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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 static int probe(AVProbeData *p)
33 {
34  int i, j;
35 
36  if(p->buf_size < 0x40)
37  return 0;
38 
39  for(i=0; i+3<p->buf_size && i< 10*0x50; ){
40  if(AV_RL16(&p->buf[0]) != SYNC_WORD)
41  return 0;
42  j=AV_RL16(&p->buf[2]);
43  if(j!=0x40 && j!=0x50)
44  return 0;
45  i+=j;
46  }
48 }
49 
51 {
52  AVStream* st;
53 
55  if (!st)
56  return AVERROR(ENOMEM);
57 
60  st->codecpar->sample_rate=8000;
61  st->codecpar->block_align = 16;
62  st->codecpar->channels=1;
63 
64  avpriv_set_pts_info(st, 64, 1, 100);
65  return 0;
66 }
67 
69  AVPacket *pkt)
70 {
71  AVIOContext *pb = s->pb;
72  PutBitContext pbo;
73  uint16_t buf[8 * MAX_FRAME_SIZE + 2];
74  int packet_size;
75  uint16_t* src=buf;
76  int i, j, ret;
77  int64_t pos= avio_tell(pb);
78 
79  if(avio_feof(pb))
80  return AVERROR_EOF;
81 
82  avio_rl16(pb); // sync word
83  packet_size = avio_rl16(pb) / 8;
84  if(packet_size > MAX_FRAME_SIZE)
85  return AVERROR_INVALIDDATA;
86 
87  ret = avio_read(pb, (uint8_t*)buf, (8 * packet_size) * sizeof(uint16_t));
88  if(ret<0)
89  return ret;
90  if(ret != 8 * packet_size * sizeof(uint16_t))
91  return AVERROR(EIO);
92 
93  if (av_new_packet(pkt, packet_size) < 0)
94  return AVERROR(ENOMEM);
95 
96  init_put_bits(&pbo, pkt->data, packet_size);
97  for(j=0; j < packet_size; j++)
98  for(i=0; i<8;i++)
99  put_bits(&pbo,1, AV_RL16(src++) == BIT_1 ? 1 : 0);
100 
101  flush_put_bits(&pbo);
102 
103  pkt->duration=1;
104  pkt->pos = pos;
105  return 0;
106 }
107 
109  .name = "bit",
110  .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
111  .read_probe = probe,
112  .read_header = read_header,
113  .read_packet = read_packet,
114  .extensions = "bit",
115 };
116 
117 #if CONFIG_MUXERS
118 static int write_header(AVFormatContext *s)
119 {
120  AVCodecParameters *par = s->streams[0]->codecpar;
121 
122  if ((par->codec_id != AV_CODEC_ID_G729) || par->channels != 1) {
123  av_log(s, AV_LOG_ERROR,
124  "only codec g729 with 1 channel is supported by this format\n");
125  return AVERROR(EINVAL);
126  }
127 
128  par->bits_per_coded_sample = 16;
129  par->block_align = (par->bits_per_coded_sample * par->channels) >> 3;
130 
131  return 0;
132 }
133 
134 static int write_packet(AVFormatContext *s, AVPacket *pkt)
135 {
136  AVIOContext *pb = s->pb;
137  GetBitContext gb;
138  int i;
139 
140  if (pkt->size != 10)
141  return AVERROR(EINVAL);
142 
143  avio_wl16(pb, SYNC_WORD);
144  avio_wl16(pb, 8 * 10);
145 
146  init_get_bits(&gb, pkt->data, 8*10);
147  for(i=0; i< 8 * 10; i++)
148  avio_wl16(pb, get_bits1(&gb) ? BIT_1 : BIT_0);
149 
150  return 0;
151 }
152 
153 AVOutputFormat ff_bit_muxer = {
154  .name = "bit",
155  .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
156  .mime_type = "audio/bit",
157  .extensions = "bit",
158  .audio_codec = AV_CODEC_ID_G729,
159  .video_codec = AV_CODEC_ID_NONE,
160  .write_header = write_header,
161  .write_packet = write_packet,
162 };
163 #endif
#define NULL
Definition: coverity.c:32
void avio_wl16(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:446
const char * s
Definition: avisynth_c.h:768
Bytestream IO Context.
Definition: avio.h:147
#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:206
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1620
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:4549
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3969
int size
Definition: avcodec.h:1601
static AVPacket pkt
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:3961
Format I/O context.
Definition: avformat.h:1330
static void write_packet(AVFormatContext *s, AVPacket *pkt, OutputStream *ost)
Definition: ffmpeg.c:635
uint8_t
AVInputFormat ff_bit_demuxer
Definition: bit.c:108
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1618
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4182
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1398
#define BIT_1
Definition: bit.c:30
uint8_t * data
Definition: avcodec.h:1600
#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:511
#define av_log(a,...)
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:604
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 AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3965
static int probe(AVProbeData *p)
Definition: bit.c:32
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:464
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:463
int block_align
Audio only.
Definition: avcodec.h:4086
#define BIT_0
Definition: bit.c:29
const char * name
Definition: avformat.h:524
#define src
Definition: vp9dsp.c:530
Stream structure.
Definition: avformat.h:881
AVIOContext * pb
I/O context.
Definition: avformat.h:1372
void * buf
Definition: avisynth_c.h:690
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:299
static int read_header(AVFormatContext *s)
Definition: bit.c:50
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:406
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:471
This structure contains the data a format has to probe a file.
Definition: avformat.h:461
int sample_rate
Audio only.
Definition: avcodec.h:4079
static int read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: bit.c:68
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:710
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:344
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:4011
int channels
Audio only.
Definition: avcodec.h:4075
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:662
AVCodecParameters * codecpar
Definition: avformat.h:1233
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:328
This structure stores compressed data.
Definition: avcodec.h:1577
bitstream writer API