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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 
23 #include "libavutil/opt.h"
24 #include "libavcodec/flac.h"
25 #include "avformat.h"
26 #include "avio_internal.h"
27 #include "flacenc.h"
28 #include "vorbiscomment.h"
29 #include "libavcodec/bytestream.h"
30 
31 
32 typedef struct FlacMuxerContext {
33  const AVClass *class;
35 
36  /* updated streaminfo sent by the encoder at the end */
39 
40 static int flac_write_block_padding(AVIOContext *pb, unsigned int n_padding_bytes,
41  int last_block)
42 {
43  avio_w8(pb, last_block ? 0x81 : 0x01);
44  avio_wb24(pb, n_padding_bytes);
45  ffio_fill(pb, 0, n_padding_bytes);
46  return 0;
47 }
48 
50  int last_block, int bitexact)
51 {
52  const char *vendor = bitexact ? "ffmpeg" : LIBAVFORMAT_IDENT;
53  int64_t len;
54  uint8_t *p, *p0;
55 
57 
58  len = ff_vorbiscomment_length(*m, vendor);
59  if (len >= ((1<<24) - 4))
60  return AVERROR(EINVAL);
61  p0 = av_malloc(len+4);
62  if (!p0)
63  return AVERROR(ENOMEM);
64  p = p0;
65 
66  bytestream_put_byte(&p, last_block ? 0x84 : 0x04);
67  bytestream_put_be24(&p, len);
68  ff_vorbiscomment_write(&p, m, vendor);
69 
70  avio_write(pb, p0, len+4);
71  av_freep(&p0);
72  p = NULL;
73 
74  return 0;
75 }
76 
77 static int flac_write_header(struct AVFormatContext *s)
78 {
79  int ret;
80  int padding = s->metadata_header_padding;
81  AVCodecParameters *par = s->streams[0]->codecpar;
83 
84  if (!c->write_header)
85  return 0;
86 
87  if (s->nb_streams > 1) {
88  av_log(s, AV_LOG_ERROR, "only one stream is supported\n");
89  return AVERROR(EINVAL);
90  }
91  if (par->codec_id != AV_CODEC_ID_FLAC) {
92  av_log(s, AV_LOG_ERROR, "unsupported codec\n");
93  return AVERROR(EINVAL);
94  }
95 
96  if (padding < 0)
97  padding = 8192;
98  /* The FLAC specification states that 24 bits are used to represent the
99  * size of a metadata block so we must clip this value to 2^24-1. */
100  padding = av_clip_uintp2(padding, 24);
101 
102  ret = ff_flac_write_header(s->pb, par->extradata,
103  par->extradata_size, 0);
104  if (ret)
105  return ret;
106 
107  /* add the channel layout tag */
108  if (par->channel_layout &&
109  !(par->channel_layout & ~0x3ffffULL) &&
111  AVDictionaryEntry *chmask = av_dict_get(s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK",
112  NULL, 0);
113 
114  if (chmask) {
115  av_log(s, AV_LOG_WARNING, "A WAVEFORMATEXTENSIBLE_CHANNEL_MASK is "
116  "already present, this muxer will not overwrite it.\n");
117  } else {
118  uint8_t buf[32];
119  snprintf(buf, sizeof(buf), "0x%"PRIx64, par->channel_layout);
120  av_dict_set(&s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", buf, 0);
121  }
122  }
123 
124  ret = flac_write_block_comment(s->pb, &s->metadata, !padding,
126  if (ret)
127  return ret;
128 
129  /* The command line flac encoder defaults to placing a seekpoint
130  * every 10s. So one might add padding to allow that later
131  * but there seems to be no simple way to get the duration here.
132  * So just add the amount requested by the user. */
133  if (padding)
134  flac_write_block_padding(s->pb, padding, 1);
135 
136  return ret;
137 }
138 
140 {
141  AVIOContext *pb = s->pb;
142  int64_t file_size;
144  uint8_t *streaminfo = c->streaminfo ? c->streaminfo :
145  s->streams[0]->codecpar->extradata;
146 
147  if (!c->write_header || !streaminfo)
148  return 0;
149 
150  if (pb->seekable) {
151  /* rewrite the STREAMINFO header block data */
152  file_size = avio_tell(pb);
153  avio_seek(pb, 8, SEEK_SET);
154  avio_write(pb, streaminfo, FLAC_STREAMINFO_SIZE);
155  avio_seek(pb, file_size, SEEK_SET);
156  avio_flush(pb);
157  } else {
158  av_log(s, AV_LOG_WARNING, "unable to rewrite FLAC header.\n");
159  }
160 
161  av_freep(&c->streaminfo);
162 
163  return 0;
164 }
165 
167 {
169  uint8_t *streaminfo;
170  int streaminfo_size;
171 
172  /* check for updated streaminfo */
174  &streaminfo_size);
175  if (streaminfo && streaminfo_size == FLAC_STREAMINFO_SIZE) {
176  av_freep(&c->streaminfo);
177 
179  if (!c->streaminfo)
180  return AVERROR(ENOMEM);
181  memcpy(c->streaminfo, streaminfo, FLAC_STREAMINFO_SIZE);
182  }
183 
184  if (pkt->size)
185  avio_write(s->pb, pkt->data, pkt->size);
186  return 0;
187 }
188 
189 static const AVOption flacenc_options[] = {
190  { "write_header", "Write the file header", offsetof(FlacMuxerContext, write_header), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },
191  { NULL },
192 };
193 
194 static const AVClass flac_muxer_class = {
195  .class_name = "flac muxer",
196  .item_name = av_default_item_name,
197  .option = flacenc_options,
198  .version = LIBAVUTIL_VERSION_INT,
199 };
200 
202  .name = "flac",
203  .long_name = NULL_IF_CONFIG_SMALL("raw FLAC"),
204  .priv_data_size = sizeof(FlacMuxerContext),
205  .mime_type = "audio/x-flac",
206  .extensions = "flac",
207  .audio_codec = AV_CODEC_ID_FLAC,
208  .video_codec = AV_CODEC_ID_NONE,
213  .priv_class = &flac_muxer_class,
214 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
Bytestream IO Context.
Definition: avio.h:111
AVOption.
Definition: opt.h:245
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
#define LIBAVUTIL_VERSION_INT
Definition: version.h:70
static int flac_write_block_padding(AVIOContext *pb, unsigned int n_padding_bytes, int last_block)
Definition: flacenc.c:40
AVOutputFormat ff_flac_muxer
Definition: flacenc.c:201
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3911
int size
Definition: avcodec.h:1575
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:213
int ff_flac_is_native_layout(uint64_t channel_layout)
static AVPacket pkt
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3903
int ff_vorbiscomment_write(uint8_t **p, AVDictionary **m, const char *vendor_string)
Write a VorbisComment into a buffer.
Definition: vorbiscomment.c:54
Format I/O context.
Definition: avformat.h:1319
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
uint8_t
#define av_malloc(s)
AVOptions.
uint8_t * streaminfo
Definition: flacenc.c:37
static int flac_write_header(struct AVFormatContext *s)
Definition: flacenc.c:77
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1387
AVDictionaryEntry * av_dict_get(const AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags)
Get a dictionary entry with matching key.
Definition: dict.c:39
int flags
Flags modifying the (de)muxer behaviour.
Definition: avformat.h:1430
uint8_t * data
Definition: avcodec.h:1574
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:447
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:187
#define AVFMT_FLAG_BITEXACT
When muxing, try to avoid writing any random/volatile data to the output.
Definition: avformat.h:1447
static int flac_write_trailer(struct AVFormatContext *s)
Definition: flacenc.c:139
uint64_t channel_layout
Audio only.
Definition: avcodec.h:4013
#define av_log(a,...)
#define AV_OPT_FLAG_ENCODING_PARAM
a generic parameter which can be set by the user for muxing or encoding
Definition: opt.h:275
unsigned m
Definition: audioconvert.c:187
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: log.h:176
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1533
FLAC (Free Lossless Audio Codec) decoder/demuxer common functions.
av_default_item_name
#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
int64_t ff_vorbiscomment_length(AVDictionary *m, const char *vendor_string)
Calculate the length in bytes of a VorbisComment.
Definition: vorbiscomment.c:41
int extradata_size
Size of the extradata content in bytes.
Definition: avcodec.h:3929
static const AVOption flacenc_options[]
Definition: flacenc.c:189
int write_header
Definition: flacenc.c:34
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1375
#define LIBAVFORMAT_IDENT
Definition: version.h:44
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:207
int void avio_flush(AVIOContext *s)
Force flushing of buffered data.
Definition: aviobuf.c:207
audio channel layout utility functions
void ffio_fill(AVIOContext *s, int b, int count)
Definition: aviobuf.c:173
static int write_trailer(AVFormatContext *s1)
Definition: v4l2enc.c:94
void avio_wb24(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:447
const char * name
Definition: avformat.h:522
#define FLAC_STREAMINFO_SIZE
Definition: flac.h:34
int ff_flac_write_header(AVIOContext *pb, uint8_t *extradata, int extradata_size, int last_block)
static int flac_write_block_comment(AVIOContext *pb, AVDictionary **m, int last_block, int bitexact)
Definition: flacenc.c:49
int metadata_header_padding
Number of bytes to be written as padding in a metadata header.
Definition: avformat.h:1793
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:484
static const AVClass flac_muxer_class
Definition: flacenc.c:194
AVIOContext * pb
I/O context.
Definition: avformat.h:1361
void avio_w8(AVIOContext *s, int b)
Definition: aviobuf.c:165
void * buf
Definition: avisynth_c.h:553
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:69
Describe the class of an AVClass context structure.
Definition: log.h:67
#define snprintf
Definition: snprintf.h:34
static int flags
Definition: cpu.c:47
static int flac_write_packet(struct AVFormatContext *s, AVPacket *pkt)
Definition: flacenc.c:166
Main libavformat public API header.
static double c[64]
void ff_metadata_conv(AVDictionary **pm, const AVMetadataConv *d_conv, const AVMetadataConv *s_conv)
Definition: metadata.c:26
int len
void * priv_data
Format private data.
Definition: avformat.h:1347
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:497
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:3925
#define av_freep(p)
uint8_t * av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type, int *size)
Get side information from packet.
Definition: avpacket.c:320
AVCodecParameters * codecpar
Definition: avformat.h:1006
This structure stores compressed data.
Definition: avcodec.h:1551
static int write_packet(AVFormatContext *s1, AVPacket *pkt)
Definition: v4l2enc.c:86