2 * Interplay MVE Video Decoder
3 * Copyright (C) 2003 the ffmpeg project
5 * This file is part of FFmpeg.
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.
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.
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
23 * @file libavcodec/interplayvideo.c
24 * Interplay MVE Video Decoder by Mike Melanson (melanson@pcisys.net)
25 * For more information about the Interplay MVE format, visit:
26 * http://www.pcisys.net/~melanson/codecs/interplay-mve.txt
27 * This code is written in such a way that the identifiers match up
28 * with the encoding descriptions in the document.
30 * This decoder presently only supports a PAL8 output colorspace.
32 * An Interplay video frame consists of 2 parts: The decoding map and
33 * the video data. A demuxer must load these 2 parts together in a single
34 * buffer before sending it through the stream to this decoder.
43 #include "bytestream.h"
46 #define PALETTE_COUNT 256
48 /* debugging support */
49 #define DEBUG_INTERPLAY 0
51 #define debug_interplay(x,...) av_log(NULL, AV_LOG_DEBUG, x, __VA_ARGS__)
53 static inline void debug_interplay(const char *format, ...) { }
56 typedef struct IpvideoContext {
58 AVCodecContext *avctx;
60 AVFrame second_last_frame;
62 AVFrame current_frame;
63 const unsigned char *decoding_map;
64 int decoding_map_size;
66 const unsigned char *buf;
69 const unsigned char *stream_ptr;
70 const unsigned char *stream_end;
71 unsigned char *pixel_ptr;
74 int upper_motion_limit_offset;
78 #define CHECK_STREAM_PTR(n) \
79 if (s->stream_end - s->stream_ptr < n) { \
80 av_log(s->avctx, AV_LOG_ERROR, "Interplay video warning: stream_ptr out of bounds (%p >= %p)\n", \
81 s->stream_ptr + n, s->stream_end); \
85 static int copy_from(IpvideoContext *s, AVFrame *src, int delta_x, int delta_y)
87 int current_offset = s->pixel_ptr - s->current_frame.data[0];
88 int motion_offset = current_offset + delta_y * s->stride + delta_x;
89 if (motion_offset < 0) {
90 av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset < 0 (%d)\n", motion_offset);
92 } else if (motion_offset > s->upper_motion_limit_offset) {
93 av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset above limit (%d >= %d)\n",
94 motion_offset, s->upper_motion_limit_offset);
97 s->dsp.put_pixels_tab[1][0](s->pixel_ptr, src->data[0] + motion_offset, s->stride, 8);
101 static int ipvideo_decode_block_opcode_0x0(IpvideoContext *s)
103 return copy_from(s, &s->last_frame, 0, 0);
106 static int ipvideo_decode_block_opcode_0x1(IpvideoContext *s)
108 return copy_from(s, &s->second_last_frame, 0, 0);
111 static int ipvideo_decode_block_opcode_0x2(IpvideoContext *s)
116 /* copy block from 2 frames ago using a motion vector; need 1 more byte */
118 B = *s->stream_ptr++;
124 x = -14 + ((B - 56) % 29);
125 y = 8 + ((B - 56) / 29);
128 debug_interplay (" motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
129 return copy_from(s, &s->second_last_frame, x, y);
132 static int ipvideo_decode_block_opcode_0x3(IpvideoContext *s)
137 /* copy 8x8 block from current frame from an up/left block */
139 /* need 1 more byte for motion */
141 B = *s->stream_ptr++;
147 x = -(-14 + ((B - 56) % 29));
148 y = -( 8 + ((B - 56) / 29));
151 debug_interplay (" motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
152 return copy_from(s, &s->current_frame, x, y);
155 static int ipvideo_decode_block_opcode_0x4(IpvideoContext *s)
158 unsigned char B, BL, BH;
160 /* copy a block from the previous frame; need 1 more byte */
163 B = *s->stream_ptr++;
165 BH = (B >> 4) & 0x0F;
169 debug_interplay (" motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
170 return copy_from(s, &s->last_frame, x, y);
173 static int ipvideo_decode_block_opcode_0x5(IpvideoContext *s)
177 /* copy a block from the previous frame using an expanded range;
178 * need 2 more bytes */
181 x = *s->stream_ptr++;
182 y = *s->stream_ptr++;
184 debug_interplay (" motion bytes = %d, %d\n", x, y);
185 return copy_from(s, &s->last_frame, x, y);
188 static int ipvideo_decode_block_opcode_0x6(IpvideoContext *s)
190 /* mystery opcode? skip multiple blocks? */
191 av_log(s->avctx, AV_LOG_ERROR, " Interplay video: Help! Mystery opcode 0x6 seen\n");
197 static int ipvideo_decode_block_opcode_0x7(IpvideoContext *s)
203 /* 2-color encoding */
206 P[0] = *s->stream_ptr++;
207 P[1] = *s->stream_ptr++;
211 /* need 8 more bytes from the stream */
214 for (y = 0; y < 8; y++) {
215 flags = *s->stream_ptr++ | 0x100;
216 for (; flags != 1; flags >>= 1) {
217 *s->pixel_ptr++ = P[flags & 1];
219 s->pixel_ptr += s->line_inc;
224 /* need 2 more bytes from the stream */
227 flags = bytestream_get_le16(&s->stream_ptr);
228 for (y = 0; y < 8; y += 2) {
229 for (x = 0; x < 8; x += 2, flags >>= 1) {
231 s->pixel_ptr[x + 1 ] =
232 s->pixel_ptr[x + s->stride] =
233 s->pixel_ptr[x + 1 + s->stride] = P[flags & 1];
235 s->pixel_ptr += s->stride * 2;
243 static int ipvideo_decode_block_opcode_0x8(IpvideoContext *s)
247 unsigned int flags = 0;
249 /* 2-color encoding for each 4x4 quadrant, or 2-color encoding on
250 * either top and bottom or left and right halves */
253 P[0] = *s->stream_ptr++;
254 P[1] = *s->stream_ptr++;
258 CHECK_STREAM_PTR(14);
261 for (y = 0; y < 16; y++) {
262 // new values for each 4x4 block
264 P[0] = *s->stream_ptr++; P[1] = *s->stream_ptr++;
265 flags = bytestream_get_le16(&s->stream_ptr);
268 for (x = 0; x < 4; x++, flags >>= 1) {
269 *s->pixel_ptr++ = P[flags & 1];
271 s->pixel_ptr += s->stride - 4;
272 // switch to right half
273 if (y == 7) s->pixel_ptr -= 8 * s->stride - 4;
278 /* need 10 more bytes */
279 CHECK_STREAM_PTR(10);
281 if (s->stream_ptr[4] <= s->stream_ptr[5]) {
283 flags = bytestream_get_le32(&s->stream_ptr);
285 /* vertical split; left & right halves are 2-color encoded */
287 for (y = 0; y < 16; y++) {
288 for (x = 0; x < 4; x++, flags >>= 1) {
289 *s->pixel_ptr++ = P[flags & 1];
291 s->pixel_ptr += s->stride - 4;
292 // switch to right half
294 s->pixel_ptr -= 8 * s->stride - 4;
295 P[0] = *s->stream_ptr++; P[1] = *s->stream_ptr++;
296 flags = bytestream_get_le32(&s->stream_ptr);
302 /* horizontal split; top & bottom halves are 2-color encoded */
304 for (y = 0; y < 8; y++) {
306 P[0] = *s->stream_ptr++;
307 P[1] = *s->stream_ptr++;
309 flags = *s->stream_ptr++ | 0x100;
311 for (; flags != 1; flags >>= 1) {
313 *s->pixel_ptr++ = P[flags & 1];
315 s->pixel_ptr += s->line_inc;
324 static int ipvideo_decode_block_opcode_0x9(IpvideoContext *s)
329 /* 4-color encoding */
332 memcpy(P, s->stream_ptr, 4);
338 /* 1 of 4 colors for each pixel, need 16 more bytes */
339 CHECK_STREAM_PTR(16);
341 for (y = 0; y < 8; y++) {
342 /* get the next set of 8 2-bit flags */
343 int flags = bytestream_get_le16(&s->stream_ptr);
344 for (x = 0; x < 8; x++, flags >>= 2) {
345 *s->pixel_ptr++ = P[flags & 0x03];
347 s->pixel_ptr += s->line_inc;
353 /* 1 of 4 colors for each 2x2 block, need 4 more bytes */
356 flags = bytestream_get_le32(&s->stream_ptr);
358 for (y = 0; y < 8; y += 2) {
359 for (x = 0; x < 8; x += 2, flags >>= 2) {
361 s->pixel_ptr[x + 1 ] =
362 s->pixel_ptr[x + s->stride] =
363 s->pixel_ptr[x + 1 + s->stride] = P[flags & 0x03];
365 s->pixel_ptr += s->stride * 2;
372 /* 1 of 4 colors for each 2x1 or 1x2 block, need 8 more bytes */
375 flags = bytestream_get_le64(&s->stream_ptr);
377 for (y = 0; y < 8; y++) {
378 for (x = 0; x < 8; x += 2, flags >>= 2) {
380 s->pixel_ptr[x + 1] = P[flags & 0x03];
382 s->pixel_ptr += s->stride;
385 for (y = 0; y < 8; y += 2) {
386 for (x = 0; x < 8; x++, flags >>= 2) {
388 s->pixel_ptr[x + s->stride] = P[flags & 0x03];
390 s->pixel_ptr += s->stride * 2;
399 static int ipvideo_decode_block_opcode_0xA(IpvideoContext *s)
407 /* 4-color encoding for each 4x4 quadrant, or 4-color encoding on
408 * either top and bottom or left and right halves */
411 memcpy(P, s->stream_ptr, 4);
416 /* 4-color encoding for each quadrant; need 28 more bytes */
417 CHECK_STREAM_PTR(28);
420 for (y = 0; y < 16; y++) {
421 // new values for each 4x4 block
423 memcpy(P, s->stream_ptr, 4);
425 flags = bytestream_get_le32(&s->stream_ptr);
428 for (x = 0; x < 4; x++, flags >>= 2) {
429 *s->pixel_ptr++ = P[flags & 0x03];
432 s->pixel_ptr += s->stride - 4;
433 // switch to right half
434 if (y == 7) s->pixel_ptr -= 8 * s->stride - 4;
439 /* 4-color encoding for either left and right or top and bottom
440 * halves; need 20 more bytes */
441 CHECK_STREAM_PTR(20);
443 memcpy(B, s->stream_ptr, 8);
445 memcpy(P + 4, s->stream_ptr, 4);
447 memcpy(B + 8, s->stream_ptr, 8);
452 /* block is divided into left and right halves */
453 for (y = 0; y < 8; y++) {
455 flags = (B[y + 8] << 8) | B[y];
458 for (x = 0; x < 8; x++, flags >>= 2) {
461 *s->pixel_ptr++ = P[split + (flags & 0x03)];
464 s->pixel_ptr += s->line_inc;
469 /* block is divided into top and bottom halves */
471 for (y = 0; y < 8; y++) {
473 flags = (B[y * 2 + 1] << 8) | B[y * 2];
477 for (x = 0; x < 8; x++, flags >>= 2)
478 *s->pixel_ptr++ = P[split + (flags & 0x03)];
480 s->pixel_ptr += s->line_inc;
489 static int ipvideo_decode_block_opcode_0xB(IpvideoContext *s)
493 /* 64-color encoding (each pixel in block is a different color) */
494 CHECK_STREAM_PTR(64);
496 for (y = 0; y < 8; y++) {
497 memcpy(s->pixel_ptr, s->stream_ptr, 8);
499 s->pixel_ptr += s->stride;
506 static int ipvideo_decode_block_opcode_0xC(IpvideoContext *s)
510 /* 16-color block encoding: each 2x2 block is a different color */
511 CHECK_STREAM_PTR(16);
513 for (y = 0; y < 8; y += 2) {
514 for (x = 0; x < 8; x += 2) {
516 s->pixel_ptr[x + 1 ] =
517 s->pixel_ptr[x + s->stride] =
518 s->pixel_ptr[x + 1 + s->stride] = *s->stream_ptr++;
520 s->pixel_ptr += s->stride * 2;
527 static int ipvideo_decode_block_opcode_0xD(IpvideoContext *s)
531 unsigned char index = 0;
533 /* 4-color block encoding: each 4x4 block is a different color */
536 memcpy(P, s->stream_ptr, 4);
539 for (y = 0; y < 8; y++) {
545 memset(s->pixel_ptr , P[index ], 4);
546 memset(s->pixel_ptr + 4, P[index + 1], 4);
547 s->pixel_ptr += s->stride;
554 static int ipvideo_decode_block_opcode_0xE(IpvideoContext *s)
559 /* 1-color encoding: the whole block is 1 solid color */
561 pix = *s->stream_ptr++;
563 for (y = 0; y < 8; y++) {
564 memset(s->pixel_ptr, pix, 8);
565 s->pixel_ptr += s->stride;
572 static int ipvideo_decode_block_opcode_0xF(IpvideoContext *s)
575 unsigned char sample[2];
577 /* dithered encoding */
579 sample[0] = *s->stream_ptr++;
580 sample[1] = *s->stream_ptr++;
582 for (y = 0; y < 8; y++) {
583 for (x = 0; x < 8; x += 2) {
584 *s->pixel_ptr++ = sample[ y & 1 ];
585 *s->pixel_ptr++ = sample[!(y & 1)];
587 s->pixel_ptr += s->line_inc;
594 static int (* const ipvideo_decode_block[])(IpvideoContext *s) = {
595 ipvideo_decode_block_opcode_0x0, ipvideo_decode_block_opcode_0x1,
596 ipvideo_decode_block_opcode_0x2, ipvideo_decode_block_opcode_0x3,
597 ipvideo_decode_block_opcode_0x4, ipvideo_decode_block_opcode_0x5,
598 ipvideo_decode_block_opcode_0x6, ipvideo_decode_block_opcode_0x7,
599 ipvideo_decode_block_opcode_0x8, ipvideo_decode_block_opcode_0x9,
600 ipvideo_decode_block_opcode_0xA, ipvideo_decode_block_opcode_0xB,
601 ipvideo_decode_block_opcode_0xC, ipvideo_decode_block_opcode_0xD,
602 ipvideo_decode_block_opcode_0xE, ipvideo_decode_block_opcode_0xF,
605 static void ipvideo_decode_opcodes(IpvideoContext *s)
609 unsigned char opcode;
611 int code_counts[16] = {0};
612 static int frame = 0;
614 debug_interplay("------------------ frame %d\n", frame);
617 /* this is PAL8, so make the palette available */
618 memcpy(s->current_frame.data[1], s->avctx->palctrl->palette, PALETTE_COUNT * 4);
620 s->stride = s->current_frame.linesize[0];
621 s->stream_ptr = s->buf + 14; /* data starts 14 bytes in */
622 s->stream_end = s->buf + s->size;
623 s->line_inc = s->stride - 8;
624 s->upper_motion_limit_offset = (s->avctx->height - 8) * s->stride
625 + s->avctx->width - 8;
627 for (y = 0; y < (s->stride * s->avctx->height); y += s->stride * 8) {
628 for (x = y; x < y + s->avctx->width; x += 8) {
629 /* bottom nibble first, then top nibble (which makes it
630 * hard to use a GetBitcontext) */
632 opcode = s->decoding_map[index >> 1] >> 4;
634 opcode = s->decoding_map[index >> 1] & 0xF;
637 debug_interplay(" block @ (%3d, %3d): encoding 0x%X, data ptr @ %p\n",
638 x - y, y / s->stride, opcode, s->stream_ptr);
639 code_counts[opcode]++;
641 s->pixel_ptr = s->current_frame.data[0] + x;
642 ret = ipvideo_decode_block[opcode](s);
644 av_log(s->avctx, AV_LOG_ERROR, " Interplay video: decode problem on frame %d, @ block (%d, %d)\n",
645 frame, x - y, y / s->stride);
650 if (s->stream_end - s->stream_ptr > 1) {
651 av_log(s->avctx, AV_LOG_ERROR, " Interplay video: decode finished with %td bytes left over\n",
652 s->stream_end - s->stream_ptr);
656 static av_cold int ipvideo_decode_init(AVCodecContext *avctx)
658 IpvideoContext *s = avctx->priv_data;
662 if (s->avctx->palctrl == NULL) {
663 av_log(avctx, AV_LOG_ERROR, " Interplay video: palette expected.\n");
667 avctx->pix_fmt = PIX_FMT_PAL8;
668 dsputil_init(&s->dsp, avctx);
670 /* decoding map contains 4 bits of information per 8x8 block */
671 s->decoding_map_size = avctx->width * avctx->height / (8 * 8 * 2);
673 s->current_frame.data[0] = s->last_frame.data[0] =
674 s->second_last_frame.data[0] = NULL;
679 static int ipvideo_decode_frame(AVCodecContext *avctx,
680 void *data, int *data_size,
681 const uint8_t *buf, int buf_size)
683 IpvideoContext *s = avctx->priv_data;
684 AVPaletteControl *palette_control = avctx->palctrl;
686 /* compressed buffer needs to be large enough to at least hold an entire
688 if (buf_size < s->decoding_map_size)
691 s->decoding_map = buf;
692 s->buf = buf + s->decoding_map_size;
693 s->size = buf_size - s->decoding_map_size;
695 s->current_frame.reference = 3;
696 if (avctx->get_buffer(avctx, &s->current_frame)) {
697 av_log(avctx, AV_LOG_ERROR, " Interplay Video: get_buffer() failed\n");
701 ipvideo_decode_opcodes(s);
703 if (palette_control->palette_changed) {
704 palette_control->palette_changed = 0;
705 s->current_frame.palette_has_changed = 1;
708 *data_size = sizeof(AVFrame);
709 *(AVFrame*)data = s->current_frame;
712 if (s->second_last_frame.data[0])
713 avctx->release_buffer(avctx, &s->second_last_frame);
714 s->second_last_frame = s->last_frame;
715 s->last_frame = s->current_frame;
716 s->current_frame.data[0] = NULL; /* catch any access attempts */
718 /* report that the buffer was completely consumed */
722 static av_cold int ipvideo_decode_end(AVCodecContext *avctx)
724 IpvideoContext *s = avctx->priv_data;
726 /* release the last frame */
727 if (s->last_frame.data[0])
728 avctx->release_buffer(avctx, &s->last_frame);
729 if (s->second_last_frame.data[0])
730 avctx->release_buffer(avctx, &s->second_last_frame);
735 AVCodec interplay_video_decoder = {
738 CODEC_ID_INTERPLAY_VIDEO,
739 sizeof(IpvideoContext),
743 ipvideo_decode_frame,
745 .long_name = NULL_IF_CONFIG_SMALL("Interplay MVE video"),