/* * Electronic Arts Madcow Video Decoder * Copyright (c) 2007-2009 Peter Ross * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * Electronic Arts Madcow Video Decoder * by Peter Ross <pross@xvid.org> * * Technical details here: * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_MAD */ #include "avcodec.h" #include "get_bits.h" #include "dsputil.h" #include "aandcttab.h" #include "mpeg12.h" #include "mpeg12data.h" #include "libavcore/imgutils.h" #define EA_PREAMBLE_SIZE 8 #define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD i-frame */ #define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD p-frame */ #define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */ typedef struct MadContext { MpegEncContext s; AVFrame frame; AVFrame last_frame; void *bitstream_buf; unsigned int bitstream_buf_size; DECLARE_ALIGNED(16, DCTELEM, block)[64]; } MadContext; static void bswap16_buf(uint16_t *dst, const uint16_t *src, int count) { int i; for (i=0; i<count; i++) dst[i] = av_bswap16(src[i]); } static av_cold int decode_init(AVCodecContext *avctx) { MadContext *t = avctx->priv_data; MpegEncContext *s = &t->s; s->avctx = avctx; avctx->pix_fmt = PIX_FMT_YUV420P; if (avctx->idct_algo == FF_IDCT_AUTO) avctx->idct_algo = FF_IDCT_EA; dsputil_init(&s->dsp, avctx); ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct); ff_mpeg12_init_vlcs(); return 0; } static inline void comp(unsigned char *dst, int dst_stride, unsigned char *src, int src_stride, int add) { int j, i; for (j=0; j<8; j++) for (i=0; i<8; i++) dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add); } static inline void comp_block(MadContext *t, int mb_x, int mb_y, int j, int mv_x, int mv_y, int add) { MpegEncContext *s = &t->s; if (j < 4) { comp(t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3), t->frame.linesize[0], 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, t->last_frame.linesize[0], add); } else if (!(s->avctx->flags & CODEC_FLAG_GRAY)) { int index = j - 3; comp(t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x * 8, t->frame.linesize[index], t->last_frame.data[index] + (mb_y * 8 + (mv_y/2))*t->last_frame.linesize[index] + mb_x * 8 + (mv_x/2), t->last_frame.linesize[index], add); } } static inline void idct_put(MadContext *t, DCTELEM *block, int mb_x, int mb_y, int j) { MpegEncContext *s = &t->s; if (j < 4) { s->dsp.idct_put( t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3), t->frame.linesize[0], block); } else if (!(s->avctx->flags & CODEC_FLAG_GRAY)) { int index = j - 3; s->dsp.idct_put( t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x*8, t->frame.linesize[index], block); } } static inline void decode_block_intra(MadContext * t, DCTELEM * block) { MpegEncContext *s = &t->s; int level, i, j, run; RLTable *rl = &ff_rl_mpeg1; const uint8_t *scantable = s->intra_scantable.permutated; int16_t *quant_matrix = s->intra_matrix; block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0]; /* The RL decoder is derived from mpeg1_decode_block_intra; Escaped level and run values a decoded differently */ i = 0; { OPEN_READER(re, &s->gb); /* now quantify & encode AC coefficients */ for (;;) { UPDATE_CACHE(re, &s->gb); GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0); if (level == 127) { break; } else if (level != 0) { i += run; j = scantable[i]; level = (level*quant_matrix[j]) >> 4; level = (level-1)|1; level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1); LAST_SKIP_BITS(re, &s->gb, 1); } else { /* escape */ UPDATE_CACHE(re, &s->gb); level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10); UPDATE_CACHE(re, &s->gb); run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6); i += run; j = scantable[i]; if (level < 0) { level = -level; level = (level*quant_matrix[j]) >> 4; level = (level-1)|1; level = -level; } else { level = (level*quant_matrix[j]) >> 4; level = (level-1)|1; } } if (i > 63) { av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y); return; } block[j] = level; } CLOSE_READER(re, &s->gb); } } static int decode_motion(GetBitContext *gb) { int value = 0; if (get_bits1(gb)) { if (get_bits1(gb)) value = -17; value += get_bits(gb, 4) + 1; } return value; } static void decode_mb(MadContext *t, int inter) { MpegEncContext *s = &t->s; int mv_map = 0; int mv_x, mv_y; int j; if (inter) { int v = decode210(&s->gb); if (v < 2) { mv_map = v ? get_bits(&s->gb, 6) : 63; mv_x = decode_motion(&s->gb); mv_y = decode_motion(&s->gb); } else { mv_map = 0; } } for (j=0; j<6; j++) { if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map int add = 2*decode_motion(&s->gb); comp_block(t, s->mb_x, s->mb_y, j, mv_x, mv_y, add); } else { s->dsp.clear_block(t->block); decode_block_intra(t, t->block); idct_put(t, t->block, s->mb_x, s->mb_y, j); } } } static void calc_intra_matrix(MadContext *t, int qscale) { MpegEncContext *s = &t->s; int i; if (s->avctx->idct_algo == FF_IDCT_EA) { s->intra_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11; for (i=1; i<64; i++) s->intra_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10; } else { s->intra_matrix[0] = ff_mpeg1_default_intra_matrix[0]; for (i=1; i<64; i++) s->intra_matrix[i] = (ff_mpeg1_default_intra_matrix[i]*qscale) << 1; } } static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; const uint8_t *buf_end = buf+buf_size; MadContext *t = avctx->priv_data; MpegEncContext *s = &t->s; int chunk_type; int inter; if (buf_size < 17) { av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n"); *data_size = 0; return -1; } chunk_type = AV_RL32(&buf[0]); inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG); buf += 8; av_reduce(&avctx->time_base.num, &avctx->time_base.den, AV_RL16(&buf[6]), 1000, 1<<30); s->width = AV_RL16(&buf[8]); s->height = AV_RL16(&buf[10]); calc_intra_matrix(t, buf[13]); buf += 16; if (avctx->width != s->width || avctx->height != s->height) { if (av_check_image_size(s->width, s->height, 0, avctx) < 0) return -1; avcodec_set_dimensions(avctx, s->width, s->height); if (t->frame.data[0]) avctx->release_buffer(avctx, &t->frame); } t->frame.reference = 1; if (!t->frame.data[0]) { if (avctx->get_buffer(avctx, &t->frame) < 0) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return -1; } } av_fast_malloc(&t->bitstream_buf, &t->bitstream_buf_size, (buf_end-buf) + FF_INPUT_BUFFER_PADDING_SIZE); if (!t->bitstream_buf) return AVERROR(ENOMEM); bswap16_buf(t->bitstream_buf, (const uint16_t*)buf, (buf_end-buf)/2); init_get_bits(&s->gb, t->bitstream_buf, 8*(buf_end-buf)); for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++) for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++) decode_mb(t, inter); *data_size = sizeof(AVFrame); *(AVFrame*)data = t->frame; if (chunk_type != MADe_TAG) FFSWAP(AVFrame, t->frame, t->last_frame); return buf_size; } static av_cold int decode_end(AVCodecContext *avctx) { MadContext *t = avctx->priv_data; if (t->frame.data[0]) avctx->release_buffer(avctx, &t->frame); if (t->last_frame.data[0]) avctx->release_buffer(avctx, &t->last_frame); av_free(t->bitstream_buf); return 0; } AVCodec eamad_decoder = { "eamad", AVMEDIA_TYPE_VIDEO, CODEC_ID_MAD, sizeof(MadContext), decode_init, NULL, decode_end, decode_frame, CODEC_CAP_DR1, .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video") };