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
33 #include "bytestream.h"
36 #include "aandcttab.h"
40 #include "mpeg12data.h"
41 #include "mpeg12vlc.h"
43 #define EA_PREAMBLE_SIZE 8
44 #define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD I-frame */
45 #define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD P-frame */
46 #define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */
48 typedef struct MadContext {
49 AVCodecContext *avctx;
51 BswapDSPContext bbdsp;
56 unsigned int bitstream_buf_size;
57 DECLARE_ALIGNED(16, int16_t, block)[64];
59 uint16_t quant_matrix[64];
64 static av_cold int decode_init(AVCodecContext *avctx)
66 MadContext *s = avctx->priv_data;
68 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
69 ff_blockdsp_init(&s->bdsp, avctx);
70 ff_bswapdsp_init(&s->bbdsp);
71 ff_idctdsp_init(&s->idsp, avctx);
72 ff_init_scantable_permutation(s->idsp.idct_permutation, FF_IDCT_PERM_NONE);
73 ff_init_scantable(s->idsp.idct_permutation, &s->scantable, ff_zigzag_direct);
74 ff_mpeg12_init_vlcs();
76 s->last_frame = av_frame_alloc();
78 return AVERROR(ENOMEM);
83 static inline void comp(unsigned char *dst, int dst_stride,
84 unsigned char *src, int src_stride, int add)
89 dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
92 static inline void comp_block(MadContext *t, AVFrame *frame,
94 int j, int mv_x, int mv_y, int add)
97 comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
99 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,
100 t->last_frame->linesize[0], add);
101 } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
103 comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
104 frame->linesize[index],
105 t->last_frame->data[index] + (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2),
106 t->last_frame->linesize[index], add);
110 static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
111 int mb_x, int mb_y, int j)
115 frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
116 frame->linesize[0], block);
117 } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
120 frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
121 frame->linesize[index], block);
125 static inline void decode_block_intra(MadContext *s, int16_t * block)
127 int level, i, j, run;
128 RLTable *rl = &ff_rl_mpeg1;
129 const uint8_t *scantable = s->scantable.permutated;
130 int16_t *quant_matrix = s->quant_matrix;
132 block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
134 /* The RL decoder is derived from mpeg1_decode_block_intra;
135 Escaped level and run values a decoded differently */
138 OPEN_READER(re, &s->gb);
139 /* now quantify & encode AC coefficients */
141 UPDATE_CACHE(re, &s->gb);
142 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
146 } else if (level != 0) {
149 av_log(s->avctx, AV_LOG_ERROR,
150 "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
154 level = (level*quant_matrix[j]) >> 4;
156 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
157 LAST_SKIP_BITS(re, &s->gb, 1);
160 UPDATE_CACHE(re, &s->gb);
161 level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
163 UPDATE_CACHE(re, &s->gb);
164 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
168 av_log(s->avctx, AV_LOG_ERROR,
169 "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
175 level = (level*quant_matrix[j]) >> 4;
179 level = (level*quant_matrix[j]) >> 4;
186 CLOSE_READER(re, &s->gb);
190 static int decode_motion(GetBitContext *gb)
196 value += get_bits(gb, 4) + 1;
201 static void decode_mb(MadContext *s, AVFrame *frame, int inter)
208 int v = decode210(&s->gb);
210 mv_map = v ? get_bits(&s->gb, 6) : 63;
211 mv_x = decode_motion(&s->gb);
212 mv_y = decode_motion(&s->gb);
218 for (j=0; j<6; j++) {
219 if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
220 int add = 2*decode_motion(&s->gb);
221 comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
223 s->bdsp.clear_block(s->block);
224 decode_block_intra(s, s->block);
225 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 MadContext *s = avctx->priv_data;
246 AVFrame *frame = data;
252 bytestream2_init(&gb, buf, buf_size);
254 chunk_type = bytestream2_get_le32(&gb);
255 inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
256 bytestream2_skip(&gb, 10);
258 av_reduce(&avctx->framerate.den, &avctx->framerate.num,
259 bytestream2_get_le16(&gb), 1000, 1<<30);
261 width = bytestream2_get_le16(&gb);
262 height = bytestream2_get_le16(&gb);
263 bytestream2_skip(&gb, 1);
264 calc_quant_matrix(s, bytestream2_get_byte(&gb));
265 bytestream2_skip(&gb, 2);
267 if (bytestream2_get_bytes_left(&gb) < 2) {
268 av_log(avctx, AV_LOG_ERROR, "Input data too small\n");
269 return AVERROR_INVALIDDATA;
272 if (avctx->width != width || avctx->height != height) {
273 av_frame_unref(s->last_frame);
274 if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
278 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) {
279 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
283 if (inter && !s->last_frame->data[0]) {
284 av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
285 ret = ff_get_buffer(avctx, s->last_frame, AV_GET_BUFFER_FLAG_REF);
288 memset(s->last_frame->data[0], 0, s->last_frame->height *
289 s->last_frame->linesize[0]);
290 memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 *
291 s->last_frame->linesize[1]);
292 memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 *
293 s->last_frame->linesize[2]);
296 av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
297 bytestream2_get_bytes_left(&gb));
298 if (!s->bitstream_buf)
299 return AVERROR(ENOMEM);
300 s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *)(buf + bytestream2_tell(&gb)),
301 bytestream2_get_bytes_left(&gb) / 2);
302 init_get_bits(&s->gb, s->bitstream_buf, 8*(bytestream2_get_bytes_left(&gb)));
304 for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
305 for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
306 decode_mb(s, frame, inter);
310 if (chunk_type != MADe_TAG) {
311 av_frame_unref(s->last_frame);
312 if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
319 static av_cold int decode_end(AVCodecContext *avctx)
321 MadContext *t = avctx->priv_data;
322 av_frame_free(&t->last_frame);
323 av_free(t->bitstream_buf);
327 AVCodec ff_eamad_decoder = {
329 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"),
330 .type = AVMEDIA_TYPE_VIDEO,
331 .id = AV_CODEC_ID_MAD,
332 .priv_data_size = sizeof(MadContext),
335 .decode = decode_frame,
336 .capabilities = AV_CODEC_CAP_DR1,