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flashsv.c
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1 /*
2  * Flash Screen Video decoder
3  * Copyright (C) 2004 Alex Beregszaszi
4  * Copyright (C) 2006 Benjamin Larsson
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * Flash Screen Video decoder
26  * @author Alex Beregszaszi
27  * @author Benjamin Larsson
28  * @author Daniel Verkamp
29  * @author Konstantin Shishkov
30  *
31  * A description of the bitstream format for Flash Screen Video version 1/2
32  * is part of the SWF File Format Specification (version 10), which can be
33  * downloaded from http://www.adobe.com/devnet/swf.html.
34  */
35 
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <zlib.h>
39 
40 #include "libavutil/intreadwrite.h"
41 #include "avcodec.h"
42 #include "bytestream.h"
43 #include "get_bits.h"
44 #include "internal.h"
45 
46 typedef struct BlockInfo {
48  int size;
49 } BlockInfo;
50 
51 typedef struct FlashSVContext {
58  z_stream zstream;
59  int ver;
60  const uint32_t *pal;
71 
72 static int decode_hybrid(const uint8_t *sptr, const uint8_t *sptr_end, uint8_t *dptr, int dx, int dy,
73  int h, int w, int stride, const uint32_t *pal)
74 {
75  int x, y;
76  const uint8_t *orig_src = sptr;
77 
78  for (y = dx + h; y > dx; y--) {
79  uint8_t *dst = dptr + (y * stride) + dy * 3;
80  for (x = 0; x < w; x++) {
81  if (sptr >= sptr_end)
82  return AVERROR_INVALIDDATA;
83  if (*sptr & 0x80) {
84  /* 15-bit color */
85  unsigned c = AV_RB16(sptr) & ~0x8000;
86  unsigned b = c & 0x1F;
87  unsigned g = (c >> 5) & 0x1F;
88  unsigned r = c >> 10;
89  /* 000aaabb -> aaabbaaa */
90  *dst++ = (b << 3) | (b >> 2);
91  *dst++ = (g << 3) | (g >> 2);
92  *dst++ = (r << 3) | (r >> 2);
93  sptr += 2;
94  } else {
95  /* palette index */
96  uint32_t c = pal[*sptr++];
97  bytestream_put_le24(&dst, c);
98  }
99  }
100  }
101  return sptr - orig_src;
102 }
103 
105 {
106  FlashSVContext *s = avctx->priv_data;
107  inflateEnd(&s->zstream);
108  /* release the frame if needed */
109  av_frame_free(&s->frame);
110 
111  /* free the tmpblock */
112  av_freep(&s->tmpblock);
113 
114  return 0;
115 }
116 
118 {
119  FlashSVContext *s = avctx->priv_data;
120  int zret; // Zlib return code
121 
122  s->avctx = avctx;
123  s->zstream.zalloc = Z_NULL;
124  s->zstream.zfree = Z_NULL;
125  s->zstream.opaque = Z_NULL;
126  zret = inflateInit(&s->zstream);
127  if (zret != Z_OK) {
128  av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
129  return 1;
130  }
131  avctx->pix_fmt = AV_PIX_FMT_BGR24;
132 
133  s->frame = av_frame_alloc();
134  if (!s->frame) {
135  flashsv_decode_end(avctx);
136  return AVERROR(ENOMEM);
137  }
138 
139  return 0;
140 }
141 
143 {
144  z_stream zs;
145  int zret; // Zlib return code
146 
147  if (!src)
148  return AVERROR_INVALIDDATA;
149 
150  zs.zalloc = NULL;
151  zs.zfree = NULL;
152  zs.opaque = NULL;
153 
154  s->zstream.next_in = src;
155  s->zstream.avail_in = size;
156  s->zstream.next_out = s->tmpblock;
157  s->zstream.avail_out = s->block_size * 3;
158  inflate(&s->zstream, Z_SYNC_FLUSH);
159 
160  if (deflateInit(&zs, 0) != Z_OK)
161  return -1;
162  zs.next_in = s->tmpblock;
163  zs.avail_in = s->block_size * 3 - s->zstream.avail_out;
164  zs.next_out = s->deflate_block;
165  zs.avail_out = s->deflate_block_size;
166  deflate(&zs, Z_SYNC_FLUSH);
167  deflateEnd(&zs);
168 
169  if ((zret = inflateReset(&s->zstream)) != Z_OK) {
170  av_log(s->avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
171  return AVERROR_UNKNOWN;
172  }
173 
174  s->zstream.next_in = s->deflate_block;
175  s->zstream.avail_in = s->deflate_block_size - zs.avail_out;
176  s->zstream.next_out = s->tmpblock;
177  s->zstream.avail_out = s->block_size * 3;
178  inflate(&s->zstream, Z_SYNC_FLUSH);
179 
180  return 0;
181 }
182 
183 static int flashsv_decode_block(AVCodecContext *avctx, AVPacket *avpkt,
184  GetBitContext *gb, int block_size,
185  int width, int height, int x_pos, int y_pos,
186  int blk_idx)
187 {
188  struct FlashSVContext *s = avctx->priv_data;
189  uint8_t *line = s->tmpblock;
190  int k;
191  int ret = inflateReset(&s->zstream);
192  if (ret != Z_OK) {
193  av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
194  return AVERROR_UNKNOWN;
195  }
196  if (s->zlibprime_curr || s->zlibprime_prev) {
197  ret = flashsv2_prime(s,
198  s->blocks[blk_idx].pos,
199  s->blocks[blk_idx].size);
200  if (ret < 0)
201  return ret;
202  }
203  s->zstream.next_in = avpkt->data + get_bits_count(gb) / 8;
204  s->zstream.avail_in = block_size;
205  s->zstream.next_out = s->tmpblock;
206  s->zstream.avail_out = s->block_size * 3;
207  ret = inflate(&s->zstream, Z_FINISH);
208  if (ret == Z_DATA_ERROR) {
209  av_log(avctx, AV_LOG_ERROR, "Zlib resync occurred\n");
210  inflateSync(&s->zstream);
211  ret = inflate(&s->zstream, Z_FINISH);
212  }
213 
214  if (ret != Z_OK && ret != Z_STREAM_END) {
215  //return -1;
216  }
217 
218  if (s->is_keyframe) {
219  s->blocks[blk_idx].pos = s->keyframedata + (get_bits_count(gb) / 8);
220  s->blocks[blk_idx].size = block_size;
221  }
222 
223  y_pos += s->diff_start;
224 
225  if (!s->color_depth) {
226  /* Flash Screen Video stores the image upside down, so copy
227  * lines to destination in reverse order. */
228  for (k = 1; k <= s->diff_height; k++) {
229  memcpy(s->frame->data[0] + x_pos * 3 +
230  (s->image_height - y_pos - k) * s->frame->linesize[0],
231  line, width * 3);
232  /* advance source pointer to next line */
233  line += width * 3;
234  }
235  } else {
236  /* hybrid 15-bit/palette mode */
237  ret = decode_hybrid(s->tmpblock, s->zstream.next_out,
238  s->frame->data[0],
239  s->image_height - (y_pos + 1 + s->diff_height),
240  x_pos, s->diff_height, width,
241  s->frame->linesize[0], s->pal);
242  if (ret < 0) {
243  av_log(avctx, AV_LOG_ERROR, "decode_hybrid failed\n");
244  return ret;
245  }
246  }
247  skip_bits_long(gb, 8 * block_size); /* skip the consumed bits */
248  return 0;
249 }
250 
251 static int calc_deflate_block_size(int tmpblock_size)
252 {
253  z_stream zstream;
254  int size;
255 
256  zstream.zalloc = Z_NULL;
257  zstream.zfree = Z_NULL;
258  zstream.opaque = Z_NULL;
259  if (deflateInit(&zstream, 0) != Z_OK)
260  return -1;
261  size = deflateBound(&zstream, tmpblock_size);
262  deflateEnd(&zstream);
263 
264  return size;
265 }
266 
268  int *got_frame, AVPacket *avpkt)
269 {
270  int buf_size = avpkt->size;
271  FlashSVContext *s = avctx->priv_data;
272  int h_blocks, v_blocks, h_part, v_part, i, j, ret;
273  GetBitContext gb;
274  int last_blockwidth = s->block_width;
275  int last_blockheight= s->block_height;
276 
277  /* no supplementary picture */
278  if (buf_size == 0)
279  return 0;
280  if (buf_size < 4)
281  return -1;
282 
283  if ((ret = init_get_bits8(&gb, avpkt->data, buf_size)) < 0)
284  return ret;
285 
286  /* start to parse the bitstream */
287  s->block_width = 16 * (get_bits(&gb, 4) + 1);
288  s->image_width = get_bits(&gb, 12);
289  s->block_height = 16 * (get_bits(&gb, 4) + 1);
290  s->image_height = get_bits(&gb, 12);
291 
292  if ( last_blockwidth != s->block_width
293  || last_blockheight!= s->block_height)
294  av_freep(&s->blocks);
295 
296  if (s->ver == 2) {
297  skip_bits(&gb, 6);
298  if (get_bits1(&gb)) {
299  avpriv_request_sample(avctx, "iframe");
300  return AVERROR_PATCHWELCOME;
301  }
302  if (get_bits1(&gb)) {
303  avpriv_request_sample(avctx, "Custom palette");
304  return AVERROR_PATCHWELCOME;
305  }
306  }
307 
308  /* calculate number of blocks and size of border (partial) blocks */
309  h_blocks = s->image_width / s->block_width;
310  h_part = s->image_width % s->block_width;
311  v_blocks = s->image_height / s->block_height;
312  v_part = s->image_height % s->block_height;
313 
314  /* the block size could change between frames, make sure the buffer
315  * is large enough, if not, get a larger one */
316  if (s->block_size < s->block_width * s->block_height) {
317  int tmpblock_size = 3 * s->block_width * s->block_height, err;
318 
319  if ((err = av_reallocp(&s->tmpblock, tmpblock_size)) < 0) {
320  s->block_size = 0;
321  av_log(avctx, AV_LOG_ERROR,
322  "Cannot allocate decompression buffer.\n");
323  return err;
324  }
325  if (s->ver == 2) {
326  s->deflate_block_size = calc_deflate_block_size(tmpblock_size);
327  if (s->deflate_block_size <= 0) {
328  av_log(avctx, AV_LOG_ERROR,
329  "Cannot determine deflate buffer size.\n");
330  return -1;
331  }
332  if ((err = av_reallocp(&s->deflate_block, s->deflate_block_size)) < 0) {
333  s->block_size = 0;
334  av_log(avctx, AV_LOG_ERROR, "Cannot allocate deflate buffer.\n");
335  return err;
336  }
337  }
338  }
339  s->block_size = s->block_width * s->block_height;
340 
341  /* initialize the image size once */
342  if (avctx->width == 0 && avctx->height == 0) {
343  if ((ret = ff_set_dimensions(avctx, s->image_width, s->image_height)) < 0)
344  return ret;
345  }
346 
347  /* check for changes of image width and image height */
348  if (avctx->width != s->image_width || avctx->height != s->image_height) {
349  av_log(avctx, AV_LOG_ERROR,
350  "Frame width or height differs from first frame!\n");
351  av_log(avctx, AV_LOG_ERROR, "fh = %d, fv %d vs ch = %d, cv = %d\n",
352  avctx->height, avctx->width, s->image_height, s->image_width);
353  return AVERROR_INVALIDDATA;
354  }
355 
356  /* we care for keyframes only in Screen Video v2 */
357  s->is_keyframe = (avpkt->flags & AV_PKT_FLAG_KEY) && (s->ver == 2);
358  if (s->is_keyframe) {
359  int err;
360  if ((err = av_reallocp(&s->keyframedata, avpkt->size)) < 0)
361  return err;
362  memcpy(s->keyframedata, avpkt->data, avpkt->size);
363  }
364  if(s->ver == 2 && !s->blocks)
365  s->blocks = av_mallocz((v_blocks + !!v_part) * (h_blocks + !!h_part) *
366  sizeof(s->blocks[0]));
367 
368  av_dlog(avctx, "image: %dx%d block: %dx%d num: %dx%d part: %dx%d\n",
370  h_blocks, v_blocks, h_part, v_part);
371 
372  if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
373  return ret;
374 
375  /* loop over all block columns */
376  for (j = 0; j < v_blocks + (v_part ? 1 : 0); j++) {
377 
378  int y_pos = j * s->block_height; // vertical position in frame
379  int cur_blk_height = (j < v_blocks) ? s->block_height : v_part;
380 
381  /* loop over all block rows */
382  for (i = 0; i < h_blocks + (h_part ? 1 : 0); i++) {
383  int x_pos = i * s->block_width; // horizontal position in frame
384  int cur_blk_width = (i < h_blocks) ? s->block_width : h_part;
385  int has_diff = 0;
386 
387  /* get the size of the compressed zlib chunk */
388  int size = get_bits(&gb, 16);
389 
390  s->color_depth = 0;
391  s->zlibprime_curr = 0;
392  s->zlibprime_prev = 0;
393  s->diff_start = 0;
394  s->diff_height = cur_blk_height;
395 
396  if (8 * size > get_bits_left(&gb)) {
397  av_frame_unref(s->frame);
398  return AVERROR_INVALIDDATA;
399  }
400 
401  if (s->ver == 2 && size) {
402  skip_bits(&gb, 3);
403  s->color_depth = get_bits(&gb, 2);
404  has_diff = get_bits1(&gb);
405  s->zlibprime_curr = get_bits1(&gb);
406  s->zlibprime_prev = get_bits1(&gb);
407 
408  if (s->color_depth != 0 && s->color_depth != 2) {
409  av_log(avctx, AV_LOG_ERROR,
410  "%dx%d invalid color depth %d\n",
411  i, j, s->color_depth);
412  return AVERROR_INVALIDDATA;
413  }
414 
415  if (has_diff) {
416  if (!s->keyframe) {
417  av_log(avctx, AV_LOG_ERROR,
418  "Inter frame without keyframe\n");
419  return AVERROR_INVALIDDATA;
420  }
421  s->diff_start = get_bits(&gb, 8);
422  s->diff_height = get_bits(&gb, 8);
423  if (s->diff_start + s->diff_height > cur_blk_height) {
424  av_log(avctx, AV_LOG_ERROR,
425  "Block parameters invalid: %d + %d > %d\n",
426  s->diff_start, s->diff_height, cur_blk_height);
427  return AVERROR_INVALIDDATA;
428  }
429  av_log(avctx, AV_LOG_DEBUG,
430  "%dx%d diff start %d height %d\n",
431  i, j, s->diff_start, s->diff_height);
432  size -= 2;
433  }
434 
435  if (s->zlibprime_prev)
436  av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_prev\n", i, j);
437 
438  if (s->zlibprime_curr) {
439  int col = get_bits(&gb, 8);
440  int row = get_bits(&gb, 8);
441  av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_curr %dx%d\n",
442  i, j, col, row);
443  size -= 2;
444  avpriv_request_sample(avctx, "zlibprime_curr");
445  return AVERROR_PATCHWELCOME;
446  }
447  if (!s->blocks && (s->zlibprime_curr || s->zlibprime_prev)) {
448  av_log(avctx, AV_LOG_ERROR,
449  "no data available for zlib priming\n");
450  return AVERROR_INVALIDDATA;
451  }
452  size--; // account for flags byte
453  }
454 
455  if (has_diff) {
456  int k;
457  int off = (s->image_height - y_pos - 1) * s->frame->linesize[0];
458 
459  for (k = 0; k < cur_blk_height; k++) {
460  int x = off - k * s->frame->linesize[0] + x_pos * 3;
461  memcpy(s->frame->data[0] + x, s->keyframe + x,
462  cur_blk_width * 3);
463  }
464  }
465 
466  /* skip unchanged blocks, which have size 0 */
467  if (size) {
468  if (flashsv_decode_block(avctx, avpkt, &gb, size,
469  cur_blk_width, cur_blk_height,
470  x_pos, y_pos,
471  i + j * (h_blocks + !!h_part)))
472  av_log(avctx, AV_LOG_ERROR,
473  "error in decompression of block %dx%d\n", i, j);
474  }
475  }
476  }
477  if (s->is_keyframe && s->ver == 2) {
478  if (!s->keyframe) {
479  s->keyframe = av_malloc(s->frame->linesize[0] * avctx->height);
480  if (!s->keyframe) {
481  av_log(avctx, AV_LOG_ERROR, "Cannot allocate image data\n");
482  return AVERROR(ENOMEM);
483  }
484  }
485  memcpy(s->keyframe, s->frame->data[0],
486  s->frame->linesize[0] * avctx->height);
487  }
488 
489  if ((ret = av_frame_ref(data, s->frame)) < 0)
490  return ret;
491 
492  *got_frame = 1;
493 
494  if ((get_bits_count(&gb) / 8) != buf_size)
495  av_log(avctx, AV_LOG_ERROR, "buffer not fully consumed (%d != %d)\n",
496  buf_size, (get_bits_count(&gb) / 8));
497 
498  /* report that the buffer was completely consumed */
499  return buf_size;
500 }
501 
502 #if CONFIG_FLASHSV_DECODER
503 AVCodec ff_flashsv_decoder = {
504  .name = "flashsv",
505  .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video v1"),
506  .type = AVMEDIA_TYPE_VIDEO,
507  .id = AV_CODEC_ID_FLASHSV,
508  .priv_data_size = sizeof(FlashSVContext),
512  .capabilities = CODEC_CAP_DR1,
513  .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
514 };
515 #endif /* CONFIG_FLASHSV_DECODER */
516 
517 #if CONFIG_FLASHSV2_DECODER
518 static const uint32_t ff_flashsv2_default_palette[128] = {
519  0x000000, 0x333333, 0x666666, 0x999999, 0xCCCCCC, 0xFFFFFF,
520  0x330000, 0x660000, 0x990000, 0xCC0000, 0xFF0000, 0x003300,
521  0x006600, 0x009900, 0x00CC00, 0x00FF00, 0x000033, 0x000066,
522  0x000099, 0x0000CC, 0x0000FF, 0x333300, 0x666600, 0x999900,
523  0xCCCC00, 0xFFFF00, 0x003333, 0x006666, 0x009999, 0x00CCCC,
524  0x00FFFF, 0x330033, 0x660066, 0x990099, 0xCC00CC, 0xFF00FF,
525  0xFFFF33, 0xFFFF66, 0xFFFF99, 0xFFFFCC, 0xFF33FF, 0xFF66FF,
526  0xFF99FF, 0xFFCCFF, 0x33FFFF, 0x66FFFF, 0x99FFFF, 0xCCFFFF,
527  0xCCCC33, 0xCCCC66, 0xCCCC99, 0xCCCCFF, 0xCC33CC, 0xCC66CC,
528  0xCC99CC, 0xCCFFCC, 0x33CCCC, 0x66CCCC, 0x99CCCC, 0xFFCCCC,
529  0x999933, 0x999966, 0x9999CC, 0x9999FF, 0x993399, 0x996699,
530  0x99CC99, 0x99FF99, 0x339999, 0x669999, 0xCC9999, 0xFF9999,
531  0x666633, 0x666699, 0x6666CC, 0x6666FF, 0x663366, 0x669966,
532  0x66CC66, 0x66FF66, 0x336666, 0x996666, 0xCC6666, 0xFF6666,
533  0x333366, 0x333399, 0x3333CC, 0x3333FF, 0x336633, 0x339933,
534  0x33CC33, 0x33FF33, 0x663333, 0x993333, 0xCC3333, 0xFF3333,
535  0x003366, 0x336600, 0x660033, 0x006633, 0x330066, 0x663300,
536  0x336699, 0x669933, 0x993366, 0x339966, 0x663399, 0x996633,
537  0x6699CC, 0x99CC66, 0xCC6699, 0x66CC99, 0x9966CC, 0xCC9966,
538  0x99CCFF, 0xCCFF99, 0xFF99CC, 0x99FFCC, 0xCC99FF, 0xFFCC99,
539  0x111111, 0x222222, 0x444444, 0x555555, 0xAAAAAA, 0xBBBBBB,
540  0xDDDDDD, 0xEEEEEE
541 };
542 
543 static av_cold int flashsv2_decode_init(AVCodecContext *avctx)
544 {
545  FlashSVContext *s = avctx->priv_data;
546  flashsv_decode_init(avctx);
547  s->pal = ff_flashsv2_default_palette;
548  s->ver = 2;
549 
550  return 0;
551 }
552 
553 static av_cold int flashsv2_decode_end(AVCodecContext *avctx)
554 {
555  FlashSVContext *s = avctx->priv_data;
556 
557  av_freep(&s->keyframedata);
558  av_freep(&s->blocks);
559  av_freep(&s->keyframe);
560  av_freep(&s->deflate_block);
561  flashsv_decode_end(avctx);
562 
563  return 0;
564 }
565 
566 AVCodec ff_flashsv2_decoder = {
567  .name = "flashsv2",
568  .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video v2"),
569  .type = AVMEDIA_TYPE_VIDEO,
570  .id = AV_CODEC_ID_FLASHSV2,
571  .priv_data_size = sizeof(FlashSVContext),
572  .init = flashsv2_decode_init,
573  .close = flashsv2_decode_end,
575  .capabilities = CODEC_CAP_DR1,
576  .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
577 };
578 #endif /* CONFIG_FLASHSV2_DECODER */