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;
72 static int decode_hybrid(const uint8_t *sptr, uint8_t *dptr, int dx, int dy,
73 int h, int w, int stride, const uint32_t *pal)
76 const uint8_t *orig_src = sptr;
78 for (y = dx + h; y > dx; y--) {
79 uint8_t *dst = dptr + (y * stride) + dy * 3;
80 for (x = 0; x < w; x++) {
83 unsigned c = AV_RB16(sptr) & ~0x8000;
84 unsigned b = c & 0x1F;
85 unsigned g = (c >> 5) & 0x1F;
87 /* 000aaabb -> aaabbaaa */
88 *dst++ = (b << 3) | (b >> 2);
89 *dst++ = (g << 3) | (g >> 2);
90 *dst++ = (r << 3) | (r >> 2);
94 uint32_t c = pal[*sptr++];
95 bytestream_put_le24(&dst, c);
99 return sptr - orig_src;
102 static av_cold int flashsv_decode_end(AVCodecContext *avctx)
104 FlashSVContext *s = avctx->priv_data;
105 inflateEnd(&s->zstream);
106 /* release the frame if needed */
107 av_frame_free(&s->frame);
109 /* free the tmpblock */
110 av_free(s->tmpblock);
115 static av_cold int flashsv_decode_init(AVCodecContext *avctx)
117 FlashSVContext *s = avctx->priv_data;
118 int zret; // Zlib return code
121 s->zstream.zalloc = Z_NULL;
122 s->zstream.zfree = Z_NULL;
123 s->zstream.opaque = Z_NULL;
124 zret = inflateInit(&s->zstream);
126 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
129 avctx->pix_fmt = AV_PIX_FMT_BGR24;
131 s->frame = av_frame_alloc();
133 flashsv_decode_end(avctx);
134 return AVERROR(ENOMEM);
140 static int flashsv2_prime(FlashSVContext *s, uint8_t *src, int size)
143 int zret; // Zlib return code
149 s->zstream.next_in = src;
150 s->zstream.avail_in = size;
151 s->zstream.next_out = s->tmpblock;
152 s->zstream.avail_out = s->block_size * 3;
153 inflate(&s->zstream, Z_SYNC_FLUSH);
156 zs.next_in = s->tmpblock;
157 zs.avail_in = s->block_size * 3 - s->zstream.avail_out;
158 zs.next_out = s->deflate_block;
159 zs.avail_out = s->deflate_block_size;
160 deflate(&zs, Z_SYNC_FLUSH);
163 if ((zret = inflateReset(&s->zstream)) != Z_OK) {
164 av_log(s->avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
165 return AVERROR_UNKNOWN;
168 s->zstream.next_in = s->deflate_block;
169 s->zstream.avail_in = s->deflate_block_size - zs.avail_out;
170 s->zstream.next_out = s->tmpblock;
171 s->zstream.avail_out = s->block_size * 3;
172 inflate(&s->zstream, Z_SYNC_FLUSH);
177 static int flashsv_decode_block(AVCodecContext *avctx, AVPacket *avpkt,
178 GetBitContext *gb, int block_size,
179 int width, int height, int x_pos, int y_pos,
182 struct FlashSVContext *s = avctx->priv_data;
183 uint8_t *line = s->tmpblock;
185 int ret = inflateReset(&s->zstream);
187 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
188 return AVERROR_UNKNOWN;
190 if (s->zlibprime_curr || s->zlibprime_prev) {
191 ret = flashsv2_prime(s,
192 s->blocks[blk_idx].pos,
193 s->blocks[blk_idx].size);
197 s->zstream.next_in = avpkt->data + get_bits_count(gb) / 8;
198 s->zstream.avail_in = block_size;
199 s->zstream.next_out = s->tmpblock;
200 s->zstream.avail_out = s->block_size * 3;
201 ret = inflate(&s->zstream, Z_FINISH);
202 if (ret == Z_DATA_ERROR) {
203 av_log(avctx, AV_LOG_ERROR, "Zlib resync occurred\n");
204 inflateSync(&s->zstream);
205 ret = inflate(&s->zstream, Z_FINISH);
208 if (ret != Z_OK && ret != Z_STREAM_END) {
212 if (s->is_keyframe) {
213 s->blocks[blk_idx].pos = s->keyframedata + (get_bits_count(gb) / 8);
214 s->blocks[blk_idx].size = block_size;
217 y_pos += s->diff_start;
219 if (!s->color_depth) {
220 /* Flash Screen Video stores the image upside down, so copy
221 * lines to destination in reverse order. */
222 for (k = 1; k <= s->diff_height; k++) {
223 memcpy(s->frame->data[0] + x_pos * 3 +
224 (s->image_height - y_pos - k) * s->frame->linesize[0],
226 /* advance source pointer to next line */
230 /* hybrid 15-bit/palette mode */
231 decode_hybrid(s->tmpblock, s->frame->data[0],
232 s->image_height - (y_pos + 1 + s->diff_height),
233 x_pos, s->diff_height, width,
234 s->frame->linesize[0], s->pal);
236 skip_bits_long(gb, 8 * block_size); /* skip the consumed bits */
240 static int calc_deflate_block_size(int tmpblock_size)
245 zstream.zalloc = Z_NULL;
246 zstream.zfree = Z_NULL;
247 zstream.opaque = Z_NULL;
248 if (deflateInit(&zstream, 0) != Z_OK)
250 size = deflateBound(&zstream, tmpblock_size);
251 deflateEnd(&zstream);
256 static int flashsv_decode_frame(AVCodecContext *avctx, void *data,
257 int *got_frame, AVPacket *avpkt)
259 int buf_size = avpkt->size;
260 FlashSVContext *s = avctx->priv_data;
261 int h_blocks, v_blocks, h_part, v_part, i, j, ret;
264 /* no supplementary picture */
270 init_get_bits(&gb, avpkt->data, buf_size * 8);
272 /* start to parse the bitstream */
273 s->block_width = 16 * (get_bits(&gb, 4) + 1);
274 s->image_width = get_bits(&gb, 12);
275 s->block_height = 16 * (get_bits(&gb, 4) + 1);
276 s->image_height = get_bits(&gb, 12);
280 if (get_bits1(&gb)) {
281 avpriv_request_sample(avctx, "iframe");
282 return AVERROR_PATCHWELCOME;
284 if (get_bits1(&gb)) {
285 avpriv_request_sample(avctx, "Custom palette");
286 return AVERROR_PATCHWELCOME;
290 /* calculate number of blocks and size of border (partial) blocks */
291 h_blocks = s->image_width / s->block_width;
292 h_part = s->image_width % s->block_width;
293 v_blocks = s->image_height / s->block_height;
294 v_part = s->image_height % s->block_height;
296 /* the block size could change between frames, make sure the buffer
297 * is large enough, if not, get a larger one */
298 if (s->block_size < s->block_width * s->block_height) {
299 int tmpblock_size = 3 * s->block_width * s->block_height, err;
301 if ((err = av_reallocp(&s->tmpblock, tmpblock_size)) < 0) {
303 av_log(avctx, AV_LOG_ERROR,
304 "Cannot allocate decompression buffer.\n");
308 s->deflate_block_size = calc_deflate_block_size(tmpblock_size);
309 if (s->deflate_block_size <= 0) {
310 av_log(avctx, AV_LOG_ERROR,
311 "Cannot determine deflate buffer size.\n");
314 if ((err = av_reallocp(&s->deflate_block, s->deflate_block_size)) < 0) {
316 av_log(avctx, AV_LOG_ERROR, "Cannot allocate deflate buffer.\n");
321 s->block_size = s->block_width * s->block_height;
323 /* initialize the image size once */
324 if (avctx->width == 0 && avctx->height == 0) {
325 avctx->width = s->image_width;
326 avctx->height = s->image_height;
329 /* check for changes of image width and image height */
330 if (avctx->width != s->image_width || avctx->height != s->image_height) {
331 av_log(avctx, AV_LOG_ERROR,
332 "Frame width or height differs from first frame!\n");
333 av_log(avctx, AV_LOG_ERROR, "fh = %d, fv %d vs ch = %d, cv = %d\n",
334 avctx->height, avctx->width, s->image_height, s->image_width);
335 return AVERROR_INVALIDDATA;
338 /* we care for keyframes only in Screen Video v2 */
339 s->is_keyframe = (avpkt->flags & AV_PKT_FLAG_KEY) && (s->ver == 2);
340 if (s->is_keyframe) {
342 int nb_blocks = (v_blocks + !!v_part) *
343 (h_blocks + !!h_part) * sizeof(s->blocks[0]);
344 if ((err = av_reallocp(&s->keyframedata, avpkt->size)) < 0)
346 memcpy(s->keyframedata, avpkt->data, avpkt->size);
347 if ((err = av_reallocp(&s->blocks, nb_blocks)) < 0)
349 memset(s->blocks, 0, nb_blocks);
352 ff_dlog(avctx, "image: %dx%d block: %dx%d num: %dx%d part: %dx%d\n",
353 s->image_width, s->image_height, s->block_width, s->block_height,
354 h_blocks, v_blocks, h_part, v_part);
356 if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) {
357 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
361 /* loop over all block columns */
362 for (j = 0; j < v_blocks + (v_part ? 1 : 0); j++) {
364 int y_pos = j * s->block_height; // vertical position in frame
365 int cur_blk_height = (j < v_blocks) ? s->block_height : v_part;
367 /* loop over all block rows */
368 for (i = 0; i < h_blocks + (h_part ? 1 : 0); i++) {
369 int x_pos = i * s->block_width; // horizontal position in frame
370 int cur_blk_width = (i < h_blocks) ? s->block_width : h_part;
373 /* get the size of the compressed zlib chunk */
374 int size = get_bits(&gb, 16);
377 s->zlibprime_curr = 0;
378 s->zlibprime_prev = 0;
380 s->diff_height = cur_blk_height;
382 if (8 * size > get_bits_left(&gb)) {
383 av_frame_unref(s->frame);
384 return AVERROR_INVALIDDATA;
387 if (s->ver == 2 && size) {
389 s->color_depth = get_bits(&gb, 2);
390 has_diff = get_bits1(&gb);
391 s->zlibprime_curr = get_bits1(&gb);
392 s->zlibprime_prev = get_bits1(&gb);
394 if (s->color_depth != 0 && s->color_depth != 2) {
395 av_log(avctx, AV_LOG_ERROR,
396 "%dx%d invalid color depth %d\n",
397 i, j, s->color_depth);
398 return AVERROR_INVALIDDATA;
403 av_log(avctx, AV_LOG_ERROR,
404 "Inter frame without keyframe\n");
405 return AVERROR_INVALIDDATA;
407 s->diff_start = get_bits(&gb, 8);
408 s->diff_height = get_bits(&gb, 8);
409 if (s->diff_start + s->diff_height > cur_blk_height) {
410 av_log(avctx, AV_LOG_ERROR,
411 "Block parameters invalid: %d + %d > %d\n",
412 s->diff_start, s->diff_height, cur_blk_height);
413 return AVERROR_INVALIDDATA;
415 av_log(avctx, AV_LOG_DEBUG,
416 "%dx%d diff start %d height %d\n",
417 i, j, s->diff_start, s->diff_height);
421 if (s->zlibprime_prev)
422 av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_prev\n", i, j);
424 if (s->zlibprime_curr) {
425 int col = get_bits(&gb, 8);
426 int row = get_bits(&gb, 8);
427 av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_curr %dx%d\n",
430 avpriv_request_sample(avctx, "zlibprime_curr");
431 return AVERROR_PATCHWELCOME;
433 if (!s->blocks && (s->zlibprime_curr || s->zlibprime_prev)) {
434 av_log(avctx, AV_LOG_ERROR,
435 "no data available for zlib priming\n");
436 return AVERROR_INVALIDDATA;
438 size--; // account for flags byte
443 int off = (s->image_height - y_pos - 1) * s->frame->linesize[0];
445 for (k = 0; k < cur_blk_height; k++) {
446 int x = off - k * s->frame->linesize[0] + x_pos * 3;
447 memcpy(s->frame->data[0] + x, s->keyframe + x,
452 /* skip unchanged blocks, which have size 0 */
454 if (flashsv_decode_block(avctx, avpkt, &gb, size,
455 cur_blk_width, cur_blk_height,
457 i + j * (h_blocks + !!h_part)))
458 av_log(avctx, AV_LOG_ERROR,
459 "error in decompression of block %dx%d\n", i, j);
463 if (s->is_keyframe && s->ver == 2) {
465 s->keyframe = av_malloc(s->frame->linesize[0] * avctx->height);
467 av_log(avctx, AV_LOG_ERROR, "Cannot allocate image data\n");
468 return AVERROR(ENOMEM);
471 memcpy(s->keyframe, s->frame->data[0],
472 s->frame->linesize[0] * avctx->height);
475 if ((ret = av_frame_ref(data, s->frame)) < 0)
480 if ((get_bits_count(&gb) / 8) != buf_size)
481 av_log(avctx, AV_LOG_ERROR, "buffer not fully consumed (%d != %d)\n",
482 buf_size, (get_bits_count(&gb) / 8));
484 /* report that the buffer was completely consumed */
488 #if CONFIG_FLASHSV_DECODER
489 AVCodec ff_flashsv_decoder = {
491 .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video v1"),
492 .type = AVMEDIA_TYPE_VIDEO,
493 .id = AV_CODEC_ID_FLASHSV,
494 .priv_data_size = sizeof(FlashSVContext),
495 .init = flashsv_decode_init,
496 .close = flashsv_decode_end,
497 .decode = flashsv_decode_frame,
498 .capabilities = AV_CODEC_CAP_DR1,
499 .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
501 #endif /* CONFIG_FLASHSV_DECODER */
503 #if CONFIG_FLASHSV2_DECODER
504 static const uint32_t ff_flashsv2_default_palette[128] = {
505 0x000000, 0x333333, 0x666666, 0x999999, 0xCCCCCC, 0xFFFFFF,
506 0x330000, 0x660000, 0x990000, 0xCC0000, 0xFF0000, 0x003300,
507 0x006600, 0x009900, 0x00CC00, 0x00FF00, 0x000033, 0x000066,
508 0x000099, 0x0000CC, 0x0000FF, 0x333300, 0x666600, 0x999900,
509 0xCCCC00, 0xFFFF00, 0x003333, 0x006666, 0x009999, 0x00CCCC,
510 0x00FFFF, 0x330033, 0x660066, 0x990099, 0xCC00CC, 0xFF00FF,
511 0xFFFF33, 0xFFFF66, 0xFFFF99, 0xFFFFCC, 0xFF33FF, 0xFF66FF,
512 0xFF99FF, 0xFFCCFF, 0x33FFFF, 0x66FFFF, 0x99FFFF, 0xCCFFFF,
513 0xCCCC33, 0xCCCC66, 0xCCCC99, 0xCCCCFF, 0xCC33CC, 0xCC66CC,
514 0xCC99CC, 0xCCFFCC, 0x33CCCC, 0x66CCCC, 0x99CCCC, 0xFFCCCC,
515 0x999933, 0x999966, 0x9999CC, 0x9999FF, 0x993399, 0x996699,
516 0x99CC99, 0x99FF99, 0x339999, 0x669999, 0xCC9999, 0xFF9999,
517 0x666633, 0x666699, 0x6666CC, 0x6666FF, 0x663366, 0x669966,
518 0x66CC66, 0x66FF66, 0x336666, 0x996666, 0xCC6666, 0xFF6666,
519 0x333366, 0x333399, 0x3333CC, 0x3333FF, 0x336633, 0x339933,
520 0x33CC33, 0x33FF33, 0x663333, 0x993333, 0xCC3333, 0xFF3333,
521 0x003366, 0x336600, 0x660033, 0x006633, 0x330066, 0x663300,
522 0x336699, 0x669933, 0x993366, 0x339966, 0x663399, 0x996633,
523 0x6699CC, 0x99CC66, 0xCC6699, 0x66CC99, 0x9966CC, 0xCC9966,
524 0x99CCFF, 0xCCFF99, 0xFF99CC, 0x99FFCC, 0xCC99FF, 0xFFCC99,
525 0x111111, 0x222222, 0x444444, 0x555555, 0xAAAAAA, 0xBBBBBB,
529 static av_cold int flashsv2_decode_init(AVCodecContext *avctx)
531 FlashSVContext *s = avctx->priv_data;
532 flashsv_decode_init(avctx);
533 s->pal = ff_flashsv2_default_palette;
539 static av_cold int flashsv2_decode_end(AVCodecContext *avctx)
541 FlashSVContext *s = avctx->priv_data;
543 av_freep(&s->keyframedata);
544 av_freep(&s->blocks);
545 av_freep(&s->keyframe);
546 av_freep(&s->deflate_block);
547 flashsv_decode_end(avctx);
552 AVCodec ff_flashsv2_decoder = {
554 .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video v2"),
555 .type = AVMEDIA_TYPE_VIDEO,
556 .id = AV_CODEC_ID_FLASHSV2,
557 .priv_data_size = sizeof(FlashSVContext),
558 .init = flashsv2_decode_init,
559 .close = flashsv2_decode_end,
560 .decode = flashsv_decode_frame,
561 .capabilities = AV_CODEC_CAP_DR1,
562 .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
564 #endif /* CONFIG_FLASHSV2_DECODER */