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"
39 #include "mpeg12data.h"
40 #include "libavutil/imgutils.h"
42 #define EA_PREAMBLE_SIZE 8
43 #define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD i-frame */
44 #define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD p-frame */
45 #define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */
47 typedef struct MadContext {
48 AVCodecContext *avctx;
50 BswapDSPContext bbdsp;
55 unsigned int bitstream_buf_size;
56 DECLARE_ALIGNED(16, int16_t, block)[64];
58 uint16_t quant_matrix[64];
63 static av_cold int decode_init(AVCodecContext *avctx)
65 MadContext *s = avctx->priv_data;
67 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
68 ff_blockdsp_init(&s->bdsp, avctx);
69 ff_bswapdsp_init(&s->bbdsp);
70 ff_idctdsp_init(&s->idsp, avctx);
71 ff_init_scantable_permutation(s->idsp.idct_permutation, FF_IDCT_PERM_NONE);
72 ff_init_scantable(s->idsp.idct_permutation, &s->scantable, ff_zigzag_direct);
73 ff_mpeg12_init_vlcs();
75 s->last_frame = av_frame_alloc();
77 return AVERROR(ENOMEM);
82 static inline void comp(unsigned char *dst, int dst_stride,
83 unsigned char *src, int src_stride, int add)
88 dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
91 static inline void comp_block(MadContext *t, AVFrame *frame,
93 int j, int mv_x, int mv_y, int add)
96 comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
98 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,
99 t->last_frame->linesize[0], add);
100 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
102 comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
103 frame->linesize[index],
104 t->last_frame->data[index] + (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2),
105 t->last_frame->linesize[index], add);
109 static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
110 int mb_x, int mb_y, int j)
114 frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
115 frame->linesize[0], block);
116 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
119 frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
120 frame->linesize[index], block);
124 static inline void decode_block_intra(MadContext *s, int16_t * block)
126 int level, i, j, run;
127 RLTable *rl = &ff_rl_mpeg1;
128 const uint8_t *scantable = s->scantable.permutated;
129 int16_t *quant_matrix = s->quant_matrix;
131 block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
133 /* The RL decoder is derived from mpeg1_decode_block_intra;
134 Escaped level and run values a decoded differently */
137 OPEN_READER(re, &s->gb);
138 /* now quantify & encode AC coefficients */
140 UPDATE_CACHE(re, &s->gb);
141 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
145 } else if (level != 0) {
148 level = (level*quant_matrix[j]) >> 4;
150 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
151 LAST_SKIP_BITS(re, &s->gb, 1);
154 UPDATE_CACHE(re, &s->gb);
155 level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
157 UPDATE_CACHE(re, &s->gb);
158 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
164 level = (level*quant_matrix[j]) >> 4;
168 level = (level*quant_matrix[j]) >> 4;
173 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
179 CLOSE_READER(re, &s->gb);
183 static int decode_motion(GetBitContext *gb)
189 value += get_bits(gb, 4) + 1;
194 static void decode_mb(MadContext *s, AVFrame *frame, int inter)
201 int v = decode210(&s->gb);
203 mv_map = v ? get_bits(&s->gb, 6) : 63;
204 mv_x = decode_motion(&s->gb);
205 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 comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
216 s->bdsp.clear_block(s->block);
217 decode_block_intra(s, s->block);
218 idct_put(s, frame, s->block, s->mb_x, s->mb_y, j);
223 static void calc_quant_matrix(MadContext *s, int qscale)
227 s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
229 s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
232 static int decode_frame(AVCodecContext *avctx,
233 void *data, int *got_frame,
236 const uint8_t *buf = avpkt->data;
237 int buf_size = avpkt->size;
238 const uint8_t *buf_end = buf+buf_size;
239 MadContext *s = avctx->priv_data;
240 AVFrame *frame = 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 av_frame_unref(s->last_frame);
265 if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
269 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) {
270 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
274 if (inter && !s->last_frame->data[0]) {
275 av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
276 ret = ff_get_buffer(avctx, s->last_frame, AV_GET_BUFFER_FLAG_REF);
279 memset(s->last_frame->data[0], 0, s->last_frame->height *
280 s->last_frame->linesize[0]);
281 memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 *
282 s->last_frame->linesize[1]);
283 memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 *
284 s->last_frame->linesize[2]);
287 av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
289 if (!s->bitstream_buf)
290 return AVERROR(ENOMEM);
291 s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *) buf,
292 (buf_end - buf) / 2);
293 init_get_bits(&s->gb, s->bitstream_buf, 8*(buf_end-buf));
295 for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
296 for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
297 decode_mb(s, frame, inter);
301 if (chunk_type != MADe_TAG) {
302 av_frame_unref(s->last_frame);
303 if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
310 static av_cold int decode_end(AVCodecContext *avctx)
312 MadContext *t = avctx->priv_data;
313 av_frame_free(&t->last_frame);
314 av_free(t->bitstream_buf);
318 AVCodec ff_eamad_decoder = {
320 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"),
321 .type = AVMEDIA_TYPE_VIDEO,
322 .id = AV_CODEC_ID_MAD,
323 .priv_data_size = sizeof(MadContext),
326 .decode = decode_frame,
327 .capabilities = CODEC_CAP_DR1,