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"
36 #include "mpeg12data.h"
37 #include "libavutil/imgutils.h"
39 #define EA_PREAMBLE_SIZE 8
40 #define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD i-frame */
41 #define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD p-frame */
42 #define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */
44 typedef struct MadContext {
45 AVCodecContext *avctx;
51 unsigned int bitstream_buf_size;
52 DECLARE_ALIGNED(16, DCTELEM, block)[64];
54 uint16_t quant_matrix[64];
59 static void bswap16_buf(uint16_t *dst, const uint16_t *src, int count)
62 for (i=0; i<count; i++)
63 dst[i] = av_bswap16(src[i]);
66 static av_cold int decode_init(AVCodecContext *avctx)
68 MadContext *s = avctx->priv_data;
70 avctx->pix_fmt = PIX_FMT_YUV420P;
71 if (avctx->idct_algo == FF_IDCT_AUTO)
72 avctx->idct_algo = FF_IDCT_EA;
73 ff_dsputil_init(&s->dsp, avctx);
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 comp(t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3),
94 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,
95 t->last_frame.linesize[0], add);
96 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
98 comp(t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x * 8,
99 t->frame.linesize[index],
100 t->last_frame.data[index] + (mb_y * 8 + (mv_y/2))*t->last_frame.linesize[index] + mb_x * 8 + (mv_x/2),
101 t->last_frame.linesize[index], add);
105 static inline void idct_put(MadContext *t, DCTELEM *block, int mb_x, int mb_y, int j)
109 t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3),
110 t->frame.linesize[0], block);
111 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
114 t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x*8,
115 t->frame.linesize[index], block);
119 static inline void decode_block_intra(MadContext *s, DCTELEM * block)
121 int level, i, j, run;
122 RLTable *rl = &ff_rl_mpeg1;
123 const uint8_t *scantable = s->scantable.permutated;
124 int16_t *quant_matrix = s->quant_matrix;
126 block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
128 /* The RL decoder is derived from mpeg1_decode_block_intra;
129 Escaped level and run values a decoded differently */
132 OPEN_READER(re, &s->gb);
133 /* now quantify & encode AC coefficients */
135 UPDATE_CACHE(re, &s->gb);
136 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
140 } else if (level != 0) {
143 level = (level*quant_matrix[j]) >> 4;
145 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
146 LAST_SKIP_BITS(re, &s->gb, 1);
149 UPDATE_CACHE(re, &s->gb);
150 level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
152 UPDATE_CACHE(re, &s->gb);
153 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
159 level = (level*quant_matrix[j]) >> 4;
163 level = (level*quant_matrix[j]) >> 4;
168 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
174 CLOSE_READER(re, &s->gb);
178 static int decode_motion(GetBitContext *gb)
184 value += get_bits(gb, 4) + 1;
189 static void decode_mb(MadContext *s, int inter)
196 int v = decode210(&s->gb);
198 mv_map = v ? get_bits(&s->gb, 6) : 63;
199 mv_x = decode_motion(&s->gb);
200 mv_y = decode_motion(&s->gb);
206 for (j=0; j<6; j++) {
207 if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
208 int add = 2*decode_motion(&s->gb);
209 comp_block(s, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
211 s->dsp.clear_block(s->block);
212 decode_block_intra(s, s->block);
213 idct_put(s, s->block, s->mb_x, s->mb_y, j);
218 static void calc_quant_matrix(MadContext *s, int qscale)
222 if (s->avctx->idct_algo == FF_IDCT_EA) {
223 s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
225 s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
227 s->quant_matrix[0] = ff_mpeg1_default_intra_matrix[0];
229 s->quant_matrix[i] = (ff_mpeg1_default_intra_matrix[i]*qscale) << 1;
233 static int decode_frame(AVCodecContext *avctx,
234 void *data, int *data_size,
237 const uint8_t *buf = avpkt->data;
238 int buf_size = avpkt->size;
239 const uint8_t *buf_end = buf+buf_size;
240 MadContext *s = avctx->priv_data;
246 av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n");
251 chunk_type = AV_RL32(&buf[0]);
252 inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
255 av_reduce(&avctx->time_base.num, &avctx->time_base.den,
256 AV_RL16(&buf[6]), 1000, 1<<30);
258 width = AV_RL16(&buf[8]);
259 height = AV_RL16(&buf[10]);
260 calc_quant_matrix(s, buf[13]);
263 if (avctx->width != width || avctx->height != height) {
264 if (av_image_check_size(width, height, 0, avctx) < 0)
266 avcodec_set_dimensions(avctx, width, height);
267 if (s->frame.data[0])
268 avctx->release_buffer(avctx, &s->frame);
271 s->frame.reference = 1;
272 if (!s->frame.data[0]) {
273 if (avctx->get_buffer(avctx, &s->frame) < 0) {
274 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
279 av_fast_malloc(&s->bitstream_buf, &s->bitstream_buf_size, (buf_end-buf) + FF_INPUT_BUFFER_PADDING_SIZE);
280 if (!s->bitstream_buf)
281 return AVERROR(ENOMEM);
282 bswap16_buf(s->bitstream_buf, (const uint16_t*)buf, (buf_end-buf)/2);
283 init_get_bits(&s->gb, s->bitstream_buf, 8*(buf_end-buf));
285 for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
286 for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
289 *data_size = sizeof(AVFrame);
290 *(AVFrame*)data = s->frame;
292 if (chunk_type != MADe_TAG)
293 FFSWAP(AVFrame, s->frame, s->last_frame);
298 static av_cold int decode_end(AVCodecContext *avctx)
300 MadContext *t = avctx->priv_data;
301 if (t->frame.data[0])
302 avctx->release_buffer(avctx, &t->frame);
303 if (t->last_frame.data[0])
304 avctx->release_buffer(avctx, &t->last_frame);
305 av_free(t->bitstream_buf);
309 AVCodec ff_eamad_decoder = {
311 .type = AVMEDIA_TYPE_VIDEO,
313 .priv_data_size = sizeof(MadContext),
316 .decode = decode_frame,
317 .capabilities = CODEC_CAP_DR1,
318 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video")