2 * Sierra VMD video decoder
4 * This file is part of Libav.
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * Sierra VMD video decoder
24 * by Vladimir "VAG" Gneushev (vagsoft at mail.ru)
25 * for more information on the Sierra VMD format, visit:
26 * http://www.pcisys.net/~melanson/codecs/
28 * The video decoder outputs PAL8 colorspace data. The decoder expects
29 * a 0x330-byte VMD file header to be transmitted via extradata during
30 * codec initialization. Each encoded frame that is sent to this decoder
31 * is expected to be prepended with the appropriate 16-byte frame
32 * information record from the VMD file.
37 #include "libavutil/common.h"
38 #include "libavutil/intreadwrite.h"
42 #include "bytestream.h"
44 #define VMD_HEADER_SIZE 0x330
45 #define PALETTE_COUNT 256
47 typedef struct VmdVideoContext {
49 AVCodecContext *avctx;
52 const unsigned char *buf;
55 unsigned char palette[PALETTE_COUNT * 4];
56 unsigned char *unpack_buffer;
57 int unpack_buffer_size;
62 #define QUEUE_SIZE 0x1000
63 #define QUEUE_MASK 0x0FFF
65 static void lz_unpack(const unsigned char *src, int src_len,
66 unsigned char *dest, int dest_len)
70 unsigned char queue[QUEUE_SIZE];
72 unsigned int dataleft;
73 unsigned int chainofs;
74 unsigned int chainlen;
80 bytestream2_init(&gb, src, src_len);
83 dataleft = bytestream2_get_le32(&gb);
84 memset(queue, 0x20, QUEUE_SIZE);
85 if (bytestream2_get_bytes_left(&gb) < 4)
87 if (bytestream2_peek_le32(&gb) == 0x56781234) {
88 bytestream2_get_le32(&gb);
93 speclen = 100; /* no speclen */
96 while (dataleft > 0 && bytestream2_get_bytes_left(&gb) > 0) {
97 tag = bytestream2_get_byteu(&gb);
98 if ((tag == 0xFF) && (dataleft > 8)) {
99 if (d + 8 > d_end || bytestream2_get_bytes_left(&gb) < 8)
101 for (i = 0; i < 8; i++) {
102 queue[qpos++] = *d++ = bytestream2_get_byteu(&gb);
107 for (i = 0; i < 8; i++) {
111 if (d + 1 > d_end || bytestream2_get_bytes_left(&gb) < 1)
113 queue[qpos++] = *d++ = bytestream2_get_byte(&gb);
117 chainofs = bytestream2_get_byte(&gb);
118 chainofs |= ((bytestream2_peek_byte(&gb) & 0xF0) << 4);
119 chainlen = (bytestream2_get_byte(&gb) & 0x0F) + 3;
120 if (chainlen == speclen) {
121 chainlen = bytestream2_get_byte(&gb) + 0xF + 3;
123 if (d + chainlen > d_end)
125 for (j = 0; j < chainlen; j++) {
126 *d = queue[chainofs++ & QUEUE_MASK];
127 queue[qpos++] = *d++;
130 dataleft -= chainlen;
138 static int rle_unpack(const unsigned char *src, unsigned char *dest,
139 int src_count, int src_size, int dest_len)
143 unsigned char *dest_end = dest + dest_len;
147 bytestream2_init(&gb, src, src_size);
150 if (bytestream2_get_bytes_left(&gb) < 1)
152 *pd++ = bytestream2_get_byteu(&gb);
157 if (bytestream2_get_bytes_left(&gb) < 1)
159 l = bytestream2_get_byteu(&gb);
162 if (pd + l > dest_end || bytestream2_get_bytes_left(&gb) < l)
163 return bytestream2_tell(&gb);
164 bytestream2_get_buffer(&gb, pd, l);
167 if (pd + l > dest_end || bytestream2_get_bytes_left(&gb) < 2)
168 return bytestream2_tell(&gb);
169 run_val = bytestream2_get_ne16(&gb);
170 for (i = 0; i < l; i++) {
171 AV_WN16(pd, run_val);
177 } while (used < src_count);
179 return bytestream2_tell(&gb);
182 static int vmd_decode(VmdVideoContext *s, AVFrame *frame)
185 unsigned int *palette32;
186 unsigned char r, g, b;
191 unsigned char *dp; /* pointer to current frame */
192 unsigned char *pp; /* pointer to previous frame */
196 int frame_x, frame_y;
197 int frame_width, frame_height;
199 frame_x = AV_RL16(&s->buf[6]);
200 frame_y = AV_RL16(&s->buf[8]);
201 frame_width = AV_RL16(&s->buf[10]) - frame_x + 1;
202 frame_height = AV_RL16(&s->buf[12]) - frame_y + 1;
203 if (frame_x < 0 || frame_width < 0 ||
204 frame_x >= s->avctx->width ||
205 frame_width > s->avctx->width ||
206 frame_x + frame_width > s->avctx->width) {
207 av_log(s->avctx, AV_LOG_ERROR,
208 "Invalid horizontal range %d-%d\n",
209 frame_x, frame_width);
210 return AVERROR_INVALIDDATA;
212 if (frame_y < 0 || frame_height < 0 ||
213 frame_y >= s->avctx->height ||
214 frame_height > s->avctx->height ||
215 frame_y + frame_height > s->avctx->height) {
216 av_log(s->avctx, AV_LOG_ERROR,
217 "Invalid vertical range %d-%d\n",
218 frame_x, frame_width);
219 return AVERROR_INVALIDDATA;
222 if ((frame_width == s->avctx->width && frame_height == s->avctx->height) &&
223 (frame_x || frame_y)) {
231 /* if only a certain region will be updated, copy the entire previous
232 * frame before the decode */
233 if (s->prev_frame->data[0] &&
234 (frame_x || frame_y || (frame_width != s->avctx->width) ||
235 (frame_height != s->avctx->height))) {
237 memcpy(frame->data[0], s->prev_frame->data[0],
238 s->avctx->height * frame->linesize[0]);
241 /* check if there is a new palette */
242 bytestream2_init(&gb, s->buf + 16, s->size - 16);
243 if (s->buf[15] & 0x02) {
244 bytestream2_skip(&gb, 2);
245 palette32 = (unsigned int *)s->palette;
246 if (bytestream2_get_bytes_left(&gb) >= PALETTE_COUNT * 3) {
247 for (i = 0; i < PALETTE_COUNT; i++) {
248 r = bytestream2_get_byteu(&gb) * 4;
249 g = bytestream2_get_byteu(&gb) * 4;
250 b = bytestream2_get_byteu(&gb) * 4;
251 palette32[i] = (r << 16) | (g << 8) | (b);
254 av_log(s->avctx, AV_LOG_ERROR, "Incomplete palette\n");
255 return AVERROR_INVALIDDATA;
257 s->size -= PALETTE_COUNT * 3 + 2;
263 /* originally UnpackFrame in VAG's code */
264 if (bytestream2_get_bytes_left(&gb) < 1)
265 return AVERROR_INVALIDDATA;
266 meth = bytestream2_get_byteu(&gb);
268 if (!s->unpack_buffer_size) {
269 av_log(s->avctx, AV_LOG_ERROR,
270 "Trying to unpack LZ-compressed frame with no LZ buffer\n");
271 return AVERROR_INVALIDDATA;
273 lz_unpack(gb.buffer, bytestream2_get_bytes_left(&gb),
274 s->unpack_buffer, s->unpack_buffer_size);
276 bytestream2_init(&gb, s->unpack_buffer, s->unpack_buffer_size);
279 dp = &frame->data[0][frame_y * frame->linesize[0] + frame_x];
280 pp = &s->prev_frame->data[0][frame_y * s->prev_frame->linesize[0] + frame_x];
283 for (i = 0; i < frame_height; i++) {
286 len = bytestream2_get_byte(&gb);
288 len = (len & 0x7F) + 1;
289 if (ofs + len > frame_width ||
290 bytestream2_get_bytes_left(&gb) < len)
291 return AVERROR_INVALIDDATA;
292 bytestream2_get_buffer(&gb, &dp[ofs], len);
295 /* interframe pixel copy */
296 if (ofs + len + 1 > frame_width || !s->prev_frame->data[0])
297 return AVERROR_INVALIDDATA;
298 memcpy(&dp[ofs], &pp[ofs], len + 1);
301 } while (ofs < frame_width);
302 if (ofs > frame_width) {
303 av_log(s->avctx, AV_LOG_ERROR,
304 "VMD video: offset > width (%d > %d)\n",
306 return AVERROR_INVALIDDATA;
308 dp += frame->linesize[0];
309 pp += s->prev_frame->linesize[0];
314 for (i = 0; i < frame_height; i++) {
315 bytestream2_get_buffer(&gb, dp, frame_width);
316 dp += frame->linesize[0];
317 pp += s->prev_frame->linesize[0];
322 for (i = 0; i < frame_height; i++) {
325 len = bytestream2_get_byte(&gb);
327 len = (len & 0x7F) + 1;
328 if (bytestream2_peek_byte(&gb) == 0xFF) {
330 bytestream2_get_byte(&gb);
331 len = rle_unpack(gb.buffer, &dp[ofs],
332 len, bytestream2_get_bytes_left(&gb),
335 bytestream2_skip(&gb, len);
337 bytestream2_get_buffer(&gb, &dp[ofs], len);
341 /* interframe pixel copy */
342 if (ofs + len + 1 > frame_width || !s->prev_frame->data[0])
343 return AVERROR_INVALIDDATA;
344 memcpy(&dp[ofs], &pp[ofs], len + 1);
347 } while (ofs < frame_width);
348 if (ofs > frame_width) {
349 av_log(s->avctx, AV_LOG_ERROR,
350 "VMD video: offset > width (%d > %d)\n",
352 return AVERROR_INVALIDDATA;
354 dp += frame->linesize[0];
355 pp += s->prev_frame->linesize[0];
362 static av_cold int vmdvideo_decode_end(AVCodecContext *avctx)
364 VmdVideoContext *s = avctx->priv_data;
366 av_frame_free(&s->prev_frame);
367 av_free(s->unpack_buffer);
372 static av_cold int vmdvideo_decode_init(AVCodecContext *avctx)
374 VmdVideoContext *s = avctx->priv_data;
376 unsigned int *palette32;
377 int palette_index = 0;
378 unsigned char r, g, b;
379 unsigned char *vmd_header;
380 unsigned char *raw_palette;
383 avctx->pix_fmt = AV_PIX_FMT_PAL8;
385 /* make sure the VMD header made it */
386 if (s->avctx->extradata_size != VMD_HEADER_SIZE) {
387 av_log(s->avctx, AV_LOG_ERROR, "VMD video: expected extradata size of %d\n",
391 vmd_header = (unsigned char *)avctx->extradata;
393 s->unpack_buffer_size = AV_RL32(&vmd_header[800]);
394 if (s->unpack_buffer_size) {
395 s->unpack_buffer = av_malloc(s->unpack_buffer_size);
396 if (!s->unpack_buffer)
397 return AVERROR(ENOMEM);
400 /* load up the initial palette */
401 raw_palette = &vmd_header[28];
402 palette32 = (unsigned int *)s->palette;
403 for (i = 0; i < PALETTE_COUNT; i++) {
404 r = raw_palette[palette_index++] * 4;
405 g = raw_palette[palette_index++] * 4;
406 b = raw_palette[palette_index++] * 4;
407 palette32[i] = (r << 16) | (g << 8) | (b);
410 s->prev_frame = av_frame_alloc();
411 if (!s->prev_frame) {
412 vmdvideo_decode_end(avctx);
413 return AVERROR(ENOMEM);
419 static int vmdvideo_decode_frame(AVCodecContext *avctx,
420 void *data, int *got_frame,
423 const uint8_t *buf = avpkt->data;
424 int buf_size = avpkt->size;
425 VmdVideoContext *s = avctx->priv_data;
426 AVFrame *frame = data;
433 return AVERROR_INVALIDDATA;
435 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) {
436 av_log(s->avctx, AV_LOG_ERROR, "VMD Video: get_buffer() failed\n");
440 if ((ret = vmd_decode(s, frame)) < 0)
443 /* make the palette available on the way out */
444 memcpy(frame->data[1], s->palette, PALETTE_COUNT * 4);
447 av_frame_unref(s->prev_frame);
448 if ((ret = av_frame_ref(s->prev_frame, frame)) < 0)
453 /* report that the buffer was completely consumed */
457 AVCodec ff_vmdvideo_decoder = {
459 .long_name = NULL_IF_CONFIG_SMALL("Sierra VMD video"),
460 .type = AVMEDIA_TYPE_VIDEO,
461 .id = AV_CODEC_ID_VMDVIDEO,
462 .priv_data_size = sizeof(VmdVideoContext),
463 .init = vmdvideo_decode_init,
464 .close = vmdvideo_decode_end,
465 .decode = vmdvideo_decode_frame,
466 .capabilities = AV_CODEC_CAP_DR1,