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"
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 {
49 unsigned int bitstream_buf_size;
50 DECLARE_ALIGNED(16, DCTELEM, block)[64];
53 static void bswap16_buf(uint16_t *dst, const uint16_t *src, int count)
56 for (i=0; i<count; i++)
57 dst[i] = av_bswap16(src[i]);
60 static av_cold int decode_init(AVCodecContext *avctx)
62 MadContext *t = avctx->priv_data;
63 MpegEncContext *s = &t->s;
65 avctx->pix_fmt = PIX_FMT_YUV420P;
66 if (avctx->idct_algo == FF_IDCT_AUTO)
67 avctx->idct_algo = FF_IDCT_EA;
68 ff_dsputil_init(&s->dsp, avctx);
69 ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
70 ff_mpeg12_init_vlcs();
74 static inline void comp(unsigned char *dst, int dst_stride,
75 unsigned char *src, int src_stride, int add)
80 dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
83 static inline void comp_block(MadContext *t, int mb_x, int mb_y,
84 int j, int mv_x, int mv_y, int add)
86 MpegEncContext *s = &t->s;
88 unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame.linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x;
89 if (offset >= (s->height - 7) * t->last_frame.linesize[0] - 7)
91 comp(t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3),
93 t->last_frame.data[0] + offset,
94 t->last_frame.linesize[0], add);
95 } else if (!(s->avctx->flags & CODEC_FLAG_GRAY)) {
97 unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame.linesize[index] + mb_x * 8 + (mv_x/2);
98 if (offset >= (s->height/2 - 7) * t->last_frame.linesize[index] - 7)
100 comp(t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x * 8,
101 t->frame.linesize[index],
102 t->last_frame.data[index] + offset,
103 t->last_frame.linesize[index], add);
107 static inline void idct_put(MadContext *t, DCTELEM *block, int mb_x, int mb_y, int j)
109 MpegEncContext *s = &t->s;
112 t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3),
113 t->frame.linesize[0], block);
114 } else if (!(s->avctx->flags & CODEC_FLAG_GRAY)) {
117 t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x*8,
118 t->frame.linesize[index], block);
122 static inline int decode_block_intra(MadContext * t, DCTELEM * block)
124 MpegEncContext *s = &t->s;
125 int level, i, j, run;
126 RLTable *rl = &ff_rl_mpeg1;
127 const uint8_t *scantable = s->intra_scantable.permutated;
128 int16_t *quant_matrix = s->intra_matrix;
130 block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
132 /* The RL decoder is derived from mpeg1_decode_block_intra;
133 Escaped level and run values a decoded differently */
136 OPEN_READER(re, &s->gb);
137 /* now quantify & encode AC coefficients */
139 UPDATE_CACHE(re, &s->gb);
140 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
144 } else if (level != 0) {
147 level = (level*quant_matrix[j]) >> 4;
149 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
150 LAST_SKIP_BITS(re, &s->gb, 1);
153 UPDATE_CACHE(re, &s->gb);
154 level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
156 UPDATE_CACHE(re, &s->gb);
157 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
163 level = (level*quant_matrix[j]) >> 4;
167 level = (level*quant_matrix[j]) >> 4;
172 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
178 CLOSE_READER(re, &s->gb);
183 static int decode_motion(GetBitContext *gb)
189 value += get_bits(gb, 4) + 1;
194 static int decode_mb(MadContext *t, int inter)
196 MpegEncContext *s = &t->s;
202 int v = decode210(&s->gb);
204 mv_map = v ? get_bits(&s->gb, 6) : 63;
205 mv_x = decode_motion(&s->gb);
206 mv_y = decode_motion(&s->gb);
210 for (j=0; j<6; j++) {
211 if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
212 int add = 2*decode_motion(&s->gb);
213 if (t->last_frame.data[0])
214 comp_block(t, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
216 s->dsp.clear_block(t->block);
217 if(decode_block_intra(t, t->block) < 0)
219 idct_put(t, t->block, s->mb_x, s->mb_y, j);
225 static void calc_intra_matrix(MadContext *t, int qscale)
227 MpegEncContext *s = &t->s;
230 if (s->avctx->idct_algo == FF_IDCT_EA) {
231 s->intra_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
233 s->intra_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
235 s->intra_matrix[0] = ff_mpeg1_default_intra_matrix[0];
237 s->intra_matrix[i] = (ff_mpeg1_default_intra_matrix[i]*qscale) << 1;
241 static int decode_frame(AVCodecContext *avctx,
242 void *data, int *data_size,
245 const uint8_t *buf = avpkt->data;
246 int buf_size = avpkt->size;
247 const uint8_t *buf_end = buf+buf_size;
248 MadContext *t = avctx->priv_data;
249 MpegEncContext *s = &t->s;
254 av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n");
259 chunk_type = AV_RL32(&buf[0]);
260 inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
263 av_reduce(&avctx->time_base.num, &avctx->time_base.den,
264 AV_RL16(&buf[6]), 1000, 1<<30);
266 s->width = AV_RL16(&buf[8]);
267 s->height = AV_RL16(&buf[10]);
268 calc_intra_matrix(t, buf[13]);
271 if (avctx->width != s->width || avctx->height != s->height) {
272 if((s->width * s->height)/2048*7 > buf_end-buf)
274 if (av_image_check_size(s->width, s->height, 0, avctx) < 0)
276 avcodec_set_dimensions(avctx, s->width, s->height);
277 if (t->frame.data[0])
278 avctx->release_buffer(avctx, &t->frame);
279 if (t->last_frame.data[0])
280 avctx->release_buffer(avctx, &t->last_frame);
283 t->frame.reference = 3;
284 if (!t->frame.data[0]) {
285 if (avctx->get_buffer(avctx, &t->frame) < 0) {
286 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
291 av_fast_malloc(&t->bitstream_buf, &t->bitstream_buf_size, (buf_end-buf) + FF_INPUT_BUFFER_PADDING_SIZE);
292 if (!t->bitstream_buf)
293 return AVERROR(ENOMEM);
294 bswap16_buf(t->bitstream_buf, (const uint16_t*)buf, (buf_end-buf)/2);
295 memset((uint8_t*)t->bitstream_buf + (buf_end-buf), 0, FF_INPUT_BUFFER_PADDING_SIZE);
296 init_get_bits(&s->gb, t->bitstream_buf, 8*(buf_end-buf));
298 for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
299 for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
300 if(decode_mb(t, inter) < 0)
303 *data_size = sizeof(AVFrame);
304 *(AVFrame*)data = t->frame;
306 if (chunk_type != MADe_TAG)
307 FFSWAP(AVFrame, t->frame, t->last_frame);
312 static av_cold int decode_end(AVCodecContext *avctx)
314 MadContext *t = avctx->priv_data;
315 if (t->frame.data[0])
316 avctx->release_buffer(avctx, &t->frame);
317 if (t->last_frame.data[0])
318 avctx->release_buffer(avctx, &t->last_frame);
319 av_free(t->bitstream_buf);
323 AVCodec ff_eamad_decoder = {
325 .type = AVMEDIA_TYPE_VIDEO,
327 .priv_data_size = sizeof(MadContext),
330 .decode = decode_frame,
331 .capabilities = CODEC_CAP_DR1,
332 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video")