1/* 2 * Sony PlayStation MDEC (Motion DECoder) 3 * Copyright (c) 2003 Michael Niedermayer 4 * 5 * based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl> 6 * 7 * This file is part of FFmpeg. 8 * 9 * FFmpeg is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU Lesser General Public 11 * License as published by the Free Software Foundation; either 12 * version 2.1 of the License, or (at your option) any later version. 13 * 14 * FFmpeg is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * Lesser General Public License for more details. 18 * 19 * You should have received a copy of the GNU Lesser General Public 20 * License along with FFmpeg; if not, write to the Free Software 21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 22 */ 23 24/** 25 * @file libavcodec/mdec.c 26 * Sony PlayStation MDEC (Motion DECoder) 27 * This is very similar to intra-only MPEG-1. 28 */ 29 30#include "avcodec.h" 31#include "dsputil.h" 32#include "mpegvideo.h" 33#include "mpeg12.h" 34 35typedef struct MDECContext{ 36 AVCodecContext *avctx; 37 DSPContext dsp; 38 AVFrame picture; 39 GetBitContext gb; 40 ScanTable scantable; 41 int version; 42 int qscale; 43 int last_dc[3]; 44 int mb_width; 45 int mb_height; 46 int mb_x, mb_y; 47 DECLARE_ALIGNED_16(DCTELEM, block[6][64]); 48 DECLARE_ALIGNED_8(uint16_t, intra_matrix[64]); 49 DECLARE_ALIGNED_8(int, q_intra_matrix[64]); 50 uint8_t *bitstream_buffer; 51 unsigned int bitstream_buffer_size; 52 int block_last_index[6]; 53} MDECContext; 54 55//very similar to MPEG-1 56static inline int mdec_decode_block_intra(MDECContext *a, DCTELEM *block, int n) 57{ 58 int level, diff, i, j, run; 59 int component; 60 RLTable *rl = &ff_rl_mpeg1; 61 uint8_t * const scantable= a->scantable.permutated; 62 const uint16_t *quant_matrix= ff_mpeg1_default_intra_matrix; 63 const int qscale= a->qscale; 64 65 /* DC coefficient */ 66 if(a->version==2){ 67 block[0]= 2*get_sbits(&a->gb, 10) + 1024; 68 }else{ 69 component = (n <= 3 ? 0 : n - 4 + 1); 70 diff = decode_dc(&a->gb, component); 71 if (diff >= 0xffff) 72 return -1; 73 a->last_dc[component]+= diff; 74 block[0] = a->last_dc[component]<<3; 75 } 76 77 i = 0; 78 { 79 OPEN_READER(re, &a->gb); 80 /* now quantify & encode AC coefficients */ 81 for(;;) { 82 UPDATE_CACHE(re, &a->gb); 83 GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0); 84 85 if(level == 127){ 86 break; 87 } else if(level != 0) { 88 i += run; 89 j = scantable[i]; 90 level= (level*qscale*quant_matrix[j])>>3; 91 level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1); 92 LAST_SKIP_BITS(re, &a->gb, 1); 93 } else { 94 /* escape */ 95 run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6); 96 UPDATE_CACHE(re, &a->gb); 97 level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10); 98 i += run; 99 j = scantable[i]; 100 if(level<0){ 101 level= -level; 102 level= (level*qscale*quant_matrix[j])>>3; 103 level= (level-1)|1; 104 level= -level; 105 }else{ 106 level= (level*qscale*quant_matrix[j])>>3; 107 level= (level-1)|1; 108 } 109 } 110 if (i > 63){ 111 av_log(a->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y); 112 return -1; 113 } 114 115 block[j] = level; 116 } 117 CLOSE_READER(re, &a->gb); 118 } 119 a->block_last_index[n] = i; 120 return 0; 121} 122 123static inline int decode_mb(MDECContext *a, DCTELEM block[6][64]){ 124 int i; 125 const int block_index[6]= {5,4,0,1,2,3}; 126 127 a->dsp.clear_blocks(block[0]); 128 129 for(i=0; i<6; i++){ 130 if( mdec_decode_block_intra(a, block[ block_index[i] ], block_index[i]) < 0) 131 return -1; 132 } 133 return 0; 134} 135 136static inline void idct_put(MDECContext *a, int mb_x, int mb_y){ 137 DCTELEM (*block)[64]= a->block; 138 int linesize= a->picture.linesize[0]; 139 140 uint8_t *dest_y = a->picture.data[0] + (mb_y * 16* linesize ) + mb_x * 16; 141 uint8_t *dest_cb = a->picture.data[1] + (mb_y * 8 * a->picture.linesize[1]) + mb_x * 8; 142 uint8_t *dest_cr = a->picture.data[2] + (mb_y * 8 * a->picture.linesize[2]) + mb_x * 8; 143 144 a->dsp.idct_put(dest_y , linesize, block[0]); 145 a->dsp.idct_put(dest_y + 8, linesize, block[1]); 146 a->dsp.idct_put(dest_y + 8*linesize , linesize, block[2]); 147 a->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]); 148 149 if(!(a->avctx->flags&CODEC_FLAG_GRAY)){ 150 a->dsp.idct_put(dest_cb, a->picture.linesize[1], block[4]); 151 a->dsp.idct_put(dest_cr, a->picture.linesize[2], block[5]); 152 } 153} 154 155static int decode_frame(AVCodecContext *avctx, 156 void *data, int *data_size, 157 const uint8_t *buf, int buf_size) 158{ 159 MDECContext * const a = avctx->priv_data; 160 AVFrame *picture = data; 161 AVFrame * const p= &a->picture; 162 int i; 163 164 if(p->data[0]) 165 avctx->release_buffer(avctx, p); 166 167 p->reference= 0; 168 if(avctx->get_buffer(avctx, p) < 0){ 169 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 170 return -1; 171 } 172 p->pict_type= FF_I_TYPE; 173 p->key_frame= 1; 174 175 a->bitstream_buffer= av_fast_realloc(a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE); 176 for(i=0; i<buf_size; i+=2){ 177 a->bitstream_buffer[i] = buf[i+1]; 178 a->bitstream_buffer[i+1]= buf[i ]; 179 } 180 init_get_bits(&a->gb, a->bitstream_buffer, buf_size*8); 181 182 /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */ 183 skip_bits(&a->gb, 32); 184 185 a->qscale= get_bits(&a->gb, 16); 186 a->version= get_bits(&a->gb, 16); 187 188 a->last_dc[0]= 189 a->last_dc[1]= 190 a->last_dc[2]= 128; 191 192 for(a->mb_x=0; a->mb_x<a->mb_width; a->mb_x++){ 193 for(a->mb_y=0; a->mb_y<a->mb_height; a->mb_y++){ 194 if( decode_mb(a, a->block) <0) 195 return -1; 196 197 idct_put(a, a->mb_x, a->mb_y); 198 } 199 } 200 201 p->quality= a->qscale * FF_QP2LAMBDA; 202 memset(p->qscale_table, a->qscale, p->qstride*a->mb_height); 203 204 *picture = a->picture; 205 *data_size = sizeof(AVPicture); 206 207 return (get_bits_count(&a->gb)+31)/32*4; 208} 209 210static av_cold void mdec_common_init(AVCodecContext *avctx){ 211 MDECContext * const a = avctx->priv_data; 212 213 dsputil_init(&a->dsp, avctx); 214 215 a->mb_width = (avctx->coded_width + 15) / 16; 216 a->mb_height = (avctx->coded_height + 15) / 16; 217 218 avctx->coded_frame= &a->picture; 219 a->avctx= avctx; 220} 221 222static av_cold int decode_init(AVCodecContext *avctx){ 223 MDECContext * const a = avctx->priv_data; 224 AVFrame *p= &a->picture; 225 226 mdec_common_init(avctx); 227 ff_mpeg12_init_vlcs(); 228 ff_init_scantable(a->dsp.idct_permutation, &a->scantable, ff_zigzag_direct); 229 230 p->qstride= a->mb_width; 231 p->qscale_table= av_mallocz( p->qstride * a->mb_height); 232 avctx->pix_fmt= PIX_FMT_YUV420P; 233 234 return 0; 235} 236 237static av_cold int decode_end(AVCodecContext *avctx){ 238 MDECContext * const a = avctx->priv_data; 239 240 av_freep(&a->bitstream_buffer); 241 av_freep(&a->picture.qscale_table); 242 a->bitstream_buffer_size=0; 243 244 return 0; 245} 246 247AVCodec mdec_decoder = { 248 "mdec", 249 CODEC_TYPE_VIDEO, 250 CODEC_ID_MDEC, 251 sizeof(MDECContext), 252 decode_init, 253 NULL, 254 decode_end, 255 decode_frame, 256 CODEC_CAP_DR1, 257 .long_name= NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"), 258}; 259 260