/* * Sony PlayStation MDEC (Motion DECoder) * Copyright (c) 2003 Michael Niedermayer * * based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl> * * 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 Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file libavcodec/mdec.c * Sony PlayStation MDEC (Motion DECoder) * This is very similar to intra-only MPEG-1. */ #include "avcodec.h" #include "dsputil.h" #include "mpegvideo.h" #include "mpeg12.h" typedef struct MDECContext{ AVCodecContext *avctx; DSPContext dsp; AVFrame picture; GetBitContext gb; ScanTable scantable; int version; int qscale; int last_dc[3]; int mb_width; int mb_height; int mb_x, mb_y; DECLARE_ALIGNED_16(DCTELEM, block)[6][64]; uint8_t *bitstream_buffer; unsigned int bitstream_buffer_size; int block_last_index[6]; } MDECContext; //very similar to MPEG-1 static inline int mdec_decode_block_intra(MDECContext *a, DCTELEM *block, int n) { int level, diff, i, j, run; int component; RLTable *rl = &ff_rl_mpeg1; uint8_t * const scantable= a->scantable.permutated; const uint16_t *quant_matrix= ff_mpeg1_default_intra_matrix; const int qscale= a->qscale; /* DC coefficient */ if(a->version==2){ block[0]= 2*get_sbits(&a->gb, 10) + 1024; }else{ component = (n <= 3 ? 0 : n - 4 + 1); diff = decode_dc(&a->gb, component); if (diff >= 0xffff) return -1; a->last_dc[component]+= diff; block[0] = a->last_dc[component]<<3; } i = 0; { OPEN_READER(re, &a->gb); /* now quantify & encode AC coefficients */ for(;;) { UPDATE_CACHE(re, &a->gb); GET_RL_VLC(level, run, re, &a->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*qscale*quant_matrix[j])>>3; level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1); LAST_SKIP_BITS(re, &a->gb, 1); } else { /* escape */ run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6); UPDATE_CACHE(re, &a->gb); level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10); i += run; j = scantable[i]; if(level<0){ level= -level; level= (level*qscale*quant_matrix[j])>>3; level= (level-1)|1; level= -level; }else{ level= (level*qscale*quant_matrix[j])>>3; level= (level-1)|1; } } if (i > 63){ av_log(a->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y); return -1; } block[j] = level; } CLOSE_READER(re, &a->gb); } a->block_last_index[n] = i; return 0; } static inline int decode_mb(MDECContext *a, DCTELEM block[6][64]){ int i; const int block_index[6]= {5,4,0,1,2,3}; a->dsp.clear_blocks(block[0]); for(i=0; i<6; i++){ if( mdec_decode_block_intra(a, block[ block_index[i] ], block_index[i]) < 0) return -1; } return 0; } static inline void idct_put(MDECContext *a, int mb_x, int mb_y){ DCTELEM (*block)[64]= a->block; int linesize= a->picture.linesize[0]; uint8_t *dest_y = a->picture.data[0] + (mb_y * 16* linesize ) + mb_x * 16; uint8_t *dest_cb = a->picture.data[1] + (mb_y * 8 * a->picture.linesize[1]) + mb_x * 8; uint8_t *dest_cr = a->picture.data[2] + (mb_y * 8 * a->picture.linesize[2]) + mb_x * 8; a->dsp.idct_put(dest_y , linesize, block[0]); a->dsp.idct_put(dest_y + 8, linesize, block[1]); a->dsp.idct_put(dest_y + 8*linesize , linesize, block[2]); a->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]); if(!(a->avctx->flags&CODEC_FLAG_GRAY)){ a->dsp.idct_put(dest_cb, a->picture.linesize[1], block[4]); a->dsp.idct_put(dest_cr, a->picture.linesize[2], block[5]); } } static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; MDECContext * const a = avctx->priv_data; AVFrame *picture = data; AVFrame * const p= &a->picture; int i; if(p->data[0]) avctx->release_buffer(avctx, p); p->reference= 0; if(avctx->get_buffer(avctx, p) < 0){ av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return -1; } p->pict_type= FF_I_TYPE; p->key_frame= 1; av_fast_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE); if (!a->bitstream_buffer) return AVERROR(ENOMEM); for(i=0; i<buf_size; i+=2){ a->bitstream_buffer[i] = buf[i+1]; a->bitstream_buffer[i+1]= buf[i ]; } init_get_bits(&a->gb, a->bitstream_buffer, buf_size*8); /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */ skip_bits(&a->gb, 32); a->qscale= get_bits(&a->gb, 16); a->version= get_bits(&a->gb, 16); a->last_dc[0]= a->last_dc[1]= a->last_dc[2]= 128; for(a->mb_x=0; a->mb_x<a->mb_width; a->mb_x++){ for(a->mb_y=0; a->mb_y<a->mb_height; a->mb_y++){ if( decode_mb(a, a->block) <0) return -1; idct_put(a, a->mb_x, a->mb_y); } } p->quality= a->qscale * FF_QP2LAMBDA; memset(p->qscale_table, a->qscale, p->qstride*a->mb_height); *picture = a->picture; *data_size = sizeof(AVPicture); return (get_bits_count(&a->gb)+31)/32*4; } static av_cold void mdec_common_init(AVCodecContext *avctx){ MDECContext * const a = avctx->priv_data; dsputil_init(&a->dsp, avctx); a->mb_width = (avctx->coded_width + 15) / 16; a->mb_height = (avctx->coded_height + 15) / 16; avctx->coded_frame= &a->picture; a->avctx= avctx; } static av_cold int decode_init(AVCodecContext *avctx){ MDECContext * const a = avctx->priv_data; AVFrame *p= &a->picture; mdec_common_init(avctx); ff_mpeg12_init_vlcs(); ff_init_scantable(a->dsp.idct_permutation, &a->scantable, ff_zigzag_direct); p->qstride= a->mb_width; p->qscale_table= av_mallocz( p->qstride * a->mb_height); avctx->pix_fmt= PIX_FMT_YUV420P; return 0; } static av_cold int decode_end(AVCodecContext *avctx){ MDECContext * const a = avctx->priv_data; av_freep(&a->bitstream_buffer); av_freep(&a->picture.qscale_table); a->bitstream_buffer_size=0; return 0; } AVCodec mdec_decoder = { "mdec", CODEC_TYPE_VIDEO, CODEC_ID_MDEC, sizeof(MDECContext), decode_init, NULL, decode_end, decode_frame, CODEC_CAP_DR1, .long_name= NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"), };