FFmpeg
nspdec.c
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1 /*
2  * NSP demuxer
3  * Copyright (c) 2017 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/avstring.h"
23 #include "libavutil/intreadwrite.h"
24 #include "avformat.h"
25 #include "internal.h"
26 #include "pcm.h"
27 
28 static int nsp_probe(const AVProbeData *p)
29 {
30  if (AV_RB32(p->buf) == AV_RB32("FORM") &&
31  AV_RB32(p->buf + 4) == AV_RB32("DS16"))
32  return AVPROBE_SCORE_MAX;
33  return 0;
34 }
35 
37 {
38  int channels = 0, rate = 0;
39  uint32_t chunk, size;
40  AVStream *st;
41  int64_t pos;
42 
43  avio_skip(s->pb, 12);
44  st = avformat_new_stream(s, NULL);
45  if (!st)
46  return AVERROR(ENOMEM);
47 
48  while (!avio_feof(s->pb)) {
49  char value[1024];
50 
51  chunk = avio_rb32(s->pb);
52  size = avio_rl32(s->pb);
53  pos = avio_tell(s->pb);
54 
55  switch (chunk) {
56  case MKBETAG('H', 'E', 'D', 'R'):
57  case MKBETAG('H', 'D', 'R', '8'):
58  if (size < 32)
59  return AVERROR_INVALIDDATA;
60  avio_skip(s->pb, 20);
61  rate = avio_rl32(s->pb);
62  avio_skip(s->pb, size - (avio_tell(s->pb) - pos));
63  break;
64  case MKBETAG('N', 'O', 'T', 'E'):
65  avio_get_str(s->pb, size, value, sizeof(value));
66  av_dict_set(&s->metadata, "Comment", value, 0);
67  avio_skip(s->pb, size & 1);
68  break;
69  case MKBETAG('S', 'D', 'A', 'B'):
70  channels = 2;
71  break;
72  case MKBETAG('S', 'D', '_', '2'):
73  case MKBETAG('S', 'D', '_', '3'):
74  case MKBETAG('S', 'D', '_', '4'):
75  case MKBETAG('S', 'D', '_', '5'):
76  case MKBETAG('S', 'D', '_', '6'):
77  case MKBETAG('S', 'D', '_', '7'):
78  case MKBETAG('S', 'D', '_', '8'):
79  av_log(s, AV_LOG_WARNING, "Unsupported chunk!\n");
80  case MKBETAG('S', 'D', 'A', '_'):
81  case MKBETAG('S', 'D', '_', 'A'):
82  channels = 1;
83  break;
84  }
85 
86  if (channels)
87  break;
88  }
89 
91  st->codecpar->channels = channels;
92  st->codecpar->sample_rate = rate;
94  st->codecpar->block_align = 2 * channels;
95 
96  return 0;
97 }
98 
100  .name = "nsp",
101  .long_name = NULL_IF_CONFIG_SMALL("Computerized Speech Lab NSP"),
102  .read_probe = nsp_probe,
103  .read_header = nsp_read_header,
104  .read_packet = ff_pcm_read_packet,
105  .read_seek = ff_pcm_read_seek,
106  .extensions = "nsp",
107  .flags = AVFMT_GENERIC_INDEX,
108 };
AV_CODEC_ID_PCM_S16LE
@ AV_CODEC_ID_PCM_S16LE
Definition: codec_id.h:313
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4374
pcm.h
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
AVCodecParameters::channels
int channels
Audio only.
Definition: codec_par.h:166
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:538
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:468
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:764
AVInputFormat
Definition: avformat.h:626
nsp_probe
static int nsp_probe(const AVProbeData *p)
Definition: nspdec.c:28
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:257
ff_nsp_demuxer
const AVInputFormat ff_nsp_demuxer
Definition: nspdec.c:99
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:631
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
channels
channels
Definition: aptx.h:33
AVFormatContext
Format I/O context.
Definition: avformat.h:1107
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:994
NULL
#define NULL
Definition: coverity.c:32
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:170
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:733
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:116
avio_get_str
int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen)
Read a string from pb into buf.
Definition: aviobuf.c:843
size
int size
Definition: twinvq_data.h:10344
AV_RB32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:96
MKBETAG
#define MKBETAG(a, b, c, d)
Definition: common.h:479
AVCodecParameters::block_align
int block_align
Audio only.
Definition: codec_par.h:177
value
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 default value
Definition: writing_filters.txt:86
nsp_read_header
static int nsp_read_header(AVFormatContext *s)
Definition: nspdec.c:36
ff_pcm_read_packet
int ff_pcm_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: pcm.c:29
AVStream
Stream structure.
Definition: avformat.h:847
ff_pcm_read_seek
int ff_pcm_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: pcm.c:56
pos
unsigned int pos
Definition: spdifenc.c:412
avformat.h
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:327
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
av_dict_set
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:70
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
avstring.h
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:354