2 * Electronic Arts Madcow Video Decoder
3 * Copyright (c) 2007-2009 Peter Ross
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 St, Fifth Floor, Boston, MA 02110-1301 USA
24 * Electronic Arts Madcow Video Decoder
25 * @author Peter Ross <pross@xvid.org>
27 * @see technical details at
28 * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_MAD
34 #include "aandcttab.h"
37 #include "mpeg12data.h"
38 #include "libavutil/imgutils.h"
40 #define EA_PREAMBLE_SIZE 8
41 #define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD i-frame */
42 #define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD p-frame */
43 #define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */
45 typedef struct MadContext {
46 AVCodecContext *avctx;
52 unsigned int bitstream_buf_size;
53 DECLARE_ALIGNED(16, DCTELEM, block)[64];
55 uint16_t quant_matrix[64];
60 static void bswap16_buf(uint16_t *dst, const uint16_t *src, int count)
63 for (i=0; i<count; i++)
64 dst[i] = av_bswap16(src[i]);
67 static av_cold int decode_init(AVCodecContext *avctx)
69 MadContext *s = avctx->priv_data;
71 avctx->pix_fmt = PIX_FMT_YUV420P;
72 ff_dsputil_init(&s->dsp, avctx);
73 ff_init_scantable_permutation(s->dsp.idct_permutation, FF_NO_IDCT_PERM);
74 ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
75 ff_mpeg12_init_vlcs();
79 static inline void comp(unsigned char *dst, int dst_stride,
80 unsigned char *src, int src_stride, int add)
85 dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
88 static inline void comp_block(MadContext *t, int mb_x, int mb_y,
89 int j, int mv_x, int mv_y, int add)
92 unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame.linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x;
93 if (offset >= (t->avctx->height - 7) * t->last_frame.linesize[0] - 7)
95 comp(t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3),
97 t->last_frame.data[0] + offset,
98 t->last_frame.linesize[0], add);
99 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
101 unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame.linesize[index] + mb_x * 8 + (mv_x/2);
102 if (offset >= (t->avctx->height/2 - 7) * t->last_frame.linesize[index] - 7)
104 comp(t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x * 8,
105 t->frame.linesize[index],
106 t->last_frame.data[index] + offset,
107 t->last_frame.linesize[index], add);
111 static inline void idct_put(MadContext *t, DCTELEM *block, int mb_x, int mb_y, int j)
115 t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3),
116 t->frame.linesize[0], block);
117 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
120 t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x*8,
121 t->frame.linesize[index], block);
125 static inline int decode_block_intra(MadContext *s, DCTELEM * block)
127 int level, i, j, run;
128 RLTable *rl = &ff_rl_mpeg1;
129 const uint8_t *scantable = s->scantable.permutated;
130 int16_t *quant_matrix = s->quant_matrix;
132 block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
134 /* The RL decoder is derived from mpeg1_decode_block_intra;
135 Escaped level and run values a decoded differently */
138 OPEN_READER(re, &s->gb);
139 /* now quantify & encode AC coefficients */
141 UPDATE_CACHE(re, &s->gb);
142 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
146 } else if (level != 0) {
149 level = (level*quant_matrix[j]) >> 4;
151 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
152 LAST_SKIP_BITS(re, &s->gb, 1);
155 UPDATE_CACHE(re, &s->gb);
156 level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
158 UPDATE_CACHE(re, &s->gb);
159 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
165 level = (level*quant_matrix[j]) >> 4;
169 level = (level*quant_matrix[j]) >> 4;
174 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
180 CLOSE_READER(re, &s->gb);
185 static int decode_motion(GetBitContext *gb)
191 value += get_bits(gb, 4) + 1;
196 static int decode_mb(MadContext *s, int inter)
203 int v = decode210(&s->gb);
205 mv_map = v ? get_bits(&s->gb, 6) : 63;
206 mv_x = decode_motion(&s->gb);
207 mv_y = decode_motion(&s->gb);
211 for (j=0; j<6; j++) {
212 if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
213 int add = 2*decode_motion(&s->gb);
214 if (s->last_frame.data[0])
215 comp_block(s, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
217 s->dsp.clear_block(s->block);
218 if(decode_block_intra(s, s->block) < 0)
220 idct_put(s, s->block, s->mb_x, s->mb_y, j);
226 static void calc_quant_matrix(MadContext *s, int qscale)
230 s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
232 s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
235 static int decode_frame(AVCodecContext *avctx,
236 void *data, int *data_size,
239 const uint8_t *buf = avpkt->data;
240 int buf_size = avpkt->size;
241 const uint8_t *buf_end = buf+buf_size;
242 MadContext *s = avctx->priv_data;
248 av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n");
253 chunk_type = AV_RL32(&buf[0]);
254 inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
257 av_reduce(&avctx->time_base.num, &avctx->time_base.den,
258 AV_RL16(&buf[6]), 1000, 1<<30);
260 width = AV_RL16(&buf[8]);
261 height = AV_RL16(&buf[10]);
262 calc_quant_matrix(s, buf[13]);
265 if (avctx->width != width || avctx->height != height) {
266 if((width * height)/2048*7 > buf_end-buf)
268 if (av_image_check_size(width, height, 0, avctx) < 0)
270 avcodec_set_dimensions(avctx, width, height);
271 if (s->frame.data[0])
272 avctx->release_buffer(avctx, &s->frame);
273 if (s->last_frame.data[0])
274 avctx->release_buffer(avctx, &s->last_frame);
277 s->frame.reference = 3;
278 if (!s->frame.data[0]) {
279 if (avctx->get_buffer(avctx, &s->frame) < 0) {
280 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
285 av_fast_malloc(&s->bitstream_buf, &s->bitstream_buf_size, (buf_end-buf) + FF_INPUT_BUFFER_PADDING_SIZE);
286 if (!s->bitstream_buf)
287 return AVERROR(ENOMEM);
288 bswap16_buf(s->bitstream_buf, (const uint16_t*)buf, (buf_end-buf)/2);
289 memset((uint8_t*)s->bitstream_buf + (buf_end-buf), 0, FF_INPUT_BUFFER_PADDING_SIZE);
290 init_get_bits(&s->gb, s->bitstream_buf, 8*(buf_end-buf));
292 for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
293 for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
294 if(decode_mb(s, inter) < 0)
297 *data_size = sizeof(AVFrame);
298 *(AVFrame*)data = s->frame;
300 if (chunk_type != MADe_TAG)
301 FFSWAP(AVFrame, s->frame, s->last_frame);
306 static av_cold int decode_end(AVCodecContext *avctx)
308 MadContext *t = avctx->priv_data;
309 if (t->frame.data[0])
310 avctx->release_buffer(avctx, &t->frame);
311 if (t->last_frame.data[0])
312 avctx->release_buffer(avctx, &t->last_frame);
313 av_free(t->bitstream_buf);
317 AVCodec ff_eamad_decoder = {
319 .type = AVMEDIA_TYPE_VIDEO,
321 .priv_data_size = sizeof(MadContext),
324 .decode = decode_frame,
325 .capabilities = CODEC_CAP_DR1,
326 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video")