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
33 #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;
51 unsigned int bitstream_buf_size;
52 DECLARE_ALIGNED(16, int16_t, block)[64];
54 uint16_t quant_matrix[64];
59 static av_cold int decode_init(AVCodecContext *avctx)
61 MadContext *s = avctx->priv_data;
63 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
64 ff_dsputil_init(&s->dsp, avctx);
65 ff_init_scantable_permutation(s->dsp.idct_permutation, FF_NO_IDCT_PERM);
66 ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
67 ff_mpeg12_init_vlcs();
71 static inline void comp(unsigned char *dst, int dst_stride,
72 unsigned char *src, int src_stride, int add)
77 dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
80 static inline void comp_block(MadContext *t, AVFrame *frame,
82 int j, int mv_x, int mv_y, int add)
85 unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame.linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x;
86 if (offset >= (t->avctx->height - 7) * t->last_frame.linesize[0] - 7)
88 comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
90 t->last_frame.data[0] + offset,
91 t->last_frame.linesize[0], add);
92 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
94 unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame.linesize[index] + mb_x * 8 + (mv_x/2);
95 if (offset >= (t->avctx->height/2 - 7) * t->last_frame.linesize[index] - 7)
97 comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
98 frame->linesize[index],
99 t->last_frame.data[index] + offset,
100 t->last_frame.linesize[index], add);
104 static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
105 int mb_x, int mb_y, int j)
109 frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
110 frame->linesize[0], block);
111 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
114 frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
115 frame->linesize[index], block);
119 static inline int decode_block_intra(MadContext *s, int16_t * 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);
179 static int decode_motion(GetBitContext *gb)
185 value += get_bits(gb, 4) + 1;
190 static int decode_mb(MadContext *s, AVFrame *frame, int inter)
197 int v = decode210(&s->gb);
199 mv_map = v ? get_bits(&s->gb, 6) : 63;
200 mv_x = decode_motion(&s->gb);
201 mv_y = decode_motion(&s->gb);
205 for (j=0; j<6; j++) {
206 if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
207 int add = 2*decode_motion(&s->gb);
208 if (s->last_frame.data[0])
209 comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
211 s->dsp.clear_block(s->block);
212 if(decode_block_intra(s, s->block) < 0)
214 idct_put(s, frame, s->block, s->mb_x, s->mb_y, j);
220 static void calc_quant_matrix(MadContext *s, int qscale)
224 s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
226 s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
229 static int decode_frame(AVCodecContext *avctx,
230 void *data, int *got_frame,
233 const uint8_t *buf = avpkt->data;
234 int buf_size = avpkt->size;
235 const uint8_t *buf_end = buf+buf_size;
236 MadContext *s = avctx->priv_data;
237 AVFrame *frame = data;
243 av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n");
245 return AVERROR_INVALIDDATA;
248 chunk_type = AV_RL32(&buf[0]);
249 inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
252 av_reduce(&avctx->time_base.num, &avctx->time_base.den,
253 AV_RL16(&buf[6]), 1000, 1<<30);
255 width = AV_RL16(&buf[8]);
256 height = AV_RL16(&buf[10]);
257 calc_quant_matrix(s, buf[13]);
260 if (width < 16 || height < 16) {
261 av_log(avctx, AV_LOG_ERROR, "Dimensions too small\n");
262 return AVERROR_INVALIDDATA;
265 if (avctx->width != width || avctx->height != height) {
266 av_frame_unref(&s->last_frame);
267 if((width * height)/2048*7 > buf_end-buf)
268 return AVERROR_INVALIDDATA;
269 if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
273 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
276 if (inter && !s->last_frame.data[0]) {
277 av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
278 ret = ff_get_buffer(avctx, &s->last_frame, AV_GET_BUFFER_FLAG_REF);
281 memset(s->last_frame.data[0], 0, s->last_frame.height *
282 s->last_frame.linesize[0]);
283 memset(s->last_frame.data[1], 0x80, s->last_frame.height / 2 *
284 s->last_frame.linesize[1]);
285 memset(s->last_frame.data[2], 0x80, s->last_frame.height / 2 *
286 s->last_frame.linesize[2]);
289 av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
291 if (!s->bitstream_buf)
292 return AVERROR(ENOMEM);
293 s->dsp.bswap16_buf(s->bitstream_buf, (const uint16_t*)buf, (buf_end-buf)/2);
294 memset((uint8_t*)s->bitstream_buf + (buf_end-buf), 0, FF_INPUT_BUFFER_PADDING_SIZE);
295 init_get_bits(&s->gb, s->bitstream_buf, 8*(buf_end-buf));
297 for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
298 for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
299 if(decode_mb(s, frame, inter) < 0)
300 return AVERROR_INVALIDDATA;
304 if (chunk_type != MADe_TAG) {
305 av_frame_unref(&s->last_frame);
306 if ((ret = av_frame_ref(&s->last_frame, frame)) < 0)
313 static av_cold int decode_end(AVCodecContext *avctx)
315 MadContext *t = avctx->priv_data;
316 av_frame_unref(&t->last_frame);
317 av_free(t->bitstream_buf);
321 AVCodec ff_eamad_decoder = {
323 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"),
324 .type = AVMEDIA_TYPE_VIDEO,
325 .id = AV_CODEC_ID_MAD,
326 .priv_data_size = sizeof(MadContext),
329 .decode = decode_frame,
330 .capabilities = CODEC_CAP_DR1,