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/*
* 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(const 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)
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