2 * Flash Screen Video decoder
3 * Copyright (C) 2004 Alex Beregszaszi
4 * Copyright (C) 2006 Benjamin Larsson
6 * This file is part of Libav.
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.
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.
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
25 * Flash Screen Video decoder
26 * @author Alex Beregszaszi
27 * @author Benjamin Larsson
28 * @author Daniel Verkamp
29 * @author Konstantin Shishkov
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.
40 #include "libavutil/intreadwrite.h"
42 #include "bytestream.h"
46 typedef struct BlockInfo {
51 typedef struct FlashSVContext {
52 AVCodecContext *avctx;
54 int image_width, image_height;
55 int block_width, block_height;
62 uint8_t *keyframedata;
65 uint8_t *deflate_block;
66 int deflate_block_size;
68 int zlibprime_curr, zlibprime_prev;
69 int diff_start, diff_height;
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)
77 const uint8_t *orig_src = sptr;
79 for (y = dx+h; y > dx; y--) {
80 uint8_t *dst = dptr + (y * stride) + dy * 3;
81 for (x = 0; x < w; x++) {
84 unsigned c = AV_RB16(sptr) & ~0x8000;
85 unsigned b = c & 0x1F;
86 unsigned g = (c >> 5) & 0x1F;
88 /* 000aaabb -> aaabbaaa */
89 *dst++ = (b << 3) | (b >> 2);
90 *dst++ = (g << 3) | (g >> 2);
91 *dst++ = (r << 3) | (r >> 2);
95 uint32_t c = pal[*sptr++];
96 bytestream_put_le24(&dst, c);
100 return sptr - orig_src;
103 static av_cold int flashsv_decode_init(AVCodecContext *avctx)
105 FlashSVContext *s = avctx->priv_data;
106 int zret; // Zlib return code
109 s->zstream.zalloc = Z_NULL;
110 s->zstream.zfree = Z_NULL;
111 s->zstream.opaque = Z_NULL;
112 zret = inflateInit(&s->zstream);
114 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
117 avctx->pix_fmt = AV_PIX_FMT_BGR24;
118 avcodec_get_frame_defaults(&s->frame);
124 static int flashsv2_prime(FlashSVContext *s, uint8_t *src, int size)
127 int zret; // Zlib return code
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);
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);
147 if ((zret = inflateReset(&s->zstream)) != Z_OK) {
148 av_log(s->avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
149 return AVERROR_UNKNOWN;
152 s->zstream.next_in = s->deflate_block;
153 s->zstream.avail_in = s->deflate_block_size - zs.avail_out;
154 s->zstream.next_out = s->tmpblock;
155 s->zstream.avail_out = s->block_size * 3;
156 inflate(&s->zstream, Z_SYNC_FLUSH);
161 static int flashsv_decode_block(AVCodecContext *avctx, AVPacket *avpkt,
162 GetBitContext *gb, int block_size,
163 int width, int height, int x_pos, int y_pos,
166 struct FlashSVContext *s = avctx->priv_data;
167 uint8_t *line = s->tmpblock;
169 int ret = inflateReset(&s->zstream);
171 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
172 return AVERROR_UNKNOWN;
174 if (s->zlibprime_curr || s->zlibprime_prev) {
175 ret = flashsv2_prime(s,
176 s->blocks[blk_idx].pos,
177 s->blocks[blk_idx].size);
181 s->zstream.next_in = avpkt->data + get_bits_count(gb) / 8;
182 s->zstream.avail_in = block_size;
183 s->zstream.next_out = s->tmpblock;
184 s->zstream.avail_out = s->block_size * 3;
185 ret = inflate(&s->zstream, Z_FINISH);
186 if (ret == Z_DATA_ERROR) {
187 av_log(avctx, AV_LOG_ERROR, "Zlib resync occurred\n");
188 inflateSync(&s->zstream);
189 ret = inflate(&s->zstream, Z_FINISH);
192 if (ret != Z_OK && ret != Z_STREAM_END) {
196 if (s->is_keyframe) {
197 s->blocks[blk_idx].pos = s->keyframedata + (get_bits_count(gb) / 8);
198 s->blocks[blk_idx].size = block_size;
201 y_pos += s->diff_start;
203 if (!s->color_depth) {
204 /* Flash Screen Video stores the image upside down, so copy
205 * lines to destination in reverse order. */
206 for (k = 1; k <= s->diff_height; k++) {
207 memcpy(s->frame.data[0] + x_pos * 3 +
208 (s->image_height - y_pos - k) * s->frame.linesize[0],
210 /* advance source pointer to next line */
214 /* hybrid 15-bit/palette mode */
215 decode_hybrid(s->tmpblock, s->frame.data[0],
216 s->image_height - (y_pos + 1 + s->diff_height),
217 x_pos, s->diff_height, width,
218 s->frame.linesize[0], s->pal);
220 skip_bits_long(gb, 8 * block_size); /* skip the consumed bits */
224 static int calc_deflate_block_size(int tmpblock_size)
229 zstream.zalloc = Z_NULL;
230 zstream.zfree = Z_NULL;
231 zstream.opaque = Z_NULL;
232 if (deflateInit(&zstream, 0) != Z_OK)
234 size = deflateBound(&zstream, tmpblock_size);
235 deflateEnd(&zstream);
240 static int flashsv_decode_frame(AVCodecContext *avctx, void *data,
241 int *got_frame, AVPacket *avpkt)
243 int buf_size = avpkt->size;
244 FlashSVContext *s = avctx->priv_data;
245 int h_blocks, v_blocks, h_part, v_part, i, j, ret;
248 /* no supplementary picture */
254 init_get_bits(&gb, avpkt->data, buf_size * 8);
256 /* start to parse the bitstream */
257 s->block_width = 16 * (get_bits(&gb, 4) + 1);
258 s->image_width = get_bits(&gb, 12);
259 s->block_height = 16 * (get_bits(&gb, 4) + 1);
260 s->image_height = get_bits(&gb, 12);
264 if (get_bits1(&gb)) {
265 avpriv_request_sample(avctx, "iframe");
266 return AVERROR_PATCHWELCOME;
268 if (get_bits1(&gb)) {
269 avpriv_request_sample(avctx, "Custom palette");
270 return AVERROR_PATCHWELCOME;
274 /* calculate number of blocks and size of border (partial) blocks */
275 h_blocks = s->image_width / s->block_width;
276 h_part = s->image_width % s->block_width;
277 v_blocks = s->image_height / s->block_height;
278 v_part = s->image_height % s->block_height;
280 /* the block size could change between frames, make sure the buffer
281 * is large enough, if not, get a larger one */
282 if (s->block_size < s->block_width * s->block_height) {
283 int tmpblock_size = 3 * s->block_width * s->block_height;
285 s->tmpblock = av_realloc(s->tmpblock, tmpblock_size);
287 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
288 return AVERROR(ENOMEM);
291 s->deflate_block_size = calc_deflate_block_size(tmpblock_size);
292 if (s->deflate_block_size <= 0) {
293 av_log(avctx, AV_LOG_ERROR, "Can't determine deflate buffer size.\n");
296 s->deflate_block = av_realloc(s->deflate_block, s->deflate_block_size);
297 if (!s->deflate_block) {
298 av_log(avctx, AV_LOG_ERROR, "Can't allocate deflate buffer.\n");
299 return AVERROR(ENOMEM);
303 s->block_size = s->block_width * s->block_height;
305 /* initialize the image size once */
306 if (avctx->width == 0 && avctx->height == 0) {
307 avctx->width = s->image_width;
308 avctx->height = s->image_height;
311 /* check for changes of image width and image height */
312 if (avctx->width != s->image_width || avctx->height != s->image_height) {
313 av_log(avctx, AV_LOG_ERROR,
314 "Frame width or height differs from first frame!\n");
315 av_log(avctx, AV_LOG_ERROR, "fh = %d, fv %d vs ch = %d, cv = %d\n",
316 avctx->height, avctx->width, s->image_height, s->image_width);
317 return AVERROR_INVALIDDATA;
320 /* we care for keyframes only in Screen Video v2 */
321 s->is_keyframe = (avpkt->flags & AV_PKT_FLAG_KEY) && (s->ver == 2);
322 if (s->is_keyframe) {
323 s->keyframedata = av_realloc(s->keyframedata, avpkt->size);
324 memcpy(s->keyframedata, avpkt->data, avpkt->size);
325 s->blocks = av_realloc(s->blocks,
326 (v_blocks + !!v_part) * (h_blocks + !!h_part)
327 * sizeof(s->blocks[0]));
330 av_dlog(avctx, "image: %dx%d block: %dx%d num: %dx%d part: %dx%d\n",
331 s->image_width, s->image_height, s->block_width, s->block_height,
332 h_blocks, v_blocks, h_part, v_part);
334 if ((ret = ff_reget_buffer(avctx, &s->frame)) < 0) {
335 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
339 /* loop over all block columns */
340 for (j = 0; j < v_blocks + (v_part ? 1 : 0); j++) {
342 int y_pos = j * s->block_height; // vertical position in frame
343 int cur_blk_height = (j < v_blocks) ? s->block_height : v_part;
345 /* loop over all block rows */
346 for (i = 0; i < h_blocks + (h_part ? 1 : 0); i++) {
347 int x_pos = i * s->block_width; // horizontal position in frame
348 int cur_blk_width = (i < h_blocks) ? s->block_width : h_part;
351 /* get the size of the compressed zlib chunk */
352 int size = get_bits(&gb, 16);
355 s->zlibprime_curr = 0;
356 s->zlibprime_prev = 0;
358 s->diff_height = cur_blk_height;
360 if (8 * size > get_bits_left(&gb)) {
361 av_frame_unref(&s->frame);
362 return AVERROR_INVALIDDATA;
365 if (s->ver == 2 && size) {
367 s->color_depth = get_bits(&gb, 2);
368 has_diff = get_bits1(&gb);
369 s->zlibprime_curr = get_bits1(&gb);
370 s->zlibprime_prev = get_bits1(&gb);
372 if (s->color_depth != 0 && s->color_depth != 2) {
373 av_log(avctx, AV_LOG_ERROR,
374 "%dx%d invalid color depth %d\n", i, j, s->color_depth);
375 return AVERROR_INVALIDDATA;
380 av_log(avctx, AV_LOG_ERROR,
381 "inter frame without keyframe\n");
382 return AVERROR_INVALIDDATA;
384 s->diff_start = get_bits(&gb, 8);
385 s->diff_height = get_bits(&gb, 8);
386 if (s->diff_start + s->diff_height > cur_blk_height) {
387 av_log(avctx, AV_LOG_ERROR,
388 "Block parameters invalid: %d + %d > %d\n",
389 s->diff_start, s->diff_height, cur_blk_height);
390 return AVERROR_INVALIDDATA;
392 av_log(avctx, AV_LOG_DEBUG,
393 "%dx%d diff start %d height %d\n",
394 i, j, s->diff_start, s->diff_height);
398 if (s->zlibprime_prev)
399 av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_prev\n", i, j);
401 if (s->zlibprime_curr) {
402 int col = get_bits(&gb, 8);
403 int row = get_bits(&gb, 8);
404 av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_curr %dx%d\n", i, j, col, row);
406 avpriv_request_sample(avctx, "zlibprime_curr");
407 return AVERROR_PATCHWELCOME;
409 if (!s->blocks && (s->zlibprime_curr || s->zlibprime_prev)) {
410 av_log(avctx, AV_LOG_ERROR, "no data available for zlib "
412 return AVERROR_INVALIDDATA;
414 size--; // account for flags byte
419 int off = (s->image_height - y_pos - 1) * s->frame.linesize[0];
421 for (k = 0; k < cur_blk_height; k++) {
422 int x = off - k * s->frame.linesize[0] + x_pos * 3;
423 memcpy(s->frame.data[0] + x, s->keyframe + x,
428 /* skip unchanged blocks, which have size 0 */
430 if (flashsv_decode_block(avctx, avpkt, &gb, size,
431 cur_blk_width, cur_blk_height,
433 i + j * (h_blocks + !!h_part)))
434 av_log(avctx, AV_LOG_ERROR,
435 "error in decompression of block %dx%d\n", i, j);
439 if (s->is_keyframe && s->ver == 2) {
441 s->keyframe = av_malloc(s->frame.linesize[0] * avctx->height);
443 av_log(avctx, AV_LOG_ERROR, "Cannot allocate image data\n");
444 return AVERROR(ENOMEM);
447 memcpy(s->keyframe, s->frame.data[0], s->frame.linesize[0] * avctx->height);
450 if ((ret = av_frame_ref(data, &s->frame)) < 0)
455 if ((get_bits_count(&gb) / 8) != buf_size)
456 av_log(avctx, AV_LOG_ERROR, "buffer not fully consumed (%d != %d)\n",
457 buf_size, (get_bits_count(&gb) / 8));
459 /* report that the buffer was completely consumed */
464 static av_cold int flashsv_decode_end(AVCodecContext *avctx)
466 FlashSVContext *s = avctx->priv_data;
467 inflateEnd(&s->zstream);
468 /* release the frame if needed */
469 av_frame_unref(&s->frame);
471 /* free the tmpblock */
472 av_free(s->tmpblock);
478 #if CONFIG_FLASHSV_DECODER
479 AVCodec ff_flashsv_decoder = {
481 .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video v1"),
482 .type = AVMEDIA_TYPE_VIDEO,
483 .id = AV_CODEC_ID_FLASHSV,
484 .priv_data_size = sizeof(FlashSVContext),
485 .init = flashsv_decode_init,
486 .close = flashsv_decode_end,
487 .decode = flashsv_decode_frame,
488 .capabilities = CODEC_CAP_DR1,
489 .pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
491 #endif /* CONFIG_FLASHSV_DECODER */
493 #if CONFIG_FLASHSV2_DECODER
494 static const uint32_t ff_flashsv2_default_palette[128] = {
495 0x000000, 0x333333, 0x666666, 0x999999, 0xCCCCCC, 0xFFFFFF,
496 0x330000, 0x660000, 0x990000, 0xCC0000, 0xFF0000, 0x003300,
497 0x006600, 0x009900, 0x00CC00, 0x00FF00, 0x000033, 0x000066,
498 0x000099, 0x0000CC, 0x0000FF, 0x333300, 0x666600, 0x999900,
499 0xCCCC00, 0xFFFF00, 0x003333, 0x006666, 0x009999, 0x00CCCC,
500 0x00FFFF, 0x330033, 0x660066, 0x990099, 0xCC00CC, 0xFF00FF,
501 0xFFFF33, 0xFFFF66, 0xFFFF99, 0xFFFFCC, 0xFF33FF, 0xFF66FF,
502 0xFF99FF, 0xFFCCFF, 0x33FFFF, 0x66FFFF, 0x99FFFF, 0xCCFFFF,
503 0xCCCC33, 0xCCCC66, 0xCCCC99, 0xCCCCFF, 0xCC33CC, 0xCC66CC,
504 0xCC99CC, 0xCCFFCC, 0x33CCCC, 0x66CCCC, 0x99CCCC, 0xFFCCCC,
505 0x999933, 0x999966, 0x9999CC, 0x9999FF, 0x993399, 0x996699,
506 0x99CC99, 0x99FF99, 0x339999, 0x669999, 0xCC9999, 0xFF9999,
507 0x666633, 0x666699, 0x6666CC, 0x6666FF, 0x663366, 0x669966,
508 0x66CC66, 0x66FF66, 0x336666, 0x996666, 0xCC6666, 0xFF6666,
509 0x333366, 0x333399, 0x3333CC, 0x3333FF, 0x336633, 0x339933,
510 0x33CC33, 0x33FF33, 0x663333, 0x993333, 0xCC3333, 0xFF3333,
511 0x003366, 0x336600, 0x660033, 0x006633, 0x330066, 0x663300,
512 0x336699, 0x669933, 0x993366, 0x339966, 0x663399, 0x996633,
513 0x6699CC, 0x99CC66, 0xCC6699, 0x66CC99, 0x9966CC, 0xCC9966,
514 0x99CCFF, 0xCCFF99, 0xFF99CC, 0x99FFCC, 0xCC99FF, 0xFFCC99,
515 0x111111, 0x222222, 0x444444, 0x555555, 0xAAAAAA, 0xBBBBBB,
519 static av_cold int flashsv2_decode_init(AVCodecContext *avctx)
521 FlashSVContext *s = avctx->priv_data;
522 flashsv_decode_init(avctx);
523 s->pal = ff_flashsv2_default_palette;
529 static av_cold int flashsv2_decode_end(AVCodecContext *avctx)
531 FlashSVContext *s = avctx->priv_data;
533 av_freep(&s->keyframedata);
534 av_freep(&s->blocks);
535 av_freep(&s->keyframe);
536 av_freep(&s->deflate_block);
537 flashsv_decode_end(avctx);
542 AVCodec ff_flashsv2_decoder = {
544 .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video v2"),
545 .type = AVMEDIA_TYPE_VIDEO,
546 .id = AV_CODEC_ID_FLASHSV2,
547 .priv_data_size = sizeof(FlashSVContext),
548 .init = flashsv2_decode_init,
549 .close = flashsv2_decode_end,
550 .decode = flashsv_decode_frame,
551 .capabilities = CODEC_CAP_DR1,
552 .pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
554 #endif /* CONFIG_FLASHSV2_DECODER */