FFmpeg
hevcdec.c
Go to the documentation of this file.
1 /*
2  * RAW HEVC video demuxer
3  * Copyright (c) 2013 Dirk Farin <dirk.farin@gmail.com>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavcodec/hevc.h"
23 
24 #include "avformat.h"
25 #include "rawdec.h"
26 
27 static int hevc_probe(const AVProbeData *p)
28 {
29  uint32_t code = -1;
30  int vps = 0, sps = 0, pps = 0, irap = 0;
31  int i;
32 
33  for (i = 0; i < p->buf_size - 1; i++) {
34  code = (code << 8) + p->buf[i];
35  if ((code & 0xffffff00) == 0x100) {
36  uint8_t nal2 = p->buf[i + 1];
37  int type = (code & 0x7E) >> 1;
38 
39  if (code & 0x81) // forbidden and reserved zero bits
40  return 0;
41 
42  if (nal2 & 0xf8) // reserved zero
43  return 0;
44 
45  switch (type) {
46  case HEVC_NAL_VPS: vps++; break;
47  case HEVC_NAL_SPS: sps++; break;
48  case HEVC_NAL_PPS: pps++; break;
49  case HEVC_NAL_BLA_N_LP:
50  case HEVC_NAL_BLA_W_LP:
52  case HEVC_NAL_CRA_NUT:
53  case HEVC_NAL_IDR_N_LP:
54  case HEVC_NAL_IDR_W_RADL: irap++; break;
55  }
56  }
57  }
58 
59  if (vps && sps && pps && irap)
60  return AVPROBE_SCORE_EXTENSION + 1; // 1 more than .mpg
61  return 0;
62 }
63 
64 FF_DEF_RAWVIDEO_DEMUXER(hevc, "raw HEVC video", hevc_probe, "hevc,h265,265", AV_CODEC_ID_HEVC)
HEVC_NAL_BLA_W_RADL
@ HEVC_NAL_BLA_W_RADL
Definition: hevc.h:46
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:454
hevc_probe
static int hevc_probe(const AVProbeData *p)
Definition: hevcdec.c:27
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
HEVC_NAL_BLA_N_LP
@ HEVC_NAL_BLA_N_LP
Definition: hevc.h:47
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:453
if
if(ret)
Definition: filter_design.txt:179
HEVC_NAL_IDR_N_LP
@ HEVC_NAL_IDR_N_LP
Definition: hevc.h:49
FF_DEF_RAWVIDEO_DEMUXER
#define FF_DEF_RAWVIDEO_DEMUXER(shortname, longname, probe, ext, id)
Definition: rawdec.h:66
rawdec.h
HEVC_NAL_PPS
@ HEVC_NAL_PPS
Definition: hevc.h:63
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:451
HEVC_NAL_CRA_NUT
@ HEVC_NAL_CRA_NUT
Definition: hevc.h:50
vps
static int FUNC() vps(CodedBitstreamContext *ctx, RWContext *rw, H265RawVPS *current)
Definition: cbs_h265_syntax_template.c:423
AVPROBE_SCORE_EXTENSION
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:461
pps
static int FUNC() pps(CodedBitstreamContext *ctx, RWContext *rw, H264RawPPS *current)
Definition: cbs_h264_syntax_template.c:404
HEVC_NAL_BLA_W_LP
@ HEVC_NAL_BLA_W_LP
Definition: hevc.h:45
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
code
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some it can consider them to be part of the FIFO and delay acknowledging a status change accordingly Example code
Definition: filter_design.txt:178
AV_CODEC_ID_HEVC
@ AV_CODEC_ID_HEVC
Definition: codec_id.h:226
hevc.h
HEVC_NAL_VPS
@ HEVC_NAL_VPS
Definition: hevc.h:61
HEVC_NAL_IDR_W_RADL
@ HEVC_NAL_IDR_W_RADL
Definition: hevc.h:48
sps
static int FUNC() sps(CodedBitstreamContext *ctx, RWContext *rw, H264RawSPS *current)
Definition: cbs_h264_syntax_template.c:260
avformat.h
HEVC_NAL_SPS
@ HEVC_NAL_SPS
Definition: hevc.h:62