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 if ((err = av_reallocp(&s->keyframedata, avpkt->size)) < 0)
344 memcpy(s->keyframedata, avpkt->data, avpkt->size);
345 if ((err = av_reallocp(&s->blocks, (v_blocks + !!v_part) *
346 (h_blocks + !!h_part) * sizeof(s->blocks[0]))) < 0)
350 av_dlog(avctx, "image: %dx%d block: %dx%d num: %dx%d part: %dx%d\n",
351 s->image_width, s->image_height, s->block_width, s->block_height,
352 h_blocks, v_blocks, h_part, v_part);
354 if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) {
355 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
359 /* loop over all block columns */
360 for (j = 0; j < v_blocks + (v_part ? 1 : 0); j++) {
362 int y_pos = j * s->block_height; // vertical position in frame
363 int cur_blk_height = (j < v_blocks) ? s->block_height : v_part;
365 /* loop over all block rows */
366 for (i = 0; i < h_blocks + (h_part ? 1 : 0); i++) {
367 int x_pos = i * s->block_width; // horizontal position in frame
368 int cur_blk_width = (i < h_blocks) ? s->block_width : h_part;
371 /* get the size of the compressed zlib chunk */
372 int size = get_bits(&gb, 16);
375 s->zlibprime_curr = 0;
376 s->zlibprime_prev = 0;
378 s->diff_height = cur_blk_height;
380 if (8 * size > get_bits_left(&gb)) {
381 av_frame_unref(s->frame);
382 return AVERROR_INVALIDDATA;
385 if (s->ver == 2 && size) {
387 s->color_depth = get_bits(&gb, 2);
388 has_diff = get_bits1(&gb);
389 s->zlibprime_curr = get_bits1(&gb);
390 s->zlibprime_prev = get_bits1(&gb);
392 if (s->color_depth != 0 && s->color_depth != 2) {
393 av_log(avctx, AV_LOG_ERROR,
394 "%dx%d invalid color depth %d\n",
395 i, j, s->color_depth);
396 return AVERROR_INVALIDDATA;
401 av_log(avctx, AV_LOG_ERROR,
402 "Inter frame without keyframe\n");
403 return AVERROR_INVALIDDATA;
405 s->diff_start = get_bits(&gb, 8);
406 s->diff_height = get_bits(&gb, 8);
407 if (s->diff_start + s->diff_height > cur_blk_height) {
408 av_log(avctx, AV_LOG_ERROR,
409 "Block parameters invalid: %d + %d > %d\n",
410 s->diff_start, s->diff_height, cur_blk_height);
411 return AVERROR_INVALIDDATA;
413 av_log(avctx, AV_LOG_DEBUG,
414 "%dx%d diff start %d height %d\n",
415 i, j, s->diff_start, s->diff_height);
419 if (s->zlibprime_prev)
420 av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_prev\n", i, j);
422 if (s->zlibprime_curr) {
423 int col = get_bits(&gb, 8);
424 int row = get_bits(&gb, 8);
425 av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_curr %dx%d\n",
428 avpriv_request_sample(avctx, "zlibprime_curr");
429 return AVERROR_PATCHWELCOME;
431 if (!s->blocks && (s->zlibprime_curr || s->zlibprime_prev)) {
432 av_log(avctx, AV_LOG_ERROR,
433 "no data available for zlib priming\n");
434 return AVERROR_INVALIDDATA;
436 size--; // account for flags byte
441 int off = (s->image_height - y_pos - 1) * s->frame->linesize[0];
443 for (k = 0; k < cur_blk_height; k++) {
444 int x = off - k * s->frame->linesize[0] + x_pos * 3;
445 memcpy(s->frame->data[0] + x, s->keyframe + x,
450 /* skip unchanged blocks, which have size 0 */
452 if (flashsv_decode_block(avctx, avpkt, &gb, size,
453 cur_blk_width, cur_blk_height,
455 i + j * (h_blocks + !!h_part)))
456 av_log(avctx, AV_LOG_ERROR,
457 "error in decompression of block %dx%d\n", i, j);
461 if (s->is_keyframe && s->ver == 2) {
463 s->keyframe = av_malloc(s->frame->linesize[0] * avctx->height);
465 av_log(avctx, AV_LOG_ERROR, "Cannot allocate image data\n");
466 return AVERROR(ENOMEM);
469 memcpy(s->keyframe, s->frame->data[0],
470 s->frame->linesize[0] * avctx->height);
473 if ((ret = av_frame_ref(data, s->frame)) < 0)
478 if ((get_bits_count(&gb) / 8) != buf_size)
479 av_log(avctx, AV_LOG_ERROR, "buffer not fully consumed (%d != %d)\n",
480 buf_size, (get_bits_count(&gb) / 8));
482 /* report that the buffer was completely consumed */
486 #if CONFIG_FLASHSV_DECODER
487 AVCodec ff_flashsv_decoder = {
489 .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video v1"),
490 .type = AVMEDIA_TYPE_VIDEO,
491 .id = AV_CODEC_ID_FLASHSV,
492 .priv_data_size = sizeof(FlashSVContext),
493 .init = flashsv_decode_init,
494 .close = flashsv_decode_end,
495 .decode = flashsv_decode_frame,
496 .capabilities = CODEC_CAP_DR1,
497 .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
499 #endif /* CONFIG_FLASHSV_DECODER */
501 #if CONFIG_FLASHSV2_DECODER
502 static const uint32_t ff_flashsv2_default_palette[128] = {
503 0x000000, 0x333333, 0x666666, 0x999999, 0xCCCCCC, 0xFFFFFF,
504 0x330000, 0x660000, 0x990000, 0xCC0000, 0xFF0000, 0x003300,
505 0x006600, 0x009900, 0x00CC00, 0x00FF00, 0x000033, 0x000066,
506 0x000099, 0x0000CC, 0x0000FF, 0x333300, 0x666600, 0x999900,
507 0xCCCC00, 0xFFFF00, 0x003333, 0x006666, 0x009999, 0x00CCCC,
508 0x00FFFF, 0x330033, 0x660066, 0x990099, 0xCC00CC, 0xFF00FF,
509 0xFFFF33, 0xFFFF66, 0xFFFF99, 0xFFFFCC, 0xFF33FF, 0xFF66FF,
510 0xFF99FF, 0xFFCCFF, 0x33FFFF, 0x66FFFF, 0x99FFFF, 0xCCFFFF,
511 0xCCCC33, 0xCCCC66, 0xCCCC99, 0xCCCCFF, 0xCC33CC, 0xCC66CC,
512 0xCC99CC, 0xCCFFCC, 0x33CCCC, 0x66CCCC, 0x99CCCC, 0xFFCCCC,
513 0x999933, 0x999966, 0x9999CC, 0x9999FF, 0x993399, 0x996699,
514 0x99CC99, 0x99FF99, 0x339999, 0x669999, 0xCC9999, 0xFF9999,
515 0x666633, 0x666699, 0x6666CC, 0x6666FF, 0x663366, 0x669966,
516 0x66CC66, 0x66FF66, 0x336666, 0x996666, 0xCC6666, 0xFF6666,
517 0x333366, 0x333399, 0x3333CC, 0x3333FF, 0x336633, 0x339933,
518 0x33CC33, 0x33FF33, 0x663333, 0x993333, 0xCC3333, 0xFF3333,
519 0x003366, 0x336600, 0x660033, 0x006633, 0x330066, 0x663300,
520 0x336699, 0x669933, 0x993366, 0x339966, 0x663399, 0x996633,
521 0x6699CC, 0x99CC66, 0xCC6699, 0x66CC99, 0x9966CC, 0xCC9966,
522 0x99CCFF, 0xCCFF99, 0xFF99CC, 0x99FFCC, 0xCC99FF, 0xFFCC99,
523 0x111111, 0x222222, 0x444444, 0x555555, 0xAAAAAA, 0xBBBBBB,
527 static av_cold int flashsv2_decode_init(AVCodecContext *avctx)
529 FlashSVContext *s = avctx->priv_data;
530 flashsv_decode_init(avctx);
531 s->pal = ff_flashsv2_default_palette;
537 static av_cold int flashsv2_decode_end(AVCodecContext *avctx)
539 FlashSVContext *s = avctx->priv_data;
541 av_freep(&s->keyframedata);
542 av_freep(&s->blocks);
543 av_freep(&s->keyframe);
544 av_freep(&s->deflate_block);
545 flashsv_decode_end(avctx);
550 AVCodec ff_flashsv2_decoder = {
552 .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video v2"),
553 .type = AVMEDIA_TYPE_VIDEO,
554 .id = AV_CODEC_ID_FLASHSV2,
555 .priv_data_size = sizeof(FlashSVContext),
556 .init = flashsv2_decode_init,
557 .close = flashsv2_decode_end,
558 .decode = flashsv_decode_frame,
559 .capabilities = CODEC_CAP_DR1,
560 .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
562 #endif /* CONFIG_FLASHSV2_DECODER */