3 * Copyright (c) 2007-2008 Ian Caulfield
5 * This file is part of FFmpeg.
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.
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.
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
31 #include "libavutil/intreadwrite.h"
33 #include "libavutil/crc.h"
35 #include "mlp_parser.h"
38 /** number of bits used for VLC lookup - longest Huffman code is 9 */
42 static const char* sample_message
=
43 "Please file a bug report following the instructions at "
44 "http://ffmpeg.org/bugreports.html and include "
45 "a sample of this file.";
47 typedef struct SubStream
{
48 //! Set if a valid restart header has been read. Otherwise the substream cannot be decoded.
52 /** restart header data */
53 //! The type of noise to be used in the rematrix stage.
56 //! The index of the first channel coded in this substream.
58 //! The index of the last channel coded in this substream.
60 //! The number of channels input into the rematrix stage.
61 uint8_t max_matrix_channel
;
62 //! For each channel output by the matrix, the output channel to map it to
63 uint8_t ch_assign
[MAX_CHANNELS
];
65 //! Channel coding parameters for channels in the substream
66 ChannelParams channel_params
[MAX_CHANNELS
];
68 //! The left shift applied to random noise in 0x31ea substreams.
70 //! The current seed value for the pseudorandom noise generator(s).
71 uint32_t noisegen_seed
;
73 //! Set if the substream contains extra info to check the size of VLC blocks.
74 uint8_t data_check_present
;
76 //! Bitmask of which parameter sets are conveyed in a decoding parameter block.
77 uint8_t param_presence_flags
;
78 #define PARAM_BLOCKSIZE (1 << 7)
79 #define PARAM_MATRIX (1 << 6)
80 #define PARAM_OUTSHIFT (1 << 5)
81 #define PARAM_QUANTSTEP (1 << 4)
82 #define PARAM_FIR (1 << 3)
83 #define PARAM_IIR (1 << 2)
84 #define PARAM_HUFFOFFSET (1 << 1)
85 #define PARAM_PRESENCE (1 << 0)
91 //! Number of matrices to be applied.
92 uint8_t num_primitive_matrices
;
94 //! matrix output channel
95 uint8_t matrix_out_ch
[MAX_MATRICES
];
97 //! Whether the LSBs of the matrix output are encoded in the bitstream.
98 uint8_t lsb_bypass
[MAX_MATRICES
];
99 //! Matrix coefficients, stored as 2.14 fixed point.
100 int32_t matrix_coeff
[MAX_MATRICES
][MAX_CHANNELS
];
101 //! Left shift to apply to noise values in 0x31eb substreams.
102 uint8_t matrix_noise_shift
[MAX_MATRICES
];
105 //! Left shift to apply to Huffman-decoded residuals.
106 uint8_t quant_step_size
[MAX_CHANNELS
];
108 //! number of PCM samples in current audio block
110 //! Number of PCM samples decoded so far in this frame.
113 //! Left shift to apply to decoded PCM values to get final 24-bit output.
114 int8_t output_shift
[MAX_CHANNELS
];
116 //! Running XOR of all output samples.
117 int32_t lossless_check_data
;
121 typedef struct MLPDecodeContext
{
122 AVCodecContext
*avctx
;
124 //! Current access unit being read has a major sync.
125 int is_major_sync_unit
;
127 //! Set if a valid major sync block has been read. Otherwise no decoding is possible.
128 uint8_t params_valid
;
130 //! Number of substreams contained within this stream.
131 uint8_t num_substreams
;
133 //! Index of the last substream to decode - further substreams are skipped.
134 uint8_t max_decoded_substream
;
136 //! number of PCM samples contained in each frame
137 int access_unit_size
;
138 //! next power of two above the number of samples in each frame
139 int access_unit_size_pow2
;
141 SubStream substream
[MAX_SUBSTREAMS
];
144 int filter_changed
[MAX_CHANNELS
][NUM_FILTERS
];
146 int8_t noise_buffer
[MAX_BLOCKSIZE_POW2
];
147 int8_t bypassed_lsbs
[MAX_BLOCKSIZE
][MAX_CHANNELS
];
148 int32_t sample_buffer
[MAX_BLOCKSIZE
][MAX_CHANNELS
];
153 static VLC huff_vlc
[3];
155 /** Initialize static data, constant between all invocations of the codec. */
157 static av_cold
void init_static(void)
159 if (!huff_vlc
[0].bits
) {
160 INIT_VLC_STATIC(&huff_vlc
[0], VLC_BITS
, 18,
161 &ff_mlp_huffman_tables
[0][0][1], 2, 1,
162 &ff_mlp_huffman_tables
[0][0][0], 2, 1, 512);
163 INIT_VLC_STATIC(&huff_vlc
[1], VLC_BITS
, 16,
164 &ff_mlp_huffman_tables
[1][0][1], 2, 1,
165 &ff_mlp_huffman_tables
[1][0][0], 2, 1, 512);
166 INIT_VLC_STATIC(&huff_vlc
[2], VLC_BITS
, 15,
167 &ff_mlp_huffman_tables
[2][0][1], 2, 1,
168 &ff_mlp_huffman_tables
[2][0][0], 2, 1, 512);
174 static inline int32_t calculate_sign_huff(MLPDecodeContext
*m
,
175 unsigned int substr
, unsigned int ch
)
177 SubStream
*s
= &m
->substream
[substr
];
178 ChannelParams
*cp
= &s
->channel_params
[ch
];
179 int lsb_bits
= cp
->huff_lsbs
- s
->quant_step_size
[ch
];
180 int sign_shift
= lsb_bits
+ (cp
->codebook
? 2 - cp
->codebook
: -1);
181 int32_t sign_huff_offset
= cp
->huff_offset
;
183 if (cp
->codebook
> 0)
184 sign_huff_offset
-= 7 << lsb_bits
;
187 sign_huff_offset
-= 1 << sign_shift
;
189 return sign_huff_offset
;
192 /** Read a sample, consisting of either, both or neither of entropy-coded MSBs
195 static inline int read_huff_channels(MLPDecodeContext
*m
, GetBitContext
*gbp
,
196 unsigned int substr
, unsigned int pos
)
198 SubStream
*s
= &m
->substream
[substr
];
199 unsigned int mat
, channel
;
201 for (mat
= 0; mat
< s
->num_primitive_matrices
; mat
++)
202 if (s
->lsb_bypass
[mat
])
203 m
->bypassed_lsbs
[pos
+ s
->blockpos
][mat
] = get_bits1(gbp
);
205 for (channel
= s
->min_channel
; channel
<= s
->max_channel
; channel
++) {
206 ChannelParams
*cp
= &s
->channel_params
[channel
];
207 int codebook
= cp
->codebook
;
208 int quant_step_size
= s
->quant_step_size
[channel
];
209 int lsb_bits
= cp
->huff_lsbs
- quant_step_size
;
213 result
= get_vlc2(gbp
, huff_vlc
[codebook
-1].table
,
214 VLC_BITS
, (9 + VLC_BITS
- 1) / VLC_BITS
);
220 result
= (result
<< lsb_bits
) + get_bits(gbp
, lsb_bits
);
222 result
+= cp
->sign_huff_offset
;
223 result
<<= quant_step_size
;
225 m
->sample_buffer
[pos
+ s
->blockpos
][channel
] = result
;
231 static av_cold
int mlp_decode_init(AVCodecContext
*avctx
)
233 MLPDecodeContext
*m
= avctx
->priv_data
;
238 for (substr
= 0; substr
< MAX_SUBSTREAMS
; substr
++)
239 m
->substream
[substr
].lossless_check_data
= 0xffffffff;
240 dsputil_init(&m
->dsp
, avctx
);
245 /** Read a major sync info header - contains high level information about
246 * the stream - sample rate, channel arrangement etc. Most of this
247 * information is not actually necessary for decoding, only for playback.
250 static int read_major_sync(MLPDecodeContext
*m
, GetBitContext
*gb
)
255 if (ff_mlp_read_major_sync(m
->avctx
, &mh
, gb
) != 0)
258 if (mh
.group1_bits
== 0) {
259 av_log(m
->avctx
, AV_LOG_ERROR
, "invalid/unknown bits per sample\n");
262 if (mh
.group2_bits
> mh
.group1_bits
) {
263 av_log(m
->avctx
, AV_LOG_ERROR
,
264 "Channel group 2 cannot have more bits per sample than group 1.\n");
268 if (mh
.group2_samplerate
&& mh
.group2_samplerate
!= mh
.group1_samplerate
) {
269 av_log(m
->avctx
, AV_LOG_ERROR
,
270 "Channel groups with differing sample rates are not currently supported.\n");
274 if (mh
.group1_samplerate
== 0) {
275 av_log(m
->avctx
, AV_LOG_ERROR
, "invalid/unknown sampling rate\n");
278 if (mh
.group1_samplerate
> MAX_SAMPLERATE
) {
279 av_log(m
->avctx
, AV_LOG_ERROR
,
280 "Sampling rate %d is greater than the supported maximum (%d).\n",
281 mh
.group1_samplerate
, MAX_SAMPLERATE
);
284 if (mh
.access_unit_size
> MAX_BLOCKSIZE
) {
285 av_log(m
->avctx
, AV_LOG_ERROR
,
286 "Block size %d is greater than the supported maximum (%d).\n",
287 mh
.access_unit_size
, MAX_BLOCKSIZE
);
290 if (mh
.access_unit_size_pow2
> MAX_BLOCKSIZE_POW2
) {
291 av_log(m
->avctx
, AV_LOG_ERROR
,
292 "Block size pow2 %d is greater than the supported maximum (%d).\n",
293 mh
.access_unit_size_pow2
, MAX_BLOCKSIZE_POW2
);
297 if (mh
.num_substreams
== 0)
299 if (m
->avctx
->codec_id
== CODEC_ID_MLP
&& mh
.num_substreams
> 2) {
300 av_log(m
->avctx
, AV_LOG_ERROR
, "MLP only supports up to 2 substreams.\n");
303 if (mh
.num_substreams
> MAX_SUBSTREAMS
) {
304 av_log(m
->avctx
, AV_LOG_ERROR
,
305 "Number of substreams %d is larger than the maximum supported "
306 "by the decoder. %s\n", mh
.num_substreams
, sample_message
);
310 m
->access_unit_size
= mh
.access_unit_size
;
311 m
->access_unit_size_pow2
= mh
.access_unit_size_pow2
;
313 m
->num_substreams
= mh
.num_substreams
;
314 m
->max_decoded_substream
= m
->num_substreams
- 1;
316 m
->avctx
->sample_rate
= mh
.group1_samplerate
;
317 m
->avctx
->frame_size
= mh
.access_unit_size
;
319 m
->avctx
->bits_per_raw_sample
= mh
.group1_bits
;
320 if (mh
.group1_bits
> 16)
321 m
->avctx
->sample_fmt
= SAMPLE_FMT_S32
;
323 m
->avctx
->sample_fmt
= SAMPLE_FMT_S16
;
326 for (substr
= 0; substr
< MAX_SUBSTREAMS
; substr
++)
327 m
->substream
[substr
].restart_seen
= 0;
332 /** Read a restart header from a block in a substream. This contains parameters
333 * required to decode the audio that do not change very often. Generally
334 * (always) present only in blocks following a major sync. */
336 static int read_restart_header(MLPDecodeContext
*m
, GetBitContext
*gbp
,
337 const uint8_t *buf
, unsigned int substr
)
339 SubStream
*s
= &m
->substream
[substr
];
343 uint8_t lossless_check
;
344 int start_count
= get_bits_count(gbp
);
345 const int max_matrix_channel
= m
->avctx
->codec_id
== CODEC_ID_MLP
346 ? MAX_MATRIX_CHANNEL_MLP
347 : MAX_MATRIX_CHANNEL_TRUEHD
;
349 sync_word
= get_bits(gbp
, 13);
351 if (sync_word
!= 0x31ea >> 1) {
352 av_log(m
->avctx
, AV_LOG_ERROR
,
353 "restart header sync incorrect (got 0x%04x)\n", sync_word
);
357 s
->noise_type
= get_bits1(gbp
);
359 if (m
->avctx
->codec_id
== CODEC_ID_MLP
&& s
->noise_type
) {
360 av_log(m
->avctx
, AV_LOG_ERROR
, "MLP must have 0x31ea sync word.\n");
364 skip_bits(gbp
, 16); /* Output timestamp */
366 s
->min_channel
= get_bits(gbp
, 4);
367 s
->max_channel
= get_bits(gbp
, 4);
368 s
->max_matrix_channel
= get_bits(gbp
, 4);
370 if (s
->max_matrix_channel
> max_matrix_channel
) {
371 av_log(m
->avctx
, AV_LOG_ERROR
,
372 "Max matrix channel cannot be greater than %d.\n",
377 if (s
->max_channel
!= s
->max_matrix_channel
) {
378 av_log(m
->avctx
, AV_LOG_ERROR
,
379 "Max channel must be equal max matrix channel.\n");
383 /* This should happen for TrueHD streams with >6 channels and MLP's noise
384 * type. It is not yet known if this is allowed. */
385 if (s
->max_channel
> MAX_MATRIX_CHANNEL_MLP
&& !s
->noise_type
) {
386 av_log(m
->avctx
, AV_LOG_ERROR
,
387 "Number of channels %d is larger than the maximum supported "
388 "by the decoder. %s\n", s
->max_channel
+2, sample_message
);
392 if (s
->min_channel
> s
->max_channel
) {
393 av_log(m
->avctx
, AV_LOG_ERROR
,
394 "Substream min channel cannot be greater than max channel.\n");
398 if (m
->avctx
->request_channels
> 0
399 && s
->max_channel
+ 1 >= m
->avctx
->request_channels
400 && substr
< m
->max_decoded_substream
) {
401 av_log(m
->avctx
, AV_LOG_DEBUG
,
402 "Extracting %d channel downmix from substream %d. "
403 "Further substreams will be skipped.\n",
404 s
->max_channel
+ 1, substr
);
405 m
->max_decoded_substream
= substr
;
408 s
->noise_shift
= get_bits(gbp
, 4);
409 s
->noisegen_seed
= get_bits(gbp
, 23);
413 s
->data_check_present
= get_bits1(gbp
);
414 lossless_check
= get_bits(gbp
, 8);
415 if (substr
== m
->max_decoded_substream
416 && s
->lossless_check_data
!= 0xffffffff) {
417 tmp
= xor_32_to_8(s
->lossless_check_data
);
418 if (tmp
!= lossless_check
)
419 av_log(m
->avctx
, AV_LOG_WARNING
,
420 "Lossless check failed - expected %02x, calculated %02x.\n",
421 lossless_check
, tmp
);
426 memset(s
->ch_assign
, 0, sizeof(s
->ch_assign
));
428 for (ch
= 0; ch
<= s
->max_matrix_channel
; ch
++) {
429 int ch_assign
= get_bits(gbp
, 6);
430 if (ch_assign
> s
->max_matrix_channel
) {
431 av_log(m
->avctx
, AV_LOG_ERROR
,
432 "Assignment of matrix channel %d to invalid output channel %d. %s\n",
433 ch
, ch_assign
, sample_message
);
436 s
->ch_assign
[ch_assign
] = ch
;
439 checksum
= ff_mlp_restart_checksum(buf
, get_bits_count(gbp
) - start_count
);
441 if (checksum
!= get_bits(gbp
, 8))
442 av_log(m
->avctx
, AV_LOG_ERROR
, "restart header checksum error\n");
444 /* Set default decoding parameters. */
445 s
->param_presence_flags
= 0xff;
446 s
->num_primitive_matrices
= 0;
448 s
->lossless_check_data
= 0;
450 memset(s
->output_shift
, 0, sizeof(s
->output_shift
));
451 memset(s
->quant_step_size
, 0, sizeof(s
->quant_step_size
));
453 for (ch
= s
->min_channel
; ch
<= s
->max_channel
; ch
++) {
454 ChannelParams
*cp
= &s
->channel_params
[ch
];
455 cp
->filter_params
[FIR
].order
= 0;
456 cp
->filter_params
[IIR
].order
= 0;
457 cp
->filter_params
[FIR
].shift
= 0;
458 cp
->filter_params
[IIR
].shift
= 0;
460 /* Default audio coding is 24-bit raw PCM. */
462 cp
->sign_huff_offset
= (-1) << 23;
467 if (substr
== m
->max_decoded_substream
)
468 m
->avctx
->channels
= s
->max_matrix_channel
+ 1;
473 /** Read parameters for one of the prediction filters. */
475 static int read_filter_params(MLPDecodeContext
*m
, GetBitContext
*gbp
,
476 unsigned int substr
, unsigned int channel
,
479 SubStream
*s
= &m
->substream
[substr
];
480 FilterParams
*fp
= &s
->channel_params
[channel
].filter_params
[filter
];
481 const int max_order
= filter
? MAX_IIR_ORDER
: MAX_FIR_ORDER
;
482 const char fchar
= filter
? 'I' : 'F';
485 // Filter is 0 for FIR, 1 for IIR.
488 if (m
->filter_changed
[channel
][filter
]++ > 1) {
489 av_log(m
->avctx
, AV_LOG_ERROR
, "Filters may change only once per access unit.\n");
493 order
= get_bits(gbp
, 4);
494 if (order
> max_order
) {
495 av_log(m
->avctx
, AV_LOG_ERROR
,
496 "%cIR filter order %d is greater than maximum %d.\n",
497 fchar
, order
, max_order
);
503 int32_t *fcoeff
= s
->channel_params
[channel
].coeff
[filter
];
504 int coeff_bits
, coeff_shift
;
506 fp
->shift
= get_bits(gbp
, 4);
508 coeff_bits
= get_bits(gbp
, 5);
509 coeff_shift
= get_bits(gbp
, 3);
510 if (coeff_bits
< 1 || coeff_bits
> 16) {
511 av_log(m
->avctx
, AV_LOG_ERROR
,
512 "%cIR filter coeff_bits must be between 1 and 16.\n",
516 if (coeff_bits
+ coeff_shift
> 16) {
517 av_log(m
->avctx
, AV_LOG_ERROR
,
518 "Sum of coeff_bits and coeff_shift for %cIR filter must be 16 or less.\n",
523 for (i
= 0; i
< order
; i
++)
524 fcoeff
[i
] = get_sbits(gbp
, coeff_bits
) << coeff_shift
;
526 if (get_bits1(gbp
)) {
527 int state_bits
, state_shift
;
530 av_log(m
->avctx
, AV_LOG_ERROR
,
531 "FIR filter has state data specified.\n");
535 state_bits
= get_bits(gbp
, 4);
536 state_shift
= get_bits(gbp
, 4);
538 /* TODO: Check validity of state data. */
540 for (i
= 0; i
< order
; i
++)
541 fp
->state
[i
] = get_sbits(gbp
, state_bits
) << state_shift
;
548 /** Read parameters for primitive matrices. */
550 static int read_matrix_params(MLPDecodeContext
*m
, unsigned int substr
, GetBitContext
*gbp
)
552 SubStream
*s
= &m
->substream
[substr
];
553 unsigned int mat
, ch
;
554 const int max_primitive_matrices
= m
->avctx
->codec_id
== CODEC_ID_MLP
556 : MAX_MATRICES_TRUEHD
;
558 if (m
->matrix_changed
++ > 1) {
559 av_log(m
->avctx
, AV_LOG_ERROR
, "Matrices may change only once per access unit.\n");
563 s
->num_primitive_matrices
= get_bits(gbp
, 4);
565 if (s
->num_primitive_matrices
> max_primitive_matrices
) {
566 av_log(m
->avctx
, AV_LOG_ERROR
,
567 "Number of primitive matrices cannot be greater than %d.\n",
568 max_primitive_matrices
);
572 for (mat
= 0; mat
< s
->num_primitive_matrices
; mat
++) {
573 int frac_bits
, max_chan
;
574 s
->matrix_out_ch
[mat
] = get_bits(gbp
, 4);
575 frac_bits
= get_bits(gbp
, 4);
576 s
->lsb_bypass
[mat
] = get_bits1(gbp
);
578 if (s
->matrix_out_ch
[mat
] > s
->max_matrix_channel
) {
579 av_log(m
->avctx
, AV_LOG_ERROR
,
580 "Invalid channel %d specified as output from matrix.\n",
581 s
->matrix_out_ch
[mat
]);
584 if (frac_bits
> 14) {
585 av_log(m
->avctx
, AV_LOG_ERROR
,
586 "Too many fractional bits specified.\n");
590 max_chan
= s
->max_matrix_channel
;
594 for (ch
= 0; ch
<= max_chan
; ch
++) {
597 coeff_val
= get_sbits(gbp
, frac_bits
+ 2);
599 s
->matrix_coeff
[mat
][ch
] = coeff_val
<< (14 - frac_bits
);
603 s
->matrix_noise_shift
[mat
] = get_bits(gbp
, 4);
605 s
->matrix_noise_shift
[mat
] = 0;
611 /** Read channel parameters. */
613 static int read_channel_params(MLPDecodeContext
*m
, unsigned int substr
,
614 GetBitContext
*gbp
, unsigned int ch
)
616 SubStream
*s
= &m
->substream
[substr
];
617 ChannelParams
*cp
= &s
->channel_params
[ch
];
618 FilterParams
*fir
= &cp
->filter_params
[FIR
];
619 FilterParams
*iir
= &cp
->filter_params
[IIR
];
621 if (s
->param_presence_flags
& PARAM_FIR
)
623 if (read_filter_params(m
, gbp
, substr
, ch
, FIR
) < 0)
626 if (s
->param_presence_flags
& PARAM_IIR
)
628 if (read_filter_params(m
, gbp
, substr
, ch
, IIR
) < 0)
631 if (fir
->order
+ iir
->order
> 8) {
632 av_log(m
->avctx
, AV_LOG_ERROR
, "Total filter orders too high.\n");
636 if (fir
->order
&& iir
->order
&&
637 fir
->shift
!= iir
->shift
) {
638 av_log(m
->avctx
, AV_LOG_ERROR
,
639 "FIR and IIR filters must use the same precision.\n");
642 /* The FIR and IIR filters must have the same precision.
643 * To simplify the filtering code, only the precision of the
644 * FIR filter is considered. If only the IIR filter is employed,
645 * the FIR filter precision is set to that of the IIR filter, so
646 * that the filtering code can use it. */
647 if (!fir
->order
&& iir
->order
)
648 fir
->shift
= iir
->shift
;
650 if (s
->param_presence_flags
& PARAM_HUFFOFFSET
)
652 cp
->huff_offset
= get_sbits(gbp
, 15);
654 cp
->codebook
= get_bits(gbp
, 2);
655 cp
->huff_lsbs
= get_bits(gbp
, 5);
657 if (cp
->huff_lsbs
> 24) {
658 av_log(m
->avctx
, AV_LOG_ERROR
, "Invalid huff_lsbs.\n");
662 cp
->sign_huff_offset
= calculate_sign_huff(m
, substr
, ch
);
667 /** Read decoding parameters that change more often than those in the restart
670 static int read_decoding_params(MLPDecodeContext
*m
, GetBitContext
*gbp
,
673 SubStream
*s
= &m
->substream
[substr
];
676 if (s
->param_presence_flags
& PARAM_PRESENCE
)
678 s
->param_presence_flags
= get_bits(gbp
, 8);
680 if (s
->param_presence_flags
& PARAM_BLOCKSIZE
)
681 if (get_bits1(gbp
)) {
682 s
->blocksize
= get_bits(gbp
, 9);
683 if (s
->blocksize
< 8 || s
->blocksize
> m
->access_unit_size
) {
684 av_log(m
->avctx
, AV_LOG_ERROR
, "Invalid blocksize.");
690 if (s
->param_presence_flags
& PARAM_MATRIX
)
692 if (read_matrix_params(m
, substr
, gbp
) < 0)
695 if (s
->param_presence_flags
& PARAM_OUTSHIFT
)
697 for (ch
= 0; ch
<= s
->max_matrix_channel
; ch
++)
698 s
->output_shift
[ch
] = get_sbits(gbp
, 4);
700 if (s
->param_presence_flags
& PARAM_QUANTSTEP
)
702 for (ch
= 0; ch
<= s
->max_channel
; ch
++) {
703 ChannelParams
*cp
= &s
->channel_params
[ch
];
705 s
->quant_step_size
[ch
] = get_bits(gbp
, 4);
707 cp
->sign_huff_offset
= calculate_sign_huff(m
, substr
, ch
);
710 for (ch
= s
->min_channel
; ch
<= s
->max_channel
; ch
++)
712 if (read_channel_params(m
, substr
, gbp
, ch
) < 0)
718 #define MSB_MASK(bits) (-1u << bits)
720 /** Generate PCM samples using the prediction filters and residual values
721 * read from the data stream, and update the filter state. */
723 static void filter_channel(MLPDecodeContext
*m
, unsigned int substr
,
724 unsigned int channel
)
726 SubStream
*s
= &m
->substream
[substr
];
727 const int32_t *fircoeff
= s
->channel_params
[channel
].coeff
[FIR
];
728 int32_t state_buffer
[NUM_FILTERS
][MAX_BLOCKSIZE
+ MAX_FIR_ORDER
];
729 int32_t *firbuf
= state_buffer
[FIR
] + MAX_BLOCKSIZE
;
730 int32_t *iirbuf
= state_buffer
[IIR
] + MAX_BLOCKSIZE
;
731 FilterParams
*fir
= &s
->channel_params
[channel
].filter_params
[FIR
];
732 FilterParams
*iir
= &s
->channel_params
[channel
].filter_params
[IIR
];
733 unsigned int filter_shift
= fir
->shift
;
734 int32_t mask
= MSB_MASK(s
->quant_step_size
[channel
]);
736 memcpy(firbuf
, fir
->state
, MAX_FIR_ORDER
* sizeof(int32_t));
737 memcpy(iirbuf
, iir
->state
, MAX_IIR_ORDER
* sizeof(int32_t));
739 m
->dsp
.mlp_filter_channel(firbuf
, fircoeff
,
740 fir
->order
, iir
->order
,
741 filter_shift
, mask
, s
->blocksize
,
742 &m
->sample_buffer
[s
->blockpos
][channel
]);
744 memcpy(fir
->state
, firbuf
- s
->blocksize
, MAX_FIR_ORDER
* sizeof(int32_t));
745 memcpy(iir
->state
, iirbuf
- s
->blocksize
, MAX_IIR_ORDER
* sizeof(int32_t));
748 /** Read a block of PCM residual data (or actual if no filtering active). */
750 static int read_block_data(MLPDecodeContext
*m
, GetBitContext
*gbp
,
753 SubStream
*s
= &m
->substream
[substr
];
754 unsigned int i
, ch
, expected_stream_pos
= 0;
756 if (s
->data_check_present
) {
757 expected_stream_pos
= get_bits_count(gbp
);
758 expected_stream_pos
+= get_bits(gbp
, 16);
759 av_log(m
->avctx
, AV_LOG_WARNING
, "This file contains some features "
760 "we have not tested yet. %s\n", sample_message
);
763 if (s
->blockpos
+ s
->blocksize
> m
->access_unit_size
) {
764 av_log(m
->avctx
, AV_LOG_ERROR
, "too many audio samples in frame\n");
768 memset(&m
->bypassed_lsbs
[s
->blockpos
][0], 0,
769 s
->blocksize
* sizeof(m
->bypassed_lsbs
[0]));
771 for (i
= 0; i
< s
->blocksize
; i
++)
772 if (read_huff_channels(m
, gbp
, substr
, i
) < 0)
775 for (ch
= s
->min_channel
; ch
<= s
->max_channel
; ch
++)
776 filter_channel(m
, substr
, ch
);
778 s
->blockpos
+= s
->blocksize
;
780 if (s
->data_check_present
) {
781 if (get_bits_count(gbp
) != expected_stream_pos
)
782 av_log(m
->avctx
, AV_LOG_ERROR
, "block data length mismatch\n");
789 /** Data table used for TrueHD noise generation function. */
791 static const int8_t noise_table
[256] = {
792 30, 51, 22, 54, 3, 7, -4, 38, 14, 55, 46, 81, 22, 58, -3, 2,
793 52, 31, -7, 51, 15, 44, 74, 30, 85, -17, 10, 33, 18, 80, 28, 62,
794 10, 32, 23, 69, 72, 26, 35, 17, 73, 60, 8, 56, 2, 6, -2, -5,
795 51, 4, 11, 50, 66, 76, 21, 44, 33, 47, 1, 26, 64, 48, 57, 40,
796 38, 16, -10, -28, 92, 22, -18, 29, -10, 5, -13, 49, 19, 24, 70, 34,
797 61, 48, 30, 14, -6, 25, 58, 33, 42, 60, 67, 17, 54, 17, 22, 30,
798 67, 44, -9, 50, -11, 43, 40, 32, 59, 82, 13, 49, -14, 55, 60, 36,
799 48, 49, 31, 47, 15, 12, 4, 65, 1, 23, 29, 39, 45, -2, 84, 69,
800 0, 72, 37, 57, 27, 41, -15, -16, 35, 31, 14, 61, 24, 0, 27, 24,
801 16, 41, 55, 34, 53, 9, 56, 12, 25, 29, 53, 5, 20, -20, -8, 20,
802 13, 28, -3, 78, 38, 16, 11, 62, 46, 29, 21, 24, 46, 65, 43, -23,
803 89, 18, 74, 21, 38, -12, 19, 12, -19, 8, 15, 33, 4, 57, 9, -8,
804 36, 35, 26, 28, 7, 83, 63, 79, 75, 11, 3, 87, 37, 47, 34, 40,
805 39, 19, 20, 42, 27, 34, 39, 77, 13, 42, 59, 64, 45, -1, 32, 37,
806 45, -5, 53, -6, 7, 36, 50, 23, 6, 32, 9, -21, 18, 71, 27, 52,
807 -25, 31, 35, 42, -1, 68, 63, 52, 26, 43, 66, 37, 41, 25, 40, 70,
810 /** Noise generation functions.
811 * I'm not sure what these are for - they seem to be some kind of pseudorandom
812 * sequence generators, used to generate noise data which is used when the
813 * channels are rematrixed. I'm not sure if they provide a practical benefit
814 * to compression, or just obfuscate the decoder. Are they for some kind of
817 /** Generate two channels of noise, used in the matrix when
818 * restart sync word == 0x31ea. */
820 static void generate_2_noise_channels(MLPDecodeContext
*m
, unsigned int substr
)
822 SubStream
*s
= &m
->substream
[substr
];
824 uint32_t seed
= s
->noisegen_seed
;
825 unsigned int maxchan
= s
->max_matrix_channel
;
827 for (i
= 0; i
< s
->blockpos
; i
++) {
828 uint16_t seed_shr7
= seed
>> 7;
829 m
->sample_buffer
[i
][maxchan
+1] = ((int8_t)(seed
>> 15)) << s
->noise_shift
;
830 m
->sample_buffer
[i
][maxchan
+2] = ((int8_t) seed_shr7
) << s
->noise_shift
;
832 seed
= (seed
<< 16) ^ seed_shr7
^ (seed_shr7
<< 5);
835 s
->noisegen_seed
= seed
;
838 /** Generate a block of noise, used when restart sync word == 0x31eb. */
840 static void fill_noise_buffer(MLPDecodeContext
*m
, unsigned int substr
)
842 SubStream
*s
= &m
->substream
[substr
];
844 uint32_t seed
= s
->noisegen_seed
;
846 for (i
= 0; i
< m
->access_unit_size_pow2
; i
++) {
847 uint8_t seed_shr15
= seed
>> 15;
848 m
->noise_buffer
[i
] = noise_table
[seed_shr15
];
849 seed
= (seed
<< 8) ^ seed_shr15
^ (seed_shr15
<< 5);
852 s
->noisegen_seed
= seed
;
856 /** Apply the channel matrices in turn to reconstruct the original audio
859 static void rematrix_channels(MLPDecodeContext
*m
, unsigned int substr
)
861 SubStream
*s
= &m
->substream
[substr
];
862 unsigned int mat
, src_ch
, i
;
863 unsigned int maxchan
;
865 maxchan
= s
->max_matrix_channel
;
866 if (!s
->noise_type
) {
867 generate_2_noise_channels(m
, substr
);
870 fill_noise_buffer(m
, substr
);
873 for (mat
= 0; mat
< s
->num_primitive_matrices
; mat
++) {
874 int matrix_noise_shift
= s
->matrix_noise_shift
[mat
];
875 unsigned int dest_ch
= s
->matrix_out_ch
[mat
];
876 int32_t mask
= MSB_MASK(s
->quant_step_size
[dest_ch
]);
877 int32_t *coeffs
= s
->matrix_coeff
[mat
];
878 int index
= s
->num_primitive_matrices
- mat
;
879 int index2
= 2 * index
+ 1;
881 /* TODO: DSPContext? */
883 for (i
= 0; i
< s
->blockpos
; i
++) {
884 int32_t bypassed_lsb
= m
->bypassed_lsbs
[i
][mat
];
885 int32_t *samples
= m
->sample_buffer
[i
];
888 for (src_ch
= 0; src_ch
<= maxchan
; src_ch
++)
889 accum
+= (int64_t) samples
[src_ch
] * coeffs
[src_ch
];
891 if (matrix_noise_shift
) {
892 index
&= m
->access_unit_size_pow2
- 1;
893 accum
+= m
->noise_buffer
[index
] << (matrix_noise_shift
+ 7);
897 samples
[dest_ch
] = ((accum
>> 14) & mask
) + bypassed_lsb
;
902 /** Write the audio data into the output buffer. */
904 static int output_data_internal(MLPDecodeContext
*m
, unsigned int substr
,
905 uint8_t *data
, unsigned int *data_size
, int is32
)
907 SubStream
*s
= &m
->substream
[substr
];
908 unsigned int i
, out_ch
= 0;
909 int32_t *data_32
= (int32_t*) data
;
910 int16_t *data_16
= (int16_t*) data
;
912 if (*data_size
< (s
->max_channel
+ 1) * s
->blockpos
* (is32
? 4 : 2))
915 for (i
= 0; i
< s
->blockpos
; i
++) {
916 for (out_ch
= 0; out_ch
<= s
->max_matrix_channel
; out_ch
++) {
917 int mat_ch
= s
->ch_assign
[out_ch
];
918 int32_t sample
= m
->sample_buffer
[i
][mat_ch
]
919 << s
->output_shift
[mat_ch
];
920 s
->lossless_check_data
^= (sample
& 0xffffff) << mat_ch
;
921 if (is32
) *data_32
++ = sample
<< 8;
922 else *data_16
++ = sample
>> 8;
926 *data_size
= i
* out_ch
* (is32
? 4 : 2);
931 static int output_data(MLPDecodeContext
*m
, unsigned int substr
,
932 uint8_t *data
, unsigned int *data_size
)
934 if (m
->avctx
->sample_fmt
== SAMPLE_FMT_S32
)
935 return output_data_internal(m
, substr
, data
, data_size
, 1);
937 return output_data_internal(m
, substr
, data
, data_size
, 0);
941 /** Read an access unit from the stream.
942 * Returns < 0 on error, 0 if not enough data is present in the input stream
943 * otherwise returns the number of bytes consumed. */
945 static int read_access_unit(AVCodecContext
*avctx
, void* data
, int *data_size
,
948 const uint8_t *buf
= avpkt
->data
;
949 int buf_size
= avpkt
->size
;
950 MLPDecodeContext
*m
= avctx
->priv_data
;
952 unsigned int length
, substr
;
953 unsigned int substream_start
;
954 unsigned int header_size
= 4;
955 unsigned int substr_header_size
= 0;
956 uint8_t substream_parity_present
[MAX_SUBSTREAMS
];
957 uint16_t substream_data_len
[MAX_SUBSTREAMS
];
963 length
= (AV_RB16(buf
) & 0xfff) * 2;
965 if (length
< 4 || length
> buf_size
)
968 init_get_bits(&gb
, (buf
+ 4), (length
- 4) * 8);
970 m
->is_major_sync_unit
= 0;
971 if (show_bits_long(&gb
, 31) == (0xf8726fba >> 1)) {
972 if (read_major_sync(m
, &gb
) < 0)
974 m
->is_major_sync_unit
= 1;
978 if (!m
->params_valid
) {
979 av_log(m
->avctx
, AV_LOG_WARNING
,
980 "Stream parameters not seen; skipping frame.\n");
987 for (substr
= 0; substr
< m
->num_substreams
; substr
++) {
988 int extraword_present
, checkdata_present
, end
, nonrestart_substr
;
990 extraword_present
= get_bits1(&gb
);
991 nonrestart_substr
= get_bits1(&gb
);
992 checkdata_present
= get_bits1(&gb
);
995 end
= get_bits(&gb
, 12) * 2;
997 substr_header_size
+= 2;
999 if (extraword_present
) {
1000 if (m
->avctx
->codec_id
== CODEC_ID_MLP
) {
1001 av_log(m
->avctx
, AV_LOG_ERROR
, "There must be no extraword for MLP.\n");
1005 substr_header_size
+= 2;
1008 if (!(nonrestart_substr
^ m
->is_major_sync_unit
)) {
1009 av_log(m
->avctx
, AV_LOG_ERROR
, "Invalid nonrestart_substr.\n");
1013 if (end
+ header_size
+ substr_header_size
> length
) {
1014 av_log(m
->avctx
, AV_LOG_ERROR
,
1015 "Indicated length of substream %d data goes off end of "
1016 "packet.\n", substr
);
1017 end
= length
- header_size
- substr_header_size
;
1020 if (end
< substream_start
) {
1021 av_log(avctx
, AV_LOG_ERROR
,
1022 "Indicated end offset of substream %d data "
1023 "is smaller than calculated start offset.\n",
1028 if (substr
> m
->max_decoded_substream
)
1031 substream_parity_present
[substr
] = checkdata_present
;
1032 substream_data_len
[substr
] = end
- substream_start
;
1033 substream_start
= end
;
1036 parity_bits
= ff_mlp_calculate_parity(buf
, 4);
1037 parity_bits
^= ff_mlp_calculate_parity(buf
+ header_size
, substr_header_size
);
1039 if ((((parity_bits
>> 4) ^ parity_bits
) & 0xF) != 0xF) {
1040 av_log(avctx
, AV_LOG_ERROR
, "Parity check failed.\n");
1044 buf
+= header_size
+ substr_header_size
;
1046 for (substr
= 0; substr
<= m
->max_decoded_substream
; substr
++) {
1047 SubStream
*s
= &m
->substream
[substr
];
1048 init_get_bits(&gb
, buf
, substream_data_len
[substr
] * 8);
1050 m
->matrix_changed
= 0;
1051 memset(m
->filter_changed
, 0, sizeof(m
->filter_changed
));
1055 if (get_bits1(&gb
)) {
1056 if (get_bits1(&gb
)) {
1057 /* A restart header should be present. */
1058 if (read_restart_header(m
, &gb
, buf
, substr
) < 0)
1060 s
->restart_seen
= 1;
1063 if (!s
->restart_seen
)
1065 if (read_decoding_params(m
, &gb
, substr
) < 0)
1069 if (!s
->restart_seen
)
1072 if (read_block_data(m
, &gb
, substr
) < 0)
1075 if (get_bits_count(&gb
) >= substream_data_len
[substr
] * 8)
1076 goto substream_length_mismatch
;
1078 } while (!get_bits1(&gb
));
1080 skip_bits(&gb
, (-get_bits_count(&gb
)) & 15);
1082 if (substream_data_len
[substr
] * 8 - get_bits_count(&gb
) >= 32) {
1085 if (get_bits(&gb
, 16) != 0xD234)
1088 shorten_by
= get_bits(&gb
, 16);
1089 if (m
->avctx
->codec_id
== CODEC_ID_TRUEHD
&& shorten_by
& 0x2000)
1090 s
->blockpos
-= FFMIN(shorten_by
& 0x1FFF, s
->blockpos
);
1091 else if (m
->avctx
->codec_id
== CODEC_ID_MLP
&& shorten_by
!= 0xD234)
1094 if (substr
== m
->max_decoded_substream
)
1095 av_log(m
->avctx
, AV_LOG_INFO
, "End of stream indicated.\n");
1098 if (substream_parity_present
[substr
]) {
1099 uint8_t parity
, checksum
;
1101 if (substream_data_len
[substr
] * 8 - get_bits_count(&gb
) != 16)
1102 goto substream_length_mismatch
;
1104 parity
= ff_mlp_calculate_parity(buf
, substream_data_len
[substr
] - 2);
1105 checksum
= ff_mlp_checksum8 (buf
, substream_data_len
[substr
] - 2);
1107 if ((get_bits(&gb
, 8) ^ parity
) != 0xa9 )
1108 av_log(m
->avctx
, AV_LOG_ERROR
, "Substream %d parity check failed.\n", substr
);
1109 if ( get_bits(&gb
, 8) != checksum
)
1110 av_log(m
->avctx
, AV_LOG_ERROR
, "Substream %d checksum failed.\n" , substr
);
1113 if (substream_data_len
[substr
] * 8 != get_bits_count(&gb
))
1114 goto substream_length_mismatch
;
1117 if (!s
->restart_seen
)
1118 av_log(m
->avctx
, AV_LOG_ERROR
,
1119 "No restart header present in substream %d.\n", substr
);
1121 buf
+= substream_data_len
[substr
];
1124 rematrix_channels(m
, m
->max_decoded_substream
);
1126 if (output_data(m
, m
->max_decoded_substream
, data
, data_size
) < 0)
1131 substream_length_mismatch
:
1132 av_log(m
->avctx
, AV_LOG_ERROR
, "substream %d length mismatch\n", substr
);
1136 m
->params_valid
= 0;
1140 AVCodec mlp_decoder
= {
1144 sizeof(MLPDecodeContext
),
1149 .long_name
= NULL_IF_CONFIG_SMALL("MLP (Meridian Lossless Packing)"),
1152 #if CONFIG_TRUEHD_DECODER
1153 AVCodec truehd_decoder
= {
1157 sizeof(MLPDecodeContext
),
1162 .long_name
= NULL_IF_CONFIG_SMALL("TrueHD"),
1164 #endif /* CONFIG_TRUEHD_DECODER */