2 * Electronic Arts Madcow Video Decoder
3 * Copyright (c) 2007-2009 Peter Ross
5 * This file is part of Libav.
7 * Libav 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 * Libav 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 Libav; 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"
38 #include "mpeg12data.h"
39 #include "libavutil/imgutils.h"
41 #define EA_PREAMBLE_SIZE 8
42 #define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD i-frame */
43 #define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD p-frame */
44 #define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */
46 typedef struct MadContext {
47 AVCodecContext *avctx;
53 unsigned int bitstream_buf_size;
54 DECLARE_ALIGNED(16, int16_t, block)[64];
56 uint16_t quant_matrix[64];
61 static av_cold int decode_init(AVCodecContext *avctx)
63 MadContext *s = avctx->priv_data;
65 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
66 ff_dsputil_init(&s->dsp, avctx);
67 ff_init_scantable_permutation(s->dsp.idct_permutation, FF_NO_IDCT_PERM);
68 ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
69 ff_mpeg12_init_vlcs();
73 static inline void comp(unsigned char *dst, int dst_stride,
74 unsigned char *src, int src_stride, int add)
79 dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
82 static inline void comp_block(MadContext *t, int mb_x, int mb_y,
83 int j, int mv_x, int mv_y, int add)
86 comp(t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3),
88 t->last_frame.data[0] + (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame.linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x,
89 t->last_frame.linesize[0], add);
90 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
92 comp(t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x * 8,
93 t->frame.linesize[index],
94 t->last_frame.data[index] + (mb_y * 8 + (mv_y/2))*t->last_frame.linesize[index] + mb_x * 8 + (mv_x/2),
95 t->last_frame.linesize[index], add);
99 static inline void idct_put(MadContext *t, int16_t *block, int mb_x, int mb_y, int j)
103 t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3),
104 t->frame.linesize[0], block);
105 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
108 t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x*8,
109 t->frame.linesize[index], block);
113 static inline void decode_block_intra(MadContext *s, int16_t * block)
115 int level, i, j, run;
116 RLTable *rl = &ff_rl_mpeg1;
117 const uint8_t *scantable = s->scantable.permutated;
118 int16_t *quant_matrix = s->quant_matrix;
120 block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
122 /* The RL decoder is derived from mpeg1_decode_block_intra;
123 Escaped level and run values a decoded differently */
126 OPEN_READER(re, &s->gb);
127 /* now quantify & encode AC coefficients */
129 UPDATE_CACHE(re, &s->gb);
130 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
134 } else if (level != 0) {
137 level = (level*quant_matrix[j]) >> 4;
139 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
140 LAST_SKIP_BITS(re, &s->gb, 1);
143 UPDATE_CACHE(re, &s->gb);
144 level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
146 UPDATE_CACHE(re, &s->gb);
147 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
153 level = (level*quant_matrix[j]) >> 4;
157 level = (level*quant_matrix[j]) >> 4;
162 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
168 CLOSE_READER(re, &s->gb);
172 static int decode_motion(GetBitContext *gb)
178 value += get_bits(gb, 4) + 1;
183 static void decode_mb(MadContext *s, int inter)
190 int v = decode210(&s->gb);
192 mv_map = v ? get_bits(&s->gb, 6) : 63;
193 mv_x = decode_motion(&s->gb);
194 mv_y = decode_motion(&s->gb);
200 for (j=0; j<6; j++) {
201 if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
202 int add = 2*decode_motion(&s->gb);
203 comp_block(s, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
205 s->dsp.clear_block(s->block);
206 decode_block_intra(s, s->block);
207 idct_put(s, s->block, s->mb_x, s->mb_y, j);
212 static void calc_quant_matrix(MadContext *s, int qscale)
216 s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
218 s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
221 static int decode_frame(AVCodecContext *avctx,
222 void *data, int *got_frame,
225 const uint8_t *buf = avpkt->data;
226 int buf_size = avpkt->size;
227 const uint8_t *buf_end = buf+buf_size;
228 MadContext *s = avctx->priv_data;
234 av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n");
239 chunk_type = AV_RL32(&buf[0]);
240 inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
243 av_reduce(&avctx->time_base.num, &avctx->time_base.den,
244 AV_RL16(&buf[6]), 1000, 1<<30);
246 width = AV_RL16(&buf[8]);
247 height = AV_RL16(&buf[10]);
248 calc_quant_matrix(s, buf[13]);
251 if (avctx->width != width || avctx->height != height) {
252 if (av_image_check_size(width, height, 0, avctx) < 0)
254 avcodec_set_dimensions(avctx, width, height);
255 if (s->frame.data[0])
256 avctx->release_buffer(avctx, &s->frame);
259 s->frame.reference = 1;
260 if (!s->frame.data[0]) {
261 if (ff_get_buffer(avctx, &s->frame) < 0) {
262 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
267 av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
269 if (!s->bitstream_buf)
270 return AVERROR(ENOMEM);
271 s->dsp.bswap16_buf(s->bitstream_buf, (const uint16_t*)buf, (buf_end-buf)/2);
272 init_get_bits(&s->gb, s->bitstream_buf, 8*(buf_end-buf));
274 for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
275 for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
279 *(AVFrame*)data = s->frame;
281 if (chunk_type != MADe_TAG)
282 FFSWAP(AVFrame, s->frame, s->last_frame);
287 static av_cold int decode_end(AVCodecContext *avctx)
289 MadContext *t = avctx->priv_data;
290 if (t->frame.data[0])
291 avctx->release_buffer(avctx, &t->frame);
292 if (t->last_frame.data[0])
293 avctx->release_buffer(avctx, &t->last_frame);
294 av_free(t->bitstream_buf);
298 AVCodec ff_eamad_decoder = {
300 .type = AVMEDIA_TYPE_VIDEO,
301 .id = AV_CODEC_ID_MAD,
302 .priv_data_size = sizeof(MadContext),
305 .decode = decode_frame,
306 .capabilities = CODEC_CAP_DR1,
307 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video")