FFmpeg
nistspheredec.c
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1 /*
2  * NIST Sphere demuxer
3  * Copyright (c) 2012 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 nist_probe(const AVProbeData *p)
29 {
30  if (AV_RL64(p->buf) == AV_RL64("NIST_1A\x0a"))
31  return AVPROBE_SCORE_MAX;
32  return 0;
33 }
34 
36 {
37  char buffer[256], coding[32] = "pcm", format[32] = "01";
38  int bps = 0, be = 0;
39  int32_t header_size = -1;
40  AVStream *st;
41 
42  st = avformat_new_stream(s, NULL);
43  if (!st)
44  return AVERROR(ENOMEM);
45 
47 
48  ff_get_line(s->pb, buffer, sizeof(buffer));
49  ff_get_line(s->pb, buffer, sizeof(buffer));
50  sscanf(buffer, "%"SCNd32, &header_size);
51  if (header_size <= 0)
52  return AVERROR_INVALIDDATA;
53 
54  while (!avio_feof(s->pb)) {
55  ff_get_line(s->pb, buffer, sizeof(buffer));
56 
57  if (avio_tell(s->pb) >= header_size)
58  return AVERROR_INVALIDDATA;
59 
60  if (!memcmp(buffer, "end_head", 8)) {
62  st->codecpar->bits_per_coded_sample = bps << 3;
63 
64  if (!av_strcasecmp(coding, "pcm")) {
67  0, be, 0xFFFF);
68  } else if (!av_strcasecmp(coding, "alaw")) {
70  } else if (!av_strcasecmp(coding, "ulaw") ||
71  !av_strcasecmp(coding, "mu-law")) {
73  } else if (!av_strncasecmp(coding, "pcm,embedded-shorten", 20)) {
75  if (ff_alloc_extradata(st->codecpar, 1))
76  st->codecpar->extradata[0] = 1;
77  } else {
78  avpriv_request_sample(s, "coding %s", coding);
79  }
80 
81  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
82 
84 
85  if (avio_tell(s->pb) > header_size)
86  return AVERROR_INVALIDDATA;
87 
88  avio_skip(s->pb, header_size - avio_tell(s->pb));
89 
90  return 0;
91  } else if (!memcmp(buffer, "channel_count", 13)) {
92  sscanf(buffer, "%*s %*s %u", &st->codecpar->channels);
93  } else if (!memcmp(buffer, "sample_byte_format", 18)) {
94  sscanf(buffer, "%*s %*s %31s", format);
95 
96  if (!av_strcasecmp(format, "01")) {
97  be = 0;
98  } else if (!av_strcasecmp(format, "10")) {
99  be = 1;
100  } else if (!av_strcasecmp(format, "mu-law")) {
102  } else if (av_strcasecmp(format, "1")) {
103  avpriv_request_sample(s, "sample byte format %s", format);
104  return AVERROR_PATCHWELCOME;
105  }
106  } else if (!memcmp(buffer, "sample_coding", 13)) {
107  sscanf(buffer, "%*s %*s %31s", coding);
108  } else if (!memcmp(buffer, "sample_count", 12)) {
109  sscanf(buffer, "%*s %*s %"SCNd64, &st->duration);
110  } else if (!memcmp(buffer, "sample_n_bytes", 14)) {
111  sscanf(buffer, "%*s %*s %d", &bps);
112  } else if (!memcmp(buffer, "sample_rate", 11)) {
113  sscanf(buffer, "%*s %*s %d", &st->codecpar->sample_rate);
114  } else if (!memcmp(buffer, "sample_sig_bits", 15)) {
115  sscanf(buffer, "%*s %*s %d", &st->codecpar->bits_per_coded_sample);
116  } else {
117  char key[32], value[32];
118  if (sscanf(buffer, "%31s %*s %31s", key, value) == 2) {
119  av_dict_set(&s->metadata, key, value, AV_DICT_APPEND);
120  } else {
121  av_log(s, AV_LOG_ERROR, "Failed to parse '%s' as metadata\n", buffer);
122  }
123  }
124  }
125 
126  return AVERROR_EOF;
127 }
128 
130  .name = "nistsphere",
131  .long_name = NULL_IF_CONFIG_SMALL("NIST SPeech HEader REsources"),
132  .read_probe = nist_probe,
133  .read_header = nist_read_header,
134  .read_packet = ff_pcm_read_packet,
135  .read_seek = ff_pcm_read_seek,
136  .extensions = "nist,sph",
137  .flags = AVFMT_GENERIC_INDEX,
138 };
#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:4929
#define avpriv_request_sample(...)
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3968
int av_strncasecmp(const char *a, const char *b, size_t n)
Locale-independent case-insensitive compare.
Definition: avstring.c:223
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:334
const char * key
uint64_t_TMPL AV_RL64
Definition: bytestream.h:87
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 format(the sample packing is implied by the sample format) and sample rate.The lists are not just lists
Format I/O context.
Definition: avformat.h:1358
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:4502
#define AVERROR_EOF
End of file.
Definition: error.h:55
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
#define av_log(a,...)
static int nist_read_header(AVFormatContext *s)
Definition: nistspheredec.c:35
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1598
#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:3964
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:4085
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:3321
int av_strcasecmp(const char *a, const char *b)
Locale-independent case-insensitive compare.
Definition: avstring.c:213
int32_t
#define s(width, name)
Definition: cbs_vp9.c:257
#define AV_DICT_APPEND
If the entry already exists, append to it.
Definition: dict.h:80
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
Read a whole line of text from AVIOContext.
Definition: aviobuf.c:811
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
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
int ff_pcm_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: pcm.c:29
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
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 be(in the first position) for now.Options-------Then comes the options array.This is what will define the user accessible options.For example
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
enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags)
Select a PCM codec based on the given parameters.
Definition: utils.c:3170
AVInputFormat ff_nistsphere_demuxer
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:930
int sample_rate
Audio only.
Definition: avcodec.h:4078
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
Main libavformat public API header.
unsigned bps
Definition: movenc.c:1532
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:4010
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:3982
int channels
Audio only.
Definition: avcodec.h:4074
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_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
static int nist_probe(const AVProbeData *p)
Definition: nistspheredec.c:28
GLuint buffer
Definition: opengl_enc.c:101