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 #include "avformat.h"
22 #include "internal.h"
23 #include "libavcodec/get_bits.h"
24 #include "libavcodec/put_bits.h"
25 
26 #define MAX_FRAME_SIZE 10
27 
28 #define SYNC_WORD 0x6b21
29 #define BIT_0 0x7f
30 #define BIT_1 0x81
31 
32 #if CONFIG_BIT_DEMUXER
33 static int probe(const AVProbeData *p)
34 {
35  int i = 0, j, valid = 0;
36 
37  while (2 * i + 3 < p->buf_size){
38  if (AV_RL16(&p->buf[2 * i++]) != SYNC_WORD)
39  return 0;
40  j = AV_RL16(&p->buf[2 * i++]);
41  if (j != 0 && j != 0x10 && j != 0x40 && j != 0x50 && j != 0x76)
42  return 0;
43  if (j)
44  valid++;
45  i += j;
46  }
47  if (valid > 10)
48  return AVPROBE_SCORE_MAX;
49  if (valid > 2)
50  return AVPROBE_SCORE_EXTENSION - 1;
51  return 0;
52 }
53 
54 static int read_header(AVFormatContext *s)
55 {
56  AVStream* st;
57 
59  if (!st)
60  return AVERROR(ENOMEM);
61 
64  st->codecpar->sample_rate=8000;
65  st->codecpar->block_align = 16;
66  st->codecpar->channels=1;
67 
68  avpriv_set_pts_info(st, 64, 1, 100);
69  return 0;
70 }
71 
72 static int read_packet(AVFormatContext *s,
73  AVPacket *pkt)
74 {
75  AVIOContext *pb = s->pb;
76  PutBitContext pbo;
77  uint16_t buf[8 * MAX_FRAME_SIZE + 2];
78  int packet_size;
79  uint16_t* src=buf;
80  int i, j, ret;
81  int64_t pos= avio_tell(pb);
82 
83  if(avio_feof(pb))
84  return AVERROR_EOF;
85 
86  avio_rl16(pb); // sync word
87  packet_size = avio_rl16(pb) / 8;
88  if(packet_size > MAX_FRAME_SIZE)
89  return AVERROR_INVALIDDATA;
90 
91  ret = avio_read(pb, (uint8_t*)buf, (8 * packet_size) * sizeof(uint16_t));
92  if(ret<0)
93  return ret;
94  if(ret != 8 * packet_size * sizeof(uint16_t))
95  return AVERROR(EIO);
96 
97  if (av_new_packet(pkt, packet_size) < 0)
98  return AVERROR(ENOMEM);
99 
100  init_put_bits(&pbo, pkt->data, packet_size);
101  for(j=0; j < packet_size; j++)
102  for(i=0; i<8;i++)
103  put_bits(&pbo,1, AV_RL16(src++) == BIT_1 ? 1 : 0);
104 
105  flush_put_bits(&pbo);
106 
107  pkt->duration=1;
108  pkt->pos = pos;
109  return 0;
110 }
111 
113  .name = "bit",
114  .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
115  .read_probe = probe,
116  .read_header = read_header,
117  .read_packet = read_packet,
118  .extensions = "bit",
119 };
120 #endif
121 
122 #if CONFIG_BIT_MUXER
123 static int write_header(AVFormatContext *s)
124 {
125  AVCodecParameters *par = s->streams[0]->codecpar;
126 
127  if ((par->codec_id != AV_CODEC_ID_G729) || par->channels != 1) {
128  av_log(s, AV_LOG_ERROR,
129  "only codec g729 with 1 channel is supported by this format\n");
130  return AVERROR(EINVAL);
131  }
132 
133  par->bits_per_coded_sample = 16;
134  par->block_align = (par->bits_per_coded_sample * par->channels) >> 3;
135 
136  return 0;
137 }
138 
139 static int write_packet(AVFormatContext *s, AVPacket *pkt)
140 {
141  AVIOContext *pb = s->pb;
142  GetBitContext gb;
143  int i;
144 
145  if (pkt->size != 10)
146  return AVERROR(EINVAL);
147 
148  avio_wl16(pb, SYNC_WORD);
149  avio_wl16(pb, 8 * pkt->size);
150 
151  init_get_bits(&gb, pkt->data, 8 * pkt->size);
152  for (i = 0; i < 8 * pkt->size; i++)
153  avio_wl16(pb, get_bits1(&gb) ? BIT_1 : BIT_0);
154 
155  return 0;
156 }
157 
159  .name = "bit",
160  .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
161  .mime_type = "audio/bit",
162  .extensions = "bit",
163  .audio_codec = AV_CODEC_ID_G729,
164  .video_codec = AV_CODEC_ID_NONE,
165  .write_header = write_header,
166  .write_packet = write_packet,
167 };
168 #endif
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:689
#define NULL
Definition: coverity.c:32
void avio_wl16(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:472
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
static void put_bits(Jpeg2000EncoderContext *s, int val, int n)
put n times val bit
Definition: j2kenc.c:208
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1500
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:4926
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3968
int size
Definition: avcodec.h:1481
static AVPacket pkt
#define src
Definition: vp8dsp.c:254
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:87
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3960
AVInputFormat ff_bit_demuxer
Format I/O context.
Definition: avformat.h:1358
uint8_t
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1498
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4499
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1426
#define BIT_1
Definition: bit.c:30
uint8_t * data
Definition: avcodec.h:1480
#define AVERROR_EOF
End of file.
Definition: error.h:55
bitstream reader API header.
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
#define av_log(a,...)
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:650
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
AVOutputFormat ff_bit_muxer
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3964
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:4085
#define BIT_0
Definition: bit.c:29
const char * name
Definition: avformat.h:505
#define s(width, name)
Definition: cbs_vp9.c:257
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
Stream structure.
Definition: avformat.h:881
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
void * buf
Definition: avisynth_c.h:766
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:659
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:456
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
static int probe(const AVProbeData *p)
Definition: act.c:36
int sample_rate
Audio only.
Definition: avcodec.h:4078
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:756
Main libavformat public API header.
static void flush_put_bits(PutBitContext *s)
Pad the end of the output stream with zeros.
Definition: put_bits.h:101
#define MAX_FRAME_SIZE
Definition: bit.c:26
static void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size)
Initialize the PutBitContext s.
Definition: put_bits.h:48
#define SYNC_WORD
Definition: bit.c:28
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:349
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:4010
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
This structure stores compressed data.
Definition: avcodec.h:1457
bitstream writer API