FFmpeg: libavcodec/vmdvideo.c Source File

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libavcodec

vmdvideo.c

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1 /*

2 * Sierra VMD video decoder

4 *

5 * This file is part of FFmpeg.

6 *

7 * FFmpeg is free software; you can redistribute it and/or

8 * modify it under the terms of the GNU Lesser General Public

9 * License as published by the Free Software Foundation; either

10 * version 2.1 of the License, or (at your option) any later version.

11 *

12 * FFmpeg is distributed in the hope that it will be useful,

13 * but WITHOUT ANY WARRANTY; without even the implied warranty of

14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

15 * Lesser General Public License for more details.

16 *

17 * You should have received a copy of the GNU Lesser General Public

18 * License along with FFmpeg; if not, write to the Free Software

19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

20 */

22 /**

23 * @file

24 * Sierra VMD video decoder

25 * by Vladimir "VAG" Gneushev (vagsoft at mail.ru)

26 * for more information on the Sierra VMD format, visit:

27 * http://www.pcisys.net/~melanson/codecs/

28 *

29 * The video decoder outputs PAL8 colorspace data. The decoder expects

30 * a 0x330-byte VMD file header to be transmitted via extradata during

31 * codec initialization. Each encoded frame that is sent to this decoder

32 * is expected to be prepended with the appropriate 16-byte frame

33 * information record from the VMD file.

34 */

36 #include <string.h>

38 #include "libavutil/common.h"

39 #include "libavutil/intreadwrite.h"

41 #include "avcodec.h"

42 #include "internal.h"

43 #include "bytestream.h"

45 #define VMD_HEADER_SIZE 0x330

46 #define PALETTE_COUNT 256

48 typedef struct VmdVideoContext {

50 AVCodecContext *avctx;

51 AVFrame *prev_frame;

53 const unsigned char *buf;

54 int size;

56 unsigned char palette[PALETTE_COUNT * 4];

57 unsigned char *unpack_buffer;

58 int unpack_buffer_size;

60 int x_off, y_off;

61 } VmdVideoContext;

63 #define QUEUE_SIZE 0x1000

64 #define QUEUE_MASK 0x0FFF

66 static int lz_unpack(const unsigned char *src, int src_len,

67 unsigned char *dest, int dest_len)

68 {

69 unsigned char *d;

70 unsigned char *d_end;

71 unsigned char queue[QUEUE_SIZE];

72 unsigned int qpos;

73 unsigned int dataleft;

74 unsigned int chainofs;

75 unsigned int chainlen;

76 unsigned int speclen;

77 unsigned char tag;

78 unsigned int i, j;

79 GetByteContext gb;

81 bytestream2_init(&gb, src, src_len);

82 d = dest;

83 d_end = d + dest_len;

84 dataleft = bytestream2_get_le32(&gb);

85 memset(queue, 0x20, QUEUE_SIZE);

86 if (bytestream2_get_bytes_left(&gb) < 4)

87 return AVERROR_INVALIDDATA;

88 if (bytestream2_peek_le32(&gb) == 0x56781234) {

89 bytestream2_skipu(&gb, 4);

90 qpos = 0x111;

91 speclen = 0xF + 3;

92 } else {

93 qpos = 0xFEE;

94 speclen = 100; /* no speclen */

95 }

97 while (dataleft > 0 && bytestream2_get_bytes_left(&gb) > 0) {

98 tag = bytestream2_get_byteu(&gb);

99 if ((tag == 0xFF) && (dataleft > 8)) {

100 if (d_end - d < 8 || bytestream2_get_bytes_left(&gb) < 8)

101 return AVERROR_INVALIDDATA;

102 for (i = 0; i < 8; i++) {

103 queue[qpos++] = *d++ = bytestream2_get_byteu(&gb);

104 qpos &= QUEUE_MASK;

105 }

106 dataleft -= 8;

107 } else {

108 for (i = 0; i < 8; i++) {

109 if (dataleft == 0)

110 break;

111 if (tag & 0x01) {

112 if (d_end - d < 1 || bytestream2_get_bytes_left(&gb) < 1)

113 return AVERROR_INVALIDDATA;

114 queue[qpos++] = *d++ = bytestream2_get_byteu(&gb);

115 qpos &= QUEUE_MASK;

116 dataleft--;

117 } else {

118 chainofs = bytestream2_get_byte(&gb);

119 chainofs |= ((bytestream2_peek_byte(&gb) & 0xF0) << 4);

120 chainlen = (bytestream2_get_byte(&gb) & 0x0F) + 3;

121 if (chainlen == speclen) {

122 chainlen = bytestream2_get_byte(&gb) + 0xF + 3;

123 }

124 if (d_end - d < chainlen)

125 return AVERROR_INVALIDDATA;

126 for (j = 0; j < chainlen; j++) {

127 *d = queue[chainofs++ & QUEUE_MASK];

128 queue[qpos++] = *d++;

129 qpos &= QUEUE_MASK;

130 }

131 dataleft -= chainlen;

132 }

133 tag >>= 1;

134 }

135 }

136 }

137 return d - dest;

138 }

139 static int rle_unpack(const unsigned char *src, unsigned char *dest,

140 int src_count, int src_size, int dest_len)

141 {

142 unsigned char *pd;

143 int i, l, used = 0;

144 unsigned char *dest_end = dest + dest_len;

145 GetByteContext gb;

146 uint16_t run_val;

147

148 bytestream2_init(&gb, src, src_size);

149 pd = dest;

150 if (src_count & 1) {

151 if (bytestream2_get_bytes_left(&gb) < 1)

152 return 0;

153 *pd++ = bytestream2_get_byteu(&gb);

154 used++;

155 }

156

157 do {

158 if (bytestream2_get_bytes_left(&gb) < 1)

159 break;

160 l = bytestream2_get_byteu(&gb);

161 if (l & 0x80) {

162 l = (l & 0x7F) * 2;

163 if (dest_end - pd < l || bytestream2_get_bytes_left(&gb) < l)

164 return bytestream2_tell(&gb);

165 bytestream2_get_bufferu(&gb, pd, l);

166 pd += l;

167 } else {

168 if (dest_end - pd < 2*l || bytestream2_get_bytes_left(&gb) < 2)

169 return bytestream2_tell(&gb);

170 run_val = bytestream2_get_ne16(&gb);

171 for (i = 0; i < l; i++) {

172 AV_WN16(pd, run_val);

173 pd += 2;

174 }

175 l *= 2;

176 }

177 used += l;

178 } while (used < src_count);

179

180 return bytestream2_tell(&gb);

181 }

182

183 static int vmd_decode(VmdVideoContext *s, AVFrame *frame)

184 {

185 int i;

186 unsigned int *palette32;

187 unsigned char r, g, b;

188

189 GetByteContext gb;

190

191 unsigned char meth;

192 unsigned char *dp; /* pointer to current frame */

193 unsigned char *pp; /* pointer to previous frame */

194 unsigned char len;

195 int ofs;

196

197 int frame_x, frame_y;

198 int frame_width, frame_height;

199

200 frame_x = AV_RL16(&s->buf[6]);

201 frame_y = AV_RL16(&s->buf[8]);

202 frame_width = AV_RL16(&s->buf[10]) - frame_x + 1;

203 frame_height = AV_RL16(&s->buf[12]) - frame_y + 1;

204

205 if ((frame_width == s->avctx->width && frame_height == s->avctx->height) &&

206 (frame_x || frame_y)) {

207

208 s->x_off = frame_x;

209 s->y_off = frame_y;

210 }

211 frame_x -= s->x_off;

212 frame_y -= s->y_off;

213

214 if (frame_x < 0 || frame_width < 0 ||

215 frame_x >= s->avctx->width ||

216 frame_width > s->avctx->width ||

217 frame_x + frame_width > s->avctx->width) {

218 av_log(s->avctx, AV_LOG_ERROR,

219 "Invalid horizontal range %d-%d\n",

220 frame_x, frame_width);

221 return AVERROR_INVALIDDATA;

222 }

223 if (frame_y < 0 || frame_height < 0 ||

224 frame_y >= s->avctx->height ||

225 frame_height > s->avctx->height ||

226 frame_y + frame_height > s->avctx->height) {

227 av_log(s->avctx, AV_LOG_ERROR,

228 "Invalid vertical range %d-%d\n",

229 frame_x, frame_width);

230 return AVERROR_INVALIDDATA;

231 }

232

233 /* if only a certain region will be updated, copy the entire previous

234 * frame before the decode */

235 if (s->prev_frame->data[0] &&

236 (frame_x || frame_y || (frame_width != s->avctx->width) ||

237 (frame_height != s->avctx->height))) {

238

239 memcpy(frame->data[0], s->prev_frame->data[0],

240 s->avctx->height * frame->linesize[0]);

241 }

242

243 /* check if there is a new palette */

244 bytestream2_init(&gb, s->buf + 16, s->size - 16);

245 if (s->buf[15] & 0x02) {

246 bytestream2_skip(&gb, 2);

247 palette32 = (unsigned int *)s->palette;

248 if (bytestream2_get_bytes_left(&gb) >= PALETTE_COUNT * 3) {

249 for (i = 0; i < PALETTE_COUNT; i++) {

250 r = bytestream2_get_byteu(&gb) * 4;

251 g = bytestream2_get_byteu(&gb) * 4;

252 b = bytestream2_get_byteu(&gb) * 4;

253 palette32[i] = 0xFFU << 24 | (r << 16) | (g << 8) | (b);

254 palette32[i] |= palette32[i] >> 6 & 0x30303;

255 }

256 } else {

257 av_log(s->avctx, AV_LOG_ERROR, "Incomplete palette\n");

258 return AVERROR_INVALIDDATA;

259 }

260 }

261

262 if (!s->size)

263 return 0;

264

265 /* originally UnpackFrame in VAG's code */

266 if (bytestream2_get_bytes_left(&gb) < 1)

267 return AVERROR_INVALIDDATA;

268 meth = bytestream2_get_byteu(&gb);

269 if (meth & 0x80) {

270 int size;

271 if (!s->unpack_buffer_size) {

272 av_log(s->avctx, AV_LOG_ERROR,

273 "Trying to unpack LZ-compressed frame with no LZ buffer\n");

274 return AVERROR_INVALIDDATA;

275 }

276 size = lz_unpack(gb.buffer, bytestream2_get_bytes_left(&gb),

277 s->unpack_buffer, s->unpack_buffer_size);

278 if (size < 0)

279 return size;

280 meth &= 0x7F;

281 bytestream2_init(&gb, s->unpack_buffer, size);

282 }

283

284 dp = &frame->data[0][frame_y * frame->linesize[0] + frame_x];

285 pp = &s->prev_frame->data[0][frame_y * s->prev_frame->linesize[0] + frame_x];

286 switch (meth) {

287 case 1:

288 for (i = 0; i < frame_height; i++) {

289 ofs = 0;

290 do {

291 len = bytestream2_get_byte(&gb);

292 if (len & 0x80) {

293 len = (len & 0x7F) + 1;

294 if (ofs + len > frame_width ||

295 bytestream2_get_bytes_left(&gb) < len)

296 return AVERROR_INVALIDDATA;

297 bytestream2_get_bufferu(&gb, &dp[ofs], len);

298 ofs += len;

299 } else {

300 /* interframe pixel copy */

301 if (ofs + len + 1 > frame_width || !s->prev_frame->data[0])

302 return AVERROR_INVALIDDATA;

303 memcpy(&dp[ofs], &pp[ofs], len + 1);

304 ofs += len + 1;

305 }

306 } while (ofs < frame_width);

307 if (ofs > frame_width) {

308 av_log(s->avctx, AV_LOG_ERROR,

309 "offset > width (%d > %d)\n",

310 ofs, frame_width);

311 return AVERROR_INVALIDDATA;

312 }

313 dp += frame->linesize[0];

314 pp += s->prev_frame->linesize[0];

315 }

316 break;

317

318 case 2:

319 for (i = 0; i < frame_height; i++) {

320 bytestream2_get_buffer(&gb, dp, frame_width);

321 dp += frame->linesize[0];

322 pp += s->prev_frame->linesize[0];

323 }

324 break;

325

326 case 3:

327 for (i = 0; i < frame_height; i++) {

328 ofs = 0;

329 do {

330 len = bytestream2_get_byte(&gb);

331 if (len & 0x80) {

332 len = (len & 0x7F) + 1;

333 if (bytestream2_peek_byte(&gb) == 0xFF) {

334 int slen = len;

335 bytestream2_get_byte(&gb);

336 len = rle_unpack(gb.buffer, &dp[ofs],

337 len, bytestream2_get_bytes_left(&gb),

338 frame_width - ofs);

339 ofs += slen;

340 bytestream2_skip(&gb, len);

341 } else {

342 if (ofs + len > frame_width ||

343 bytestream2_get_bytes_left(&gb) < len)

344 return AVERROR_INVALIDDATA;

345 bytestream2_get_buffer(&gb, &dp[ofs], len);

346 ofs += len;

347 }

348 } else {

349 /* interframe pixel copy */

350 if (ofs + len + 1 > frame_width || !s->prev_frame->data[0])

351 return AVERROR_INVALIDDATA;

352 memcpy(&dp[ofs], &pp[ofs], len + 1);

353 ofs += len + 1;

354 }

355 } while (ofs < frame_width);

356 if (ofs > frame_width) {

357 av_log(s->avctx, AV_LOG_ERROR,

358 "offset > width (%d > %d)\n",

359 ofs, frame_width);

360 return AVERROR_INVALIDDATA;

361 }

362 dp += frame->linesize[0];

363 pp += s->prev_frame->linesize[0];

364 }

365 break;

366 }

367 return 0;

368 }

369

370 static av_cold int vmdvideo_decode_end(AVCodecContext *avctx)

371 {

372 VmdVideoContext *s = avctx->priv_data;

373

374 av_frame_free(&s->prev_frame);

375 av_freep(&s->unpack_buffer);

376 s->unpack_buffer_size = 0;

377

378 return 0;

379 }

380

381 static av_cold int vmdvideo_decode_init(AVCodecContext *avctx)

382 {

383 VmdVideoContext *s = avctx->priv_data;

384 int i;

385 unsigned int *palette32;

386 int palette_index = 0;

387 unsigned char r, g, b;

388 unsigned char *vmd_header;

389 unsigned char *raw_palette;

390

391 s->avctx = avctx;

392 avctx->pix_fmt = AV_PIX_FMT_PAL8;

393

394 /* make sure the VMD header made it */

395 if (s->avctx->extradata_size != VMD_HEADER_SIZE) {

396 av_log(s->avctx, AV_LOG_ERROR, "expected extradata size of %d\n",

397 VMD_HEADER_SIZE);

398 return AVERROR_INVALIDDATA;

399 }

400 vmd_header = (unsigned char *)avctx->extradata;

401

402 s->unpack_buffer_size = AV_RL32(&vmd_header[800]);

403 if (s->unpack_buffer_size) {

404 s->unpack_buffer = av_malloc(s->unpack_buffer_size);

405 if (!s->unpack_buffer)

406 return AVERROR(ENOMEM);

407 }

408

409 /* load up the initial palette */

410 raw_palette = &vmd_header[28];

411 palette32 = (unsigned int *)s->palette;

412 for (i = 0; i < PALETTE_COUNT; i++) {

413 r = raw_palette[palette_index++] * 4;

414 g = raw_palette[palette_index++] * 4;

415 b = raw_palette[palette_index++] * 4;

416 palette32[i] = 0xFFU << 24 | (r << 16) | (g << 8) | (b);

417 palette32[i] |= palette32[i] >> 6 & 0x30303;

418 }

419

420 s->prev_frame = av_frame_alloc();

421 if (!s->prev_frame) {

422 vmdvideo_decode_end(avctx);

423 return AVERROR(ENOMEM);

424 }

425

426 return 0;

427 }

428

429 static int vmdvideo_decode_frame(AVCodecContext *avctx,

430 void *data, int *got_frame,

431 AVPacket *avpkt)

432 {

433 const uint8_t *buf = avpkt->data;

434 int buf_size = avpkt->size;

435 VmdVideoContext *s = avctx->priv_data;

436 AVFrame *frame = data;

437 int ret;

438

439 s->buf = buf;

440 s->size = buf_size;

441

442 if (buf_size < 16)

443 return AVERROR_INVALIDDATA;

444

445 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)

446 return ret;

447

448 if ((ret = vmd_decode(s, frame)) < 0)

449 return ret;

450

451 /* make the palette available on the way out */

452 memcpy(frame->data[1], s->palette, PALETTE_COUNT * 4);

453

454 /* shuffle frames */

455 av_frame_unref(s->prev_frame);

456 if ((ret = av_frame_ref(s->prev_frame, frame)) < 0)

457 return ret;

458

459 *got_frame = 1;

460

461 /* report that the buffer was completely consumed */

462 return buf_size;

463 }

464

465 AVCodec ff_vmdvideo_decoder = {

466 .name = "vmdvideo",

467 .long_name = NULL_IF_CONFIG_SMALL("Sierra VMD video"),

468 .type = AVMEDIA_TYPE_VIDEO,

469 .id = AV_CODEC_ID_VMDVIDEO,

470 .priv_data_size = sizeof(VmdVideoContext),

471 .init = vmdvideo_decode_init,

472 .close = vmdvideo_decode_end,

473 .decode = vmdvideo_decode_frame,

474 .capabilities = CODEC_CAP_DR1,

475 };

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