FFmpeg
nspdec.c
Go to the documentation of this file.
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 };
#define NULL
Definition: coverity.c:32
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
channels
Definition: aptx.c:30
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3959
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:334
Format I/O context.
Definition: avformat.h:1358
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:803
GLsizei GLboolean const GLfloat * value
Definition: opengl_enc.c:108
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4470
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:87
ptrdiff_t size
Definition: opengl_enc.c:100
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
#define av_log(a,...)
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1598
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:772
#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:3955
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:4076
#define s(width, name)
Definition: cbs_vp9.c:257
int ff_pcm_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: pcm.c:52
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
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
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:468
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
int sample_rate
Audio only.
Definition: avcodec.h:4069
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
Main libavformat public API header.
#define MKBETAG(a, b, c, d)
Definition: common.h:367
static int nsp_probe(const AVProbeData *p)
Definition: nspdec.c:28
int channels
Audio only.
Definition: avcodec.h:4065
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
int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen)
Read a string from pb into buf.
Definition: aviobuf.c:882
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:361
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
AVInputFormat ff_nsp_demuxer
Definition: nspdec.c:99
static int nsp_read_header(AVFormatContext *s)
Definition: nspdec.c:36