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)
200 unsigned char P0, P1;
203 /* 2-color encoding */
206 P0 = *s->stream_ptr++;
207 P1 = *s->stream_ptr++;
211 /* need 8 more bytes from the stream */
214 for (y = 0; y < 8; y++) {
215 flags = *s->stream_ptr++;
216 for (x = 0x01; x <= 0x80; x <<= 1) {
218 *s->pixel_ptr++ = P1;
220 *s->pixel_ptr++ = P0;
222 s->pixel_ptr += s->line_inc;
227 /* need 2 more bytes from the stream */
230 flags = bytestream_get_le16(&s->stream_ptr);
231 for (y = 0; y < 8; y += 2) {
232 for (x = 0; x < 8; x += 2, flags >>= 1) {
235 s->pixel_ptr[x + 1 ] =
236 s->pixel_ptr[x + s->stride] =
237 s->pixel_ptr[x + 1 + s->stride] = P1;
240 s->pixel_ptr[x + 1 ] =
241 s->pixel_ptr[x + s->stride] =
242 s->pixel_ptr[x + 1 + s->stride] = P0;
245 s->pixel_ptr += s->stride * 2;
253 static int ipvideo_decode_block_opcode_0x8(IpvideoContext *s)
258 unsigned int flags = 0;
259 unsigned char P0 = 0, P1 = 0;
262 /* 2-color encoding for each 4x4 quadrant, or 2-color encoding on
263 * either top and bottom or left and right halves */
266 P[0] = *s->stream_ptr++;
267 P[1] = *s->stream_ptr++;
271 /* need 12 more bytes */
272 CHECK_STREAM_PTR(12);
273 B[0] = *s->stream_ptr++; B[1] = *s->stream_ptr++;
274 P[2] = *s->stream_ptr++; P[3] = *s->stream_ptr++;
275 B[2] = *s->stream_ptr++; B[3] = *s->stream_ptr++;
276 P[4] = *s->stream_ptr++; P[5] = *s->stream_ptr++;
277 B[4] = *s->stream_ptr++; B[5] = *s->stream_ptr++;
278 P[6] = *s->stream_ptr++; P[7] = *s->stream_ptr++;
279 B[6] = *s->stream_ptr++; B[7] = *s->stream_ptr++;
281 for (y = 0; y < 8; y++) {
283 /* time to reload flags? */
286 ((B[0] & 0xF0) << 4) | ((B[4] & 0xF0) << 8) |
287 ((B[0] & 0x0F) ) | ((B[4] & 0x0F) << 4) |
288 ((B[1] & 0xF0) << 20) | ((B[5] & 0xF0) << 24) |
289 ((B[1] & 0x0F) << 16) | ((B[5] & 0x0F) << 20);
290 lower_half = 0; /* still on top half */
293 ((B[2] & 0xF0) << 4) | ((B[6] & 0xF0) << 8) |
294 ((B[2] & 0x0F) ) | ((B[6] & 0x0F) << 4) |
295 ((B[3] & 0xF0) << 20) | ((B[7] & 0xF0) << 24) |
296 ((B[3] & 0x0F) << 16) | ((B[7] & 0x0F) << 20);
300 for (x = 0; x < 8; x++, flags >>= 1) {
301 /* get the pixel values ready for this quadrant */
303 P0 = P[lower_half + 0];
304 P1 = P[lower_half + 1];
306 P0 = P[lower_half + 4];
307 P1 = P[lower_half + 5];
311 *s->pixel_ptr++ = P1;
313 *s->pixel_ptr++ = P0;
315 s->pixel_ptr += s->line_inc;
320 /* need 10 more bytes */
321 CHECK_STREAM_PTR(10);
322 B[0] = *s->stream_ptr++; B[1] = *s->stream_ptr++;
323 B[2] = *s->stream_ptr++; B[3] = *s->stream_ptr++;
324 P[2] = *s->stream_ptr++; P[3] = *s->stream_ptr++;
325 B[4] = *s->stream_ptr++; B[5] = *s->stream_ptr++;
326 B[6] = *s->stream_ptr++; B[7] = *s->stream_ptr++;
330 /* vertical split; left & right halves are 2-color encoded */
332 for (y = 0; y < 8; y++) {
334 /* time to reload flags? */
337 ((B[0] & 0xF0) << 4) | ((B[4] & 0xF0) << 8) |
338 ((B[0] & 0x0F) ) | ((B[4] & 0x0F) << 4) |
339 ((B[1] & 0xF0) << 20) | ((B[5] & 0xF0) << 24) |
340 ((B[1] & 0x0F) << 16) | ((B[5] & 0x0F) << 20);
343 ((B[2] & 0xF0) << 4) | ((B[6] & 0xF0) << 8) |
344 ((B[2] & 0x0F) ) | ((B[6] & 0x0F) << 4) |
345 ((B[3] & 0xF0) << 20) | ((B[7] & 0xF0) << 24) |
346 ((B[3] & 0x0F) << 16) | ((B[7] & 0x0F) << 20);
349 for (x = 0; x < 8; x++, flags >>= 1) {
350 /* get the pixel values ready for this half */
360 *s->pixel_ptr++ = P1;
362 *s->pixel_ptr++ = P0;
364 s->pixel_ptr += s->line_inc;
369 /* horizontal split; top & bottom halves are 2-color encoded */
371 for (y = 0; y < 8; y++) {
383 for (bitmask = 0x01; bitmask <= 0x80; bitmask <<= 1) {
386 *s->pixel_ptr++ = P1;
388 *s->pixel_ptr++ = P0;
390 s->pixel_ptr += s->line_inc;
399 static int ipvideo_decode_block_opcode_0x9(IpvideoContext *s)
403 unsigned int flags = 0;
406 /* 4-color encoding */
409 memcpy(P, s->stream_ptr, 4);
412 if ((P[0] <= P[1]) && (P[2] <= P[3])) {
414 /* 1 of 4 colors for each pixel, need 16 more bytes */
415 CHECK_STREAM_PTR(16);
417 for (y = 0; y < 8; y++) {
418 /* get the next set of 8 2-bit flags */
419 flags = bytestream_get_le16(&s->stream_ptr);
420 for (x = 0; x < 8; x++, flags >>= 2) {
421 *s->pixel_ptr++ = P[flags & 0x03];
423 s->pixel_ptr += s->line_inc;
426 } else if ((P[0] <= P[1]) && (P[2] > P[3])) {
428 /* 1 of 4 colors for each 2x2 block, need 4 more bytes */
431 flags = bytestream_get_le32(&s->stream_ptr);
433 for (y = 0; y < 8; y += 2) {
434 for (x = 0; x < 8; x += 2, flags >>= 2) {
435 pix = P[flags & 0x03];
437 s->pixel_ptr[x + 1 ] =
438 s->pixel_ptr[x + s->stride] =
439 s->pixel_ptr[x + 1 + s->stride] = pix;
441 s->pixel_ptr += s->stride * 2;
444 } else if ((P[0] > P[1]) && (P[2] <= P[3])) {
446 /* 1 of 4 colors for each 2x1 block, need 8 more bytes */
449 for (y = 0; y < 8; y++) {
450 /* time to reload flags? */
451 if ((y == 0) || (y == 4)) {
452 flags = bytestream_get_le32(&s->stream_ptr);
454 for (x = 0; x < 8; x += 2, flags >>= 2) {
455 pix = P[flags & 0x03];
457 s->pixel_ptr[x + 1] = pix;
459 s->pixel_ptr += s->stride;
464 /* 1 of 4 colors for each 1x2 block, need 8 more bytes */
467 for (y = 0; y < 8; y += 2) {
468 /* time to reload flags? */
469 if ((y == 0) || (y == 4)) {
470 flags = bytestream_get_le32(&s->stream_ptr);
472 for (x = 0; x < 8; x++, flags >>= 2) {
473 pix = P[flags & 0x03];
475 s->pixel_ptr[x + s->stride] = pix;
477 s->pixel_ptr += s->stride * 2;
485 static int ipvideo_decode_block_opcode_0xA(IpvideoContext *s)
495 /* 4-color encoding for each 4x4 quadrant, or 4-color encoding on
496 * either top and bottom or left and right halves */
499 memcpy(P, s->stream_ptr, 4);
504 /* 4-color encoding for each quadrant; need 28 more bytes */
505 CHECK_STREAM_PTR(28);
507 memcpy(B, s->stream_ptr, 4);
509 for (y = 4; y < 16; y += 4) {
510 memcpy(P + y, s->stream_ptr, 4);
512 memcpy(B + y, s->stream_ptr, 4);
516 for (y = 0; y < 8; y++) {
518 lower_half = (y >= 4) ? 4 : 0;
519 flags = (B[y + 8] << 8) | B[y];
521 for (x = 0; x < 8; x++, flags >>= 2) {
522 split = (x >= 4) ? 8 : 0;
523 index = split + lower_half + (flags & 0x03);
524 *s->pixel_ptr++ = P[index];
527 s->pixel_ptr += s->line_inc;
532 /* 4-color encoding for either left and right or top and bottom
533 * halves; need 20 more bytes */
534 CHECK_STREAM_PTR(20);
536 memcpy(B, s->stream_ptr, 8);
538 memcpy(P + 4, s->stream_ptr, 4);
540 memcpy(B + 8, s->stream_ptr, 8);
545 /* block is divided into left and right halves */
546 for (y = 0; y < 8; y++) {
548 flags = (B[y + 8] << 8) | B[y];
551 for (x = 0; x < 8; x++, flags >>= 2) {
554 *s->pixel_ptr++ = P[split + (flags & 0x03)];
557 s->pixel_ptr += s->line_inc;
562 /* block is divided into top and bottom halves */
564 for (y = 0; y < 8; y++) {
566 flags = (B[y * 2 + 1] << 8) | B[y * 2];
570 for (x = 0; x < 8; x++, flags >>= 2)
571 *s->pixel_ptr++ = P[split + (flags & 0x03)];
573 s->pixel_ptr += s->line_inc;
582 static int ipvideo_decode_block_opcode_0xB(IpvideoContext *s)
586 /* 64-color encoding (each pixel in block is a different color) */
587 CHECK_STREAM_PTR(64);
589 for (y = 0; y < 8; y++) {
590 memcpy(s->pixel_ptr, s->stream_ptr, 8);
592 s->pixel_ptr += s->stride;
599 static int ipvideo_decode_block_opcode_0xC(IpvideoContext *s)
604 /* 16-color block encoding: each 2x2 block is a different color */
605 CHECK_STREAM_PTR(16);
607 for (y = 0; y < 8; y += 2) {
608 for (x = 0; x < 8; x += 2) {
609 pix = *s->stream_ptr++;
611 s->pixel_ptr[x + 1 ] =
612 s->pixel_ptr[x + s->stride] =
613 s->pixel_ptr[x + 1 + s->stride] = pix;
615 s->pixel_ptr += s->stride * 2;
622 static int ipvideo_decode_block_opcode_0xD(IpvideoContext *s)
626 unsigned char index = 0;
628 /* 4-color block encoding: each 4x4 block is a different color */
631 memcpy(P, s->stream_ptr, 4);
634 for (y = 0; y < 8; y++) {
640 memset(s->pixel_ptr , P[index ], 4);
641 memset(s->pixel_ptr + 4, P[index + 1], 4);
642 s->pixel_ptr += s->stride;
649 static int ipvideo_decode_block_opcode_0xE(IpvideoContext *s)
654 /* 1-color encoding: the whole block is 1 solid color */
656 pix = *s->stream_ptr++;
658 for (y = 0; y < 8; y++) {
659 memset(s->pixel_ptr, pix, 8);
660 s->pixel_ptr += s->stride;
667 static int ipvideo_decode_block_opcode_0xF(IpvideoContext *s)
670 unsigned char sample0, sample1;
672 /* dithered encoding */
674 sample0 = *s->stream_ptr++;
675 sample1 = *s->stream_ptr++;
677 for (y = 0; y < 8; y++) {
678 for (x = 0; x < 8; x += 2) {
680 *s->pixel_ptr++ = sample1;
681 *s->pixel_ptr++ = sample0;
683 *s->pixel_ptr++ = sample0;
684 *s->pixel_ptr++ = sample1;
687 s->pixel_ptr += s->line_inc;
694 static int (* const ipvideo_decode_block[])(IpvideoContext *s) = {
695 ipvideo_decode_block_opcode_0x0, ipvideo_decode_block_opcode_0x1,
696 ipvideo_decode_block_opcode_0x2, ipvideo_decode_block_opcode_0x3,
697 ipvideo_decode_block_opcode_0x4, ipvideo_decode_block_opcode_0x5,
698 ipvideo_decode_block_opcode_0x6, ipvideo_decode_block_opcode_0x7,
699 ipvideo_decode_block_opcode_0x8, ipvideo_decode_block_opcode_0x9,
700 ipvideo_decode_block_opcode_0xA, ipvideo_decode_block_opcode_0xB,
701 ipvideo_decode_block_opcode_0xC, ipvideo_decode_block_opcode_0xD,
702 ipvideo_decode_block_opcode_0xE, ipvideo_decode_block_opcode_0xF,
705 static void ipvideo_decode_opcodes(IpvideoContext *s)
709 unsigned char opcode;
711 int code_counts[16] = {0};
712 static int frame = 0;
714 debug_interplay("------------------ frame %d\n", frame);
717 /* this is PAL8, so make the palette available */
718 memcpy(s->current_frame.data[1], s->avctx->palctrl->palette, PALETTE_COUNT * 4);
720 s->stride = s->current_frame.linesize[0];
721 s->stream_ptr = s->buf + 14; /* data starts 14 bytes in */
722 s->stream_end = s->buf + s->size;
723 s->line_inc = s->stride - 8;
724 s->upper_motion_limit_offset = (s->avctx->height - 8) * s->stride
725 + s->avctx->width - 8;
727 for (y = 0; y < (s->stride * s->avctx->height); y += s->stride * 8) {
728 for (x = y; x < y + s->avctx->width; x += 8) {
729 /* bottom nibble first, then top nibble (which makes it
730 * hard to use a GetBitcontext) */
732 opcode = s->decoding_map[index >> 1] >> 4;
734 opcode = s->decoding_map[index >> 1] & 0xF;
737 debug_interplay(" block @ (%3d, %3d): encoding 0x%X, data ptr @ %p\n",
738 x - y, y / s->stride, opcode, s->stream_ptr);
739 code_counts[opcode]++;
741 s->pixel_ptr = s->current_frame.data[0] + x;
742 ret = ipvideo_decode_block[opcode](s);
744 av_log(s->avctx, AV_LOG_ERROR, " Interplay video: decode problem on frame %d, @ block (%d, %d)\n",
745 frame, x - y, y / s->stride);
750 if (s->stream_end - s->stream_ptr > 1) {
751 av_log(s->avctx, AV_LOG_ERROR, " Interplay video: decode finished with %td bytes left over\n",
752 s->stream_end - s->stream_ptr);
756 static av_cold int ipvideo_decode_init(AVCodecContext *avctx)
758 IpvideoContext *s = avctx->priv_data;
762 if (s->avctx->palctrl == NULL) {
763 av_log(avctx, AV_LOG_ERROR, " Interplay video: palette expected.\n");
767 avctx->pix_fmt = PIX_FMT_PAL8;
768 dsputil_init(&s->dsp, avctx);
770 /* decoding map contains 4 bits of information per 8x8 block */
771 s->decoding_map_size = avctx->width * avctx->height / (8 * 8 * 2);
773 s->current_frame.data[0] = s->last_frame.data[0] =
774 s->second_last_frame.data[0] = NULL;
779 static int ipvideo_decode_frame(AVCodecContext *avctx,
780 void *data, int *data_size,
781 const uint8_t *buf, int buf_size)
783 IpvideoContext *s = avctx->priv_data;
784 AVPaletteControl *palette_control = avctx->palctrl;
786 /* compressed buffer needs to be large enough to at least hold an entire
788 if (buf_size < s->decoding_map_size)
791 s->decoding_map = buf;
792 s->buf = buf + s->decoding_map_size;
793 s->size = buf_size - s->decoding_map_size;
795 s->current_frame.reference = 3;
796 if (avctx->get_buffer(avctx, &s->current_frame)) {
797 av_log(avctx, AV_LOG_ERROR, " Interplay Video: get_buffer() failed\n");
801 ipvideo_decode_opcodes(s);
803 if (palette_control->palette_changed) {
804 palette_control->palette_changed = 0;
805 s->current_frame.palette_has_changed = 1;
808 *data_size = sizeof(AVFrame);
809 *(AVFrame*)data = s->current_frame;
812 if (s->second_last_frame.data[0])
813 avctx->release_buffer(avctx, &s->second_last_frame);
814 s->second_last_frame = s->last_frame;
815 s->last_frame = s->current_frame;
816 s->current_frame.data[0] = NULL; /* catch any access attempts */
818 /* report that the buffer was completely consumed */
822 static av_cold int ipvideo_decode_end(AVCodecContext *avctx)
824 IpvideoContext *s = avctx->priv_data;
826 /* release the last frame */
827 if (s->last_frame.data[0])
828 avctx->release_buffer(avctx, &s->last_frame);
829 if (s->second_last_frame.data[0])
830 avctx->release_buffer(avctx, &s->second_last_frame);
835 AVCodec interplay_video_decoder = {
838 CODEC_ID_INTERPLAY_VIDEO,
839 sizeof(IpvideoContext),
843 ipvideo_decode_frame,
845 .long_name = NULL_IF_CONFIG_SMALL("Interplay MVE video"),