source: trunk/libavcodec/shorten.c@ 269

Last change on this file since 269 was 269, checked in by vladest, 18 years ago

Fixed a couple of traps
Updated libavcodec/libavformat
File size: 16.9 KB
Line 
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 shorten.c
24 * Shorten decoder
25 * @author Jeff Muizelaar
26 *
27 */
28
29#define DEBUG
30#include <limits.h>
31#include "avcodec.h"
32#include "bitstream.h"
33#include "golomb.h"
34
35#define MAX_CHANNELS 8
36#define MAX_BLOCKSIZE 65535
37
38#define OUT_BUFFER_SIZE 16384
39
40#define ULONGSIZE 2
41
42#define WAVE_FORMAT_PCM 0x0001
43
44#define DEFAULT_BLOCK_SIZE 256
45
46#define TYPESIZE 4
47#define CHANSIZE 0
48#define LPCQSIZE 2
49#define ENERGYSIZE 3
50#define BITSHIFTSIZE 2
51
52#define TYPE_S16HL 3
53#define TYPE_S16LH 5
54
55#define NWRAP 3
56#define NSKIPSIZE 1
57
58#define LPCQUANT 5
59#define V2LPCQOFFSET (1 << LPCQUANT)
60
61#define FNSIZE 2
62#define FN_DIFF0 0
63#define FN_DIFF1 1
64#define FN_DIFF2 2
65#define FN_DIFF3 3
66#define FN_QUIT 4
67#define FN_BLOCKSIZE 5
68#define FN_BITSHIFT 6
69#define FN_QLPC 7
70#define FN_ZERO 8
71#define FN_VERBATIM 9
72
73#define VERBATIM_CKSIZE_SIZE 5
74#define VERBATIM_BYTE_SIZE 8
75#define CANONICAL_HEADER_SIZE 44
76
77typedef struct ShortenContext {
78 AVCodecContext *avctx;
79 GetBitContext gb;
80
81 int min_framesize, max_framesize;
82 int channels;
83
84 int32_t *decoded[MAX_CHANNELS];
85 int32_t *offset[MAX_CHANNELS];
86 uint8_t *bitstream;
87 int bitstream_size;
88 int bitstream_index;
89 unsigned int allocated_bitstream_size;
90 int header_size;
91 uint8_t header[OUT_BUFFER_SIZE];
92 int version;
93 int cur_chan;
94 int bitshift;
95 int nmean;
96 int internal_ftype;
97 int nwrap;
98 int blocksize;
99 int bitindex;
100 int32_t lpcqoffset;
101} ShortenContext;
102
103static int shorten_decode_init(AVCodecContext * avctx)
104{
105 ShortenContext *s = avctx->priv_data;
106 s->avctx = avctx;
107
108 return 0;
109}
110
111static int allocate_buffers(ShortenContext *s)
112{
113 int i, chan;
114 for (chan=0; chan<s->channels; chan++) {
115 if(FFMAX(1, s->nmean) >= UINT_MAX/sizeof(int32_t)){
116 av_log(s->avctx, AV_LOG_ERROR, "nmean too large\n");
117 return -1;
118 }
119 if(s->blocksize + s->nwrap >= UINT_MAX/sizeof(int32_t) || s->blocksize + s->nwrap <= (unsigned)s->nwrap){
120 av_log(s->avctx, AV_LOG_ERROR, "s->blocksize + s->nwrap too large\n");
121 return -1;
122 }
123
124 s->offset[chan] = av_realloc(s->offset[chan], sizeof(int32_t)*FFMAX(1, s->nmean));
125
126 s->decoded[chan] = av_realloc(s->decoded[chan], sizeof(int32_t)*(s->blocksize + s->nwrap));
127 for (i=0; i<s->nwrap; i++)
128 s->decoded[chan][i] = 0;
129 s->decoded[chan] += s->nwrap;
130 }
131 return 0;
132}
133
134
135static inline unsigned int get_uint(ShortenContext *s, int k)
136{
137 if (s->version != 0)
138 k = get_ur_golomb_shorten(&s->gb, ULONGSIZE);
139 return get_ur_golomb_shorten(&s->gb, k);
140}
141
142
143static void fix_bitshift(ShortenContext *s, int32_t *buffer)
144{
145 int i;
146
147 if (s->bitshift != 0)
148 for (i = 0; i < s->blocksize; i++)
149 buffer[s->nwrap + i] <<= s->bitshift;
150}
151
152
153static void init_offset(ShortenContext *s)
154{
155 int32_t mean = 0;
156 int chan, i;
157 int nblock = FFMAX(1, s->nmean);
158 /* initialise offset */
159 switch (s->internal_ftype)
160 {
161 case TYPE_S16HL:
162 case TYPE_S16LH:
163 mean = 0;
164 break;
165 default:
166 av_log(s->avctx, AV_LOG_ERROR, "unknown audio type");
167 abort();
168 }
169
170 for (chan = 0; chan < s->channels; chan++)
171 for (i = 0; i < nblock; i++)
172 s->offset[chan][i] = mean;
173}
174
175static int inline get_le32(GetBitContext *gb)
176{
177 return bswap_32(get_bits_long(gb, 32));
178}
179
180static short inline get_le16(GetBitContext *gb)
181{
182 return bswap_16(get_bits_long(gb, 16));
183}
184
185static int decode_wave_header(AVCodecContext *avctx, uint8_t *header, int header_size)
186{
187 GetBitContext hb;
188 int len;
189 int chunk_size;
190 short wave_format;
191
192 init_get_bits(&hb, header, header_size*8);
193 if (get_le32(&hb) != MKTAG('R','I','F','F')) {
194 av_log(avctx, AV_LOG_ERROR, "missing RIFF tag\n");
195 return -1;
196 }
197
198 chunk_size = get_le32(&hb);
199
200 if (get_le32(&hb) != MKTAG('W','A','V','E')) {
201 av_log(avctx, AV_LOG_ERROR, "missing WAVE tag\n");
202 return -1;
203 }
204
205 while (get_le32(&hb) != MKTAG('f','m','t',' ')) {
206 len = get_le32(&hb);
207 skip_bits(&hb, 8*len);
208 }
209 len = get_le32(&hb);
210
211 if (len < 16) {
212 av_log(avctx, AV_LOG_ERROR, "fmt chunk was too short\n");
213 return -1;
214 }
215
216 wave_format = get_le16(&hb);
217
218 switch (wave_format) {
219 case WAVE_FORMAT_PCM:
220 break;
221 default:
222 av_log(avctx, AV_LOG_ERROR, "unsupported wave format\n");
223 return -1;
224 }
225
226 avctx->channels = get_le16(&hb);
227 avctx->sample_rate = get_le32(&hb);
228 avctx->bit_rate = get_le32(&hb) * 8;
229 avctx->block_align = get_le16(&hb);
230 avctx->bits_per_sample = get_le16(&hb);
231
232 if (avctx->bits_per_sample != 16) {
233 av_log(avctx, AV_LOG_ERROR, "unsupported number of bits per sample\n");
234 return -1;
235 }
236
237 len -= 16;
238 if (len > 0)
239 av_log(avctx, AV_LOG_INFO, "%d header bytes unparsed\n", len);
240
241 return 0;
242}
243
244static int16_t * interleave_buffer(int16_t *samples, int nchan, int blocksize, int32_t **buffer) {
245 int i, chan;
246 for (i=0; i<blocksize; i++)
247 for (chan=0; chan < nchan; chan++)
248 *samples++ = FFMIN(buffer[chan][i], 32768);
249 return samples;
250}
251
252static void decode_subframe_lpc(ShortenContext *s, int channel, int residual_size, int pred_order)
253{
254 int sum, i, j;
255 int coeffs[pred_order];
256
257 for (i=0; i<pred_order; i++)
258 coeffs[i] = get_sr_golomb_shorten(&s->gb, LPCQUANT);
259
260 for (i=0; i < s->blocksize; i++) {
261 sum = s->lpcqoffset;
262 for (j=0; j<pred_order; j++)
263 sum += coeffs[j] * s->decoded[channel][i-j-1];
264 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + (sum >> LPCQUANT);
265 }
266}
267
268
269static int shorten_decode_frame(AVCodecContext *avctx,
270 void *data, int *data_size,
271 uint8_t *buf, int buf_size)
272{
273 ShortenContext *s = avctx->priv_data;
274 int i, input_buf_size = 0;
275 int16_t *samples = data;
276 if(s->max_framesize == 0){
277 s->max_framesize= 1024; // should hopefully be enough for the first header
278 s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
279 }
280
281 if(1 && s->max_framesize){//FIXME truncated
282 buf_size= FFMIN(buf_size, s->max_framesize - s->bitstream_size);
283 input_buf_size= buf_size;
284
285 if(s->bitstream_index + s->bitstream_size + buf_size > s->allocated_bitstream_size){
286 // printf("memmove\n");
287 memmove(s->bitstream, &s->bitstream[s->bitstream_index], s->bitstream_size);
288 s->bitstream_index=0;
289 }
290 memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], buf, buf_size);
291 buf= &s->bitstream[s->bitstream_index];
292 buf_size += s->bitstream_size;
293 s->bitstream_size= buf_size;
294
295 if(buf_size < s->max_framesize){
296 //dprintf("wanna more data ... %d\n", buf_size);
297 return input_buf_size;
298 }
299 }
300 init_get_bits(&s->gb, buf, buf_size*8);
301 get_bits(&s->gb, s->bitindex);
302 if (!s->blocksize)
303 {
304 int maxnlpc = 0;
305 /* shorten signature */
306 if (get_bits_long(&s->gb, 32) != bswap_32(ff_get_fourcc("ajkg"))) {
307 av_log(s->avctx, AV_LOG_ERROR, "missing shorten magic 'ajkg'\n");
308 return -1;
309 }
310
311 s->lpcqoffset = 0;
312 s->blocksize = DEFAULT_BLOCK_SIZE;
313 s->channels = 1;
314 s->nmean = -1;
315 s->version = get_bits(&s->gb, 8);
316 s->internal_ftype = get_uint(s, TYPESIZE);
317
318 s->channels = get_uint(s, CHANSIZE);
319 if (s->channels > MAX_CHANNELS) {
320 av_log(s->avctx, AV_LOG_ERROR, "too many channels: %d\n", s->channels);
321 return -1;
322 }
323
324 /* get blocksize if version > 0 */
325 if (s->version > 0) {
326 int skip_bytes;
327 s->blocksize = get_uint(s, av_log2(DEFAULT_BLOCK_SIZE));
328 maxnlpc = get_uint(s, LPCQSIZE);
329 s->nmean = get_uint(s, 0);
330
331 skip_bytes = get_uint(s, NSKIPSIZE);
332 for (i=0; i<skip_bytes; i++) {
333 skip_bits(&s->gb, 8);
334 }
335 }
336 s->nwrap = FFMAX(NWRAP, maxnlpc);
337
338 if (allocate_buffers(s))
339 return -1;
340
341 init_offset(s);
342
343 if (s->version > 1)
344 s->lpcqoffset = V2LPCQOFFSET;
345
346 if (get_ur_golomb_shorten(&s->gb, FNSIZE) != FN_VERBATIM) {
347 av_log(s->avctx, AV_LOG_ERROR, "missing verbatim section at begining of stream\n");
348 return -1;
349 }
350
351 s->header_size = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
352 if (s->header_size >= OUT_BUFFER_SIZE || s->header_size < CANONICAL_HEADER_SIZE) {
353 av_log(s->avctx, AV_LOG_ERROR, "header is wrong size: %d\n", s->header_size);
354 return -1;
355 }
356
357 for (i=0; i<s->header_size; i++)
358 s->header[i] = (char)get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
359
360 if (decode_wave_header(avctx, s->header, s->header_size) < 0)
361 return -1;
362
363 s->cur_chan = 0;
364 s->bitshift = 0;
365 }
366 else
367 {
368 int cmd;
369 int len;
370 cmd = get_ur_golomb_shorten(&s->gb, FNSIZE);
371 switch (cmd) {
372 case FN_ZERO:
373 case FN_DIFF0:
374 case FN_DIFF1:
375 case FN_DIFF2:
376 case FN_DIFF3:
377 case FN_QLPC:
378 {
379 int residual_size = 0;
380 int channel = s->cur_chan;
381 int32_t coffset;
382 if (cmd != FN_ZERO) {
383 residual_size = get_ur_golomb_shorten(&s->gb, ENERGYSIZE);
384 /* this is a hack as version 0 differed in defintion of get_sr_golomb_shorten */
385 if (s->version == 0)
386 residual_size--;
387 }
388
389 if (s->nmean == 0)
390 coffset = s->offset[channel][0];
391 else {
392 int32_t sum = (s->version < 2) ? 0 : s->nmean / 2;
393 for (i=0; i<s->nmean; i++)
394 sum += s->offset[channel][i];
395 coffset = sum / s->nmean;
396 if (s->version >= 2)
397 coffset >>= FFMIN(1, s->bitshift);
398 }
399 switch (cmd) {
400 case FN_ZERO:
401 for (i=0; i<s->blocksize; i++)
402 s->decoded[channel][i] = 0;
403 break;
404 case FN_DIFF0:
405 for (i=0; i<s->blocksize; i++)
406 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + coffset;
407 break;
408 case FN_DIFF1:
409 for (i=0; i<s->blocksize; i++)
410 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + s->decoded[channel][i - 1];
411 break;
412 case FN_DIFF2:
413 for (i=0; i<s->blocksize; i++)
414 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + 2*s->decoded[channel][i-1]
415 - s->decoded[channel][i-2];
416 break;
417 case FN_DIFF3:
418 for (i=0; i<s->blocksize; i++)
419 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + 3*s->decoded[channel][i-1]
420 - 3*s->decoded[channel][i-2]
421 + s->decoded[channel][i-3];
422 break;
423 case FN_QLPC:
424 {
425 int pred_order = get_ur_golomb_shorten(&s->gb, LPCQSIZE);
426 for (i=0; i<pred_order; i++)
427 s->decoded[channel][i - pred_order] -= coffset;
428 decode_subframe_lpc(s, channel, residual_size, pred_order);
429 if (coffset != 0)
430 for (i=0; i < s->blocksize; i++)
431 s->decoded[channel][i] += coffset;
432 }
433 }
434 if (s->nmean > 0) {
435 int32_t sum = (s->version < 2) ? 0 : s->blocksize / 2;
436 for (i=0; i<s->blocksize; i++)
437 sum += s->decoded[channel][i];
438
439 for (i=1; i<s->nmean; i++)
440 s->offset[channel][i-1] = s->offset[channel][i];
441
442 if (s->version < 2)
443 s->offset[channel][s->nmean - 1] = sum / s->blocksize;
444 else
445 s->offset[channel][s->nmean - 1] = (sum / s->blocksize) << s->bitshift;
446 }
447 for (i=-s->nwrap; i<0; i++)
448 s->decoded[channel][i] = s->decoded[channel][i + s->blocksize];
449
450 fix_bitshift(s, s->decoded[channel]);
451
452 s->cur_chan++;
453 if (s->cur_chan == s->channels) {
454 samples = interleave_buffer(samples, s->channels, s->blocksize, s->decoded);
455 s->cur_chan = 0;
456 goto frame_done;
457 }
458 break;
459 }
460 break;
461 case FN_VERBATIM:
462 len = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
463 while (len--) {
464 get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
465 }
466 break;
467 case FN_BITSHIFT:
468 s->bitshift = get_ur_golomb_shorten(&s->gb, BITSHIFTSIZE);
469 break;
470 case FN_BLOCKSIZE:
471 s->blocksize = get_uint(s, av_log2(s->blocksize));
472 break;
473 case FN_QUIT:
474 return buf_size;
475 break;
476 default:
477 av_log(avctx, AV_LOG_ERROR, "unknown shorten function %d\n", cmd);
478 return -1;
479 break;
480 }
481 }
482frame_done:
483 *data_size = (int8_t *)samples - (int8_t *)data;
484
485 // s->last_blocksize = s->blocksize;
486 s->bitindex = get_bits_count(&s->gb) - 8*((get_bits_count(&s->gb))/8);
487 i= (get_bits_count(&s->gb))/8;
488 if (i > buf_size) {
489 av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", i - buf_size);
490 s->bitstream_size=0;
491 s->bitstream_index=0;
492 return -1;
493 }
494 if (s->bitstream_size) {
495 s->bitstream_index += i;
496 s->bitstream_size -= i;
497 return input_buf_size;
498 } else
499 return i;
500}
501
502static int shorten_decode_close(AVCodecContext *avctx)
503{
504 ShortenContext *s = avctx->priv_data;
505 int i;
506
507 for (i = 0; i < s->channels; i++) {
508 s->decoded[i] -= s->nwrap;
509 av_freep(&s->decoded[i]);
510 av_freep(&s->offset[i]);
511 }
512 av_freep(&s->bitstream);
513 return 0;
514}
515
516static void shorten_flush(AVCodecContext *avctx){
517 ShortenContext *s = avctx->priv_data;
518
519 s->bitstream_size=
520 s->bitstream_index= 0;
521}
522
523AVCodec shorten_decoder = {
524 "shorten",
525 CODEC_TYPE_AUDIO,
526 CODEC_ID_SHORTEN,
527 sizeof(ShortenContext),
528 shorten_decode_init,
529 NULL,
530 shorten_decode_close,
531 shorten_decode_frame,
532 .flush= shorten_flush,
533};
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