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1/*
2 * Shorten decoder
3 * Copyright (c) 2005 Jeff Muizelaar
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 * @file
24 * Shorten decoder
25 * @author Jeff Muizelaar
26 */
27
28#include <limits.h>
29#include "avcodec.h"
30#include "bswapdsp.h"
31#include "bytestream.h"
32#include "get_bits.h"
33#include "golomb.h"
34#include "internal.h"
35
36#define MAX_CHANNELS 8
37#define MAX_BLOCKSIZE 65535
38
39#define OUT_BUFFER_SIZE 16384
40
41#define ULONGSIZE 2
42
43#define WAVE_FORMAT_PCM 0x0001
44
45#define DEFAULT_BLOCK_SIZE 256
46
47#define TYPESIZE 4
48#define CHANSIZE 0
49#define LPCQSIZE 2
50#define ENERGYSIZE 3
51#define BITSHIFTSIZE 2
52
53#define TYPE_S8 1
54#define TYPE_U8 2
55#define TYPE_S16HL 3
56#define TYPE_U16HL 4
57#define TYPE_S16LH 5
58#define TYPE_U16LH 6
59
60#define NWRAP 3
61#define NSKIPSIZE 1
62
63#define LPCQUANT 5
64#define V2LPCQOFFSET (1 << LPCQUANT)
65
66#define FNSIZE 2
67#define FN_DIFF0 0
68#define FN_DIFF1 1
69#define FN_DIFF2 2
70#define FN_DIFF3 3
71#define FN_QUIT 4
72#define FN_BLOCKSIZE 5
73#define FN_BITSHIFT 6
74#define FN_QLPC 7
75#define FN_ZERO 8
76#define FN_VERBATIM 9
77
78/** indicates if the FN_* command is audio or non-audio */
79static const uint8_t is_audio_command[10] = { 1, 1, 1, 1, 0, 0, 0, 1, 1, 0 };
80
81#define VERBATIM_CKSIZE_SIZE 5
82#define VERBATIM_BYTE_SIZE 8
83#define CANONICAL_HEADER_SIZE 44
84
85typedef struct ShortenContext {
86 AVCodecContext *avctx;
87 GetBitContext gb;
88
89 int min_framesize, max_framesize;
90 unsigned channels;
91
92 int32_t *decoded[MAX_CHANNELS];
93 int32_t *decoded_base[MAX_CHANNELS];
94 int32_t *offset[MAX_CHANNELS];
95 int *coeffs;
96 uint8_t *bitstream;
97 int bitstream_size;
98 int bitstream_index;
99 unsigned int allocated_bitstream_size;
100 int header_size;
101 uint8_t header[OUT_BUFFER_SIZE];
102 int version;
103 int cur_chan;
104 int bitshift;
105 int nmean;
106 int internal_ftype;
107 int nwrap;
108 int blocksize;
109 int bitindex;
110 int32_t lpcqoffset;
111 int got_header;
112 int got_quit_command;
113 int swap;
114 BswapDSPContext bdsp;
115} ShortenContext;
116
117static av_cold int shorten_decode_init(AVCodecContext *avctx)
118{
119 ShortenContext *s = avctx->priv_data;
120 s->avctx = avctx;
121
122 ff_bswapdsp_init(&s->bdsp);
123
124 return 0;
125}
126
127static int allocate_buffers(ShortenContext *s)
128{
129 int i, chan, err;
130
131 for (chan = 0; chan < s->channels; chan++) {
132 if (FFMAX(1, s->nmean) >= UINT_MAX / sizeof(int32_t)) {
133 av_log(s->avctx, AV_LOG_ERROR, "nmean too large\n");
134 return AVERROR_INVALIDDATA;
135 }
136 if (s->blocksize + (uint64_t)s->nwrap >= UINT_MAX / sizeof(int32_t)) {
137 av_log(s->avctx, AV_LOG_ERROR,
138 "s->blocksize + s->nwrap too large\n");
139 return AVERROR_INVALIDDATA;
140 }
141
142 if ((err = av_reallocp_array(&s->offset[chan],
143 sizeof(int32_t),
144 FFMAX(1, s->nmean))) < 0)
145 return err;
146
147 if ((err = av_reallocp_array(&s->decoded_base[chan], (s->blocksize + s->nwrap),
148 sizeof(s->decoded_base[0][0]))) < 0)
149 return err;
150 for (i = 0; i < s->nwrap; i++)
151 s->decoded_base[chan][i] = 0;
152 s->decoded[chan] = s->decoded_base[chan] + s->nwrap;
153 }
154
155 if ((err = av_reallocp_array(&s->coeffs, s->nwrap, sizeof(*s->coeffs))) < 0)
156 return err;
157
158 return 0;
159}
160
161static inline unsigned int get_uint(ShortenContext *s, int k)
162{
163 if (s->version != 0)
164 k = get_ur_golomb_shorten(&s->gb, ULONGSIZE);
165 return get_ur_golomb_shorten(&s->gb, k);
166}
167
168static void fix_bitshift(ShortenContext *s, int32_t *buffer)
169{
170 int i;
171
172 if (s->bitshift == 32) {
173 for (i = 0; i < s->blocksize; i++)
174 buffer[i] = 0;
175 } else if (s->bitshift != 0) {
176 for (i = 0; i < s->blocksize; i++)
177 buffer[i] <<= s->bitshift;
178 }
179}
180
181static int init_offset(ShortenContext *s)
182{
183 int32_t mean = 0;
184 int chan, i;
185 int nblock = FFMAX(1, s->nmean);
186 /* initialise offset */
187 switch (s->internal_ftype) {
188 case TYPE_U8:
189 s->avctx->sample_fmt = AV_SAMPLE_FMT_U8P;
190 mean = 0x80;
191 break;
192 case TYPE_S16HL:
193 case TYPE_S16LH:
194 s->avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
195 break;
196 default:
197 av_log(s->avctx, AV_LOG_ERROR, "unknown audio type\n");
198 return AVERROR_PATCHWELCOME;
199 }
200
201 for (chan = 0; chan < s->channels; chan++)
202 for (i = 0; i < nblock; i++)
203 s->offset[chan][i] = mean;
204 return 0;
205}
206
207static int decode_aiff_header(AVCodecContext *avctx, const uint8_t *header,
208 int header_size)
209{
210 ShortenContext *s = avctx->priv_data;
211 int len, bps, exp;
212 GetByteContext gb;
213 uint64_t val;
214 uint32_t tag;
215
216 bytestream2_init(&gb, header, header_size);
217
218 if (bytestream2_get_le32(&gb) != MKTAG('F', 'O', 'R', 'M')) {
219 av_log(avctx, AV_LOG_ERROR, "missing FORM tag\n");
220 return AVERROR_INVALIDDATA;
221 }
222
223 bytestream2_skip(&gb, 4); /* chunk size */
224
225 tag = bytestream2_get_le32(&gb);
226 if (tag != MKTAG('A', 'I', 'F', 'F') &&
227 tag != MKTAG('A', 'I', 'F', 'C')) {
228 av_log(avctx, AV_LOG_ERROR, "missing AIFF tag\n");
229 return AVERROR_INVALIDDATA;
230 }
231
232 while (bytestream2_get_le32(&gb) != MKTAG('C', 'O', 'M', 'M')) {
233 len = bytestream2_get_be32(&gb);
234 bytestream2_skip(&gb, len + (len & 1));
235 if (len < 0 || bytestream2_get_bytes_left(&gb) < 18) {
236 av_log(avctx, AV_LOG_ERROR, "no COMM chunk found\n");
237 return AVERROR_INVALIDDATA;
238 }
239 }
240 len = bytestream2_get_be32(&gb);
241
242 if (len < 18) {
243 av_log(avctx, AV_LOG_ERROR, "COMM chunk was too short\n");
244 return AVERROR_INVALIDDATA;
245 }
246
247 bytestream2_skip(&gb, 6);
248 bps = bytestream2_get_be16(&gb);
249 avctx->bits_per_coded_sample = bps;
250
251 s->swap = tag == MKTAG('A', 'I', 'F', 'C');
252
253 if (bps != 16 && bps != 8) {
254 av_log(avctx, AV_LOG_ERROR, "unsupported number of bits per sample: %d\n", bps);
255 return AVERROR(ENOSYS);
256 }
257
258 exp = bytestream2_get_be16(&gb) - 16383 - 63;
259 val = bytestream2_get_be64(&gb);
260 if (exp < -63 || exp > 63) {
261 av_log(avctx, AV_LOG_ERROR, "exp %d is out of range\n", exp);
262 return AVERROR_INVALIDDATA;
263 }
264 if (exp >= 0)
265 avctx->sample_rate = val << exp;
266 else
267 avctx->sample_rate = (val + (1ULL<<(-exp-1))) >> -exp;
268 len -= 18;
269 if (len > 0)
270 av_log(avctx, AV_LOG_INFO, "%d header bytes unparsed\n", len);
271
272 return 0;
273}
274
275static int decode_wave_header(AVCodecContext *avctx, const uint8_t *header,
276 int header_size)
277{
278 int len, bps;
279 short wave_format;
280 GetByteContext gb;
281
282 bytestream2_init(&gb, header, header_size);
283
284 if (bytestream2_get_le32(&gb) != MKTAG('R', 'I', 'F', 'F')) {
285 av_log(avctx, AV_LOG_ERROR, "missing RIFF tag\n");
286 return AVERROR_INVALIDDATA;
287 }
288
289 bytestream2_skip(&gb, 4); /* chunk size */
290
291 if (bytestream2_get_le32(&gb) != MKTAG('W', 'A', 'V', 'E')) {
292 av_log(avctx, AV_LOG_ERROR, "missing WAVE tag\n");
293 return AVERROR_INVALIDDATA;
294 }
295
296 while (bytestream2_get_le32(&gb) != MKTAG('f', 'm', 't', ' ')) {
297 len = bytestream2_get_le32(&gb);
298 bytestream2_skip(&gb, len);
299 if (len < 0 || bytestream2_get_bytes_left(&gb) < 16) {
300 av_log(avctx, AV_LOG_ERROR, "no fmt chunk found\n");
301 return AVERROR_INVALIDDATA;
302 }
303 }
304 len = bytestream2_get_le32(&gb);
305
306 if (len < 16) {
307 av_log(avctx, AV_LOG_ERROR, "fmt chunk was too short\n");
308 return AVERROR_INVALIDDATA;
309 }
310
311 wave_format = bytestream2_get_le16(&gb);
312
313 switch (wave_format) {
314 case WAVE_FORMAT_PCM:
315 break;
316 default:
317 av_log(avctx, AV_LOG_ERROR, "unsupported wave format\n");
318 return AVERROR(ENOSYS);
319 }
320
321 bytestream2_skip(&gb, 2); // skip channels (already got from shorten header)
322 avctx->sample_rate = bytestream2_get_le32(&gb);
323 bytestream2_skip(&gb, 4); // skip bit rate (represents original uncompressed bit rate)
324 bytestream2_skip(&gb, 2); // skip block align (not needed)
325 bps = bytestream2_get_le16(&gb);
326 avctx->bits_per_coded_sample = bps;
327
328 if (bps != 16 && bps != 8) {
329 av_log(avctx, AV_LOG_ERROR, "unsupported number of bits per sample: %d\n", bps);
330 return AVERROR(ENOSYS);
331 }
332
333 len -= 16;
334 if (len > 0)
335 av_log(avctx, AV_LOG_INFO, "%d header bytes unparsed\n", len);
336
337 return 0;
338}
339
340static const int fixed_coeffs[][3] = {
341 { 0, 0, 0 },
342 { 1, 0, 0 },
343 { 2, -1, 0 },
344 { 3, -3, 1 }
345};
346
347static int decode_subframe_lpc(ShortenContext *s, int command, int channel,
348 int residual_size, int32_t coffset)
349{
350 int pred_order, sum, qshift, init_sum, i, j;
351 const int *coeffs;
352
353 if (command == FN_QLPC) {
354 /* read/validate prediction order */
355 pred_order = get_ur_golomb_shorten(&s->gb, LPCQSIZE);
356 if ((unsigned)pred_order > s->nwrap) {
357 av_log(s->avctx, AV_LOG_ERROR, "invalid pred_order %d\n",
358 pred_order);
359 return AVERROR(EINVAL);
360 }
361 /* read LPC coefficients */
362 for (i = 0; i < pred_order; i++)
363 s->coeffs[i] = get_sr_golomb_shorten(&s->gb, LPCQUANT);
364 coeffs = s->coeffs;
365
366 qshift = LPCQUANT;
367 } else {
368 /* fixed LPC coeffs */
369 pred_order = command;
370 if (pred_order >= FF_ARRAY_ELEMS(fixed_coeffs)) {
371 av_log(s->avctx, AV_LOG_ERROR, "invalid pred_order %d\n",
372 pred_order);
373 return AVERROR_INVALIDDATA;
374 }
375 coeffs = fixed_coeffs[pred_order];
376 qshift = 0;
377 }
378
379 /* subtract offset from previous samples to use in prediction */
380 if (command == FN_QLPC && coffset)
381 for (i = -pred_order; i < 0; i++)
382 s->decoded[channel][i] -= coffset;
383
384 /* decode residual and do LPC prediction */
385 init_sum = pred_order ? (command == FN_QLPC ? s->lpcqoffset : 0) : coffset;
386 for (i = 0; i < s->blocksize; i++) {
387 sum = init_sum;
388 for (j = 0; j < pred_order; j++)
389 sum += coeffs[j] * s->decoded[channel][i - j - 1];
390 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) +
391 (sum >> qshift);
392 }
393
394 /* add offset to current samples */
395 if (command == FN_QLPC && coffset)
396 for (i = 0; i < s->blocksize; i++)
397 s->decoded[channel][i] += coffset;
398
399 return 0;
400}
401
402static int read_header(ShortenContext *s)
403{
404 int i, ret;
405 int maxnlpc = 0;
406 /* shorten signature */
407 if (get_bits_long(&s->gb, 32) != AV_RB32("ajkg")) {
408 av_log(s->avctx, AV_LOG_ERROR, "missing shorten magic 'ajkg'\n");
409 return AVERROR_INVALIDDATA;
410 }
411
412 s->lpcqoffset = 0;
413 s->blocksize = DEFAULT_BLOCK_SIZE;
414 s->nmean = -1;
415 s->version = get_bits(&s->gb, 8);
416 s->internal_ftype = get_uint(s, TYPESIZE);
417
418 s->channels = get_uint(s, CHANSIZE);
419 if (!s->channels) {
420 av_log(s->avctx, AV_LOG_ERROR, "No channels reported\n");
421 return AVERROR_INVALIDDATA;
422 }
423 if (s->channels > MAX_CHANNELS) {
424 av_log(s->avctx, AV_LOG_ERROR, "too many channels: %d\n", s->channels);
425 s->channels = 0;
426 return AVERROR_INVALIDDATA;
427 }
428 s->avctx->channels = s->channels;
429
430 /* get blocksize if version > 0 */
431 if (s->version > 0) {
432 int skip_bytes;
433 unsigned blocksize;
434
435 blocksize = get_uint(s, av_log2(DEFAULT_BLOCK_SIZE));
436 if (!blocksize || blocksize > MAX_BLOCKSIZE) {
437 av_log(s->avctx, AV_LOG_ERROR,
438 "invalid or unsupported block size: %d\n",
439 blocksize);
440 return AVERROR(EINVAL);
441 }
442 s->blocksize = blocksize;
443
444 maxnlpc = get_uint(s, LPCQSIZE);
445 s->nmean = get_uint(s, 0);
446
447 skip_bytes = get_uint(s, NSKIPSIZE);
448 if ((unsigned)skip_bytes > get_bits_left(&s->gb)/8) {
449 av_log(s->avctx, AV_LOG_ERROR, "invalid skip_bytes: %d\n", skip_bytes);
450 return AVERROR_INVALIDDATA;
451 }
452
453 for (i = 0; i < skip_bytes; i++)
454 skip_bits(&s->gb, 8);
455 }
456 s->nwrap = FFMAX(NWRAP, maxnlpc);
457
458 if ((ret = allocate_buffers(s)) < 0)
459 return ret;
460
461 if ((ret = init_offset(s)) < 0)
462 return ret;
463
464 if (s->version > 1)
465 s->lpcqoffset = V2LPCQOFFSET;
466
467 if (s->avctx->extradata_size > 0)
468 goto end;
469
470 if (get_ur_golomb_shorten(&s->gb, FNSIZE) != FN_VERBATIM) {
471 av_log(s->avctx, AV_LOG_ERROR,
472 "missing verbatim section at beginning of stream\n");
473 return AVERROR_INVALIDDATA;
474 }
475
476 s->header_size = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
477 if (s->header_size >= OUT_BUFFER_SIZE ||
478 s->header_size < CANONICAL_HEADER_SIZE) {
479 av_log(s->avctx, AV_LOG_ERROR, "header is wrong size: %d\n",
480 s->header_size);
481 return AVERROR_INVALIDDATA;
482 }
483
484 for (i = 0; i < s->header_size; i++)
485 s->header[i] = (char)get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
486
487 if (AV_RL32(s->header) == MKTAG('R','I','F','F')) {
488 if ((ret = decode_wave_header(s->avctx, s->header, s->header_size)) < 0)
489 return ret;
490 } else if (AV_RL32(s->header) == MKTAG('F','O','R','M')) {
491 if ((ret = decode_aiff_header(s->avctx, s->header, s->header_size)) < 0)
492 return ret;
493 } else {
494 avpriv_report_missing_feature(s->avctx, "unsupported bit packing %"
495 PRIX32, AV_RL32(s->header));
496 return AVERROR_PATCHWELCOME;
497 }
498
499end:
500 s->cur_chan = 0;
501 s->bitshift = 0;
502
503 s->got_header = 1;
504
505 return 0;
506}
507
508static int shorten_decode_frame(AVCodecContext *avctx, void *data,
509 int *got_frame_ptr, AVPacket *avpkt)
510{
511 AVFrame *frame = data;
512 const uint8_t *buf = avpkt->data;
513 int buf_size = avpkt->size;
514 ShortenContext *s = avctx->priv_data;
515 int i, input_buf_size = 0;
516 int ret;
517
518 /* allocate internal bitstream buffer */
519 if (s->max_framesize == 0) {
520 void *tmp_ptr;
521 s->max_framesize = 8192; // should hopefully be enough for the first header
522 tmp_ptr = av_fast_realloc(s->bitstream, &s->allocated_bitstream_size,
523 s->max_framesize + AV_INPUT_BUFFER_PADDING_SIZE);
524 if (!tmp_ptr) {
525 s->max_framesize = 0;
526 av_log(avctx, AV_LOG_ERROR, "error allocating bitstream buffer\n");
527 return AVERROR(ENOMEM);
528 }
529 memset(tmp_ptr, 0, s->allocated_bitstream_size);
530 s->bitstream = tmp_ptr;
531 }
532
533 /* append current packet data to bitstream buffer */
534 buf_size = FFMIN(buf_size, s->max_framesize - s->bitstream_size);
535 input_buf_size = buf_size;
536
537 if (s->bitstream_index + s->bitstream_size + buf_size + AV_INPUT_BUFFER_PADDING_SIZE >
538 s->allocated_bitstream_size) {
539 memmove(s->bitstream, &s->bitstream[s->bitstream_index],
540 s->bitstream_size);
541 s->bitstream_index = 0;
542 }
543 if (buf)
544 memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], buf,
545 buf_size);
546 buf = &s->bitstream[s->bitstream_index];
547 buf_size += s->bitstream_size;
548 s->bitstream_size = buf_size;
549
550 /* do not decode until buffer has at least max_framesize bytes or
551 * the end of the file has been reached */
552 if (buf_size < s->max_framesize && avpkt->data) {
553 *got_frame_ptr = 0;
554 return input_buf_size;
555 }
556 /* init and position bitstream reader */
557 if ((ret = init_get_bits8(&s->gb, buf, buf_size)) < 0)
558 return ret;
559 skip_bits(&s->gb, s->bitindex);
560
561 /* process header or next subblock */
562 if (!s->got_header) {
563
564 if ((ret = read_header(s)) < 0)
565 return ret;
566
567 if (avpkt->size) {
568 int max_framesize;
569 void *tmp_ptr;
570
571 max_framesize = FFMAX(s->max_framesize, s->blocksize * s->channels * 8);
572 tmp_ptr = av_fast_realloc(s->bitstream, &s->allocated_bitstream_size,
573 max_framesize + AV_INPUT_BUFFER_PADDING_SIZE);
574 if (!tmp_ptr) {
575 av_log(avctx, AV_LOG_ERROR, "error allocating bitstream buffer\n");
576 return AVERROR(ENOMEM);
577 }
578 s->bitstream = tmp_ptr;
579 s->max_framesize = max_framesize;
580 *got_frame_ptr = 0;
581 goto finish_frame;
582 }
583 }
584
585 /* if quit command was read previously, don't decode anything */
586 if (s->got_quit_command) {
587 *got_frame_ptr = 0;
588 return avpkt->size;
589 }
590
591 s->cur_chan = 0;
592 while (s->cur_chan < s->channels) {
593 unsigned cmd;
594 int len;
595
596 if (get_bits_left(&s->gb) < 3 + FNSIZE) {
597 *got_frame_ptr = 0;
598 break;
599 }
600
601 cmd = get_ur_golomb_shorten(&s->gb, FNSIZE);
602
603 if (cmd > FN_VERBATIM) {
604 av_log(avctx, AV_LOG_ERROR, "unknown shorten function %d\n", cmd);
605 *got_frame_ptr = 0;
606 break;
607 }
608
609 if (!is_audio_command[cmd]) {
610 /* process non-audio command */
611 switch (cmd) {
612 case FN_VERBATIM:
613 len = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
614 while (len--)
615 get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
616 break;
617 case FN_BITSHIFT: {
618 unsigned bitshift = get_ur_golomb_shorten(&s->gb, BITSHIFTSIZE);
619 if (bitshift > 32) {
620 av_log(avctx, AV_LOG_ERROR, "bitshift %d is invalid\n",
621 bitshift);
622 return AVERROR_INVALIDDATA;
623 }
624 s->bitshift = bitshift;
625 break;
626 }
627 case FN_BLOCKSIZE: {
628 unsigned blocksize = get_uint(s, av_log2(s->blocksize));
629 if (blocksize > s->blocksize) {
630 avpriv_report_missing_feature(avctx,
631 "Increasing block size");
632 return AVERROR_PATCHWELCOME;
633 }
634 if (!blocksize || blocksize > MAX_BLOCKSIZE) {
635 av_log(avctx, AV_LOG_ERROR, "invalid or unsupported "
636 "block size: %d\n", blocksize);
637 return AVERROR(EINVAL);
638 }
639 s->blocksize = blocksize;
640 break;
641 }
642 case FN_QUIT:
643 s->got_quit_command = 1;
644 break;
645 }
646 if (cmd == FN_QUIT)
647 break;
648 } else {
649 /* process audio command */
650 int residual_size = 0;
651 int channel = s->cur_chan;
652 int32_t coffset;
653
654 /* get Rice code for residual decoding */
655 if (cmd != FN_ZERO) {
656 residual_size = get_ur_golomb_shorten(&s->gb, ENERGYSIZE);
657 /* This is a hack as version 0 differed in the definition
658 * of get_sr_golomb_shorten(). */
659 if (s->version == 0)
660 residual_size--;
661 }
662
663 /* calculate sample offset using means from previous blocks */
664 if (s->nmean == 0)
665 coffset = s->offset[channel][0];
666 else {
667 int32_t sum = (s->version < 2) ? 0 : s->nmean / 2;
668 for (i = 0; i < s->nmean; i++)
669 sum += s->offset[channel][i];
670 coffset = sum / s->nmean;
671 if (s->version >= 2)
672 coffset = s->bitshift == 0 ? coffset : coffset >> s->bitshift - 1 >> 1;
673 }
674
675 /* decode samples for this channel */
676 if (cmd == FN_ZERO) {
677 for (i = 0; i < s->blocksize; i++)
678 s->decoded[channel][i] = 0;
679 } else {
680 if ((ret = decode_subframe_lpc(s, cmd, channel,
681 residual_size, coffset)) < 0)
682 return ret;
683 }
684
685 /* update means with info from the current block */
686 if (s->nmean > 0) {
687 int32_t sum = (s->version < 2) ? 0 : s->blocksize / 2;
688 for (i = 0; i < s->blocksize; i++)
689 sum += s->decoded[channel][i];
690
691 for (i = 1; i < s->nmean; i++)
692 s->offset[channel][i - 1] = s->offset[channel][i];
693
694 if (s->version < 2)
695 s->offset[channel][s->nmean - 1] = sum / s->blocksize;
696 else
697 s->offset[channel][s->nmean - 1] = s->bitshift == 32 ? 0 : (sum / s->blocksize) << s->bitshift;
698 }
699
700 /* copy wrap samples for use with next block */
701 for (i = -s->nwrap; i < 0; i++)
702 s->decoded[channel][i] = s->decoded[channel][i + s->blocksize];
703
704 /* shift samples to add in unused zero bits which were removed
705 * during encoding */
706 fix_bitshift(s, s->decoded[channel]);
707
708 /* if this is the last channel in the block, output the samples */
709 s->cur_chan++;
710 if (s->cur_chan == s->channels) {
711 uint8_t *samples_u8;
712 int16_t *samples_s16;
713 int chan;
714
715 /* get output buffer */
716 frame->nb_samples = s->blocksize;
717 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
718 return ret;
719
720 for (chan = 0; chan < s->channels; chan++) {
721 samples_u8 = ((uint8_t **)frame->extended_data)[chan];
722 samples_s16 = ((int16_t **)frame->extended_data)[chan];
723 for (i = 0; i < s->blocksize; i++) {
724 switch (s->internal_ftype) {
725 case TYPE_U8:
726 *samples_u8++ = av_clip_uint8(s->decoded[chan][i]);
727 break;
728 case TYPE_S16HL:
729 case TYPE_S16LH:
730 *samples_s16++ = av_clip_int16(s->decoded[chan][i]);
731 break;
732 }
733 }
734 if (s->swap && s->internal_ftype != TYPE_U8)
735 s->bdsp.bswap16_buf(((uint16_t **)frame->extended_data)[chan],
736 ((uint16_t **)frame->extended_data)[chan],
737 s->blocksize);
738
739 }
740
741 *got_frame_ptr = 1;
742 }
743 }
744 }
745 if (s->cur_chan < s->channels)
746 *got_frame_ptr = 0;
747
748finish_frame:
749 s->bitindex = get_bits_count(&s->gb) - 8 * (get_bits_count(&s->gb) / 8);
750 i = get_bits_count(&s->gb) / 8;
751 if (i > buf_size) {
752 av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", i - buf_size);
753 s->bitstream_size = 0;
754 s->bitstream_index = 0;
755 return AVERROR_INVALIDDATA;
756 }
757 if (s->bitstream_size) {
758 s->bitstream_index += i;
759 s->bitstream_size -= i;
760 return input_buf_size;
761 } else
762 return i;
763}
764
765static av_cold int shorten_decode_close(AVCodecContext *avctx)
766{
767 ShortenContext *s = avctx->priv_data;
768 int i;
769
770 for (i = 0; i < s->channels; i++) {
771 s->decoded[i] = NULL;
772 av_freep(&s->decoded_base[i]);
773 av_freep(&s->offset[i]);
774 }
775 av_freep(&s->bitstream);
776 av_freep(&s->coeffs);
777
778 return 0;
779}
780
781AVCodec ff_shorten_decoder = {
782 .name = "shorten",
783 .long_name = NULL_IF_CONFIG_SMALL("Shorten"),
784 .type = AVMEDIA_TYPE_AUDIO,
785 .id = AV_CODEC_ID_SHORTEN,
786 .priv_data_size = sizeof(ShortenContext),
787 .init = shorten_decode_init,
788 .close = shorten_decode_close,
789 .decode = shorten_decode_frame,
790 .capabilities = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DELAY | AV_CODEC_CAP_DR1,
791 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
792 AV_SAMPLE_FMT_U8P,
793 AV_SAMPLE_FMT_NONE },
794};
795
generated by cgit at 2024-05-17 04:13:42 (GMT)