FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
smacker.c
Go to the documentation of this file.
1 /*
2  * Smacker decoder
3  * Copyright (c) 2006 Konstantin Shishkov
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  * Smacker decoder
25  */
26 
27 /*
28  * Based on http://wiki.multimedia.cx/index.php?title=Smacker
29  */
30 
31 #include <stdio.h>
32 #include <stdlib.h>
33 
34 #include "libavutil/channel_layout.h"
35 #include "avcodec.h"
36 #include "internal.h"
37 #include "mathops.h"
38 
39 #define BITSTREAM_READER_LE
40 #include "get_bits.h"
41 #include "bytestream.h"
42 
43 #define SMKTREE_BITS 9
44 #define SMK_NODE 0x80000000
45 
46 /*
47  * Decoder context
48  */
49 typedef struct SmackVContext {
50  AVCodecContext *avctx;
51  AVFrame *pic;
52 
53  int *mmap_tbl, *mclr_tbl, *full_tbl, *type_tbl;
54  int mmap_last[3], mclr_last[3], full_last[3], type_last[3];
55 } SmackVContext;
56 
57 /**
58  * Context used for code reconstructing
59  */
60 typedef struct HuffContext {
61  int length;
62  int maxlength;
63  int current;
64  uint32_t *bits;
65  int *lengths;
66  int *values;
67 } HuffContext;
68 
69 /* common parameters used for decode_bigtree */
70 typedef struct DBCtx {
71  VLC *v1, *v2;
72  int *recode1, *recode2;
73  int escapes[3];
74  int *last;
75  int lcur;
76 } DBCtx;
77 
78 /* possible runs of blocks */
79 static const int block_runs[64] = {
80  1, 2, 3, 4, 5, 6, 7, 8,
81  9, 10, 11, 12, 13, 14, 15, 16,
82  17, 18, 19, 20, 21, 22, 23, 24,
83  25, 26, 27, 28, 29, 30, 31, 32,
84  33, 34, 35, 36, 37, 38, 39, 40,
85  41, 42, 43, 44, 45, 46, 47, 48,
86  49, 50, 51, 52, 53, 54, 55, 56,
87  57, 58, 59, 128, 256, 512, 1024, 2048 };
88 
89 enum SmkBlockTypes {
90  SMK_BLK_MONO = 0,
91  SMK_BLK_FULL = 1,
92  SMK_BLK_SKIP = 2,
93  SMK_BLK_FILL = 3 };
94 
95 /**
96  * Decode local frame tree
97  */
98 static int smacker_decode_tree(GetBitContext *gb, HuffContext *hc, uint32_t prefix, int length)
99 {
100  if(length > 32 || length > 3*SMKTREE_BITS) {
101  av_log(NULL, AV_LOG_ERROR, "length too long\n");
102  return AVERROR_INVALIDDATA;
103  }
104  if(!get_bits1(gb)){ //Leaf
105  if(hc->current >= hc->length){
106  av_log(NULL, AV_LOG_ERROR, "Tree size exceeded!\n");
107  return AVERROR_INVALIDDATA;
108  }
109  if(length){
110  hc->bits[hc->current] = prefix;
111  hc->lengths[hc->current] = length;
112  } else {
113  hc->bits[hc->current] = 0;
114  hc->lengths[hc->current] = 0;
115  }
116  hc->values[hc->current] = get_bits(gb, 8);
117  hc->current++;
118  if(hc->maxlength < length)
119  hc->maxlength = length;
120  return 0;
121  } else { //Node
122  int r;
123  length++;
124  r = smacker_decode_tree(gb, hc, prefix, length);
125  if(r)
126  return r;
127  return smacker_decode_tree(gb, hc, prefix | (1 << (length - 1)), length);
128  }
129 }
130 
131 /**
132  * Decode header tree
133  */
134 static int smacker_decode_bigtree(GetBitContext *gb, HuffContext *hc, DBCtx *ctx)
135 {
136  if (hc->current + 1 >= hc->length) {
137  av_log(NULL, AV_LOG_ERROR, "Tree size exceeded!\n");
138  return AVERROR_INVALIDDATA;
139  }
140  if(!get_bits1(gb)){ //Leaf
141  int val, i1, i2;
142  i1 = ctx->v1->table ? get_vlc2(gb, ctx->v1->table, SMKTREE_BITS, 3) : 0;
143  i2 = ctx->v2->table ? get_vlc2(gb, ctx->v2->table, SMKTREE_BITS, 3) : 0;
144  if (i1 < 0 || i2 < 0)
145  return AVERROR_INVALIDDATA;
146  val = ctx->recode1[i1] | (ctx->recode2[i2] << 8);
147  if(val == ctx->escapes[0]) {
148  ctx->last[0] = hc->current;
149  val = 0;
150  } else if(val == ctx->escapes[1]) {
151  ctx->last[1] = hc->current;
152  val = 0;
153  } else if(val == ctx->escapes[2]) {
154  ctx->last[2] = hc->current;
155  val = 0;
156  }
157 
158  hc->values[hc->current++] = val;
159  return 1;
160  } else { //Node
161  int r = 0, r_new, t;
162 
163  t = hc->current++;
164  r = smacker_decode_bigtree(gb, hc, ctx);
165  if(r < 0)
166  return r;
167  hc->values[t] = SMK_NODE | r;
168  r++;
169  r_new = smacker_decode_bigtree(gb, hc, ctx);
170  if (r_new < 0)
171  return r_new;
172  return r + r_new;
173  }
174 }
175 
176 /**
177  * Store large tree as FFmpeg's vlc codes
178  */
179 static int smacker_decode_header_tree(SmackVContext *smk, GetBitContext *gb, int **recodes, int *last, int size)
180 {
181  int res;
182  HuffContext huff;
183  HuffContext tmp1, tmp2;
184  VLC vlc[2] = { { 0 } };
185  int escapes[3];
186  DBCtx ctx;
187  int err = 0;
188 
189  if(size >= UINT_MAX>>4){ // (((size + 3) >> 2) + 3) << 2 must not overflow
190  av_log(smk->avctx, AV_LOG_ERROR, "size too large\n");
191  return AVERROR_INVALIDDATA;
192  }
193 
194  tmp1.length = 256;
195  tmp1.maxlength = 0;
196  tmp1.current = 0;
197  tmp1.bits = av_mallocz(256 * 4);
198  tmp1.lengths = av_mallocz(256 * sizeof(int));
199  tmp1.values = av_mallocz(256 * sizeof(int));
200 
201  tmp2.length = 256;
202  tmp2.maxlength = 0;
203  tmp2.current = 0;
204  tmp2.bits = av_mallocz(256 * 4);
205  tmp2.lengths = av_mallocz(256 * sizeof(int));
206  tmp2.values = av_mallocz(256 * sizeof(int));
207  if (!tmp1.bits || !tmp1.lengths || !tmp1.values ||
208  !tmp2.bits || !tmp2.lengths || !tmp2.values) {
209  err = AVERROR(ENOMEM);
210  goto error;
211  }
212 
213  if(get_bits1(gb)) {
214  res = smacker_decode_tree(gb, &tmp1, 0, 0);
215  if (res < 0) {
216  err = res;
217  goto error;
218  }
219  skip_bits1(gb);
220  if(tmp1.current > 1) {
221  res = init_vlc(&vlc[0], SMKTREE_BITS, tmp1.length,
222  tmp1.lengths, sizeof(int), sizeof(int),
223  tmp1.bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
224  if(res < 0) {
225  av_log(smk->avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
226  err = res;
227  goto error;
228  }
229  }
230  }
231  if (!vlc[0].table) {
232  av_log(smk->avctx, AV_LOG_ERROR, "Skipping low bytes tree\n");
233  }
234  if(get_bits1(gb)){
235  res = smacker_decode_tree(gb, &tmp2, 0, 0);
236  if (res < 0) {
237  err = res;
238  goto error;
239  }
240  skip_bits1(gb);
241  if(tmp2.current > 1) {
242  res = init_vlc(&vlc[1], SMKTREE_BITS, tmp2.length,
243  tmp2.lengths, sizeof(int), sizeof(int),
244  tmp2.bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
245  if(res < 0) {
246  av_log(smk->avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
247  err = res;
248  goto error;
249  }
250  }
251  }
252  if (!vlc[1].table) {
253  av_log(smk->avctx, AV_LOG_ERROR, "Skipping high bytes tree\n");
254  }
255 
256  escapes[0] = get_bits(gb, 16);
257  escapes[1] = get_bits(gb, 16);
258  escapes[2] = get_bits(gb, 16);
259 
260  last[0] = last[1] = last[2] = -1;
261 
262  ctx.escapes[0] = escapes[0];
263  ctx.escapes[1] = escapes[1];
264  ctx.escapes[2] = escapes[2];
265  ctx.v1 = &vlc[0];
266  ctx.v2 = &vlc[1];
267  ctx.recode1 = tmp1.values;
268  ctx.recode2 = tmp2.values;
269  ctx.last = last;
270 
271  huff.length = ((size + 3) >> 2) + 4;
272  huff.maxlength = 0;
273  huff.current = 0;
274  huff.values = av_mallocz_array(huff.length, sizeof(int));
275  if (!huff.values) {
276  err = AVERROR(ENOMEM);
277  goto error;
278  }
279 
280  if (smacker_decode_bigtree(gb, &huff, &ctx) < 0)
281  err = -1;
282  skip_bits1(gb);
283  if(ctx.last[0] == -1) ctx.last[0] = huff.current++;
284  if(ctx.last[1] == -1) ctx.last[1] = huff.current++;
285  if(ctx.last[2] == -1) ctx.last[2] = huff.current++;
286  if (ctx.last[0] >= huff.length ||
287  ctx.last[1] >= huff.length ||
288  ctx.last[2] >= huff.length) {
289  av_log(smk->avctx, AV_LOG_ERROR, "Huffman codes out of range\n");
290  err = AVERROR_INVALIDDATA;
291  }
292 
293  *recodes = huff.values;
294 
295 error:
296  if(vlc[0].table)
297  ff_free_vlc(&vlc[0]);
298  if(vlc[1].table)
299  ff_free_vlc(&vlc[1]);
300  av_free(tmp1.bits);
301  av_free(tmp1.lengths);
302  av_free(tmp1.values);
303  av_free(tmp2.bits);
304  av_free(tmp2.lengths);
305  av_free(tmp2.values);
306 
307  return err;
308 }
309 
310 static int decode_header_trees(SmackVContext *smk) {
311  GetBitContext gb;
312  int mmap_size, mclr_size, full_size, type_size, ret;
313 
314  mmap_size = AV_RL32(smk->avctx->extradata);
315  mclr_size = AV_RL32(smk->avctx->extradata + 4);
316  full_size = AV_RL32(smk->avctx->extradata + 8);
317  type_size = AV_RL32(smk->avctx->extradata + 12);
318 
319  init_get_bits8(&gb, smk->avctx->extradata + 16, smk->avctx->extradata_size - 16);
320 
321  if(!get_bits1(&gb)) {
322  av_log(smk->avctx, AV_LOG_INFO, "Skipping MMAP tree\n");
323  smk->mmap_tbl = av_malloc(sizeof(int) * 2);
324  if (!smk->mmap_tbl)
325  return AVERROR(ENOMEM);
326  smk->mmap_tbl[0] = 0;
327  smk->mmap_last[0] = smk->mmap_last[1] = smk->mmap_last[2] = 1;
328  } else {
329  ret = smacker_decode_header_tree(smk, &gb, &smk->mmap_tbl, smk->mmap_last, mmap_size);
330  if (ret < 0)
331  return ret;
332  }
333  if(!get_bits1(&gb)) {
334  av_log(smk->avctx, AV_LOG_INFO, "Skipping MCLR tree\n");
335  smk->mclr_tbl = av_malloc(sizeof(int) * 2);
336  if (!smk->mclr_tbl)
337  return AVERROR(ENOMEM);
338  smk->mclr_tbl[0] = 0;
339  smk->mclr_last[0] = smk->mclr_last[1] = smk->mclr_last[2] = 1;
340  } else {
341  ret = smacker_decode_header_tree(smk, &gb, &smk->mclr_tbl, smk->mclr_last, mclr_size);
342  if (ret < 0)
343  return ret;
344  }
345  if(!get_bits1(&gb)) {
346  av_log(smk->avctx, AV_LOG_INFO, "Skipping FULL tree\n");
347  smk->full_tbl = av_malloc(sizeof(int) * 2);
348  if (!smk->full_tbl)
349  return AVERROR(ENOMEM);
350  smk->full_tbl[0] = 0;
351  smk->full_last[0] = smk->full_last[1] = smk->full_last[2] = 1;
352  } else {
353  ret = smacker_decode_header_tree(smk, &gb, &smk->full_tbl, smk->full_last, full_size);
354  if (ret < 0)
355  return ret;
356  }
357  if(!get_bits1(&gb)) {
358  av_log(smk->avctx, AV_LOG_INFO, "Skipping TYPE tree\n");
359  smk->type_tbl = av_malloc(sizeof(int) * 2);
360  if (!smk->type_tbl)
361  return AVERROR(ENOMEM);
362  smk->type_tbl[0] = 0;
363  smk->type_last[0] = smk->type_last[1] = smk->type_last[2] = 1;
364  } else {
365  ret = smacker_decode_header_tree(smk, &gb, &smk->type_tbl, smk->type_last, type_size);
366  if (ret < 0)
367  return ret;
368  }
369 
370  return 0;
371 }
372 
373 static av_always_inline void last_reset(int *recode, int *last) {
374  recode[last[0]] = recode[last[1]] = recode[last[2]] = 0;
375 }
376 
377 /* get code and update history */
378 static av_always_inline int smk_get_code(GetBitContext *gb, int *recode, int *last) {
379  register int *table = recode;
380  int v;
381 
382  while(*table & SMK_NODE) {
383  if(get_bits1(gb))
384  table += (*table) & (~SMK_NODE);
385  table++;
386  }
387  v = *table;
388 
389  if(v != recode[last[0]]) {
390  recode[last[2]] = recode[last[1]];
391  recode[last[1]] = recode[last[0]];
392  recode[last[0]] = v;
393  }
394  return v;
395 }
396 
397 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
398  AVPacket *avpkt)
399 {
400  SmackVContext * const smk = avctx->priv_data;
401  uint8_t *out;
402  uint32_t *pal;
403  GetByteContext gb2;
404  GetBitContext gb;
405  int blocks, blk, bw, bh;
406  int i, ret;
407  int stride;
408  int flags;
409 
410  if (avpkt->size <= 769)
411  return AVERROR_INVALIDDATA;
412 
413  if ((ret = ff_reget_buffer(avctx, smk->pic)) < 0)
414  return ret;
415 
416  /* make the palette available on the way out */
417  pal = (uint32_t*)smk->pic->data[1];
418  bytestream2_init(&gb2, avpkt->data, avpkt->size);
419  flags = bytestream2_get_byteu(&gb2);
420  smk->pic->palette_has_changed = flags & 1;
421  smk->pic->key_frame = !!(flags & 2);
422  if (smk->pic->key_frame)
423  smk->pic->pict_type = AV_PICTURE_TYPE_I;
424  else
425  smk->pic->pict_type = AV_PICTURE_TYPE_P;
426 
427  for(i = 0; i < 256; i++)
428  *pal++ = 0xFFU << 24 | bytestream2_get_be24u(&gb2);
429 
430  last_reset(smk->mmap_tbl, smk->mmap_last);
431  last_reset(smk->mclr_tbl, smk->mclr_last);
432  last_reset(smk->full_tbl, smk->full_last);
433  last_reset(smk->type_tbl, smk->type_last);
434  if ((ret = init_get_bits8(&gb, avpkt->data + 769, avpkt->size - 769)) < 0)
435  return ret;
436 
437  blk = 0;
438  bw = avctx->width >> 2;
439  bh = avctx->height >> 2;
440  blocks = bw * bh;
441  stride = smk->pic->linesize[0];
442  while(blk < blocks) {
443  int type, run, mode;
444  uint16_t pix;
445 
446  type = smk_get_code(&gb, smk->type_tbl, smk->type_last);
447  run = block_runs[(type >> 2) & 0x3F];
448  switch(type & 3){
449  case SMK_BLK_MONO:
450  while(run-- && blk < blocks){
451  int clr, map;
452  int hi, lo;
453  clr = smk_get_code(&gb, smk->mclr_tbl, smk->mclr_last);
454  map = smk_get_code(&gb, smk->mmap_tbl, smk->mmap_last);
455  out = smk->pic->data[0] + (blk / bw) * (stride * 4) + (blk % bw) * 4;
456  hi = clr >> 8;
457  lo = clr & 0xFF;
458  for(i = 0; i < 4; i++) {
459  if(map & 1) out[0] = hi; else out[0] = lo;
460  if(map & 2) out[1] = hi; else out[1] = lo;
461  if(map & 4) out[2] = hi; else out[2] = lo;
462  if(map & 8) out[3] = hi; else out[3] = lo;
463  map >>= 4;
464  out += stride;
465  }
466  blk++;
467  }
468  break;
469  case SMK_BLK_FULL:
470  mode = 0;
471  if(avctx->codec_tag == MKTAG('S', 'M', 'K', '4')) { // In case of Smacker v4 we have three modes
472  if(get_bits1(&gb)) mode = 1;
473  else if(get_bits1(&gb)) mode = 2;
474  }
475  while(run-- && blk < blocks){
476  out = smk->pic->data[0] + (blk / bw) * (stride * 4) + (blk % bw) * 4;
477  switch(mode){
478  case 0:
479  for(i = 0; i < 4; i++) {
480  pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);
481  AV_WL16(out+2,pix);
482  pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);
483  AV_WL16(out,pix);
484  out += stride;
485  }
486  break;
487  case 1:
488  pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);
489  out[0] = out[1] = pix & 0xFF;
490  out[2] = out[3] = pix >> 8;
491  out += stride;
492  out[0] = out[1] = pix & 0xFF;
493  out[2] = out[3] = pix >> 8;
494  out += stride;
495  pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);
496  out[0] = out[1] = pix & 0xFF;
497  out[2] = out[3] = pix >> 8;
498  out += stride;
499  out[0] = out[1] = pix & 0xFF;
500  out[2] = out[3] = pix >> 8;
501  break;
502  case 2:
503  for(i = 0; i < 2; i++) {
504  uint16_t pix1, pix2;
505  pix2 = smk_get_code(&gb, smk->full_tbl, smk->full_last);
506  pix1 = smk_get_code(&gb, smk->full_tbl, smk->full_last);
507  AV_WL16(out,pix1);
508  AV_WL16(out+2,pix2);
509  out += stride;
510  AV_WL16(out,pix1);
511  AV_WL16(out+2,pix2);
512  out += stride;
513  }
514  break;
515  }
516  blk++;
517  }
518  break;
519  case SMK_BLK_SKIP:
520  while(run-- && blk < blocks)
521  blk++;
522  break;
523  case SMK_BLK_FILL:
524  mode = type >> 8;
525  while(run-- && blk < blocks){
526  uint32_t col;
527  out = smk->pic->data[0] + (blk / bw) * (stride * 4) + (blk % bw) * 4;
528  col = mode * 0x01010101;
529  for(i = 0; i < 4; i++) {
530  *((uint32_t*)out) = col;
531  out += stride;
532  }
533  blk++;
534  }
535  break;
536  }
537 
538  }
539 
540  if ((ret = av_frame_ref(data, smk->pic)) < 0)
541  return ret;
542 
543  *got_frame = 1;
544 
545  /* always report that the buffer was completely consumed */
546  return avpkt->size;
547 }
548 
549 
550 
551 /*
552  *
553  * Uninit smacker decoder
554  *
555  */
556 static av_cold int decode_end(AVCodecContext *avctx)
557 {
558  SmackVContext * const smk = avctx->priv_data;
559 
560  av_freep(&smk->mmap_tbl);
561  av_freep(&smk->mclr_tbl);
562  av_freep(&smk->full_tbl);
563  av_freep(&smk->type_tbl);
564 
565  av_frame_free(&smk->pic);
566 
567  return 0;
568 }
569 
570 
571 /*
572  *
573  * Init smacker decoder
574  *
575  */
576 static av_cold int decode_init(AVCodecContext *avctx)
577 {
578  SmackVContext * const c = avctx->priv_data;
579  int ret;
580 
581  c->avctx = avctx;
582 
583  avctx->pix_fmt = AV_PIX_FMT_PAL8;
584 
585  c->pic = av_frame_alloc();
586  if (!c->pic)
587  return AVERROR(ENOMEM);
588 
589  /* decode huffman trees from extradata */
590  if(avctx->extradata_size < 16){
591  av_log(avctx, AV_LOG_ERROR, "Extradata missing!\n");
592  return AVERROR(EINVAL);
593  }
594 
595  ret = decode_header_trees(c);
596  if (ret < 0) {
597  decode_end(avctx);
598  return ret;
599  }
600 
601  return 0;
602 }
603 
604 
605 static av_cold int smka_decode_init(AVCodecContext *avctx)
606 {
607  if (avctx->channels < 1 || avctx->channels > 2) {
608  av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
609  return AVERROR(EINVAL);
610  }
611  avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
612  avctx->sample_fmt = avctx->bits_per_coded_sample == 8 ? AV_SAMPLE_FMT_U8 : AV_SAMPLE_FMT_S16;
613 
614  return 0;
615 }
616 
617 /**
618  * Decode Smacker audio data
619  */
620 static int smka_decode_frame(AVCodecContext *avctx, void *data,
621  int *got_frame_ptr, AVPacket *avpkt)
622 {
623  AVFrame *frame = data;
624  const uint8_t *buf = avpkt->data;
625  int buf_size = avpkt->size;
626  GetBitContext gb;
627  HuffContext h[4] = { { 0 } };
628  VLC vlc[4] = { { 0 } };
629  int16_t *samples;
630  uint8_t *samples8;
631  int val;
632  int i, res, ret;
633  int unp_size;
634  int bits, stereo;
635  int pred[2] = {0, 0};
636 
637  if (buf_size <= 4) {
638  av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
639  return AVERROR(EINVAL);
640  }
641 
642  unp_size = AV_RL32(buf);
643 
644  if (unp_size > (1U<<24)) {
645  av_log(avctx, AV_LOG_ERROR, "packet is too big\n");
646  return AVERROR_INVALIDDATA;
647  }
648 
649  if ((ret = init_get_bits8(&gb, buf + 4, buf_size - 4)) < 0)
650  return ret;
651 
652  if(!get_bits1(&gb)){
653  av_log(avctx, AV_LOG_INFO, "Sound: no data\n");
654  *got_frame_ptr = 0;
655  return 1;
656  }
657  stereo = get_bits1(&gb);
658  bits = get_bits1(&gb);
659  if (stereo ^ (avctx->channels != 1)) {
660  av_log(avctx, AV_LOG_ERROR, "channels mismatch\n");
661  return AVERROR(EINVAL);
662  }
663  if (bits == (avctx->sample_fmt == AV_SAMPLE_FMT_U8)) {
664  av_log(avctx, AV_LOG_ERROR, "sample format mismatch\n");
665  return AVERROR(EINVAL);
666  }
667 
668  /* get output buffer */
669  frame->nb_samples = unp_size / (avctx->channels * (bits + 1));
670  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
671  return ret;
672  samples = (int16_t *)frame->data[0];
673  samples8 = frame->data[0];
674 
675  // Initialize
676  for(i = 0; i < (1 << (bits + stereo)); i++) {
677  h[i].length = 256;
678  h[i].maxlength = 0;
679  h[i].current = 0;
680  h[i].bits = av_mallocz(256 * 4);
681  h[i].lengths = av_mallocz(256 * sizeof(int));
682  h[i].values = av_mallocz(256 * sizeof(int));
683  if (!h[i].bits || !h[i].lengths || !h[i].values) {
684  ret = AVERROR(ENOMEM);
685  goto error;
686  }
687  skip_bits1(&gb);
688  if (smacker_decode_tree(&gb, &h[i], 0, 0) < 0) {
689  ret = AVERROR_INVALIDDATA;
690  goto error;
691  }
692  skip_bits1(&gb);
693  if(h[i].current > 1) {
694  res = init_vlc(&vlc[i], SMKTREE_BITS, h[i].length,
695  h[i].lengths, sizeof(int), sizeof(int),
696  h[i].bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
697  if(res < 0) {
698  av_log(avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
699  ret = AVERROR_INVALIDDATA;
700  goto error;
701  }
702  }
703  }
704  /* this codec relies on wraparound instead of clipping audio */
705  if(bits) { //decode 16-bit data
706  for(i = stereo; i >= 0; i--)
707  pred[i] = sign_extend(av_bswap16(get_bits(&gb, 16)), 16);
708  for(i = 0; i <= stereo; i++)
709  *samples++ = pred[i];
710  for(; i < unp_size / 2; i++) {
711  if(get_bits_left(&gb)<0)
712  return AVERROR_INVALIDDATA;
713  if(i & stereo) {
714  if(vlc[2].table)
715  res = get_vlc2(&gb, vlc[2].table, SMKTREE_BITS, 3);
716  else
717  res = 0;
718  if (res < 0) {
719  av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
720  return AVERROR_INVALIDDATA;
721  }
722  val = h[2].values[res];
723  if(vlc[3].table)
724  res = get_vlc2(&gb, vlc[3].table, SMKTREE_BITS, 3);
725  else
726  res = 0;
727  if (res < 0) {
728  av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
729  return AVERROR_INVALIDDATA;
730  }
731  val |= h[3].values[res] << 8;
732  pred[1] += sign_extend(val, 16);
733  *samples++ = pred[1];
734  } else {
735  if(vlc[0].table)
736  res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
737  else
738  res = 0;
739  if (res < 0) {
740  av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
741  return AVERROR_INVALIDDATA;
742  }
743  val = h[0].values[res];
744  if(vlc[1].table)
745  res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
746  else
747  res = 0;
748  if (res < 0) {
749  av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
750  return AVERROR_INVALIDDATA;
751  }
752  val |= h[1].values[res] << 8;
753  pred[0] += sign_extend(val, 16);
754  *samples++ = pred[0];
755  }
756  }
757  } else { //8-bit data
758  for(i = stereo; i >= 0; i--)
759  pred[i] = get_bits(&gb, 8);
760  for(i = 0; i <= stereo; i++)
761  *samples8++ = pred[i];
762  for(; i < unp_size; i++) {
763  if(get_bits_left(&gb)<0)
764  return AVERROR_INVALIDDATA;
765  if(i & stereo){
766  if(vlc[1].table)
767  res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
768  else
769  res = 0;
770  if (res < 0) {
771  av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
772  return AVERROR_INVALIDDATA;
773  }
774  pred[1] += sign_extend(h[1].values[res], 8);
775  *samples8++ = pred[1];
776  } else {
777  if(vlc[0].table)
778  res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
779  else
780  res = 0;
781  if (res < 0) {
782  av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
783  return AVERROR_INVALIDDATA;
784  }
785  pred[0] += sign_extend(h[0].values[res], 8);
786  *samples8++ = pred[0];
787  }
788  }
789  }
790 
791  *got_frame_ptr = 1;
792  ret = buf_size;
793 
794 error:
795  for(i = 0; i < 4; i++) {
796  if(vlc[i].table)
797  ff_free_vlc(&vlc[i]);
798  av_free(h[i].bits);
799  av_free(h[i].lengths);
800  av_free(h[i].values);
801  }
802 
803  return ret;
804 }
805 
806 AVCodec ff_smacker_decoder = {
807  .name = "smackvid",
808  .long_name = NULL_IF_CONFIG_SMALL("Smacker video"),
809  .type = AVMEDIA_TYPE_VIDEO,
810  .id = AV_CODEC_ID_SMACKVIDEO,
811  .priv_data_size = sizeof(SmackVContext),
812  .init = decode_init,
813  .close = decode_end,
814  .decode = decode_frame,
815  .capabilities = CODEC_CAP_DR1,
816 };
817 
818 AVCodec ff_smackaud_decoder = {
819  .name = "smackaud",
820  .long_name = NULL_IF_CONFIG_SMALL("Smacker audio"),
821  .type = AVMEDIA_TYPE_AUDIO,
822  .id = AV_CODEC_ID_SMACKAUDIO,
823  .init = smka_decode_init,
824  .decode = smka_decode_frame,
825  .capabilities = CODEC_CAP_DR1,
826 };
Generated on Sun Sep 14 2014 18:56:03 for FFmpeg by   doxygen 1.8.2