/* * 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 * @author Peter Ross <pross@xvid.org> * * @see technical details at * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_MAD */ #include "avcodec.h" #include "get_bits.h" #include "aandcttab.h" #include "eaidct.h" #include "internal.h" #include "mpeg12.h" #include "mpeg12data.h" #include "libavutil/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 { AVCodecContext *avctx; DSPContext dsp; AVFrame last_frame; GetBitContext gb; void *bitstream_buf; unsigned int bitstream_buf_size; DECLARE_ALIGNED(16, int16_t, block)[64]; ScanTable scantable; uint16_t quant_matrix[64]; int mb_x; int mb_y; } MadContext; static av_cold int decode_init(AVCodecContext *avctx) { MadContext *s = avctx->priv_data; s->avctx = avctx; avctx->pix_fmt = AV_PIX_FMT_YUV420P; ff_dsputil_init(&s->dsp, avctx); ff_init_scantable_permutation(s->dsp.idct_permutation, FF_NO_IDCT_PERM); ff_init_scantable(s->dsp.idct_permutation, &s->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, AVFrame *frame, int mb_x, int mb_y, int j, int mv_x, int mv_y, int add) { if (j < 4) { unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame.linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x; if (offset >= (t->avctx->height - 7) * t->last_frame.linesize[0] - 7) return; comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3), frame->linesize[0], t->last_frame.data[0] + offset, t->last_frame.linesize[0], add); } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) { int index = j - 3; unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame.linesize[index] + mb_x * 8 + (mv_x/2); if (offset >= (t->avctx->height/2 - 7) * t->last_frame.linesize[index] - 7) return; comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8, frame->linesize[index], t->last_frame.data[index] + offset, t->last_frame.linesize[index], add); } } static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block, int mb_x, int mb_y, int j) { if (j < 4) { ff_ea_idct_put_c( frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3), frame->linesize[0], block); } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) { int index = j - 3; ff_ea_idct_put_c( frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8, frame->linesize[index], block); } } static inline int decode_block_intra(MadContext *s, int16_t * block) { int level, i, j, run; RLTable *rl = &ff_rl_mpeg1; const uint8_t *scantable = s->scantable.permutated; int16_t *quant_matrix = s->quant_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 -1; } block[j] = level; } CLOSE_READER(re, &s->gb); } return 0; } 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 int decode_mb(MadContext *s, AVFrame *frame, int inter) { 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); } } 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); if (s->last_frame.data[0]) comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add); } else { s->dsp.clear_block(s->block); if(decode_block_intra(s, s->block) < 0) return -1; idct_put(s, frame, s->block, s->mb_x, s->mb_y, j); } } return 0; } static void calc_quant_matrix(MadContext *s, int qscale) { int i; s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11; for (i=1; i<64; i++) s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10; } static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; const uint8_t *buf_end = buf+buf_size; MadContext *s = avctx->priv_data; AVFrame *frame = data; int width, height; int chunk_type; int inter, ret; if (buf_size < 26) { av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n"); *got_frame = 0; return AVERROR_INVALIDDATA; } 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); width = AV_RL16(&buf[8]); height = AV_RL16(&buf[10]); calc_quant_matrix(s, buf[13]); buf += 16; if (avctx->width != width || avctx->height != height) { if((width * height)/2048*7 > buf_end-buf) return AVERROR_INVALIDDATA; if ((ret = av_image_check_size(width, height, 0, avctx)) < 0) return ret; avcodec_set_dimensions(avctx, width, height); av_frame_unref(&s->last_frame); } if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) return ret; if (inter && !s->last_frame.data[0]) { av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n"); ret = ff_get_buffer(avctx, &s->last_frame, AV_GET_BUFFER_FLAG_REF); if (ret < 0) return ret; memset(s->last_frame.data[0], 0, s->last_frame.height * s->last_frame.linesize[0]); memset(s->last_frame.data[1], 0x80, s->last_frame.height / 2 * s->last_frame.linesize[1]); memset(s->last_frame.data[2], 0x80, s->last_frame.height / 2 * s->last_frame.linesize[2]); } av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size, buf_end - buf); if (!s->bitstream_buf) return AVERROR(ENOMEM); s->dsp.bswap16_buf(s->bitstream_buf, (const uint16_t*)buf, (buf_end-buf)/2); memset((uint8_t*)s->bitstream_buf + (buf_end-buf), 0, FF_INPUT_BUFFER_PADDING_SIZE); init_get_bits(&s->gb, s->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++) if(decode_mb(s, frame, inter) < 0) return AVERROR_INVALIDDATA; *got_frame = 1; if (chunk_type != MADe_TAG) { av_frame_unref(&s->last_frame); if ((ret = av_frame_ref(&s->last_frame, frame)) < 0) return ret; } return buf_size; } static av_cold int decode_end(AVCodecContext *avctx) { MadContext *t = avctx->priv_data; av_frame_unref(&t->last_frame); av_free(t->bitstream_buf); return 0; } AVCodec ff_eamad_decoder = { .name = "eamad", .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_MAD, .priv_data_size = sizeof(MadContext), .init = decode_init, .close = decode_end, .decode = decode_frame, .capabilities = CODEC_CAP_DR1, .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video") };