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
32 #include "bitstream.h"
34 #include "bytestream.h"
36 #include "aandcttab.h"
40 #include "mpeg12data.h"
41 #include "mpeg12vlc.h"
44 #define EA_PREAMBLE_SIZE 8
45 #define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD I-frame */
46 #define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD P-frame */
47 #define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */
49 typedef struct MadContext {
50 AVCodecContext *avctx;
52 BswapDSPContext bbdsp;
57 unsigned int bitstream_buf_size;
58 DECLARE_ALIGNED(16, int16_t, block)[64];
60 uint16_t quant_matrix[64];
65 static av_cold int decode_init(AVCodecContext *avctx)
67 MadContext *s = avctx->priv_data;
69 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
70 ff_blockdsp_init(&s->bdsp);
71 ff_bswapdsp_init(&s->bbdsp);
72 ff_idctdsp_init(&s->idsp, avctx);
73 ff_init_scantable_permutation(s->idsp.idct_permutation, FF_IDCT_PERM_NONE);
74 ff_init_scantable(s->idsp.idct_permutation, &s->scantable, ff_zigzag_direct);
75 ff_mpeg12_init_vlcs();
77 s->last_frame = av_frame_alloc();
79 return AVERROR(ENOMEM);
84 static inline void comp(unsigned char *dst, ptrdiff_t dst_stride,
85 unsigned char *src, ptrdiff_t src_stride, int add)
90 dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
93 static inline void comp_block(MadContext *t, AVFrame *frame,
95 int j, int mv_x, int mv_y, int add)
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] + (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame->linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x,
101 t->last_frame->linesize[0], add);
102 } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
104 comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
105 frame->linesize[index],
106 t->last_frame->data[index] + (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2),
107 t->last_frame->linesize[index], add);
111 static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
112 int mb_x, int mb_y, int j)
116 frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
117 frame->linesize[0], block);
118 } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
121 frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
122 frame->linesize[index], block);
126 static inline void decode_block_intra(MadContext *s, int16_t * block)
128 int level, i, j, run;
129 RLTable *rl = &ff_rl_mpeg1;
130 const uint8_t *scantable = s->scantable.permutated;
131 int16_t *quant_matrix = s->quant_matrix;
133 block[0] = (128 + bitstream_read_signed(&s->bc, 8)) * quant_matrix[0];
135 /* The RL decoder is derived from mpeg1_decode_block_intra;
136 Escaped level and run values a decoded differently */
139 /* now quantify & encode AC coefficients */
141 BITSTREAM_RL_VLC(level, run, &s->bc, rl->rl_vlc[0], TEX_VLC_BITS, 2);
145 } else if (level != 0) {
148 av_log(s->avctx, AV_LOG_ERROR,
149 "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
153 level = (level*quant_matrix[j]) >> 4;
155 level = bitstream_apply_sign(&s->bc, level);
158 level = bitstream_read_signed(&s->bc, 10);
160 run = bitstream_read(&s->bc, 6) + 1;
164 av_log(s->avctx, AV_LOG_ERROR,
165 "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
171 level = (level*quant_matrix[j]) >> 4;
175 level = (level*quant_matrix[j]) >> 4;
185 static int decode_motion(BitstreamContext *bc)
189 if (bitstream_read_bit(bc)) {
190 if (bitstream_read_bit(bc))
192 value += bitstream_read(bc, 4) + 1;
197 static void decode_mb(MadContext *s, AVFrame *frame, int inter)
204 int v = bitstream_decode210(&s->bc);
206 mv_map = v ? bitstream_read(&s->bc, 6) : 63;
207 mv_x = decode_motion(&s->bc);
208 mv_y = decode_motion(&s->bc);
214 for (j=0; j<6; j++) {
215 if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
216 int add = 2 * decode_motion(&s->bc);
217 comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
219 s->bdsp.clear_block(s->block);
220 decode_block_intra(s, s->block);
221 idct_put(s, frame, s->block, s->mb_x, s->mb_y, j);
226 static void calc_quant_matrix(MadContext *s, int qscale)
230 s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
232 s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
235 static int decode_frame(AVCodecContext *avctx,
236 void *data, int *got_frame,
239 const uint8_t *buf = avpkt->data;
240 int buf_size = avpkt->size;
241 MadContext *s = avctx->priv_data;
242 AVFrame *frame = data;
248 bytestream2_init(&gb, buf, buf_size);
250 chunk_type = bytestream2_get_le32(&gb);
251 inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
252 bytestream2_skip(&gb, 10);
254 av_reduce(&avctx->framerate.den, &avctx->framerate.num,
255 bytestream2_get_le16(&gb), 1000, 1<<30);
257 width = bytestream2_get_le16(&gb);
258 height = bytestream2_get_le16(&gb);
259 bytestream2_skip(&gb, 1);
260 calc_quant_matrix(s, bytestream2_get_byte(&gb));
261 bytestream2_skip(&gb, 2);
263 if (bytestream2_get_bytes_left(&gb) < 2) {
264 av_log(avctx, AV_LOG_ERROR, "Input data too small\n");
265 return AVERROR_INVALIDDATA;
268 if (avctx->width != width || avctx->height != height) {
269 av_frame_unref(s->last_frame);
270 if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
274 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) {
275 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
279 if (inter && !s->last_frame->data[0]) {
280 av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
281 ret = ff_get_buffer(avctx, s->last_frame, AV_GET_BUFFER_FLAG_REF);
284 memset(s->last_frame->data[0], 0, s->last_frame->height *
285 s->last_frame->linesize[0]);
286 memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 *
287 s->last_frame->linesize[1]);
288 memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 *
289 s->last_frame->linesize[2]);
292 av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
293 bytestream2_get_bytes_left(&gb));
294 if (!s->bitstream_buf)
295 return AVERROR(ENOMEM);
296 s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *)(buf + bytestream2_tell(&gb)),
297 bytestream2_get_bytes_left(&gb) / 2);
298 bitstream_init8(&s->bc, s->bitstream_buf, bytestream2_get_bytes_left(&gb));
300 for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
301 for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
302 decode_mb(s, frame, inter);
306 if (chunk_type != MADe_TAG) {
307 av_frame_unref(s->last_frame);
308 if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
315 static av_cold int decode_end(AVCodecContext *avctx)
317 MadContext *t = avctx->priv_data;
318 av_frame_free(&t->last_frame);
319 av_free(t->bitstream_buf);
323 AVCodec ff_eamad_decoder = {
325 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"),
326 .type = AVMEDIA_TYPE_VIDEO,
327 .id = AV_CODEC_ID_MAD,
328 .priv_data_size = sizeof(MadContext),
331 .decode = decode_frame,
332 .capabilities = AV_CODEC_CAP_DR1,