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 Libav.
7  *
8  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
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 
45 typedef struct BlockInfo {
46  uint8_t *pos;
47  int size;
48  int unp_size;
49 } BlockInfo;
50 
51 typedef struct FlashSVContext {
56  uint8_t *tmpblock;
58  z_stream zstream;
59  int ver;
60  const uint32_t *pal;
62  uint8_t *keyframedata;
63  uint8_t *keyframe;
65  uint8_t *deflate_block;
71 
72 
73 static int decode_hybrid(const uint8_t *sptr, uint8_t *dptr, int dx, int dy,
74  int h, int w, int stride, const uint32_t *pal)
75 {
76  int x, y;
77  const uint8_t *orig_src = sptr;
78 
79  for (y = dx+h; y > dx; y--) {
80  uint8_t *dst = dptr + (y * stride) + dy * 3;
81  for (x = 0; x < w; x++) {
82  if (*sptr & 0x80) {
83  /* 15-bit color */
84  unsigned c = AV_RB16(sptr) & ~0x8000;
85  unsigned b = c & 0x1F;
86  unsigned g = (c >> 5) & 0x1F;
87  unsigned r = c >> 10;
88  /* 000aaabb -> aaabbaaa */
89  *dst++ = (b << 3) | (b >> 2);
90  *dst++ = (g << 3) | (g >> 2);
91  *dst++ = (r << 3) | (r >> 2);
92  sptr += 2;
93  } else {
94  /* palette index */
95  uint32_t c = pal[*sptr++];
96  bytestream_put_le24(&dst, c);
97  }
98  }
99  }
100  return sptr - orig_src;
101 }
102 
104 {
105  FlashSVContext *s = avctx->priv_data;
106  int zret; // Zlib return code
107 
108  s->avctx = avctx;
109  s->zstream.zalloc = Z_NULL;
110  s->zstream.zfree = Z_NULL;
111  s->zstream.opaque = Z_NULL;
112  zret = inflateInit(&s->zstream);
113  if (zret != Z_OK) {
114  av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
115  return 1;
116  }
117  avctx->pix_fmt = PIX_FMT_BGR24;
118  s->frame.data[0] = NULL;
119 
120  return 0;
121 }
122 
123 
124 static void flashsv2_prime(FlashSVContext *s, uint8_t *src,
125  int size, int unp_size)
126 {
127  z_stream zs;
128 
129  zs.zalloc = NULL;
130  zs.zfree = NULL;
131  zs.opaque = NULL;
132 
133  s->zstream.next_in = src;
134  s->zstream.avail_in = size;
135  s->zstream.next_out = s->tmpblock;
136  s->zstream.avail_out = s->block_size * 3;
137  inflate(&s->zstream, Z_SYNC_FLUSH);
138 
139  deflateInit(&zs, 0);
140  zs.next_in = s->tmpblock;
141  zs.avail_in = s->block_size * 3 - s->zstream.avail_out;
142  zs.next_out = s->deflate_block;
143  zs.avail_out = s->deflate_block_size;
144  deflate(&zs, Z_SYNC_FLUSH);
145  deflateEnd(&zs);
146 
147  inflateReset(&s->zstream);
148 
149  s->zstream.next_in = s->deflate_block;
150  s->zstream.avail_in = s->deflate_block_size - zs.avail_out;
151  s->zstream.next_out = s->tmpblock;
152  s->zstream.avail_out = s->block_size * 3;
153  inflate(&s->zstream, Z_SYNC_FLUSH);
154 }
155 
156 static int flashsv_decode_block(AVCodecContext *avctx, AVPacket *avpkt,
157  GetBitContext *gb, int block_size,
158  int width, int height, int x_pos, int y_pos,
159  int blk_idx)
160 {
161  struct FlashSVContext *s = avctx->priv_data;
162  uint8_t *line = s->tmpblock;
163  int k;
164  int ret = inflateReset(&s->zstream);
165  if (ret != Z_OK) {
166  //return -1;
167  }
168  if (s->zlibprime_curr || s->zlibprime_prev) {
169  flashsv2_prime(s, s->blocks[blk_idx].pos, s->blocks[blk_idx].size,
170  s->blocks[blk_idx].unp_size);
171  }
172  s->zstream.next_in = avpkt->data + get_bits_count(gb) / 8;
173  s->zstream.avail_in = block_size;
174  s->zstream.next_out = s->tmpblock;
175  s->zstream.avail_out = s->block_size * 3;
176  ret = inflate(&s->zstream, Z_FINISH);
177  if (ret == Z_DATA_ERROR) {
178  av_log(avctx, AV_LOG_ERROR, "Zlib resync occurred\n");
179  inflateSync(&s->zstream);
180  ret = inflate(&s->zstream, Z_FINISH);
181  }
182 
183  if (ret != Z_OK && ret != Z_STREAM_END) {
184  //return -1;
185  }
186 
187  if (s->is_keyframe) {
188  s->blocks[blk_idx].pos = s->keyframedata + (get_bits_count(gb) / 8);
189  s->blocks[blk_idx].size = block_size;
190  s->blocks[blk_idx].unp_size = s->block_size * 3 - s->zstream.avail_out;
191  }
192  if (!s->color_depth) {
193  /* Flash Screen Video stores the image upside down, so copy
194  * lines to destination in reverse order. */
195  for (k = 1; k <= s->diff_height; k++) {
196  memcpy(s->frame.data[0] + x_pos * 3 +
197  (s->image_height - y_pos - s->diff_start - k) * s->frame.linesize[0],
198  line, width * 3);
199  /* advance source pointer to next line */
200  line += width * 3;
201  }
202  } else {
203  /* hybrid 15-bit/palette mode */
204  decode_hybrid(s->tmpblock, s->frame.data[0],
205  s->image_height - (y_pos + 1 + s->diff_start + s->diff_height),
206  x_pos, s->diff_height, width,
207  s->frame.linesize[0], s->pal);
208  }
209  skip_bits_long(gb, 8 * block_size); /* skip the consumed bits */
210  return 0;
211 }
212 
213 static int calc_deflate_block_size(int tmpblock_size)
214 {
215  z_stream zstream;
216  int size;
217 
218  zstream.zalloc = Z_NULL;
219  zstream.zfree = Z_NULL;
220  zstream.opaque = Z_NULL;
221  if (deflateInit(&zstream, 0) != Z_OK)
222  return -1;
223  size = deflateBound(&zstream, tmpblock_size);
224  deflateEnd(&zstream);
225 
226  return size;
227 }
228 
230  int *data_size, AVPacket *avpkt)
231 {
232  int buf_size = avpkt->size;
233  FlashSVContext *s = avctx->priv_data;
234  int h_blocks, v_blocks, h_part, v_part, i, j;
235  GetBitContext gb;
236 
237  /* no supplementary picture */
238  if (buf_size == 0)
239  return 0;
240  if (buf_size < 4)
241  return -1;
242 
243  init_get_bits(&gb, avpkt->data, buf_size * 8);
244 
245  /* start to parse the bitstream */
246  s->block_width = 16 * (get_bits(&gb, 4) + 1);
247  s->image_width = get_bits(&gb, 12);
248  s->block_height = 16 * (get_bits(&gb, 4) + 1);
249  s->image_height = get_bits(&gb, 12);
250 
251  if (s->ver == 2) {
252  skip_bits(&gb, 6);
253  if (get_bits1(&gb)) {
254  av_log_missing_feature(avctx, "iframe", 1);
255  return AVERROR_PATCHWELCOME;
256  }
257  if (get_bits1(&gb)) {
258  av_log_missing_feature(avctx, "custom palette", 1);
259  return AVERROR_PATCHWELCOME;
260  }
261  }
262 
263  /* calculate number of blocks and size of border (partial) blocks */
264  h_blocks = s->image_width / s->block_width;
265  h_part = s->image_width % s->block_width;
266  v_blocks = s->image_height / s->block_height;
267  v_part = s->image_height % s->block_height;
268 
269  /* the block size could change between frames, make sure the buffer
270  * is large enough, if not, get a larger one */
271  if (s->block_size < s->block_width * s->block_height) {
272  int tmpblock_size = 3 * s->block_width * s->block_height;
273 
274  s->tmpblock = av_realloc(s->tmpblock, tmpblock_size);
275  if (!s->tmpblock) {
276  av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
277  return AVERROR(ENOMEM);
278  }
279  if (s->ver == 2) {
280  s->deflate_block_size = calc_deflate_block_size(tmpblock_size);
281  if (s->deflate_block_size <= 0) {
282  av_log(avctx, AV_LOG_ERROR, "Can't determine deflate buffer size.\n");
283  return -1;
284  }
286  if (!s->deflate_block) {
287  av_log(avctx, AV_LOG_ERROR, "Can't allocate deflate buffer.\n");
288  return AVERROR(ENOMEM);
289  }
290  }
291  }
292  s->block_size = s->block_width * s->block_height;
293 
294  /* initialize the image size once */
295  if (avctx->width == 0 && avctx->height == 0) {
296  avctx->width = s->image_width;
297  avctx->height = s->image_height;
298  }
299 
300  /* check for changes of image width and image height */
301  if (avctx->width != s->image_width || avctx->height != s->image_height) {
302  av_log(avctx, AV_LOG_ERROR,
303  "Frame width or height differs from first frame!\n");
304  av_log(avctx, AV_LOG_ERROR, "fh = %d, fv %d vs ch = %d, cv = %d\n",
305  avctx->height, avctx->width, s->image_height, s->image_width);
306  return AVERROR_INVALIDDATA;
307  }
308 
309  /* we care for keyframes only in Screen Video v2 */
310  s->is_keyframe = (avpkt->flags & AV_PKT_FLAG_KEY) && (s->ver == 2);
311  if (s->is_keyframe) {
312  s->keyframedata = av_realloc(s->keyframedata, avpkt->size);
313  memcpy(s->keyframedata, avpkt->data, avpkt->size);
314  s->blocks = av_realloc(s->blocks,
315  (v_blocks + !!v_part) * (h_blocks + !!h_part)
316  * sizeof(s->blocks[0]));
317  }
318 
319  av_dlog(avctx, "image: %dx%d block: %dx%d num: %dx%d part: %dx%d\n",
321  h_blocks, v_blocks, h_part, v_part);
322 
323  s->frame.reference = 3;
327  if (avctx->reget_buffer(avctx, &s->frame) < 0) {
328  av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
329  return -1;
330  }
331 
332  /* loop over all block columns */
333  for (j = 0; j < v_blocks + (v_part ? 1 : 0); j++) {
334 
335  int y_pos = j * s->block_height; // vertical position in frame
336  int cur_blk_height = (j < v_blocks) ? s->block_height : v_part;
337 
338  /* loop over all block rows */
339  for (i = 0; i < h_blocks + (h_part ? 1 : 0); i++) {
340  int x_pos = i * s->block_width; // horizontal position in frame
341  int cur_blk_width = (i < h_blocks) ? s->block_width : h_part;
342  int has_diff = 0;
343 
344  /* get the size of the compressed zlib chunk */
345  int size = get_bits(&gb, 16);
346 
347  s->color_depth = 0;
348  s->zlibprime_curr = 0;
349  s->zlibprime_prev = 0;
350  s->diff_start = 0;
351  s->diff_height = cur_blk_height;
352 
353  if (8 * size > get_bits_left(&gb)) {
354  avctx->release_buffer(avctx, &s->frame);
355  s->frame.data[0] = NULL;
356  return AVERROR_INVALIDDATA;
357  }
358 
359  if (s->ver == 2 && size) {
360  skip_bits(&gb, 3);
361  s->color_depth = get_bits(&gb, 2);
362  has_diff = get_bits1(&gb);
363  s->zlibprime_curr = get_bits1(&gb);
364  s->zlibprime_prev = get_bits1(&gb);
365 
366  if (s->color_depth != 0 && s->color_depth != 2) {
367  av_log(avctx, AV_LOG_ERROR,
368  "%dx%d invalid color depth %d\n", i, j, s->color_depth);
369  return AVERROR_INVALIDDATA;
370  }
371 
372  if (has_diff) {
373  if (!s->keyframe) {
374  av_log(avctx, AV_LOG_ERROR,
375  "inter frame without keyframe\n");
376  return AVERROR_INVALIDDATA;
377  }
378  s->diff_start = get_bits(&gb, 8);
379  s->diff_height = get_bits(&gb, 8);
380  av_log(avctx, AV_LOG_DEBUG,
381  "%dx%d diff start %d height %d\n",
382  i, j, s->diff_start, s->diff_height);
383  size -= 2;
384  }
385 
386  if (s->zlibprime_prev)
387  av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_prev\n", i, j);
388 
389  if (s->zlibprime_curr) {
390  int col = get_bits(&gb, 8);
391  int row = get_bits(&gb, 8);
392  av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_curr %dx%d\n", i, j, col, row);
393  size -= 2;
394  av_log_missing_feature(avctx, "zlibprime_curr", 1);
395  return AVERROR_PATCHWELCOME;
396  }
397  if (!s->blocks && (s->zlibprime_curr || s->zlibprime_prev)) {
398  av_log(avctx, AV_LOG_ERROR, "no data available for zlib "
399  "priming\n");
400  return AVERROR_INVALIDDATA;
401  }
402  size--; // account for flags byte
403  }
404 
405  if (has_diff) {
406  int k;
407  int off = (s->image_height - y_pos - 1) * s->frame.linesize[0];
408 
409  for (k = 0; k < cur_blk_height; k++)
410  memcpy(s->frame.data[0] + off - k*s->frame.linesize[0] + x_pos*3,
411  s->keyframe + off - k*s->frame.linesize[0] + x_pos*3,
412  cur_blk_width * 3);
413  }
414 
415  /* skip unchanged blocks, which have size 0 */
416  if (size) {
417  if (flashsv_decode_block(avctx, avpkt, &gb, size,
418  cur_blk_width, cur_blk_height,
419  x_pos, y_pos,
420  i + j * (h_blocks + !!h_part)))
421  av_log(avctx, AV_LOG_ERROR,
422  "error in decompression of block %dx%d\n", i, j);
423  }
424  }
425  }
426  if (s->is_keyframe && s->ver == 2) {
427  if (!s->keyframe) {
428  s->keyframe = av_malloc(s->frame.linesize[0] * avctx->height);
429  if (!s->keyframe) {
430  av_log(avctx, AV_LOG_ERROR, "Cannot allocate image data\n");
431  return AVERROR(ENOMEM);
432  }
433  }
434  memcpy(s->keyframe, s->frame.data[0], s->frame.linesize[0] * avctx->height);
435  }
436 
437  *data_size = sizeof(AVFrame);
438  *(AVFrame*)data = s->frame;
439 
440  if ((get_bits_count(&gb) / 8) != buf_size)
441  av_log(avctx, AV_LOG_ERROR, "buffer not fully consumed (%d != %d)\n",
442  buf_size, (get_bits_count(&gb) / 8));
443 
444  /* report that the buffer was completely consumed */
445  return buf_size;
446 }
447 
448 
450 {
451  FlashSVContext *s = avctx->priv_data;
452  inflateEnd(&s->zstream);
453  /* release the frame if needed */
454  if (s->frame.data[0])
455  avctx->release_buffer(avctx, &s->frame);
456 
457  /* free the tmpblock */
458  av_free(s->tmpblock);
459 
460  return 0;
461 }
462 
463 
464 #if CONFIG_FLASHSV_DECODER
465 AVCodec ff_flashsv_decoder = {
466  .name = "flashsv",
467  .type = AVMEDIA_TYPE_VIDEO,
468  .id = CODEC_ID_FLASHSV,
469  .priv_data_size = sizeof(FlashSVContext),
473  .capabilities = CODEC_CAP_DR1,
474  .pix_fmts = (const enum PixelFormat[]){PIX_FMT_BGR24, PIX_FMT_NONE},
475  .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video v1"),
476 };
477 #endif /* CONFIG_FLASHSV_DECODER */
478 
479 #if CONFIG_FLASHSV2_DECODER
480 static const uint32_t ff_flashsv2_default_palette[128] = {
481  0x000000, 0x333333, 0x666666, 0x999999, 0xCCCCCC, 0xFFFFFF,
482  0x330000, 0x660000, 0x990000, 0xCC0000, 0xFF0000, 0x003300,
483  0x006600, 0x009900, 0x00CC00, 0x00FF00, 0x000033, 0x000066,
484  0x000099, 0x0000CC, 0x0000FF, 0x333300, 0x666600, 0x999900,
485  0xCCCC00, 0xFFFF00, 0x003333, 0x006666, 0x009999, 0x00CCCC,
486  0x00FFFF, 0x330033, 0x660066, 0x990099, 0xCC00CC, 0xFF00FF,
487  0xFFFF33, 0xFFFF66, 0xFFFF99, 0xFFFFCC, 0xFF33FF, 0xFF66FF,
488  0xFF99FF, 0xFFCCFF, 0x33FFFF, 0x66FFFF, 0x99FFFF, 0xCCFFFF,
489  0xCCCC33, 0xCCCC66, 0xCCCC99, 0xCCCCFF, 0xCC33CC, 0xCC66CC,
490  0xCC99CC, 0xCCFFCC, 0x33CCCC, 0x66CCCC, 0x99CCCC, 0xFFCCCC,
491  0x999933, 0x999966, 0x9999CC, 0x9999FF, 0x993399, 0x996699,
492  0x99CC99, 0x99FF99, 0x339999, 0x669999, 0xCC9999, 0xFF9999,
493  0x666633, 0x666699, 0x6666CC, 0x6666FF, 0x663366, 0x669966,
494  0x66CC66, 0x66FF66, 0x336666, 0x996666, 0xCC6666, 0xFF6666,
495  0x333366, 0x333399, 0x3333CC, 0x3333FF, 0x336633, 0x339933,
496  0x33CC33, 0x33FF33, 0x663333, 0x993333, 0xCC3333, 0xFF3333,
497  0x003366, 0x336600, 0x660033, 0x006633, 0x330066, 0x663300,
498  0x336699, 0x669933, 0x993366, 0x339966, 0x663399, 0x996633,
499  0x6699CC, 0x99CC66, 0xCC6699, 0x66CC99, 0x9966CC, 0xCC9966,
500  0x99CCFF, 0xCCFF99, 0xFF99CC, 0x99FFCC, 0xCC99FF, 0xFFCC99,
501  0x111111, 0x222222, 0x444444, 0x555555, 0xAAAAAA, 0xBBBBBB,
502  0xDDDDDD, 0xEEEEEE
503 };
504 
505 static av_cold int flashsv2_decode_init(AVCodecContext *avctx)
506 {
507  FlashSVContext *s = avctx->priv_data;
508  flashsv_decode_init(avctx);
509  s->pal = ff_flashsv2_default_palette;
510  s->ver = 2;
511 
512  return 0;
513 }
514 
515 static av_cold int flashsv2_decode_end(AVCodecContext *avctx)
516 {
517  FlashSVContext *s = avctx->priv_data;
518 
519  av_freep(&s->keyframedata);
520  av_freep(&s->blocks);
521  av_freep(&s->keyframe);
522  av_freep(&s->deflate_block);
523  flashsv_decode_end(avctx);
524 
525  return 0;
526 }
527 
528 AVCodec ff_flashsv2_decoder = {
529  .name = "flashsv2",
530  .type = AVMEDIA_TYPE_VIDEO,
531  .id = CODEC_ID_FLASHSV2,
532  .priv_data_size = sizeof(FlashSVContext),
533  .init = flashsv2_decode_init,
534  .close = flashsv2_decode_end,
536  .capabilities = CODEC_CAP_DR1,
537  .pix_fmts = (const enum PixelFormat[]){PIX_FMT_BGR24, PIX_FMT_NONE},
538  .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video v2"),
539 };
540 #endif /* CONFIG_FLASHSV2_DECODER */