mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-12 19:18:44 +02:00
78 lines
2.7 KiB
C
78 lines
2.7 KiB
C
/*
|
|
* RAW MPEG-4 video demuxer
|
|
* Copyright (c) 2006 Thijs Vermeir <thijs.vermeir@barco.com>
|
|
*
|
|
* 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"
|
|
|
|
#define VOS_STARTCODE 0x1B0
|
|
#define USER_DATA_STARTCODE 0x1B2
|
|
#define GOP_STARTCODE 0x1B3
|
|
#define VISUAL_OBJ_STARTCODE 0x1B5
|
|
#define VOP_STARTCODE 0x1B6
|
|
#define SLICE_STARTCODE 0x1B7
|
|
#define EXT_STARTCODE 0x1B8
|
|
|
|
static int mpeg4video_probe(AVProbeData *probe_packet)
|
|
{
|
|
uint32_t temp_buffer = -1;
|
|
int VO = 0, VOL = 0, VOP = 0, VISO = 0, res = 0;
|
|
int res_main = 0;
|
|
int i;
|
|
|
|
for (i = 0; i < probe_packet->buf_size; i++) {
|
|
temp_buffer = (temp_buffer << 8) + probe_packet->buf[i];
|
|
if (temp_buffer & 0xfffffe00)
|
|
continue;
|
|
if (temp_buffer < 2)
|
|
continue;
|
|
|
|
if (temp_buffer == VOP_STARTCODE)
|
|
VOP++;
|
|
else if (temp_buffer == VISUAL_OBJ_STARTCODE)
|
|
VISO++;
|
|
else if (temp_buffer >= 0x100 && temp_buffer < 0x120)
|
|
VO++;
|
|
else if (temp_buffer >= 0x120 && temp_buffer < 0x130)
|
|
VOL++;
|
|
else if (temp_buffer == SLICE_STARTCODE || temp_buffer == EXT_STARTCODE)
|
|
res_main++;
|
|
else if (!(0x1AF < temp_buffer && temp_buffer < 0x1B7) &&
|
|
!(0x1B9 < temp_buffer && temp_buffer < 0x1C4))
|
|
res++;
|
|
}
|
|
|
|
// res_main repesents the reserved codes within the "main" profile, they are
|
|
// added to the reserved ones if it appears that this is a "main" profile
|
|
// stream
|
|
if (res_main && 2*res_main < VOP)
|
|
res += res_main;
|
|
|
|
if (VOP >= VISO && VOP >= VOL && VO >= VOL && VOL > 0 && res == 0)
|
|
return VOP+VO > 4 ? AVPROBE_SCORE_EXTENSION : AVPROBE_SCORE_EXTENSION/2;
|
|
|
|
if (VOP >= VISO && VOP >= VOL && VO >= VOL && VOL > 0 && VOP+VO > 4)
|
|
return AVPROBE_SCORE_EXTENSION/10;
|
|
return 0;
|
|
}
|
|
|
|
FF_DEF_RAWVIDEO_DEMUXER2(m4v, "raw MPEG-4 video", mpeg4video_probe, "m4v",
|
|
AV_CODEC_ID_MPEG4, AVFMT_GENERIC_INDEX | AVFMT_TS_DISCONT)
|