FFmpeg  4.2.3
hcom.c
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1 /*
2  * HCOM demuxer
3  * Copyright (c) 2019 Paul B Mahol
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 "libavutil/intreadwrite.h"
23 #include "libavcodec/internal.h"
24 #include "avformat.h"
25 #include "internal.h"
26 #include "pcm.h"
27 
28 static int hcom_probe(const AVProbeData *p)
29 {
30  if (p->buf_size < 132)
31  return 0;
32  if (!memcmp(p->buf+65, "FSSD", 4) &&
33  !memcmp(p->buf+128, "HCOM", 4))
34  return AVPROBE_SCORE_MAX;
35  return 0;
36 }
37 
39 {
40  AVStream *st;
41  unsigned data_size, rsrc_size, huffcount;
42  unsigned compresstype, divisor;
43  unsigned dict_entries;
44  int ret;
45 
46  avio_skip(s->pb, 83);
47  data_size = avio_rb32(s->pb);
48  rsrc_size = avio_rb32(s->pb);
49  avio_skip(s->pb, 128-91+4);
50  huffcount = avio_rb32(s->pb);
51  avio_skip(s->pb, 4);
52  compresstype = avio_rb32(s->pb);
53  if (compresstype > 1)
54  return AVERROR_INVALIDDATA;
55  divisor = avio_rb32(s->pb);
56  if (divisor == 0 || divisor > 4)
57  return AVERROR_INVALIDDATA;
58  dict_entries = avio_rb16(s->pb);
59 
60  st = avformat_new_stream(s, NULL);
61  if (!st)
62  return AVERROR(ENOMEM);
63 
65  st->codecpar->channels = 1;
66  st->codecpar->sample_rate = 22050 / divisor;
69  st->codecpar->block_align = 4;
70 
71  ret = ff_alloc_extradata(st->codecpar, dict_entries * 4 + 7);
72  if (ret < 0)
73  return ret;
74  AV_WB16(st->codecpar->extradata, dict_entries);
75  AV_WB32(st->codecpar->extradata + 2, compresstype);
76  avio_read(s->pb, st->codecpar->extradata + 6, dict_entries * 4);
77  avio_skip(s->pb, 1);
78  st->codecpar->extradata[dict_entries * 4 + 6] = avio_r8(s->pb);
79 
80  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
81 
82  return 0;
83 }
84 
86  .name = "hcom",
87  .long_name = NULL_IF_CONFIG_SMALL("Macintosh HCOM"),
88  .read_probe = hcom_probe,
89  .read_header = hcom_read_header,
90  .read_packet = ff_pcm_read_packet,
91 };
#define NULL
Definition: coverity.c:32
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4903
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3957
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:331
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:785
Format I/O context.
Definition: avformat.h:1358
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:800
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4476
#define AV_WB16(p, v)
Definition: intreadwrite.h:405
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:647
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3953
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:638
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:449
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
int block_align
Audio only.
Definition: avcodec.h:4074
int ff_alloc_extradata(AVCodecParameters *par, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0...
Definition: utils.c:3305
static int hcom_read_header(AVFormatContext *s)
Definition: hcom.c:38
#define s(width, name)
Definition: cbs_vp9.c:257
Stream structure.
Definition: avformat.h:881
int ff_pcm_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: pcm.c:29
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
static int hcom_probe(const AVProbeData *p)
Definition: hcom.c:28
#define AV_WB32(p, v)
Definition: intreadwrite.h:419
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
int sample_rate
Audio only.
Definition: avcodec.h:4067
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
Main libavformat public API header.
common internal api header.
AVInputFormat ff_hcom_demuxer
Definition: hcom.c:85
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:3999
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:3971
int channels
Audio only.
Definition: avcodec.h:4063
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028