 9731e7f1 | Ramiro Polla | s->ch_assign[ch_assign] = ch; |

436 | b517af05 | Ramiro Polla | } |

437 | |||

438 | ce15710f | Ramiro Polla | checksum = ff_mlp_restart_checksum(buf, get_bits_count(gbp) - start_count); |

439 | b517af05 | Ramiro Polla | |

440 | if (checksum != get_bits(gbp, 8)) |
||

441 | 9906a2be | Diego Biurrun | ```
av_log(m->avctx, AV_LOG_ERROR, "restart header checksum error\n");
``` |

442 | b517af05 | Ramiro Polla | |

443 | 9906a2be | Diego Biurrun | ```
/* Set default decoding parameters. */
``` |

444 | b517af05 | Ramiro Polla | ```
s->param_presence_flags = 0xff;
``` |

445 | ```
s->num_primitive_matrices = 0;
``` |
||

446 | ```
s->blocksize = 8;
``` |
||

447 | ```
s->lossless_check_data = 0;
``` |
||

448 | |||

449 | memset(s->output_shift , 0, sizeof(s->output_shift )); |
||

450 | memset(s->quant_step_size, 0, sizeof(s->quant_step_size)); |
||

451 | |||

452 | ```
for (ch = s->min_channel; ch <= s->max_channel; ch++) {
``` |
||

453 | f53acb7b | Ramiro Polla | ChannelParams *cp = &m->channel_params[ch]; |

454 | ```
cp->filter_params[FIR].order = 0;
``` |
||

455 | ```
cp->filter_params[IIR].order = 0;
``` |
||

456 | ```
cp->filter_params[FIR].shift = 0;
``` |
||

457 | ```
cp->filter_params[IIR].shift = 0;
``` |
||

458 | b517af05 | Ramiro Polla | |

459 | 9906a2be | Diego Biurrun | ```
/* Default audio coding is 24-bit raw PCM. */
``` |

460 | f53acb7b | Ramiro Polla | ```
cp->huff_offset = 0;
``` |

461 | cp->sign_huff_offset = (-1) << 23; |
||

462 | ```
cp->codebook = 0;
``` |
||

463 | ```
cp->huff_lsbs = 24;
``` |
||

464 | b517af05 | Ramiro Polla | } |

465 | |||

466 | f95f6ab9 | Ramiro Polla | ```
if (substr == m->max_decoded_substream)
``` |

467 | 9731e7f1 | Ramiro Polla | ```
m->avctx->channels = s->max_matrix_channel + 1;
``` |

468 | b517af05 | Ramiro Polla | |

469 | return 0; |
||

470 | } |
||

471 | |||

472 | ```
/** Read parameters for one of the prediction filters. */
``` |
||

473 | |||

474 | static int read_filter_params(MLPDecodeContext *m, GetBitContext *gbp, |
||

475 | unsigned int channel, unsigned int filter) |
||

476 | { |
||

477 | f53acb7b | Ramiro Polla | FilterParams *fp = &m->channel_params[channel].filter_params[filter]; |

478 | 0c5670a0 | Ramiro Polla | const int max_order = filter ? MAX_IIR_ORDER : MAX_FIR_ORDER; |

479 | b517af05 | Ramiro Polla | const char fchar = filter ? 'I' : 'F'; |

480 | ```
int i, order;
``` |
||

481 | |||

482 | 9906a2be | Diego Biurrun | ```
// Filter is 0 for FIR, 1 for IIR.
``` |

483 | b517af05 | Ramiro Polla | ```
assert(filter < 2);
``` |

484 | |||

485 | 5d9e4eaa | Ramiro Polla | if (m->filter_changed[channel][filter]++ > 1) { |

486 | ```
av_log(m->avctx, AV_LOG_ERROR, "Filters may change only once per access unit.\n");
``` |
||

487 | return -1; |
||

488 | } |
||

489 | 75428fa4 | Ramiro Polla | |

490 | b517af05 | Ramiro Polla | ```
order = get_bits(gbp, 4);
``` |

491 | 0c5670a0 | Ramiro Polla | ```
if (order > max_order) {
``` |

492 | b517af05 | Ramiro Polla | av_log(m->avctx, AV_LOG_ERROR, |

493 | 9906a2be | Diego Biurrun | ```
"%cIR filter order %d is greater than maximum %d.\n",
``` |

494 | 0c5670a0 | Ramiro Polla | fchar, order, max_order); |

495 | b517af05 | Ramiro Polla | return -1; |

496 | } |
||

497 | d6aa052d | Ramiro Polla | fp->order = order; |

498 | b517af05 | Ramiro Polla | |

499 | if (order > 0) { |
||

500 | 13bd2044 | Ramiro Polla | int32_t *fcoeff = m->channel_params[channel].coeff[filter]; |

501 | b517af05 | Ramiro Polla | ```
int coeff_bits, coeff_shift;
``` |

502 | |||

503 | d6aa052d | Ramiro Polla | ```
fp->shift = get_bits(gbp, 4);
``` |

504 | b517af05 | Ramiro Polla | |

505 | ```
coeff_bits = get_bits(gbp, 5);
``` |
||

506 | ```
coeff_shift = get_bits(gbp, 3);
``` |
||

507 | if (coeff_bits < 1 || coeff_bits > 16) { |
||

508 | av_log(m->avctx, AV_LOG_ERROR, |
||

509 | 9906a2be | Diego Biurrun | ```
"%cIR filter coeff_bits must be between 1 and 16.\n",
``` |

510 | b517af05 | Ramiro Polla | fchar); |

511 | return -1; |
||

512 | } |
||

513 | if (coeff_bits + coeff_shift > 16) { |
||

514 | av_log(m->avctx, AV_LOG_ERROR, |
||

515 | 9906a2be | Diego Biurrun | ```
"Sum of coeff_bits and coeff_shift for %cIR filter must be 16 or less.\n",
``` |

516 | b517af05 | Ramiro Polla | fchar); |

517 | return -1; |
||

518 | } |
||

519 | |||

520 | for (i = 0; i < order; i++) |
||

521 | 13bd2044 | Ramiro Polla | fcoeff[i] = get_sbits(gbp, coeff_bits) << coeff_shift; |

522 | b517af05 | Ramiro Polla | |

523 | ```
if (get_bits1(gbp)) {
``` |
||

524 | ```
int state_bits, state_shift;
``` |
||

525 | |||

526 | ```
if (filter == FIR) {
``` |
||

527 | av_log(m->avctx, AV_LOG_ERROR, |
||

528 | 9906a2be | Diego Biurrun | ```
"FIR filter has state data specified.\n");
``` |

529 | b517af05 | Ramiro Polla | return -1; |

530 | } |
||

531 | |||

532 | ```
state_bits = get_bits(gbp, 4);
``` |
||

533 | ```
state_shift = get_bits(gbp, 4);
``` |
||

534 | |||

535 | 9906a2be | Diego Biurrun | ```
/* TODO: Check validity of state data. */
``` |

536 | b517af05 | Ramiro Polla | |

537 | for (i = 0; i < order; i++) |
||

538 | db01fa13 | Ramiro Polla | fp->state[i] = get_sbits(gbp, state_bits) << state_shift; |

539 | b517af05 | Ramiro Polla | } |

540 | } |
||

541 | |||

542 | return 0; |
||

543 | } |
||

544 | |||

545 | f8e6293b | Ramiro Polla | ```
/** Read parameters for primitive matrices. */
``` |

546 | |||

547 | 95c14b1e | Ramiro Polla | static int read_matrix_params(MLPDecodeContext *m, unsigned int substr, GetBitContext *gbp) |

548 | f8e6293b | Ramiro Polla | { |

549 | 95c14b1e | Ramiro Polla | SubStream *s = &m->substream[substr]; |

550 | f8e6293b | Ramiro Polla | unsigned int mat, ch; |

551 | 309616b2 | Ramiro Polla | const int max_primitive_matrices = m->avctx->codec_id == CODEC_ID_MLP |

552 | ? MAX_MATRICES_MLP |
||

553 | : MAX_MATRICES_TRUEHD; |
||

554 | f8e6293b | Ramiro Polla | |

555 | 5d9e4eaa | Ramiro Polla | if (m->matrix_changed++ > 1) { |

556 | ```
av_log(m->avctx, AV_LOG_ERROR, "Matrices may change only once per access unit.\n");
``` |
||

557 | return -1; |
||

558 | } |
||

559 | |||

560 | f8e6293b | Ramiro Polla | ```
s->num_primitive_matrices = get_bits(gbp, 4);
``` |

561 | |||

562 | 309616b2 | Ramiro Polla | ```
if (s->num_primitive_matrices > max_primitive_matrices) {
``` |

563 | av_log(m->avctx, AV_LOG_ERROR, |
||

564 | ```
"Number of primitive matrices cannot be greater than %d.\n",
``` |
||

565 | max_primitive_matrices); |
||

566 | return -1; |
||

567 | } |
||

568 | |||

569 | f8e6293b | Ramiro Polla | for (mat = 0; mat < s->num_primitive_matrices; mat++) { |

570 | ```
int frac_bits, max_chan;
``` |
||

571 | ```
s->matrix_out_ch[mat] = get_bits(gbp, 4);
``` |
||

572 | ```
frac_bits = get_bits(gbp, 4);
``` |
||

573 | s->lsb_bypass [mat] = get_bits1(gbp); |
||

574 | |||

575 | 0091d8a1 | Ramiro Polla | ```
if (s->matrix_out_ch[mat] > s->max_matrix_channel) {
``` |

576 | f8e6293b | Ramiro Polla | av_log(m->avctx, AV_LOG_ERROR, |

577 | ```
"Invalid channel %d specified as output from matrix.\n",
``` |
||

578 | s->matrix_out_ch[mat]); |
||

579 | return -1; |
||

580 | } |
||

581 | if (frac_bits > 14) { |
||

582 | av_log(m->avctx, AV_LOG_ERROR, |
||

583 | ```
"Too many fractional bits specified.\n");
``` |
||

584 | return -1; |
||

585 | } |
||

586 | |||

587 | max_chan = s->max_matrix_channel; |
||

588 | ```
if (!s->noise_type)
``` |
||

589 | ```
max_chan+=2;
``` |
||

590 | |||

591 | for (ch = 0; ch <= max_chan; ch++) { |
||

592 | int coeff_val = 0; |
||

593 | ```
if (get_bits1(gbp))
``` |
||

594 | ```
coeff_val = get_sbits(gbp, frac_bits + 2);
``` |
||

595 | |||

596 | ```
s->matrix_coeff[mat][ch] = coeff_val << (14 - frac_bits);
``` |
||

597 | } |
||

598 | |||

599 | ```
if (s->noise_type)
``` |
||

600 | ```
s->matrix_noise_shift[mat] = get_bits(gbp, 4);
``` |
||

601 | ```
else
``` |
||

602 | ```
s->matrix_noise_shift[mat] = 0;
``` |
||

603 | } |
||

604 | |||

605 | return 0; |
||

606 | } |
||

607 | |||

608 | 43ee5fe0 | Ramiro Polla | ```
/** Read channel parameters. */
``` |

609 | |||

610 | static int read_channel_params(MLPDecodeContext *m, unsigned int substr, |
||

611 | GetBitContext *gbp, unsigned int ch) |
||

612 | { |
||

613 | ChannelParams *cp = &m->channel_params[ch]; |
||

614 | FilterParams *fir = &cp->filter_params[FIR]; |
||

615 | FilterParams *iir = &cp->filter_params[IIR]; |
||

616 | SubStream *s = &m->substream[substr]; |
||

617 | |||

618 | ```
if (s->param_presence_flags & PARAM_FIR)
``` |
||

619 | ```
if (get_bits1(gbp))
``` |
||

620 | if (read_filter_params(m, gbp, ch, FIR) < 0) |
||

621 | return -1; |
||

622 | |||

623 | ```
if (s->param_presence_flags & PARAM_IIR)
``` |
||

624 | ```
if (get_bits1(gbp))
``` |
||

625 | if (read_filter_params(m, gbp, ch, IIR) < 0) |
||

626 | return -1; |
||

627 | |||

628 | 125cf771 | Ramiro Polla | if (fir->order + iir->order > 8) { |

629 | ```
av_log(m->avctx, AV_LOG_ERROR, "Total filter orders too high.\n");
``` |
||

630 | return -1; |
||

631 | } |
||

632 | |||

633 | 43ee5fe0 | Ramiro Polla | ```
if (fir->order && iir->order &&
``` |

634 | fir->shift != iir->shift) { |
||

635 | av_log(m->avctx, AV_LOG_ERROR, |
||

636 | ```
"FIR and IIR filters must use the same precision.\n");
``` |
||

637 | return -1; |
||

638 | } |
||

639 | ```
/* The FIR and IIR filters must have the same precision.
``` |
||

640 | aff42ee0 | Ramiro Polla | ```
* To simplify the filtering code, only the precision of the
``` |

641 | ```
* FIR filter is considered. If only the IIR filter is employed,
``` |
||

642 | ```
* the FIR filter precision is set to that of the IIR filter, so
``` |
||

643 | ```
* that the filtering code can use it. */
``` |
||

644 | 43ee5fe0 | Ramiro Polla | ```
if (!fir->order && iir->order)
``` |

645 | fir->shift = iir->shift; |
||

646 | |||

647 | ```
if (s->param_presence_flags & PARAM_HUFFOFFSET)
``` |
||

648 | ```
if (get_bits1(gbp))
``` |
||

649 | ```
cp->huff_offset = get_sbits(gbp, 15);
``` |
||

650 | |||

651 | ```
cp->codebook = get_bits(gbp, 2);
``` |
||

652 | ```
cp->huff_lsbs = get_bits(gbp, 5);
``` |
||

653 | |||

654 | 125cf771 | Ramiro Polla | if (cp->huff_lsbs > 24) { |

655 | ```
av_log(m->avctx, AV_LOG_ERROR, "Invalid huff_lsbs.\n");
``` |
||

656 | return -1; |
||

657 | } |
||

658 | 43ee5fe0 | Ramiro Polla | |

659 | 125cf771 | Ramiro Polla | cp->sign_huff_offset = calculate_sign_huff(m, substr, ch); |

660 | 43ee5fe0 | Ramiro Polla | |

661 | return 0; |
||

662 | } |
||

663 | |||

664 | b517af05 | Ramiro Polla | ```
/** Read decoding parameters that change more often than those in the restart
``` |

665 | ```
* header. */
``` |
||

666 | |||

667 | static int read_decoding_params(MLPDecodeContext *m, GetBitContext *gbp, |
||

668 | unsigned int substr) |
||

669 | { |
||

670 | SubStream *s = &m->substream[substr]; |
||

671 | f8e6293b | Ramiro Polla | unsigned int ch; |

672 | b517af05 | Ramiro Polla | |

673 | cbf3cf19 | Ramiro Polla | ```
if (s->param_presence_flags & PARAM_PRESENCE)
``` |

674 | f95f6ab9 | Ramiro Polla | ```
if (get_bits1(gbp))
``` |

675 | ```
s->param_presence_flags = get_bits(gbp, 8);
``` |
||

676 | b517af05 | Ramiro Polla | |

677 | ```
if (s->param_presence_flags & PARAM_BLOCKSIZE)
``` |
||

678 | ```
if (get_bits1(gbp)) {
``` |
||

679 | ```
s->blocksize = get_bits(gbp, 9);
``` |
||

680 | b864098c | Ramiro Polla | if (s->blocksize < 8 || s->blocksize > m->access_unit_size) { |

681 | ```
av_log(m->avctx, AV_LOG_ERROR, "Invalid blocksize.");
``` |
||

682 | b517af05 | Ramiro Polla | ```
s->blocksize = 0;
``` |

683 | return -1; |
||

684 | } |
||

685 | } |
||

686 | |||

687 | ```
if (s->param_presence_flags & PARAM_MATRIX)
``` |
||

688 | f95f6ab9 | Ramiro Polla | ```
if (get_bits1(gbp))
``` |

689 | 95c14b1e | Ramiro Polla | if (read_matrix_params(m, substr, gbp) < 0) |

690 | f8e6293b | Ramiro Polla | return -1; |

691 | b517af05 | Ramiro Polla | |

692 | ```
if (s->param_presence_flags & PARAM_OUTSHIFT)
``` |
||

693 | ```
if (get_bits1(gbp))
``` |
||

694 | f95f6ab9 | Ramiro Polla | for (ch = 0; ch <= s->max_matrix_channel; ch++) |

695 | af048026 | Ramiro Polla | ```
s->output_shift[ch] = get_sbits(gbp, 4);
``` |

696 | b517af05 | Ramiro Polla | |

697 | ```
if (s->param_presence_flags & PARAM_QUANTSTEP)
``` |
||

698 | ```
if (get_bits1(gbp))
``` |
||

699 | for (ch = 0; ch <= s->max_channel; ch++) { |
||

700 | f53acb7b | Ramiro Polla | ChannelParams *cp = &m->channel_params[ch]; |

701 | |||

702 | b517af05 | Ramiro Polla | ```
s->quant_step_size[ch] = get_bits(gbp, 4);
``` |

703 | |||

704 | f53acb7b | Ramiro Polla | cp->sign_huff_offset = calculate_sign_huff(m, substr, ch); |

705 | b517af05 | Ramiro Polla | } |

706 | |||

707 | ```
for (ch = s->min_channel; ch <= s->max_channel; ch++)
``` |
||

708 | f95f6ab9 | Ramiro Polla | ```
if (get_bits1(gbp))
``` |

709 | 43ee5fe0 | Ramiro Polla | if (read_channel_params(m, substr, gbp, ch) < 0) |

710 | b517af05 | Ramiro Polla | return -1; |

711 | |||

712 | return 0; |
||

713 | } |
||

714 | |||

715 | #define MSB_MASK(bits) (-1u << bits) |
||

716 | |||

717 | ```
/** Generate PCM samples using the prediction filters and residual values
``` |
||

718 | ```
* read from the data stream, and update the filter state. */
``` |
||

719 | |||

720 | static void filter_channel(MLPDecodeContext *m, unsigned int substr, |
||

721 | unsigned int channel) |
||

722 | { |
||

723 | SubStream *s = &m->substream[substr]; |
||

724 | 13bd2044 | Ramiro Polla | ```
const int32_t *fircoeff = m->channel_params[channel].coeff[FIR];
``` |

725 | int32_t state_buffer[NUM_FILTERS][MAX_BLOCKSIZE + MAX_FIR_ORDER]; |
||

726 | int32_t *firbuf = state_buffer[FIR] + MAX_BLOCKSIZE; |
||

727 | int32_t *iirbuf = state_buffer[IIR] + MAX_BLOCKSIZE; |
||

728 | e71365f4 | Ramiro Polla | FilterParams *fir = &m->channel_params[channel].filter_params[FIR]; |

729 | FilterParams *iir = &m->channel_params[channel].filter_params[IIR]; |
||

730 | unsigned int filter_shift = fir->shift; |
||

731 | b517af05 | Ramiro Polla | int32_t mask = MSB_MASK(s->quant_step_size[channel]); |

732 | |||

733 | 77b12f80 | Ramiro Polla | ```
memcpy(firbuf, fir->state, MAX_FIR_ORDER * sizeof(int32_t));
``` |

734 | ```
memcpy(iirbuf, iir->state, MAX_IIR_ORDER * sizeof(int32_t));
``` |
||

735 | b517af05 | Ramiro Polla | |

736 | 13bd2044 | Ramiro Polla | m->dsp.mlp_filter_channel(firbuf, fircoeff, |

737 | fir->order, iir->order, |
||

738 | bf4f19dc | Ramiro Polla | filter_shift, mask, s->blocksize, |

739 | &m->sample_buffer[s->blockpos][channel]); |
||

740 | b517af05 | Ramiro Polla | |

741 | bf4f19dc | Ramiro Polla | ```
memcpy(fir->state, firbuf - s->blocksize, MAX_FIR_ORDER * sizeof(int32_t));
``` |

742 | ```
memcpy(iir->state, iirbuf - s->blocksize, MAX_IIR_ORDER * sizeof(int32_t));
``` |
||

743 | b517af05 | Ramiro Polla | } |

744 | |||

745 | ```
/** Read a block of PCM residual data (or actual if no filtering active). */
``` |
||

746 | |||

747 | static int read_block_data(MLPDecodeContext *m, GetBitContext *gbp, |
||

748 | unsigned int substr) |
||

749 | { |
||

750 | SubStream *s = &m->substream[substr]; |
||

751 | unsigned int i, ch, expected_stream_pos = 0; |
||

752 | |||

753 | ```
if (s->data_check_present) {
``` |
||

754 | expected_stream_pos = get_bits_count(gbp); |
||

755 | ```
expected_stream_pos += get_bits(gbp, 16);
``` |
||

756 | ```
av_log(m->avctx, AV_LOG_WARNING, "This file contains some features "
``` |
||

757 | ```
"we have not tested yet. %s\n", sample_message);
``` |
||

758 | } |
||

759 | |||

760 | ```
if (s->blockpos + s->blocksize > m->access_unit_size) {
``` |
||

761 | 9906a2be | Diego Biurrun | ```
av_log(m->avctx, AV_LOG_ERROR, "too many audio samples in frame\n");
``` |

762 | b517af05 | Ramiro Polla | return -1; |

763 | } |
||

764 | |||

765 | memset(&m->bypassed_lsbs[s->blockpos][0], 0, |
||

766 | s->blocksize * sizeof(m->bypassed_lsbs[0])); |
||

767 | |||

768 | f95f6ab9 | Ramiro Polla | for (i = 0; i < s->blocksize; i++) |

769 | b517af05 | Ramiro Polla | if (read_huff_channels(m, gbp, substr, i) < 0) |

770 | return -1; |
||

771 | |||

772 | f95f6ab9 | Ramiro Polla | ```
for (ch = s->min_channel; ch <= s->max_channel; ch++)
``` |

773 | b517af05 | Ramiro Polla | filter_channel(m, substr, ch); |

774 | |||

775 | s->blockpos += s->blocksize; |
||

776 | |||

777 | ```
if (s->data_check_present) {
``` |
||

778 | ```
if (get_bits_count(gbp) != expected_stream_pos)
``` |
||

779 | 9906a2be | Diego Biurrun | ```
av_log(m->avctx, AV_LOG_ERROR, "block data length mismatch\n");
``` |

780 | b517af05 | Ramiro Polla | ```
skip_bits(gbp, 8);
``` |

781 | } |
||

782 | |||

783 | return 0; |
||

784 | } |
||

785 | |||

786 | 9906a2be | Diego Biurrun | ```
/** Data table used for TrueHD noise generation function. */
``` |

787 | b517af05 | Ramiro Polla | |

788 | static const int8_t noise_table[256] = { |
||

789 | 30, 51, 22, 54, 3, 7, -4, 38, 14, 55, 46, 81, 22, 58, -3, 2, |
||

790 | 52, 31, -7, 51, 15, 44, 74, 30, 85, -17, 10, 33, 18, 80, 28, 62, |
||

791 | 10, 32, 23, 69, 72, 26, 35, 17, 73, 60, 8, 56, 2, 6, -2, -5, |
||

792 | 51, 4, 11, 50, 66, 76, 21, 44, 33, 47, 1, 26, 64, 48, 57, 40, |
||

793 | 38, 16, -10, -28, 92, 22, -18, 29, -10, 5, -13, 49, 19, 24, 70, 34, |
||

794 | 61, 48, 30, 14, -6, 25, 58, 33, 42, 60, 67, 17, 54, 17, 22, 30, |
||

795 | 67, 44, -9, 50, -11, 43, 40, 32, 59, 82, 13, 49, -14, 55, 60, 36, |
||

796 | 48, 49, 31, 47, 15, 12, 4, 65, 1, 23, 29, 39, 45, -2, 84, 69, |
||

797 | 0, 72, 37, 57, 27, 41, -15, -16, 35, 31, 14, 61, 24, 0, 27, 24, |
||

798 | 16, 41, 55, 34, 53, 9, 56, 12, 25, 29, 53, 5, 20, -20, -8, 20, |
||

799 | 13, 28, -3, 78, 38, 16, 11, 62, 46, 29, 21, 24, 46, 65, 43, -23, |
||

800 | 89, 18, 74, 21, 38, -12, 19, 12, -19, 8, 15, 33, 4, 57, 9, -8, |
||

801 | 36, 35, 26, 28, 7, 83, 63, 79, 75, 11, 3, 87, 37, 47, 34, 40, |
||

802 | 39, 19, 20, 42, 27, 34, 39, 77, 13, 42, 59, 64, 45, -1, 32, 37, |
||

803 | 45, -5, 53, -6, 7, 36, 50, 23, 6, 32, 9, -21, 18, 71, 27, 52, |
||

804 | -25, 31, 35, 42, -1, 68, 63, 52, 26, 43, 66, 37, 41, 25, 40, 70, |
||

805 | }; |
||

806 | |||

807 | ```
/** Noise generation functions.
``` |
||

808 | ```
* I'm not sure what these are for - they seem to be some kind of pseudorandom
``` |
||

809 | ```
* sequence generators, used to generate noise data which is used when the
``` |
||

810 | ```
* channels are rematrixed. I'm not sure if they provide a practical benefit
``` |
||

811 | ```
* to compression, or just obfuscate the decoder. Are they for some kind of
``` |
||

812 | ```
* dithering? */
``` |
||

813 | |||

814 | ```
/** Generate two channels of noise, used in the matrix when
``` |
||

815 | ```
* restart sync word == 0x31ea. */
``` |
||

816 | |||

817 | static void generate_2_noise_channels(MLPDecodeContext *m, unsigned int substr) |
||

818 | { |
||

819 | SubStream *s = &m->substream[substr]; |
||

820 | unsigned int i; |
||

821 | uint32_t seed = s->noisegen_seed; |
||

822 | unsigned int maxchan = s->max_matrix_channel; |
||

823 | |||

824 | for (i = 0; i < s->blockpos; i++) { |
||

825 | ```
uint16_t seed_shr7 = seed >> 7;
``` |
||

826 | m->sample_buffer[i][maxchan+1] = ((int8_t)(seed >> 15)) << s->noise_shift; |
||

827 | ```
m->sample_buffer[i][maxchan+2] = ((int8_t) seed_shr7) << s->noise_shift;
``` |
||

828 | |||

829 | seed = (seed << 16) ^ seed_shr7 ^ (seed_shr7 << 5); |
||

830 | } |
||

831 | |||

832 | s->noisegen_seed = seed; |
||

833 | } |
||

834 | |||

835 | ```
/** Generate a block of noise, used when restart sync word == 0x31eb. */
``` |
||

836 | |||

837 | static void fill_noise_buffer(MLPDecodeContext *m, unsigned int substr) |
||

838 | { |
||

839 | SubStream *s = &m->substream[substr]; |
||

840 | unsigned int i; |
||

841 | uint32_t seed = s->noisegen_seed; |
||

842 | |||

843 | for (i = 0; i < m->access_unit_size_pow2; i++) { |
||

844 | ```
uint8_t seed_shr15 = seed >> 15;
``` |
||

845 | m->noise_buffer[i] = noise_table[seed_shr15]; |
||

846 | seed = (seed << 8) ^ seed_shr15 ^ (seed_shr15 << 5); |
||

847 | } |
||

848 | |||

849 | s->noisegen_seed = seed; |
||

850 | } |
||

851 | |||

852 | |||

853 | ```
/** Apply the channel matrices in turn to reconstruct the original audio
``` |
||

854 | ```
* samples. */
``` |
||

855 | |||

856 | static void rematrix_channels(MLPDecodeContext *m, unsigned int substr) |
||

857 | { |
||

858 | SubStream *s = &m->substream[substr]; |
||

859 | unsigned int mat, src_ch, i; |
||

860 | unsigned int maxchan; |
||

861 | |||

862 | maxchan = s->max_matrix_channel; |
||

863 | ```
if (!s->noise_type) {
``` |
||

864 | generate_2_noise_channels(m, substr); |
||

865 | ```
maxchan += 2;
``` |
||

866 | ```
} else {
``` |
||

867 | fill_noise_buffer(m, substr); |
||

868 | } |
||

869 | |||

870 | for (mat = 0; mat < s->num_primitive_matrices; mat++) { |
||

871 | ```
int matrix_noise_shift = s->matrix_noise_shift[mat];
``` |
||

872 | unsigned int dest_ch = s->matrix_out_ch[mat]; |
||

873 | int32_t mask = MSB_MASK(s->quant_step_size[dest_ch]); |
||

874 | 63ad832d | Ramiro Polla | int32_t *coeffs = s->matrix_coeff[mat]; |

875 | 15e6748b | Ramiro Polla | ```
int index = s->num_primitive_matrices - mat;
``` |

876 | int index2 = 2 * index + 1; |
||

877 | b517af05 | Ramiro Polla | |

878 | ```
/* TODO: DSPContext? */
``` |
||

879 | |||

880 | for (i = 0; i < s->blockpos; i++) { |
||

881 | a256445e | Ramiro Polla | int32_t bypassed_lsb = m->bypassed_lsbs[i][mat]; |

882 | 63ad832d | Ramiro Polla | int32_t *samples = m->sample_buffer[i]; |

883 | b517af05 | Ramiro Polla | ```
int64_t accum = 0;
``` |

884 | f95f6ab9 | Ramiro Polla | |

885 | for (src_ch = 0; src_ch <= maxchan; src_ch++) |
||

886 | accum += (int64_t) samples[src_ch] * coeffs[src_ch]; |
||

887 | |||

888 | b517af05 | Ramiro Polla | ```
if (matrix_noise_shift) {
``` |

889 | 15e6748b | Ramiro Polla | ```
index &= m->access_unit_size_pow2 - 1;
``` |

890 | b517af05 | Ramiro Polla | ```
accum += m->noise_buffer[index] << (matrix_noise_shift + 7);
``` |

891 | 15e6748b | Ramiro Polla | index += index2; |

892 | b517af05 | Ramiro Polla | } |

893 | f95f6ab9 | Ramiro Polla | |

894 | a256445e | Ramiro Polla | ```
samples[dest_ch] = ((accum >> 14) & mask) + bypassed_lsb;
``` |

895 | b517af05 | Ramiro Polla | } |

896 | } |
||

897 | } |
||

898 | |||

899 | ```
/** Write the audio data into the output buffer. */
``` |
||

900 | |||

901 | static int output_data_internal(MLPDecodeContext *m, unsigned int substr, |
||

902 | uint8_t *data, unsigned int *data_size, int is32) |
||

903 | { |
||

904 | SubStream *s = &m->substream[substr]; |
||

905 | 9731e7f1 | Ramiro Polla | unsigned int i, out_ch = 0; |

906 | b517af05 | Ramiro Polla | int32_t *data_32 = (int32_t*) data; |

907 | int16_t *data_16 = (int16_t*) data; |
||

908 | |||

909 | if (*data_size < (s->max_channel + 1) * s->blockpos * (is32 ? 4 : 2)) |
||

910 | return -1; |
||

911 | |||

912 | for (i = 0; i < s->blockpos; i++) { |
||

913 | 9731e7f1 | Ramiro Polla | for (out_ch = 0; out_ch <= s->max_matrix_channel; out_ch++) { |

914 | ```
int mat_ch = s->ch_assign[out_ch];
``` |
||

915 | int32_t sample = m->sample_buffer[i][mat_ch] |
||

916 | << s->output_shift[mat_ch]; |
||

917 | ```
s->lossless_check_data ^= (sample & 0xffffff) << mat_ch;
``` |
||

918 | b517af05 | Ramiro Polla | if (is32) *data_32++ = sample << 8; |

919 | else *data_16++ = sample >> 8; |
||

920 | } |
||

921 | } |
||

922 | |||

923 | 9731e7f1 | Ramiro Polla | *data_size = i * out_ch * (is32 ? 4 : 2); |

924 | b517af05 | Ramiro Polla | |

925 | return 0; |
||

926 | } |
||

927 | |||

928 | static int output_data(MLPDecodeContext *m, unsigned int substr, |
||

929 | uint8_t *data, unsigned int *data_size) |
||

930 | { |
||

931 | ```
if (m->avctx->sample_fmt == SAMPLE_FMT_S32)
``` |
||

932 | return output_data_internal(m, substr, data, data_size, 1); |
||

933 | ```
else
``` |
||

934 | return output_data_internal(m, substr, data, data_size, 0); |
||

935 | } |
||

936 | |||

937 | |||

938 | ```
/** Read an access unit from the stream.
``` |
||

939 | ```
* Returns < 0 on error, 0 if not enough data is present in the input stream
``` |
||

940 | ```
* otherwise returns the number of bytes consumed. */
``` |
||

941 | |||

942 | static int read_access_unit(AVCodecContext *avctx, void* data, int *data_size, |
||

943 | 7a00bbad | Thilo Borgmann | AVPacket *avpkt) |

944 | b517af05 | Ramiro Polla | { |

945 | 7a00bbad | Thilo Borgmann | ```
const uint8_t *buf = avpkt->data;
``` |

946 | ```
int buf_size = avpkt->size;
``` |
||

947 | b517af05 | Ramiro Polla | MLPDecodeContext *m = avctx->priv_data; |

948 | GetBitContext gb; |
||

949 | unsigned int length, substr; |
||

950 | unsigned int substream_start; |
||

951 | unsigned int header_size = 4; |
||

952 | unsigned int substr_header_size = 0; |
||

953 | uint8_t substream_parity_present[MAX_SUBSTREAMS]; |
||

954 | uint16_t substream_data_len[MAX_SUBSTREAMS]; |
||

955 | uint8_t parity_bits; |
||

956 | |||

957 | if (buf_size < 4) |
||

958 | return 0; |
||

959 | |||

960 | length = (AV_RB16(buf) & 0xfff) * 2; |
||

961 | |||

962 | 0b882b40 | Reimar DÃ¶ffinger | if (length < 4 || length > buf_size) |

963 | b517af05 | Ramiro Polla | return -1; |

964 | |||

965 | init_get_bits(&gb, (buf + 4), (length - 4) * 8); |
||

966 | |||

967 | cc9c5126 | Ramiro Polla | ```
m->is_major_sync_unit = 0;
``` |

968 | b517af05 | Ramiro Polla | if (show_bits_long(&gb, 31) == (0xf8726fba >> 1)) { |

969 | if (read_major_sync(m, &gb) < 0) |
||

970 | ```
goto error;
``` |
||

971 | cc9c5126 | Ramiro Polla | ```
m->is_major_sync_unit = 1;
``` |

972 | b517af05 | Ramiro Polla | ```
header_size += 28;
``` |

973 | } |
||

974 | |||

975 | ```
if (!m->params_valid) {
``` |
||

976 | av_log(m->avctx, AV_LOG_WARNING, |
||

977 | 9906a2be | Diego Biurrun | ```
"Stream parameters not seen; skipping frame.\n");
``` |

978 | b517af05 | Ramiro Polla | ```
*data_size = 0;
``` |

979 | ```
return length;
``` |
||

980 | } |
||

981 | |||

982 | ```
substream_start = 0;
``` |
||

983 | |||

984 | for (substr = 0; substr < m->num_substreams; substr++) { |
||

985 | cc9c5126 | Ramiro Polla | ```
int extraword_present, checkdata_present, end, nonrestart_substr;
``` |

986 | b517af05 | Ramiro Polla | |

987 | extraword_present = get_bits1(&gb); |
||

988 | cc9c5126 | Ramiro Polla | nonrestart_substr = get_bits1(&gb); |

989 | b517af05 | Ramiro Polla | checkdata_present = get_bits1(&gb); |

990 | skip_bits1(&gb); |
||

991 | |||

992 | end = get_bits(&gb, 12) * 2; |
||

993 | |||

994 | ```
substr_header_size += 2;
``` |
||

995 | |||

996 | ```
if (extraword_present) {
``` |
||

997 | 89e39be3 | Ramiro Polla | ```
if (m->avctx->codec_id == CODEC_ID_MLP) {
``` |

998 | ```
av_log(m->avctx, AV_LOG_ERROR, "There must be no extraword for MLP.\n");
``` |
||

999 | ```
goto error;
``` |
||

1000 | } |
||

1001 | b517af05 | Ramiro Polla | ```
skip_bits(&gb, 16);
``` |

1002 | ```
substr_header_size += 2;
``` |
||

1003 | } |
||

1004 | |||

1005 | cc9c5126 | Ramiro Polla | ```
if (!(nonrestart_substr ^ m->is_major_sync_unit)) {
``` |

1006 | ```
av_log(m->avctx, AV_LOG_ERROR, "Invalid nonrestart_substr.\n");
``` |
||

1007 | ```
goto error;
``` |
||

1008 | } |
||

1009 | |||

1010 | b517af05 | Ramiro Polla | ```
if (end + header_size + substr_header_size > length) {
``` |

1011 | av_log(m->avctx, AV_LOG_ERROR, |
||

1012 | ```
"Indicated length of substream %d data goes off end of "
``` |
||

1013 | ```
"packet.\n", substr);
``` |
||

1014 | end = length - header_size - substr_header_size; |
||

1015 | } |
||

1016 | |||

1017 | ```
if (end < substream_start) {
``` |
||

1018 | av_log(avctx, AV_LOG_ERROR, |
||

1019 | ```
"Indicated end offset of substream %d data "
``` |
||

1020 | ```
"is smaller than calculated start offset.\n",
``` |
||

1021 | substr); |
||

1022 | ```
goto error;
``` |
||

1023 | } |
||

1024 | |||

1025 | ```
if (substr > m->max_decoded_substream)
``` |
||

1026 | ```
continue;
``` |
||

1027 | |||

1028 | substream_parity_present[substr] = checkdata_present; |
||

1029 | substream_data_len[substr] = end - substream_start; |
||

1030 | substream_start = end; |
||

1031 | } |
||

1032 | |||

1033 | ce15710f | Ramiro Polla | ```
parity_bits = ff_mlp_calculate_parity(buf, 4);
``` |

1034 | parity_bits ^= ff_mlp_calculate_parity(buf + header_size, substr_header_size); |
||

1035 | b517af05 | Ramiro Polla | |

1036 | if ((((parity_bits >> 4) ^ parity_bits) & 0xF) != 0xF) { |
||

1037 | ```
av_log(avctx, AV_LOG_ERROR, "Parity check failed.\n");
``` |
||

1038 | ```
goto error;
``` |
||

1039 | } |
||

1040 | |||

1041 | buf += header_size + substr_header_size; |
||

1042 | |||

1043 | for (substr = 0; substr <= m->max_decoded_substream; substr++) { |
||

1044 | SubStream *s = &m->substream[substr]; |
||

1045 | ```
init_get_bits(&gb, buf, substream_data_len[substr] * 8);
``` |
||

1046 | |||

1047 | 75428fa4 | Ramiro Polla | ```
m->matrix_changed = 0;
``` |

1048 | memset(m->filter_changed, 0, sizeof(m->filter_changed)); |
||

1049 | |||

1050 | b517af05 | Ramiro Polla | ```
s->blockpos = 0;
``` |

1051 | ```
do {
``` |
||

1052 | ```
if (get_bits1(&gb)) {
``` |
||

1053 | ```
if (get_bits1(&gb)) {
``` |
||

1054 | 9906a2be | Diego Biurrun | ```
/* A restart header should be present. */
``` |

1055 | b517af05 | Ramiro Polla | if (read_restart_header(m, &gb, buf, substr) < 0) |

1056 | ```
goto next_substr;
``` |
||

1057 | ```
s->restart_seen = 1;
``` |
||

1058 | } |
||

1059 | |||

1060 | f95f6ab9 | Ramiro Polla | ```
if (!s->restart_seen)
``` |

1061 | b517af05 | Ramiro Polla | ```
goto next_substr;
``` |

1062 | if (read_decoding_params(m, &gb, substr) < 0) |
||

1063 | ```
goto next_substr;
``` |
||

1064 | } |
||

1065 | |||

1066 | f95f6ab9 | Ramiro Polla | ```
if (!s->restart_seen)
``` |

1067 | b517af05 | Ramiro Polla | ```
goto next_substr;
``` |

1068 | |||

1069 | if (read_block_data(m, &gb, substr) < 0) |
||

1070 | return -1; |
||

1071 | |||

1072 | d7952be3 | Ramiro Polla | if (get_bits_count(&gb) >= substream_data_len[substr] * 8) |

1073 | ```
goto substream_length_mismatch;
``` |
||

1074 | |||

1075 | ```
} while (!get_bits1(&gb));
``` |
||

1076 | b517af05 | Ramiro Polla | |

1077 | ```
skip_bits(&gb, (-get_bits_count(&gb)) & 15);
``` |
||

1078 | f95f6ab9 | Ramiro Polla | |

1079 | 7b18e13a | Ramiro Polla | if (substream_data_len[substr] * 8 - get_bits_count(&gb) >= 32) { |

1080 | ```
int shorten_by;
``` |
||

1081 | |||

1082 | if (get_bits(&gb, 16) != 0xD234) |
||

1083 | return -1; |
||

1084 | |||

1085 | ```
shorten_by = get_bits(&gb, 16);
``` |
||

1086 | if (m->avctx->codec_id == CODEC_ID_TRUEHD && shorten_by & 0x2000) |
||

1087 | ```
s->blockpos -= FFMIN(shorten_by & 0x1FFF, s->blockpos);
``` |
||

1088 | else if (m->avctx->codec_id == CODEC_ID_MLP && shorten_by != 0xD234) |
||

1089 | return -1; |
||

1090 | |||

1091 | b517af05 | Ramiro Polla | ```
if (substr == m->max_decoded_substream)
``` |

1092 | 9906a2be | Diego Biurrun | ```
av_log(m->avctx, AV_LOG_INFO, "End of stream indicated.\n");
``` |

1093 | b517af05 | Ramiro Polla | } |

1094 | f95f6ab9 | Ramiro Polla | |

1095 | ab79fa44 | Ramiro Polla | ```
if (substream_parity_present[substr]) {
``` |

1096 | b517af05 | Ramiro Polla | uint8_t parity, checksum; |

1097 | |||

1098 | ab79fa44 | Ramiro Polla | if (substream_data_len[substr] * 8 - get_bits_count(&gb) != 16) |

1099 | ```
goto substream_length_mismatch;
``` |
||

1100 | |||

1101 | d544dcdf | Ramiro Polla | ```
parity = ff_mlp_calculate_parity(buf, substream_data_len[substr] - 2);
``` |

1102 | ```
checksum = ff_mlp_checksum8 (buf, substream_data_len[substr] - 2);
``` |
||

1103 | b517af05 | Ramiro Polla | |

1104 | d544dcdf | Ramiro Polla | if ((get_bits(&gb, 8) ^ parity) != 0xa9 ) |

1105 | ```
av_log(m->avctx, AV_LOG_ERROR, "Substream %d parity check failed.\n", substr);
``` |
||

1106 | if ( get_bits(&gb, 8) != checksum) |
||

1107 | ```
av_log(m->avctx, AV_LOG_ERROR, "Substream %d checksum failed.\n" , substr);
``` |
||

1108 | b517af05 | Ramiro Polla | } |

1109 | f95f6ab9 | Ramiro Polla | |

1110 | if (substream_data_len[substr] * 8 != get_bits_count(&gb)) |
||

1111 | d7952be3 | Ramiro Polla | ```
goto substream_length_mismatch;
``` |

1112 | b517af05 | Ramiro Polla | |

1113 | ```
next_substr:
``` |
||

1114 | f95f6ab9 | Ramiro Polla | ```
if (!s->restart_seen)
``` |

1115 | 01aaf092 | Ramiro Polla | av_log(m->avctx, AV_LOG_ERROR, |

1116 | ```
"No restart header present in substream %d.\n", substr);
``` |
||

1117 | |||

1118 | b517af05 | Ramiro Polla | buf += substream_data_len[substr]; |

1119 | } |
||

1120 | |||

1121 | rematrix_channels(m, m->max_decoded_substream); |
||

1122 | |||

1123 | if (output_data(m, m->max_decoded_substream, data, data_size) < 0) |
||

1124 | return -1; |
||

1125 | |||

1126 | ```
return length;
``` |
||

1127 | |||

1128 | d7952be3 | Ramiro Polla | ```
substream_length_mismatch:
``` |

1129 | ```
av_log(m->avctx, AV_LOG_ERROR, "substream %d length mismatch\n", substr);
``` |
||

1130 | return -1; |
||

1131 | |||

1132 | b517af05 | Ramiro Polla | ```
error:
``` |

1133 | ```
m->params_valid = 0;
``` |
||

1134 | return -1; |
||

1135 | } |
||

1136 | |||

1137 | AVCodec mlp_decoder = { |
||

1138 | ```
"mlp",
``` |
||

1139 | 72415b2a | Stefano Sabatini | AVMEDIA_TYPE_AUDIO, |

1140 | b517af05 | Ramiro Polla | CODEC_ID_MLP, |

1141 | ```
sizeof(MLPDecodeContext),
``` |
||

1142 | mlp_decode_init, |
||

1143 | ```
NULL,
``` |
||

1144 | ```
NULL,
``` |
||

1145 | read_access_unit, |
||

1146 | 9ba4821d | Ramiro Polla | ```
.long_name = NULL_IF_CONFIG_SMALL("MLP (Meridian Lossless Packing)"),
``` |

1147 | b517af05 | Ramiro Polla | }; |

1148 | |||

1149 | 9ba4821d | Ramiro Polla | ```
#if CONFIG_TRUEHD_DECODER
``` |

1150 | AVCodec truehd_decoder = { |
||

1151 | ```
"truehd",
``` |
||

1152 | 72415b2a | Stefano Sabatini | AVMEDIA_TYPE_AUDIO, |

1153 | 9ba4821d | Ramiro Polla | CODEC_ID_TRUEHD, |

1154 | ```
sizeof(MLPDecodeContext),
``` |
||

1155 | mlp_decode_init, |
||

1156 | ```
NULL,
``` |
||

1157 | ```
NULL,
``` |
||

1158 | read_access_unit, |
||

1159 | ```
.long_name = NULL_IF_CONFIG_SMALL("TrueHD"),
``` |
||

1160 | }; |
||

1161 | #endif /* CONFIG_TRUEHD_DECODER */ |