yading@11: /*
yading@11:  * RAW MPEG video demuxer
yading@11:  * Copyright (c) 2002-2003 Fabrice Bellard
yading@11:  * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "rawdec.h"
yading@11: 
yading@11: #define SEQ_START_CODE          0x000001b3
yading@11: #define GOP_START_CODE          0x000001b8
yading@11: #define PICTURE_START_CODE      0x00000100
yading@11: #define SLICE_START_CODE        0x00000101
yading@11: #define PACK_START_CODE         0x000001ba
yading@11: #define VIDEO_ID                0x000001e0
yading@11: #define AUDIO_ID                0x000001c0
yading@11: 
yading@11: static int mpegvideo_probe(AVProbeData *p)
yading@11: {
yading@11:     uint32_t code= -1;
yading@11:     int pic=0, seq=0, slice=0, pspack=0, vpes=0, apes=0, res=0, sicle=0;
yading@11:     int i;
yading@11:     uint32_t last = 0;
yading@11: 
yading@11:     for(i=0; i<p->buf_size; i++){
yading@11:         code = (code<<8) + p->buf[i];
yading@11:         if ((code & 0xffffff00) == 0x100) {
yading@11:             switch(code){
yading@11:             case     SEQ_START_CODE:   seq++; break;
yading@11:             case PICTURE_START_CODE:   pic++; break;
yading@11:             case    PACK_START_CODE: pspack++; break;
yading@11:             case              0x1b6:
yading@11:                                         res++; break;
yading@11:             }
yading@11:             if (code >= SLICE_START_CODE && code <= 0x1af) {
yading@11:                 if (last >= SLICE_START_CODE && last <= 0x1af) {
yading@11:                     if (code >= last) slice++;
yading@11:                     else              sicle++;
yading@11:                 }else{
yading@11:                     if (code == SLICE_START_CODE) slice++;
yading@11:                     else                          sicle++;
yading@11:                 }
yading@11:             }
yading@11:             if     ((code & 0x1f0) == VIDEO_ID)   vpes++;
yading@11:             else if((code & 0x1e0) == AUDIO_ID)   apes++;
yading@11:             last = code;
yading@11:         }
yading@11:     }
yading@11:     if(seq && seq*9<=pic*10 && pic*9<=slice*10 && !pspack && !apes && !res && slice > sicle) {
yading@11:         if(vpes) return AVPROBE_SCORE_MAX/8;
yading@11:         else     return pic>1 ? AVPROBE_SCORE_MAX/2+1 : AVPROBE_SCORE_MAX/4; // +1 for .mpg
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: FF_DEF_RAWVIDEO_DEMUXER(mpegvideo, "raw MPEG video", mpegvideo_probe, NULL, AV_CODEC_ID_MPEG1VIDEO)