FFmpeg  2.1.1
flacenc.c
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1 /*
2  * raw FLAC muxer
3  * Copyright (c) 2006-2009 Justin Ruggles
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 "libavcodec/flac.h"
23 #include "avformat.h"
24 #include "avio_internal.h"
25 #include "flacenc.h"
26 #include "vorbiscomment.h"
27 #include "libavcodec/bytestream.h"
28 
29 
30 static int flac_write_block_padding(AVIOContext *pb, unsigned int n_padding_bytes,
31  int last_block)
32 {
33  avio_w8(pb, last_block ? 0x81 : 0x01);
34  avio_wb24(pb, n_padding_bytes);
35  ffio_fill(pb, 0, n_padding_bytes);
36  return 0;
37 }
38 
40  int last_block, int bitexact)
41 {
42  const char *vendor = bitexact ? "ffmpeg" : LIBAVFORMAT_IDENT;
43  unsigned int len, count;
44  uint8_t *p, *p0;
45 
47 
48  len = ff_vorbiscomment_length(*m, vendor, &count);
49  p0 = av_malloc(len+4);
50  if (!p0)
51  return AVERROR(ENOMEM);
52  p = p0;
53 
54  bytestream_put_byte(&p, last_block ? 0x84 : 0x04);
55  bytestream_put_be24(&p, len);
56  ff_vorbiscomment_write(&p, m, vendor, count);
57 
58  avio_write(pb, p0, len+4);
59  av_freep(&p0);
60  p = NULL;
61 
62  return 0;
63 }
64 
65 static int flac_write_header(struct AVFormatContext *s)
66 {
67  int ret;
68  AVCodecContext *codec = s->streams[0]->codec;
69 
70  if (s->nb_streams > 1) {
71  av_log(s, AV_LOG_ERROR, "only one stream is supported\n");
72  return AVERROR(EINVAL);
73  }
74  if (codec->codec_id != AV_CODEC_ID_FLAC) {
75  av_log(s, AV_LOG_ERROR, "unsupported codec\n");
76  return AVERROR(EINVAL);
77  }
78 
79  ret = ff_flac_write_header(s->pb, codec, 0);
80  if (ret)
81  return ret;
82 
83  ret = flac_write_block_comment(s->pb, &s->metadata, 0,
84  codec->flags & CODEC_FLAG_BITEXACT);
85  if (ret)
86  return ret;
87 
88  /* The command line flac encoder defaults to placing a seekpoint
89  * every 10s. So one might add padding to allow that later
90  * but there seems to be no simple way to get the duration here.
91  * So let's try the flac default of 8192 bytes */
92  flac_write_block_padding(s->pb, 8192, 1);
93 
94  return ret;
95 }
96 
98 {
99  AVIOContext *pb = s->pb;
100  uint8_t *streaminfo;
101  enum FLACExtradataFormat format;
102  int64_t file_size;
103 
104  if (!avpriv_flac_is_extradata_valid(s->streams[0]->codec, &format, &streaminfo))
105  return -1;
106 
107  if (pb->seekable) {
108  /* rewrite the STREAMINFO header block data */
109  file_size = avio_tell(pb);
110  avio_seek(pb, 8, SEEK_SET);
111  avio_write(pb, streaminfo, FLAC_STREAMINFO_SIZE);
112  avio_seek(pb, file_size, SEEK_SET);
113  avio_flush(pb);
114  } else {
115  av_log(s, AV_LOG_WARNING, "unable to rewrite FLAC header.\n");
116  }
117  return 0;
118 }
119 
121 {
122  avio_write(s->pb, pkt->data, pkt->size);
123  return 0;
124 }
125 
127  .name = "flac",
128  .long_name = NULL_IF_CONFIG_SMALL("raw FLAC"),
129  .mime_type = "audio/x-flac",
130  .extensions = "flac",
131  .audio_codec = AV_CODEC_ID_FLAC,
132  .video_codec = AV_CODEC_ID_NONE,
133  .write_header = flac_write_header,
134  .write_packet = flac_write_packet,
135  .write_trailer = flac_write_trailer,
136  .flags = AVFMT_NOTIMESTAMPS,
137 };
const char * s
Definition: avisynth_c.h:668
int ff_vorbiscomment_length(AVDictionary *m, const char *vendor_string, unsigned *count)
Calculate the length in bytes of a VorbisComment.
Definition: vorbiscomment.c:41
Bytestream IO Context.
Definition: avio.h:68
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: avcodec.h:4153
static int flac_write_block_padding(AVIOContext *pb, unsigned int n_padding_bytes, int last_block)
Definition: flacenc.c:30
AVOutputFormat ff_flac_muxer
Definition: flacenc.c:126
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:686
int size
Definition: avcodec.h:1064
void av_log(void *avcl, int level, const char *fmt,...) av_printf_format(3
Send the specified message to the log if the level is less than or equal to the current av_log_level...
int avpriv_flac_is_extradata_valid(AVCodecContext *avctx, enum FLACExtradataFormat *format, uint8_t **streaminfo_start)
Validate the FLAC extradata.
Definition: flac.c:169
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:173
int void avio_flush(AVIOContext *s)
Force flushing of buffered data to the output s.
Definition: aviobuf.c:193
void av_freep(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc() and set the pointer ...
Definition: mem.c:234
Format I/O context.
Definition: avformat.h:968
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:354
uint8_t
static int flac_write_header(struct AVFormatContext *s)
Definition: flacenc.c:65
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:248
#define CODEC_FLAG_BITEXACT
Use only bitexact stuff (except (I)DCT).
Definition: avcodec.h:714
#define LIBAVFORMAT_IDENT
Definition: version.h:44
static int flac_write_trailer(struct AVFormatContext *s)
Definition: flacenc.c:97
FLACExtradataFormat
Definition: flac.h:57
const AVMetadataConv ff_vorbiscomment_metadata_conv[]
VorbisComment metadata conversion mapping.
Definition: vorbiscomment.c:33
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: avcodec.h:4147
FLAC (Free Lossless Audio Codec) decoder/demuxer common functions.
unsigned m
Definition: audioconvert.c:186
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:151
int flags
CODEC_FLAG_*.
Definition: avcodec.h:1234
int ff_vorbiscomment_write(uint8_t **p, AVDictionary **m, const char *vendor_string, const unsigned count)
Write a VorbisComment into a buffer.
Definition: vorbiscomment.c:57
unsigned int nb_streams
A list of all streams in the file.
Definition: avformat.h:1015
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:117
void ffio_fill(AVIOContext *s, int b, int count)
Definition: aviobuf.c:159
ret
Definition: avfilter.c:961
AVStream ** streams
Definition: avformat.h:1016
void * av_malloc(size_t size) av_malloc_attrib 1(1)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:73
#define FLAC_STREAMINFO_SIZE
Definition: flac.h:33
const char * name
Definition: avformat.h:395
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:199
static int flac_write_block_comment(AVIOContext *pb, AVDictionary **m, int last_block, int bitexact)
Definition: flacenc.c:39
void avio_w8(AVIOContext *s, int b)
Definition: aviobuf.c:151
enum AVCodecID codec_id
Definition: avcodec.h:1157
main external API structure.
Definition: avcodec.h:1146
AVIOContext * pb
I/O context.
Definition: avformat.h:1001
uint8_t * data
Definition: avcodec.h:1063
AVDictionary * metadata
Definition: avformat.h:1128
int ff_flac_write_header(AVIOContext *pb, AVCodecContext *codec, int last_block)
static int flac_write_packet(struct AVFormatContext *s, AVPacket *pkt)
Definition: flacenc.c:120
Main libavformat public API header.
void ff_metadata_conv(AVDictionary **pm, const AVMetadataConv *d_conv, const AVMetadataConv *s_conv)
Definition: metadata.c:26
int len
void avio_wb24(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:385
#define AVERROR(e)
void INT64 INT64 count
Definition: avisynth_c.h:594
static AVPacket pkt
Definition: demuxing.c:52
This structure stores compressed data.
Definition: avcodec.h:1040