FFmpeg
bit.c
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1 /*
2  * G.729 bit format muxer and demuxer
3  * Copyright (c) 2007-2008 Vladimir Voroshilov
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 "config_components.h"
23 
24 #include "avformat.h"
25 #include "internal.h"
26 #include "libavcodec/get_bits.h"
27 #include "libavcodec/put_bits.h"
28 
29 #define MAX_FRAME_SIZE 10
30 
31 #define SYNC_WORD 0x6b21
32 #define BIT_0 0x7f
33 #define BIT_1 0x81
34 
35 #if CONFIG_BIT_DEMUXER
36 static int probe(const AVProbeData *p)
37 {
38  int i = 0, j, valid = 0;
39 
40  while (2 * i + 3 < p->buf_size){
41  if (AV_RL16(&p->buf[2 * i++]) != SYNC_WORD)
42  return 0;
43  j = AV_RL16(&p->buf[2 * i++]);
44  if (j != 0 && j != 0x10 && j != 0x40 && j != 0x50 && j != 0x76)
45  return 0;
46  if (j)
47  valid++;
48  i += j;
49  }
50  if (valid > 10)
51  return AVPROBE_SCORE_MAX;
52  if (valid > 2)
53  return AVPROBE_SCORE_EXTENSION - 1;
54  return 0;
55 }
56 
57 static int read_header(AVFormatContext *s)
58 {
59  AVStream* st;
60 
62  if (!st)
63  return AVERROR(ENOMEM);
64 
67  st->codecpar->sample_rate=8000;
68  st->codecpar->block_align = 16;
70 
71  avpriv_set_pts_info(st, 64, 1, 100);
72  return 0;
73 }
74 
75 static int read_packet(AVFormatContext *s,
76  AVPacket *pkt)
77 {
78  AVIOContext *pb = s->pb;
79  PutBitContext pbo;
80  uint16_t buf[8 * MAX_FRAME_SIZE + 2];
81  int packet_size;
82  uint16_t* src=buf;
83  int i, j, ret;
84  int64_t pos= avio_tell(pb);
85 
86  if(avio_feof(pb))
87  return AVERROR_EOF;
88 
89  avio_rl16(pb); // sync word
90  packet_size = avio_rl16(pb) / 8;
91  if(packet_size > MAX_FRAME_SIZE)
92  return AVERROR_INVALIDDATA;
93 
94  ret = avio_read(pb, (uint8_t*)buf, (8 * packet_size) * sizeof(uint16_t));
95  if(ret<0)
96  return ret;
97  if(ret != 8 * packet_size * sizeof(uint16_t))
98  return AVERROR(EIO);
99 
100  if ((ret = av_new_packet(pkt, packet_size)) < 0)
101  return ret;
102 
103  init_put_bits(&pbo, pkt->data, packet_size);
104  for(j=0; j < packet_size; j++)
105  for(i=0; i<8;i++)
106  put_bits(&pbo,1, AV_RL16(src++) == BIT_1 ? 1 : 0);
107 
108  flush_put_bits(&pbo);
109 
110  pkt->duration=1;
111  pkt->pos = pos;
112  return 0;
113 }
114 
116  .name = "bit",
117  .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
118  .read_probe = probe,
119  .read_header = read_header,
120  .read_packet = read_packet,
121  .extensions = "bit",
122 };
123 #endif
124 
125 #if CONFIG_BIT_MUXER
126 static int write_header(AVFormatContext *s)
127 {
128  AVCodecParameters *par = s->streams[0]->codecpar;
129 
130  if ((par->codec_id != AV_CODEC_ID_G729) || par->ch_layout.nb_channels != 1) {
132  "only codec g729 with 1 channel is supported by this format\n");
133  return AVERROR(EINVAL);
134  }
135 
136  par->bits_per_coded_sample = 16;
137  par->block_align = (par->bits_per_coded_sample * par->ch_layout.nb_channels) >> 3;
138 
139  return 0;
140 }
141 
143 {
144  AVIOContext *pb = s->pb;
145  GetBitContext gb;
146  int i;
147 
148  if (pkt->size != 10)
149  return AVERROR(EINVAL);
150 
151  avio_wl16(pb, SYNC_WORD);
152  avio_wl16(pb, 8 * pkt->size);
153 
154  init_get_bits(&gb, pkt->data, 8 * pkt->size);
155  for (i = 0; i < 8 * pkt->size; i++)
156  avio_wl16(pb, get_bits1(&gb) ? BIT_1 : BIT_0);
157 
158  return 0;
159 }
160 
162  .name = "bit",
163  .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
164  .mime_type = "audio/bit",
165  .extensions = "bit",
166  .audio_codec = AV_CODEC_ID_G729,
167  .video_codec = AV_CODEC_ID_NONE,
168  .write_header = write_header,
169  .write_packet = write_packet,
170 };
171 #endif
AVOutputFormat::name
const char * name
Definition: avformat.h:510
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
ff_bit_muxer
const AVOutputFormat ff_bit_muxer
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: options.c:237
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:57
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:53
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
init_put_bits
static void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size)
Initialize the PutBitContext s.
Definition: put_bits.h:62
put_bits
static void put_bits(Jpeg2000EncoderContext *s, int val, int n)
put n times val bit
Definition: j2kenc.c:221
AVPacket::data
uint8_t * data
Definition: packet.h:374
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:392
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:456
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:303
init_get_bits
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:649
avio_wl16
void avio_wl16(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:466
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:465
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:763
BIT_1
#define BIT_1
Definition: bit.c:33
GetBitContext
Definition: get_bits.h:61
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:505
avio_rl16
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:743
MAX_FRAME_SIZE
#define MAX_FRAME_SIZE
Definition: bit.c:29
pkt
AVPacket * pkt
Definition: movenc.c:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
AVInputFormat
Definition: avformat.h:656
s
#define s(width, name)
Definition: cbs_vp9.c:256
av_new_packet
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:97
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:661
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:455
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
get_bits.h
AV_RL16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:94
PutBitContext
Definition: put_bits.h:50
AVFormatContext
Format I/O context.
Definition: avformat.h:1216
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1108
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
NULL
#define NULL
Definition: coverity.c:32
get_bits1
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:453
SYNC_WORD
#define SYNC_WORD
Definition: bit.c:31
AVCodecParameters::ch_layout
AVChannelLayout ch_layout
Audio only.
Definition: codec_par.h:212
AVPROBE_SCORE_EXTENSION
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:463
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:177
ff_bit_demuxer
const AVInputFormat ff_bit_demuxer
AVIOContext
Bytestream IO Context.
Definition: avio.h:162
AVPacket::size
int size
Definition: packet.h:375
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:115
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:50
AVOutputFormat
Definition: avformat.h:509
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
AVCodecParameters::block_align
int block_align
Audio only.
Definition: codec_par.h:184
ret
ret
Definition: filter_design.txt:187
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVStream
Stream structure.
Definition: avformat.h:948
pos
unsigned int pos
Definition: spdifenc.c:412
avformat.h
probe
static int probe(const AVProbeData *p)
Definition: act.c:38
AV_CODEC_ID_G729
@ AV_CODEC_ID_G729
Definition: codec_id.h:486
avio_read
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:641
BIT_0
#define BIT_0
Definition: bit.c:32
AVCodecParameters::bits_per_coded_sample
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: codec_par.h:103
flush_put_bits
static void flush_put_bits(PutBitContext *s)
Pad the end of the output stream with zeros.
Definition: put_bits.h:143
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:61
AVPacket
This structure stores compressed data.
Definition: packet.h:351
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:394
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
write_header
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:346
put_bits.h
write_packet
static int write_packet(OutputFile *of, OutputStream *ost, AVPacket *pkt)
Definition: ffmpeg_mux.c:90
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:375