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/*
* RAW H.264 video demuxer
* Copyright (c) 2008 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 "libavcodec/get_bits.h"
#include "libavcodec/golomb.h"
#include "avformat.h"
#include "rawdec.h"
#include "libavcodec/internal.h"
#define MAX_SPS_COUNT 32
#define MAX_PPS_COUNT 256
static int h264_probe(const AVProbeData *p)
{
uint32_t code = -1;
int sps = 0, pps = 0, idr = 0, res = 0, sli = 0;
int i, ret;
int pps_ids[MAX_PPS_COUNT+1] = {0};
int sps_ids[MAX_SPS_COUNT+1] = {0};
unsigned pps_id, sps_id;
GetBitContext gb;
for (i = 0; i + 2 < p->buf_size; i++) {
code = (code << 8) + p->buf[i];
if ((code & 0xffffff00) == 0x100) {
int ref_idc = (code >> 5) & 3;
int type = code & 0x1F;
static const int8_t ref_zero[] = {
2, 0, 0, 0, 0, -1, 1, -1,
-1, 1, 1, 1, 1, -1, 2, 2,
2, 2, 2, 0, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2
};
if (code & 0x80) // forbidden_bit
return 0;
if (ref_zero[type] == 1 && ref_idc)
return 0;
if (ref_zero[type] == -1 && !ref_idc)
return 0;
if (ref_zero[type] == 2) {
if (!(code == 0x100 && !p->buf[i + 1] && !p->buf[i + 2]))
res++;
}
ret = init_get_bits8(&gb, p->buf + i + 1, p->buf_size - i - 1);
if (ret < 0)
return 0;
switch (type) {
case 1:
case 5:
get_ue_golomb_long(&gb);
if (get_ue_golomb_long(&gb) > 9U)
return 0;
pps_id = get_ue_golomb_long(&gb);
if (pps_id > MAX_PPS_COUNT)
return 0;
if (!pps_ids[pps_id])
break;
if (type == 1)
sli++;
else
idr++;
break;
case 7:
skip_bits(&gb, 14);
if (get_bits(&gb, 2))
return 0;
skip_bits(&gb, 8);
sps_id = get_ue_golomb_long(&gb);
if (sps_id > MAX_SPS_COUNT)
return 0;
sps_ids[sps_id] = 1;
sps++;
break;
case 8:
pps_id = get_ue_golomb_long(&gb);
if (pps_id > MAX_PPS_COUNT)
return 0;
sps_id = get_ue_golomb_long(&gb);
if (sps_id > MAX_SPS_COUNT)
return 0;
if (!sps_ids[sps_id])
break;
pps_ids[pps_id] = 1;
pps++;
break;
}
}
}
ff_tlog(NULL, "sps:%d pps:%d idr:%d sli:%d res:%d\n", sps, pps, idr, sli, res);
if (sps && pps && (idr || sli > 3) && res < (sps + pps + idr))
return AVPROBE_SCORE_EXTENSION + 1; // 1 more than .mpg
return 0;
}
FF_DEF_RAWVIDEO_DEMUXER(h264, "raw H.264 video", h264_probe, "h26l,h264,264,avc", AV_CODEC_ID_H264)
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