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"
43 #include "bitstream.h"
44 #include "bytestream.h"
47 typedef struct BlockInfo {
52 typedef struct FlashSVContext {
53 AVCodecContext *avctx;
55 int image_width, image_height;
56 int block_width, block_height;
63 uint8_t *keyframedata;
66 uint8_t *deflate_block;
67 int deflate_block_size;
69 int zlibprime_curr, zlibprime_prev;
70 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_end(AVCodecContext *avctx)
105 FlashSVContext *s = avctx->priv_data;
106 inflateEnd(&s->zstream);
107 /* release the frame if needed */
108 av_frame_free(&s->frame);
110 /* free the tmpblock */
111 av_free(s->tmpblock);
116 static av_cold int flashsv_decode_init(AVCodecContext *avctx)
118 FlashSVContext *s = avctx->priv_data;
119 int zret; // Zlib return code
122 s->zstream.zalloc = Z_NULL;
123 s->zstream.zfree = Z_NULL;
124 s->zstream.opaque = Z_NULL;
125 zret = inflateInit(&s->zstream);
127 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
130 avctx->pix_fmt = AV_PIX_FMT_BGR24;
132 s->frame = av_frame_alloc();
134 flashsv_decode_end(avctx);
135 return AVERROR(ENOMEM);
141 static int flashsv2_prime(FlashSVContext *s, uint8_t *src, int size)
144 int zret; // Zlib return code
150 s->zstream.next_in = src;
151 s->zstream.avail_in = size;
152 s->zstream.next_out = s->tmpblock;
153 s->zstream.avail_out = s->block_size * 3;
154 inflate(&s->zstream, Z_SYNC_FLUSH);
157 zs.next_in = s->tmpblock;
158 zs.avail_in = s->block_size * 3 - s->zstream.avail_out;
159 zs.next_out = s->deflate_block;
160 zs.avail_out = s->deflate_block_size;
161 deflate(&zs, Z_SYNC_FLUSH);
164 if ((zret = inflateReset(&s->zstream)) != Z_OK) {
165 av_log(s->avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
166 return AVERROR_UNKNOWN;
169 s->zstream.next_in = s->deflate_block;
170 s->zstream.avail_in = s->deflate_block_size - zs.avail_out;
171 s->zstream.next_out = s->tmpblock;
172 s->zstream.avail_out = s->block_size * 3;
173 inflate(&s->zstream, Z_SYNC_FLUSH);
178 static int flashsv_decode_block(AVCodecContext *avctx, AVPacket *avpkt,
179 BitstreamContext *bc, int block_size,
180 int width, int height, int x_pos, int y_pos,
183 struct FlashSVContext *s = avctx->priv_data;
184 uint8_t *line = s->tmpblock;
186 int ret = inflateReset(&s->zstream);
188 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
189 return AVERROR_UNKNOWN;
191 if (s->zlibprime_curr || s->zlibprime_prev) {
192 ret = flashsv2_prime(s,
193 s->blocks[blk_idx].pos,
194 s->blocks[blk_idx].size);
198 s->zstream.next_in = avpkt->data + bitstream_tell(bc) / 8;
199 s->zstream.avail_in = block_size;
200 s->zstream.next_out = s->tmpblock;
201 s->zstream.avail_out = s->block_size * 3;
202 ret = inflate(&s->zstream, Z_FINISH);
203 if (ret == Z_DATA_ERROR) {
204 av_log(avctx, AV_LOG_ERROR, "Zlib resync occurred\n");
205 inflateSync(&s->zstream);
206 ret = inflate(&s->zstream, Z_FINISH);
209 if (ret != Z_OK && ret != Z_STREAM_END) {
213 if (s->is_keyframe) {
214 s->blocks[blk_idx].pos = s->keyframedata + (bitstream_tell(bc) / 8);
215 s->blocks[blk_idx].size = block_size;
218 y_pos += s->diff_start;
220 if (!s->color_depth) {
221 /* Flash Screen Video stores the image upside down, so copy
222 * lines to destination in reverse order. */
223 for (k = 1; k <= s->diff_height; k++) {
224 memcpy(s->frame->data[0] + x_pos * 3 +
225 (s->image_height - y_pos - k) * s->frame->linesize[0],
227 /* advance source pointer to next line */
231 /* hybrid 15-bit/palette mode */
232 decode_hybrid(s->tmpblock, s->frame->data[0],
233 s->image_height - (y_pos + 1 + s->diff_height),
234 x_pos, s->diff_height, width,
235 s->frame->linesize[0], s->pal);
237 bitstream_skip(bc, 8 * block_size); /* skip the consumed bits */
241 static int calc_deflate_block_size(int tmpblock_size)
246 zstream.zalloc = Z_NULL;
247 zstream.zfree = Z_NULL;
248 zstream.opaque = Z_NULL;
249 if (deflateInit(&zstream, 0) != Z_OK)
251 size = deflateBound(&zstream, tmpblock_size);
252 deflateEnd(&zstream);
257 static int flashsv_decode_frame(AVCodecContext *avctx, void *data,
258 int *got_frame, AVPacket *avpkt)
260 int buf_size = avpkt->size;
261 FlashSVContext *s = avctx->priv_data;
262 int h_blocks, v_blocks, h_part, v_part, i, j, ret;
265 /* no supplementary picture */
271 bitstream_init8(&bc, avpkt->data, buf_size);
273 /* start to parse the bitstream */
274 s->block_width = 16 * (bitstream_read(&bc, 4) + 1);
275 s->image_width = bitstream_read(&bc, 12);
276 s->block_height = 16 * (bitstream_read(&bc, 4) + 1);
277 s->image_height = bitstream_read(&bc, 12);
280 bitstream_skip(&bc, 6);
281 if (bitstream_read_bit(&bc)) {
282 avpriv_request_sample(avctx, "iframe");
283 return AVERROR_PATCHWELCOME;
285 if (bitstream_read_bit(&bc)) {
286 avpriv_request_sample(avctx, "Custom palette");
287 return AVERROR_PATCHWELCOME;
291 /* calculate number of blocks and size of border (partial) blocks */
292 h_blocks = s->image_width / s->block_width;
293 h_part = s->image_width % s->block_width;
294 v_blocks = s->image_height / s->block_height;
295 v_part = s->image_height % s->block_height;
297 /* the block size could change between frames, make sure the buffer
298 * is large enough, if not, get a larger one */
299 if (s->block_size < s->block_width * s->block_height) {
300 int tmpblock_size = 3 * s->block_width * s->block_height, err;
302 if ((err = av_reallocp(&s->tmpblock, tmpblock_size)) < 0) {
304 av_log(avctx, AV_LOG_ERROR,
305 "Cannot allocate decompression buffer.\n");
309 s->deflate_block_size = calc_deflate_block_size(tmpblock_size);
310 if (s->deflate_block_size <= 0) {
311 av_log(avctx, AV_LOG_ERROR,
312 "Cannot determine deflate buffer size.\n");
315 if ((err = av_reallocp(&s->deflate_block, s->deflate_block_size)) < 0) {
317 av_log(avctx, AV_LOG_ERROR, "Cannot allocate deflate buffer.\n");
322 s->block_size = s->block_width * s->block_height;
324 /* initialize the image size once */
325 if (avctx->width == 0 && avctx->height == 0) {
326 avctx->width = s->image_width;
327 avctx->height = s->image_height;
330 /* check for changes of image width and image height */
331 if (avctx->width != s->image_width || avctx->height != s->image_height) {
332 av_log(avctx, AV_LOG_ERROR,
333 "Frame width or height differs from first frame!\n");
334 av_log(avctx, AV_LOG_ERROR, "fh = %d, fv %d vs ch = %d, cv = %d\n",
335 avctx->height, avctx->width, s->image_height, s->image_width);
336 return AVERROR_INVALIDDATA;
339 /* we care for keyframes only in Screen Video v2 */
340 s->is_keyframe = (avpkt->flags & AV_PKT_FLAG_KEY) && (s->ver == 2);
341 if (s->is_keyframe) {
343 int nb_blocks = (v_blocks + !!v_part) *
344 (h_blocks + !!h_part) * sizeof(s->blocks[0]);
345 if ((err = av_reallocp(&s->keyframedata, avpkt->size)) < 0)
347 memcpy(s->keyframedata, avpkt->data, avpkt->size);
348 if ((err = av_reallocp(&s->blocks, nb_blocks)) < 0)
350 memset(s->blocks, 0, nb_blocks);
353 ff_dlog(avctx, "image: %dx%d block: %dx%d num: %dx%d part: %dx%d\n",
354 s->image_width, s->image_height, s->block_width, s->block_height,
355 h_blocks, v_blocks, h_part, v_part);
357 if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) {
358 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
362 /* loop over all block columns */
363 for (j = 0; j < v_blocks + (v_part ? 1 : 0); j++) {
365 int y_pos = j * s->block_height; // vertical position in frame
366 int cur_blk_height = (j < v_blocks) ? s->block_height : v_part;
368 /* loop over all block rows */
369 for (i = 0; i < h_blocks + (h_part ? 1 : 0); i++) {
370 int x_pos = i * s->block_width; // horizontal position in frame
371 int cur_blk_width = (i < h_blocks) ? s->block_width : h_part;
374 /* get the size of the compressed zlib chunk */
375 int size = bitstream_read(&bc, 16);
378 s->zlibprime_curr = 0;
379 s->zlibprime_prev = 0;
381 s->diff_height = cur_blk_height;
383 if (8 * size > bitstream_bits_left(&bc)) {
384 av_frame_unref(s->frame);
385 return AVERROR_INVALIDDATA;
388 if (s->ver == 2 && size) {
389 bitstream_skip(&bc, 3);
390 s->color_depth = bitstream_read(&bc, 2);
391 has_diff = bitstream_read_bit(&bc);
392 s->zlibprime_curr = bitstream_read_bit(&bc);
393 s->zlibprime_prev = bitstream_read_bit(&bc);
395 if (s->color_depth != 0 && s->color_depth != 2) {
396 av_log(avctx, AV_LOG_ERROR,
397 "%dx%d invalid color depth %d\n",
398 i, j, s->color_depth);
399 return AVERROR_INVALIDDATA;
404 av_log(avctx, AV_LOG_ERROR,
405 "Inter frame without keyframe\n");
406 return AVERROR_INVALIDDATA;
408 s->diff_start = bitstream_read(&bc, 8);
409 s->diff_height = bitstream_read(&bc, 8);
410 if (s->diff_start + s->diff_height > cur_blk_height) {
411 av_log(avctx, AV_LOG_ERROR,
412 "Block parameters invalid: %d + %d > %d\n",
413 s->diff_start, s->diff_height, cur_blk_height);
414 return AVERROR_INVALIDDATA;
416 av_log(avctx, AV_LOG_DEBUG,
417 "%dx%d diff start %d height %d\n",
418 i, j, s->diff_start, s->diff_height);
422 if (s->zlibprime_prev)
423 av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_prev\n", i, j);
425 if (s->zlibprime_curr) {
426 int col = bitstream_read(&bc, 8);
427 int row = bitstream_read(&bc, 8);
428 av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_curr %dx%d\n",
431 avpriv_request_sample(avctx, "zlibprime_curr");
432 return AVERROR_PATCHWELCOME;
434 if (!s->blocks && (s->zlibprime_curr || s->zlibprime_prev)) {
435 av_log(avctx, AV_LOG_ERROR,
436 "no data available for zlib priming\n");
437 return AVERROR_INVALIDDATA;
439 size--; // account for flags byte
444 int off = (s->image_height - y_pos - 1) * s->frame->linesize[0];
446 for (k = 0; k < cur_blk_height; k++) {
447 int x = off - k * s->frame->linesize[0] + x_pos * 3;
448 memcpy(s->frame->data[0] + x, s->keyframe + x,
453 /* skip unchanged blocks, which have size 0 */
455 if (flashsv_decode_block(avctx, avpkt, &bc, size,
456 cur_blk_width, cur_blk_height,
458 i + j * (h_blocks + !!h_part)))
459 av_log(avctx, AV_LOG_ERROR,
460 "error in decompression of block %dx%d\n", i, j);
464 if (s->is_keyframe && s->ver == 2) {
466 s->keyframe = av_malloc(s->frame->linesize[0] * avctx->height);
468 av_log(avctx, AV_LOG_ERROR, "Cannot allocate image data\n");
469 return AVERROR(ENOMEM);
472 memcpy(s->keyframe, s->frame->data[0],
473 s->frame->linesize[0] * avctx->height);
476 if ((ret = av_frame_ref(data, s->frame)) < 0)
481 if ((bitstream_tell(&bc) / 8) != buf_size)
482 av_log(avctx, AV_LOG_ERROR, "buffer not fully consumed (%d != %d)\n",
483 buf_size, (bitstream_tell(&bc) / 8));
485 /* report that the buffer was completely consumed */
489 #if CONFIG_FLASHSV_DECODER
490 AVCodec ff_flashsv_decoder = {
492 .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video v1"),
493 .type = AVMEDIA_TYPE_VIDEO,
494 .id = AV_CODEC_ID_FLASHSV,
495 .priv_data_size = sizeof(FlashSVContext),
496 .init = flashsv_decode_init,
497 .close = flashsv_decode_end,
498 .decode = flashsv_decode_frame,
499 .capabilities = AV_CODEC_CAP_DR1,
500 .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
502 #endif /* CONFIG_FLASHSV_DECODER */
504 #if CONFIG_FLASHSV2_DECODER
505 static const uint32_t ff_flashsv2_default_palette[128] = {
506 0x000000, 0x333333, 0x666666, 0x999999, 0xCCCCCC, 0xFFFFFF,
507 0x330000, 0x660000, 0x990000, 0xCC0000, 0xFF0000, 0x003300,
508 0x006600, 0x009900, 0x00CC00, 0x00FF00, 0x000033, 0x000066,
509 0x000099, 0x0000CC, 0x0000FF, 0x333300, 0x666600, 0x999900,
510 0xCCCC00, 0xFFFF00, 0x003333, 0x006666, 0x009999, 0x00CCCC,
511 0x00FFFF, 0x330033, 0x660066, 0x990099, 0xCC00CC, 0xFF00FF,
512 0xFFFF33, 0xFFFF66, 0xFFFF99, 0xFFFFCC, 0xFF33FF, 0xFF66FF,
513 0xFF99FF, 0xFFCCFF, 0x33FFFF, 0x66FFFF, 0x99FFFF, 0xCCFFFF,
514 0xCCCC33, 0xCCCC66, 0xCCCC99, 0xCCCCFF, 0xCC33CC, 0xCC66CC,
515 0xCC99CC, 0xCCFFCC, 0x33CCCC, 0x66CCCC, 0x99CCCC, 0xFFCCCC,
516 0x999933, 0x999966, 0x9999CC, 0x9999FF, 0x993399, 0x996699,
517 0x99CC99, 0x99FF99, 0x339999, 0x669999, 0xCC9999, 0xFF9999,
518 0x666633, 0x666699, 0x6666CC, 0x6666FF, 0x663366, 0x669966,
519 0x66CC66, 0x66FF66, 0x336666, 0x996666, 0xCC6666, 0xFF6666,
520 0x333366, 0x333399, 0x3333CC, 0x3333FF, 0x336633, 0x339933,
521 0x33CC33, 0x33FF33, 0x663333, 0x993333, 0xCC3333, 0xFF3333,
522 0x003366, 0x336600, 0x660033, 0x006633, 0x330066, 0x663300,
523 0x336699, 0x669933, 0x993366, 0x339966, 0x663399, 0x996633,
524 0x6699CC, 0x99CC66, 0xCC6699, 0x66CC99, 0x9966CC, 0xCC9966,
525 0x99CCFF, 0xCCFF99, 0xFF99CC, 0x99FFCC, 0xCC99FF, 0xFFCC99,
526 0x111111, 0x222222, 0x444444, 0x555555, 0xAAAAAA, 0xBBBBBB,
530 static av_cold int flashsv2_decode_init(AVCodecContext *avctx)
532 FlashSVContext *s = avctx->priv_data;
533 flashsv_decode_init(avctx);
534 s->pal = ff_flashsv2_default_palette;
540 static av_cold int flashsv2_decode_end(AVCodecContext *avctx)
542 FlashSVContext *s = avctx->priv_data;
544 av_freep(&s->keyframedata);
545 av_freep(&s->blocks);
546 av_freep(&s->keyframe);
547 av_freep(&s->deflate_block);
548 flashsv_decode_end(avctx);
553 AVCodec ff_flashsv2_decoder = {
555 .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video v2"),
556 .type = AVMEDIA_TYPE_VIDEO,
557 .id = AV_CODEC_ID_FLASHSV2,
558 .priv_data_size = sizeof(FlashSVContext),
559 .init = flashsv2_decode_init,
560 .close = flashsv2_decode_end,
561 .decode = flashsv_decode_frame,
562 .capabilities = AV_CODEC_CAP_DR1,
563 .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
565 #endif /* CONFIG_FLASHSV2_DECODER */