mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-11-26 19:01:44 +02:00
90 lines
3.2 KiB
C
90 lines
3.2 KiB
C
/*
|
|
* RAW MPEG video demuxer
|
|
* Copyright (c) 2002-2003 Fabrice Bellard
|
|
* Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
#include "avformat.h"
|
|
#include "rawdec.h"
|
|
|
|
#include "libavutil/intreadwrite.h"
|
|
|
|
#define SEQ_START_CODE 0x000001b3
|
|
#define GOP_START_CODE 0x000001b8
|
|
#define PICTURE_START_CODE 0x00000100
|
|
#define SLICE_START_CODE 0x00000101
|
|
#define PACK_START_CODE 0x000001ba
|
|
#define VIDEO_ID 0x000001e0
|
|
#define AUDIO_ID 0x000001c0
|
|
|
|
static int mpegvideo_probe(AVProbeData *p)
|
|
{
|
|
uint32_t code= -1;
|
|
int pic=0, seq=0, slice=0, pspack=0, vpes=0, apes=0, res=0, sicle=0;
|
|
int i, j;
|
|
uint32_t last = 0;
|
|
|
|
for(i=0; i<p->buf_size; i++){
|
|
code = (code<<8) + p->buf[i];
|
|
if ((code & 0xffffff00) == 0x100) {
|
|
switch(code){
|
|
case SEQ_START_CODE:
|
|
if (!(p->buf[i+1+3+1+2] & 0x20))
|
|
break;
|
|
j = i;
|
|
if (p->buf[j+8] & 2)
|
|
j+= 64;
|
|
if (j >= p->buf_size)
|
|
break;
|
|
if (p->buf[j+8] & 1)
|
|
j+= 64;
|
|
if (j >= p->buf_size)
|
|
break;
|
|
if (AV_RB24(p->buf + j + 9) & 0xFFFFFE)
|
|
break;
|
|
seq++;
|
|
break;
|
|
case PICTURE_START_CODE: pic++; break;
|
|
case PACK_START_CODE: pspack++; break;
|
|
case 0x1b6:
|
|
res++; break;
|
|
}
|
|
if (code >= SLICE_START_CODE && code <= 0x1af) {
|
|
if (last >= SLICE_START_CODE && last <= 0x1af) {
|
|
if (code >= last) slice++;
|
|
else sicle++;
|
|
}else{
|
|
if (code == SLICE_START_CODE) slice++;
|
|
else sicle++;
|
|
}
|
|
}
|
|
if ((code & 0x1f0) == VIDEO_ID) vpes++;
|
|
else if((code & 0x1e0) == AUDIO_ID) apes++;
|
|
last = code;
|
|
}
|
|
}
|
|
if(seq && seq*9<=pic*10 && pic*9<=slice*10 && !pspack && !apes && !res && slice > sicle) {
|
|
if(vpes) return AVPROBE_SCORE_EXTENSION / 4;
|
|
else return pic>1 ? AVPROBE_SCORE_EXTENSION + 1 : AVPROBE_SCORE_EXTENSION / 2; // +1 for .mpg
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
FF_DEF_RAWVIDEO_DEMUXER(mpegvideo, "raw MPEG video", mpegvideo_probe, NULL, AV_CODEC_ID_MPEG1VIDEO)
|