Libav
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00001 /* 00002 * Sony PlayStation MDEC (Motion DECoder) 00003 * Copyright (c) 2003 Michael Niedermayer 00004 * 00005 * based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl> 00006 * 00007 * This file is part of FFmpeg. 00008 * 00009 * FFmpeg is free software; you can redistribute it and/or 00010 * modify it under the terms of the GNU Lesser General Public 00011 * License as published by the Free Software Foundation; either 00012 * version 2.1 of the License, or (at your option) any later version. 00013 * 00014 * FFmpeg is distributed in the hope that it will be useful, 00015 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00017 * Lesser General Public License for more details. 00018 * 00019 * You should have received a copy of the GNU Lesser General Public 00020 * License along with FFmpeg; if not, write to the Free Software 00021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00022 */ 00023 00030 #include "avcodec.h" 00031 #include "dsputil.h" 00032 #include "mpegvideo.h" 00033 #include "mpeg12.h" 00034 00035 typedef struct MDECContext{ 00036 AVCodecContext *avctx; 00037 DSPContext dsp; 00038 AVFrame picture; 00039 GetBitContext gb; 00040 ScanTable scantable; 00041 int version; 00042 int qscale; 00043 int last_dc[3]; 00044 int mb_width; 00045 int mb_height; 00046 int mb_x, mb_y; 00047 DECLARE_ALIGNED(16, DCTELEM, block)[6][64]; 00048 uint8_t *bitstream_buffer; 00049 unsigned int bitstream_buffer_size; 00050 int block_last_index[6]; 00051 } MDECContext; 00052 00053 //very similar to MPEG-1 00054 static inline int mdec_decode_block_intra(MDECContext *a, DCTELEM *block, int n) 00055 { 00056 int level, diff, i, j, run; 00057 int component; 00058 RLTable *rl = &ff_rl_mpeg1; 00059 uint8_t * const scantable= a->scantable.permutated; 00060 const uint16_t *quant_matrix= ff_mpeg1_default_intra_matrix; 00061 const int qscale= a->qscale; 00062 00063 /* DC coefficient */ 00064 if(a->version==2){ 00065 block[0]= 2*get_sbits(&a->gb, 10) + 1024; 00066 }else{ 00067 component = (n <= 3 ? 0 : n - 4 + 1); 00068 diff = decode_dc(&a->gb, component); 00069 if (diff >= 0xffff) 00070 return -1; 00071 a->last_dc[component]+= diff; 00072 block[0] = a->last_dc[component]<<3; 00073 } 00074 00075 i = 0; 00076 { 00077 OPEN_READER(re, &a->gb); 00078 /* now quantify & encode AC coefficients */ 00079 for(;;) { 00080 UPDATE_CACHE(re, &a->gb); 00081 GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0); 00082 00083 if(level == 127){ 00084 break; 00085 } else if(level != 0) { 00086 i += run; 00087 j = scantable[i]; 00088 level= (level*qscale*quant_matrix[j])>>3; 00089 level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1); 00090 LAST_SKIP_BITS(re, &a->gb, 1); 00091 } else { 00092 /* escape */ 00093 run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6); 00094 UPDATE_CACHE(re, &a->gb); 00095 level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10); 00096 i += run; 00097 j = scantable[i]; 00098 if(level<0){ 00099 level= -level; 00100 level= (level*qscale*quant_matrix[j])>>3; 00101 level= (level-1)|1; 00102 level= -level; 00103 }else{ 00104 level= (level*qscale*quant_matrix[j])>>3; 00105 level= (level-1)|1; 00106 } 00107 } 00108 if (i > 63){ 00109 av_log(a->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y); 00110 return -1; 00111 } 00112 00113 block[j] = level; 00114 } 00115 CLOSE_READER(re, &a->gb); 00116 } 00117 a->block_last_index[n] = i; 00118 return 0; 00119 } 00120 00121 static inline int decode_mb(MDECContext *a, DCTELEM block[6][64]){ 00122 int i; 00123 const int block_index[6]= {5,4,0,1,2,3}; 00124 00125 a->dsp.clear_blocks(block[0]); 00126 00127 for(i=0; i<6; i++){ 00128 if( mdec_decode_block_intra(a, block[ block_index[i] ], block_index[i]) < 0) 00129 return -1; 00130 } 00131 return 0; 00132 } 00133 00134 static inline void idct_put(MDECContext *a, int mb_x, int mb_y){ 00135 DCTELEM (*block)[64]= a->block; 00136 int linesize= a->picture.linesize[0]; 00137 00138 uint8_t *dest_y = a->picture.data[0] + (mb_y * 16* linesize ) + mb_x * 16; 00139 uint8_t *dest_cb = a->picture.data[1] + (mb_y * 8 * a->picture.linesize[1]) + mb_x * 8; 00140 uint8_t *dest_cr = a->picture.data[2] + (mb_y * 8 * a->picture.linesize[2]) + mb_x * 8; 00141 00142 a->dsp.idct_put(dest_y , linesize, block[0]); 00143 a->dsp.idct_put(dest_y + 8, linesize, block[1]); 00144 a->dsp.idct_put(dest_y + 8*linesize , linesize, block[2]); 00145 a->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]); 00146 00147 if(!(a->avctx->flags&CODEC_FLAG_GRAY)){ 00148 a->dsp.idct_put(dest_cb, a->picture.linesize[1], block[4]); 00149 a->dsp.idct_put(dest_cr, a->picture.linesize[2], block[5]); 00150 } 00151 } 00152 00153 static int decode_frame(AVCodecContext *avctx, 00154 void *data, int *data_size, 00155 AVPacket *avpkt) 00156 { 00157 const uint8_t *buf = avpkt->data; 00158 int buf_size = avpkt->size; 00159 MDECContext * const a = avctx->priv_data; 00160 AVFrame *picture = data; 00161 AVFrame * const p= &a->picture; 00162 int i; 00163 00164 if(p->data[0]) 00165 avctx->release_buffer(avctx, p); 00166 00167 p->reference= 0; 00168 if(avctx->get_buffer(avctx, p) < 0){ 00169 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 00170 return -1; 00171 } 00172 p->pict_type= FF_I_TYPE; 00173 p->key_frame= 1; 00174 00175 av_fast_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE); 00176 if (!a->bitstream_buffer) 00177 return AVERROR(ENOMEM); 00178 for(i=0; i<buf_size; i+=2){ 00179 a->bitstream_buffer[i] = buf[i+1]; 00180 a->bitstream_buffer[i+1]= buf[i ]; 00181 } 00182 init_get_bits(&a->gb, a->bitstream_buffer, buf_size*8); 00183 00184 /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */ 00185 skip_bits(&a->gb, 32); 00186 00187 a->qscale= get_bits(&a->gb, 16); 00188 a->version= get_bits(&a->gb, 16); 00189 00190 a->last_dc[0]= 00191 a->last_dc[1]= 00192 a->last_dc[2]= 128; 00193 00194 for(a->mb_x=0; a->mb_x<a->mb_width; a->mb_x++){ 00195 for(a->mb_y=0; a->mb_y<a->mb_height; a->mb_y++){ 00196 if( decode_mb(a, a->block) <0) 00197 return -1; 00198 00199 idct_put(a, a->mb_x, a->mb_y); 00200 } 00201 } 00202 00203 p->quality= a->qscale * FF_QP2LAMBDA; 00204 memset(p->qscale_table, a->qscale, a->mb_width); 00205 00206 *picture = a->picture; 00207 *data_size = sizeof(AVPicture); 00208 00209 return (get_bits_count(&a->gb)+31)/32*4; 00210 } 00211 00212 static av_cold void mdec_common_init(AVCodecContext *avctx){ 00213 MDECContext * const a = avctx->priv_data; 00214 00215 dsputil_init(&a->dsp, avctx); 00216 00217 a->mb_width = (avctx->coded_width + 15) / 16; 00218 a->mb_height = (avctx->coded_height + 15) / 16; 00219 00220 avctx->coded_frame= &a->picture; 00221 a->avctx= avctx; 00222 } 00223 00224 static av_cold int decode_init(AVCodecContext *avctx){ 00225 MDECContext * const a = avctx->priv_data; 00226 AVFrame *p= &a->picture; 00227 00228 mdec_common_init(avctx); 00229 ff_mpeg12_init_vlcs(); 00230 ff_init_scantable(a->dsp.idct_permutation, &a->scantable, ff_zigzag_direct); 00231 00232 p->qstride= 0; 00233 p->qscale_table= av_mallocz(a->mb_width); 00234 avctx->pix_fmt= PIX_FMT_YUV420P; 00235 00236 return 0; 00237 } 00238 00239 static av_cold int decode_end(AVCodecContext *avctx){ 00240 MDECContext * const a = avctx->priv_data; 00241 00242 if(a->picture.data[0]) 00243 avctx->release_buffer(avctx, &a->picture); 00244 av_freep(&a->bitstream_buffer); 00245 av_freep(&a->picture.qscale_table); 00246 a->bitstream_buffer_size=0; 00247 00248 return 0; 00249 } 00250 00251 AVCodec mdec_decoder = { 00252 "mdec", 00253 AVMEDIA_TYPE_VIDEO, 00254 CODEC_ID_MDEC, 00255 sizeof(MDECContext), 00256 decode_init, 00257 NULL, 00258 decode_end, 00259 decode_frame, 00260 CODEC_CAP_DR1, 00261 .long_name= NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"), 00262 }; 00263