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"
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;
49 BswapDSPContext bbdsp;
54 unsigned int bitstream_buf_size;
55 DECLARE_ALIGNED(16, int16_t, block)[64];
57 uint16_t quant_matrix[64];
62 static av_cold int decode_init(AVCodecContext *avctx)
64 MadContext *s = avctx->priv_data;
66 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
67 ff_blockdsp_init(&s->bdsp, avctx);
68 ff_bswapdsp_init(&s->bbdsp);
69 ff_dsputil_init(&s->dsp, avctx);
70 ff_init_scantable_permutation(s->dsp.idct_permutation, FF_NO_IDCT_PERM);
71 ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
72 ff_mpeg12_init_vlcs();
74 s->last_frame = av_frame_alloc();
76 return AVERROR(ENOMEM);
81 static inline void comp(unsigned char *dst, int dst_stride,
82 unsigned char *src, int src_stride, int add)
87 dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
90 static inline void comp_block(MadContext *t, AVFrame *frame,
92 int j, int mv_x, int mv_y, int add)
95 unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame->linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x;
96 if (offset >= (t->avctx->height - 7) * t->last_frame->linesize[0] - 7)
98 comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
100 t->last_frame->data[0] + offset,
101 t->last_frame->linesize[0], add);
102 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
104 unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2);
105 if (offset >= (t->avctx->height/2 - 7) * t->last_frame->linesize[index] - 7)
107 comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
108 frame->linesize[index],
109 t->last_frame->data[index] + offset,
110 t->last_frame->linesize[index], add);
114 static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
115 int mb_x, int mb_y, int j)
119 frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
120 frame->linesize[0], block);
121 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
124 frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
125 frame->linesize[index], block);
129 static inline int decode_block_intra(MadContext *s, int16_t * block)
131 int level, i, j, run;
132 RLTable *rl = &ff_rl_mpeg1;
133 const uint8_t *scantable = s->scantable.permutated;
134 int16_t *quant_matrix = s->quant_matrix;
136 block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
138 /* The RL decoder is derived from mpeg1_decode_block_intra;
139 Escaped level and run values a decoded differently */
142 OPEN_READER(re, &s->gb);
143 /* now quantify & encode AC coefficients */
145 UPDATE_CACHE(re, &s->gb);
146 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
150 } else if (level != 0) {
153 level = (level*quant_matrix[j]) >> 4;
155 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
156 LAST_SKIP_BITS(re, &s->gb, 1);
159 UPDATE_CACHE(re, &s->gb);
160 level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
162 UPDATE_CACHE(re, &s->gb);
163 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
169 level = (level*quant_matrix[j]) >> 4;
173 level = (level*quant_matrix[j]) >> 4;
178 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
184 CLOSE_READER(re, &s->gb);
189 static int decode_motion(GetBitContext *gb)
195 value += get_bits(gb, 4) + 1;
200 static int decode_mb(MadContext *s, AVFrame *frame, int inter)
203 int av_uninit(mv_x), av_uninit(mv_y);
207 int v = decode210(&s->gb);
209 mv_map = v ? get_bits(&s->gb, 6) : 63;
210 mv_x = decode_motion(&s->gb);
211 mv_y = decode_motion(&s->gb);
215 for (j=0; j<6; j++) {
216 if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
217 int add = 2*decode_motion(&s->gb);
218 if (s->last_frame->data[0])
219 comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
221 s->bdsp.clear_block(s->block);
222 if(decode_block_intra(s, s->block) < 0)
224 idct_put(s, frame, s->block, s->mb_x, s->mb_y, j);
230 static void calc_quant_matrix(MadContext *s, int qscale)
234 s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
236 s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
239 static int decode_frame(AVCodecContext *avctx,
240 void *data, int *got_frame,
243 const uint8_t *buf = avpkt->data;
244 int buf_size = avpkt->size;
245 const uint8_t *buf_end = buf+buf_size;
246 MadContext *s = avctx->priv_data;
247 AVFrame *frame = data;
253 av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n");
255 return AVERROR_INVALIDDATA;
258 chunk_type = AV_RL32(&buf[0]);
259 inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
262 av_reduce(&avctx->time_base.num, &avctx->time_base.den,
263 AV_RL16(&buf[6]), 1000, 1<<30);
265 width = AV_RL16(&buf[8]);
266 height = AV_RL16(&buf[10]);
267 calc_quant_matrix(s, buf[13]);
270 if (width < 16 || height < 16) {
271 av_log(avctx, AV_LOG_ERROR, "Dimensions too small\n");
272 return AVERROR_INVALIDDATA;
275 if (avctx->width != width || avctx->height != height) {
276 av_frame_unref(s->last_frame);
277 if((width * height)/2048*7 > buf_end-buf)
278 return AVERROR_INVALIDDATA;
279 if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
283 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
286 if (inter && !s->last_frame->data[0]) {
287 av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
288 ret = ff_get_buffer(avctx, s->last_frame, AV_GET_BUFFER_FLAG_REF);
291 memset(s->last_frame->data[0], 0, s->last_frame->height *
292 s->last_frame->linesize[0]);
293 memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 *
294 s->last_frame->linesize[1]);
295 memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 *
296 s->last_frame->linesize[2]);
299 av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
301 if (!s->bitstream_buf)
302 return AVERROR(ENOMEM);
303 s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *) buf,
304 (buf_end - buf) / 2);
305 memset((uint8_t*)s->bitstream_buf + (buf_end-buf), 0, FF_INPUT_BUFFER_PADDING_SIZE);
306 init_get_bits(&s->gb, s->bitstream_buf, 8*(buf_end-buf));
308 for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
309 for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
310 if(decode_mb(s, frame, inter) < 0)
311 return AVERROR_INVALIDDATA;
315 if (chunk_type != MADe_TAG) {
316 av_frame_unref(s->last_frame);
317 if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
324 static av_cold int decode_end(AVCodecContext *avctx)
326 MadContext *t = avctx->priv_data;
327 av_frame_free(&t->last_frame);
328 av_free(t->bitstream_buf);
332 AVCodec ff_eamad_decoder = {
334 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"),
335 .type = AVMEDIA_TYPE_VIDEO,
336 .id = AV_CODEC_ID_MAD,
337 .priv_data_size = sizeof(MadContext),
340 .decode = decode_frame,
341 .capabilities = CODEC_CAP_DR1,