FFmpeg  2.1.1
libvorbisenc.c
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1 /*
2  * Copyright (c) 2002 Mark Hills <mark@pogo.org.uk>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include <vorbis/vorbisenc.h>
22 
23 #include "libavutil/avassert.h"
24 #include "libavutil/fifo.h"
25 #include "libavutil/opt.h"
26 #include "avcodec.h"
27 #include "audio_frame_queue.h"
28 #include "internal.h"
29 #include "vorbis.h"
30 #include "vorbis_parser.h"
31 
32 
33 /* Number of samples the user should send in each call.
34  * This value is used because it is the LCD of all possible frame sizes, so
35  * an output packet will always start at the same point as one of the input
36  * packets.
37  */
38 #define OGGVORBIS_FRAME_SIZE 64
39 
40 #define BUFFER_SIZE (1024 * 64)
41 
42 typedef struct OggVorbisEncContext {
43  AVClass *av_class; /**< class for AVOptions */
45  vorbis_info vi; /**< vorbis_info used during init */
46  vorbis_dsp_state vd; /**< DSP state used for analysis */
47  vorbis_block vb; /**< vorbis_block used for analysis */
48  AVFifoBuffer *pkt_fifo; /**< output packet buffer */
49  int eof; /**< end-of-file flag */
50  int dsp_initialized; /**< vd has been initialized */
51  vorbis_comment vc; /**< VorbisComment info */
52  double iblock; /**< impulse block bias option */
53  VorbisParseContext vp; /**< parse context to get durations */
54  AudioFrameQueue afq; /**< frame queue for timestamps */
56 
57 static const AVOption options[] = {
58  { "iblock", "Sets the impulse block bias", offsetof(OggVorbisEncContext, iblock), AV_OPT_TYPE_DOUBLE, { .dbl = 0 }, -15, 0, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM },
59  { NULL }
60 };
61 
62 static const AVCodecDefault defaults[] = {
63  { "b", "0" },
64  { NULL },
65 };
66 
67 static const AVClass vorbis_class = {
68  .class_name = "libvorbis",
69  .item_name = av_default_item_name,
70  .option = options,
71  .version = LIBAVUTIL_VERSION_INT,
72 };
73 
74 static int vorbis_error_to_averror(int ov_err)
75 {
76  switch (ov_err) {
77  case OV_EFAULT: return AVERROR_BUG;
78  case OV_EINVAL: return AVERROR(EINVAL);
79  case OV_EIMPL: return AVERROR(EINVAL);
80  default: return AVERROR_UNKNOWN;
81  }
82 }
83 
84 static av_cold int oggvorbis_init_encoder(vorbis_info *vi,
85  AVCodecContext *avctx)
86 {
88  double cfreq;
89  int ret;
90 
91  if (avctx->flags & CODEC_FLAG_QSCALE || !avctx->bit_rate) {
92  /* variable bitrate
93  * NOTE: we use the oggenc range of -1 to 10 for global_quality for
94  * user convenience, but libvorbis uses -0.1 to 1.0.
95  */
96  float q = avctx->global_quality / (float)FF_QP2LAMBDA;
97  /* default to 3 if the user did not set quality or bitrate */
98  if (!(avctx->flags & CODEC_FLAG_QSCALE))
99  q = 3.0;
100  if ((ret = vorbis_encode_setup_vbr(vi, avctx->channels,
101  avctx->sample_rate,
102  q / 10.0)))
103  goto error;
104  } else {
105  int minrate = avctx->rc_min_rate > 0 ? avctx->rc_min_rate : -1;
106  int maxrate = avctx->rc_max_rate > 0 ? avctx->rc_max_rate : -1;
107 
108  /* average bitrate */
109  if ((ret = vorbis_encode_setup_managed(vi, avctx->channels,
110  avctx->sample_rate, maxrate,
111  avctx->bit_rate, minrate)))
112  goto error;
113 
114  /* variable bitrate by estimate, disable slow rate management */
115  if (minrate == -1 && maxrate == -1)
116  if ((ret = vorbis_encode_ctl(vi, OV_ECTL_RATEMANAGE2_SET, NULL)))
117  goto error; /* should not happen */
118  }
119 
120  /* cutoff frequency */
121  if (avctx->cutoff > 0) {
122  cfreq = avctx->cutoff / 1000.0;
123  if ((ret = vorbis_encode_ctl(vi, OV_ECTL_LOWPASS_SET, &cfreq)))
124  goto error; /* should not happen */
125  }
126 
127  /* impulse block bias */
128  if (s->iblock) {
129  if ((ret = vorbis_encode_ctl(vi, OV_ECTL_IBLOCK_SET, &s->iblock)))
130  goto error;
131  }
132 
133  if (avctx->channels == 3 &&
135  avctx->channels == 4 &&
136  avctx->channel_layout != AV_CH_LAYOUT_2_2 &&
137  avctx->channel_layout != AV_CH_LAYOUT_QUAD ||
138  avctx->channels == 5 &&
141  avctx->channels == 6 &&
144  avctx->channels == 7 &&
146  avctx->channels == 8 &&
148  if (avctx->channel_layout) {
149  char name[32];
150  av_get_channel_layout_string(name, sizeof(name), avctx->channels,
151  avctx->channel_layout);
152  av_log(avctx, AV_LOG_ERROR, "%s not supported by Vorbis: "
153  "output stream will have incorrect "
154  "channel layout.\n", name);
155  } else {
156  av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The encoder "
157  "will use Vorbis channel layout for "
158  "%d channels.\n", avctx->channels);
159  }
160  }
161 
162  if ((ret = vorbis_encode_setup_init(vi)))
163  goto error;
164 
165  return 0;
166 error:
167  return vorbis_error_to_averror(ret);
168 }
169 
170 /* How many bytes are needed for a buffer of length 'l' */
171 static int xiph_len(int l)
172 {
173  return 1 + l / 255 + l;
174 }
175 
177 {
178  OggVorbisEncContext *s = avctx->priv_data;
179 
180  /* notify vorbisenc this is EOF */
181  if (s->dsp_initialized)
182  vorbis_analysis_wrote(&s->vd, 0);
183 
184  vorbis_block_clear(&s->vb);
185  vorbis_dsp_clear(&s->vd);
186  vorbis_info_clear(&s->vi);
187 
189  ff_af_queue_close(&s->afq);
190  av_freep(&avctx->extradata);
191 
192  return 0;
193 }
194 
196 {
197  OggVorbisEncContext *s = avctx->priv_data;
198  ogg_packet header, header_comm, header_code;
199  uint8_t *p;
200  unsigned int offset;
201  int ret;
202 
203  vorbis_info_init(&s->vi);
204  if ((ret = oggvorbis_init_encoder(&s->vi, avctx))) {
205  av_log(avctx, AV_LOG_ERROR, "encoder setup failed\n");
206  goto error;
207  }
208  if ((ret = vorbis_analysis_init(&s->vd, &s->vi))) {
209  av_log(avctx, AV_LOG_ERROR, "analysis init failed\n");
210  ret = vorbis_error_to_averror(ret);
211  goto error;
212  }
213  s->dsp_initialized = 1;
214  if ((ret = vorbis_block_init(&s->vd, &s->vb))) {
215  av_log(avctx, AV_LOG_ERROR, "dsp init failed\n");
216  ret = vorbis_error_to_averror(ret);
217  goto error;
218  }
219 
220  vorbis_comment_init(&s->vc);
221  if (!(avctx->flags & CODEC_FLAG_BITEXACT))
222  vorbis_comment_add_tag(&s->vc, "encoder", LIBAVCODEC_IDENT);
223 
224  if ((ret = vorbis_analysis_headerout(&s->vd, &s->vc, &header, &header_comm,
225  &header_code))) {
226  ret = vorbis_error_to_averror(ret);
227  goto error;
228  }
229 
230  avctx->extradata_size = 1 + xiph_len(header.bytes) +
231  xiph_len(header_comm.bytes) +
232  header_code.bytes;
233  p = avctx->extradata = av_malloc(avctx->extradata_size +
235  if (!p) {
236  ret = AVERROR(ENOMEM);
237  goto error;
238  }
239  p[0] = 2;
240  offset = 1;
241  offset += av_xiphlacing(&p[offset], header.bytes);
242  offset += av_xiphlacing(&p[offset], header_comm.bytes);
243  memcpy(&p[offset], header.packet, header.bytes);
244  offset += header.bytes;
245  memcpy(&p[offset], header_comm.packet, header_comm.bytes);
246  offset += header_comm.bytes;
247  memcpy(&p[offset], header_code.packet, header_code.bytes);
248  offset += header_code.bytes;
249  av_assert0(offset == avctx->extradata_size);
250 
251  if ((ret = avpriv_vorbis_parse_extradata(avctx, &s->vp)) < 0) {
252  av_log(avctx, AV_LOG_ERROR, "invalid extradata\n");
253  return ret;
254  }
255 
256  vorbis_comment_clear(&s->vc);
257 
259  ff_af_queue_init(avctx, &s->afq);
260 
262  if (!s->pkt_fifo) {
263  ret = AVERROR(ENOMEM);
264  goto error;
265  }
266 
267  return 0;
268 error:
269  oggvorbis_encode_close(avctx);
270  return ret;
271 }
272 
274  const AVFrame *frame, int *got_packet_ptr)
275 {
276  OggVorbisEncContext *s = avctx->priv_data;
277  ogg_packet op;
278  int ret, duration;
279 
280  /* send samples to libvorbis */
281  if (frame) {
282  const int samples = frame->nb_samples;
283  float **buffer;
284  int c, channels = s->vi.channels;
285 
286  buffer = vorbis_analysis_buffer(&s->vd, samples);
287  for (c = 0; c < channels; c++) {
288  int co = (channels > 8) ? c :
290  memcpy(buffer[c], frame->extended_data[co],
291  samples * sizeof(*buffer[c]));
292  }
293  if ((ret = vorbis_analysis_wrote(&s->vd, samples)) < 0) {
294  av_log(avctx, AV_LOG_ERROR, "error in vorbis_analysis_wrote()\n");
295  return vorbis_error_to_averror(ret);
296  }
297  if ((ret = ff_af_queue_add(&s->afq, frame)) < 0)
298  return ret;
299  } else {
300  if (!s->eof)
301  if ((ret = vorbis_analysis_wrote(&s->vd, 0)) < 0) {
302  av_log(avctx, AV_LOG_ERROR, "error in vorbis_analysis_wrote()\n");
303  return vorbis_error_to_averror(ret);
304  }
305  s->eof = 1;
306  }
307 
308  /* retrieve available packets from libvorbis */
309  while ((ret = vorbis_analysis_blockout(&s->vd, &s->vb)) == 1) {
310  if ((ret = vorbis_analysis(&s->vb, NULL)) < 0)
311  break;
312  if ((ret = vorbis_bitrate_addblock(&s->vb)) < 0)
313  break;
314 
315  /* add any available packets to the output packet buffer */
316  while ((ret = vorbis_bitrate_flushpacket(&s->vd, &op)) == 1) {
317  if (av_fifo_space(s->pkt_fifo) < sizeof(ogg_packet) + op.bytes) {
318  av_log(avctx, AV_LOG_ERROR, "packet buffer is too small\n");
319  return AVERROR_BUG;
320  }
321  av_fifo_generic_write(s->pkt_fifo, &op, sizeof(ogg_packet), NULL);
322  av_fifo_generic_write(s->pkt_fifo, op.packet, op.bytes, NULL);
323  }
324  if (ret < 0) {
325  av_log(avctx, AV_LOG_ERROR, "error getting available packets\n");
326  break;
327  }
328  }
329  if (ret < 0) {
330  av_log(avctx, AV_LOG_ERROR, "error getting available packets\n");
331  return vorbis_error_to_averror(ret);
332  }
333 
334  /* check for available packets */
335  if (av_fifo_size(s->pkt_fifo) < sizeof(ogg_packet))
336  return 0;
337 
338  av_fifo_generic_read(s->pkt_fifo, &op, sizeof(ogg_packet), NULL);
339 
340  if ((ret = ff_alloc_packet2(avctx, avpkt, op.bytes)) < 0)
341  return ret;
342  av_fifo_generic_read(s->pkt_fifo, avpkt->data, op.bytes, NULL);
343 
344  avpkt->pts = ff_samples_to_time_base(avctx, op.granulepos);
345 
346  duration = avpriv_vorbis_parse_frame(&s->vp, avpkt->data, avpkt->size);
347  if (duration > 0) {
348  /* we do not know encoder delay until we get the first packet from
349  * libvorbis, so we have to update the AudioFrameQueue counts */
350  if (!avctx->delay && s->afq.frames) {
351  avctx->delay = duration;
353  s->afq.frames->duration += duration;
354  s->afq.frames->pts -= duration;
356  }
357  ff_af_queue_remove(&s->afq, duration, &avpkt->pts, &avpkt->duration);
358  }
359 
360  *got_packet_ptr = 1;
361  return 0;
362 }
363 
365  .name = "libvorbis",
366  .long_name = NULL_IF_CONFIG_SMALL("libvorbis"),
367  .type = AVMEDIA_TYPE_AUDIO,
368  .id = AV_CODEC_ID_VORBIS,
369  .priv_data_size = sizeof(OggVorbisEncContext),
371  .encode2 = oggvorbis_encode_frame,
373  .capabilities = CODEC_CAP_DELAY,
374  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
376  .priv_class = &vorbis_class,
377  .defaults = defaults,
378 };
const char * name
Definition: avisynth_c.h:675
int ff_alloc_packet2(AVCodecContext *avctx, AVPacket *avpkt, int64_t size)
Check AVPacket size and/or allocate data.
Definition: utils.c:1500
#define AV_CH_LAYOUT_7POINT1
const char * s
Definition: avisynth_c.h:668
This structure describes decoded (raw) audio or video data.
Definition: frame.h:96
AVOption.
Definition: opt.h:253
VorbisParseContext vp
parse context to get durations
Definition: libvorbisenc.c:53
int avpriv_vorbis_parse_frame(VorbisParseContext *s, const uint8_t *buf, int buf_size)
Get the duration for a Vorbis packet.
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: avcodec.h:4153
#define LIBAVUTIL_VERSION_INT
Definition: avcodec.h:820
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1064
AudioFrame * frames
uint8_t ** extended_data
pointers to the data planes/channels.
Definition: frame.h:140
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...
double iblock
impulse block bias option
Definition: libvorbisenc.c:52
static av_cold int oggvorbis_encode_close(AVCodecContext *avctx)
Definition: libvorbisenc.c:176
#define AV_CH_LAYOUT_STEREO
AVClass * av_class
class for AVOptions
Definition: libvorbisenc.c:43
AVCodec.
Definition: avcodec.h:2922
#define av_cold
Definition: avcodec.h:653
#define AV_CH_LAYOUT_5POINT0
static int xiph_len(int l)
Definition: libvorbisenc.c:171
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1254
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
int av_fifo_size(AVFifoBuffer *f)
Return the amount of data in bytes in the AVFifoBuffer, that is the amount of data you can read from ...
Definition: fifo.c:54
const char * av_default_item_name(void *ctx)
Return the context name.
Definition: log.c:145
uint8_t
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:55
static const uint8_t offset[511][2]
Definition: vf_uspp.c:58
av_cold void ff_af_queue_init(AVCodecContext *avctx, AudioFrameQueue *afq)
Initialize AudioFrameQueue.
static av_cold int oggvorbis_encode_init(AVCodecContext *avctx)
Definition: libvorbisenc.c:195
const char * name
Name of the codec implementation.
Definition: avcodec.h:2929
Vorbis audio parser.
static const AVCodecDefault defaults[]
Definition: libvorbisenc.c:62
#define CODEC_FLAG_BITEXACT
Use only bitexact stuff (except (I)DCT).
Definition: avcodec.h:714
void av_fifo_free(AVFifoBuffer *f)
Free an AVFifoBuffer.
Definition: fifo.c:40
static int64_t duration
Definition: ffplay.c:306
int duration
Duration of this packet in AVStream-&gt;time_base units, 0 if unknown.
Definition: avcodec.h:1085
const OptionDef options[]
Definition: ffserver.c:4682
vorbis_dsp_state vd
DSP state used for analysis.
Definition: libvorbisenc.c:46
static AVFrame * frame
Definition: demuxing.c:51
#define BUFFER_SIZE
Definition: libvorbisenc.c:40
static const AVClass vorbis_class
Definition: libvorbisenc.c:67
#define AV_CH_LAYOUT_5POINT1
const AVS_VideoInfo * vi
Definition: avisynth_c.h:695
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: avcodec.h:4147
#define AVERROR_UNKNOWN
#define AV_OPT_FLAG_AUDIO_PARAM
Definition: opt.h:286
#define CODEC_CAP_DELAY
Encoder or decoder requires flushing with NULL input at the end in order to give the complete and cor...
Definition: avcodec.h:769
#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
#define CODEC_FLAG_QSCALE
Use fixed qscale.
Definition: avcodec.h:692
int rc_max_rate
maximum bitrate
Definition: avcodec.h:2213
#define AV_CH_LAYOUT_QUAD
AVCodec ff_libvorbis_encoder
Definition: libvorbisenc.c:364
int dsp_initialized
vd has been initialized
Definition: libvorbisenc.c:50
int ff_af_queue_add(AudioFrameQueue *afq, const AVFrame *f)
Add a frame to the queue.
Libavcodec external API header.
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:1934
int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int(*func)(void *, void *, int))
Feed data from a user-supplied callback to an AVFifoBuffer.
Definition: fifo.c:99
#define AV_CH_LAYOUT_2_2
#define FF_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:580
int bit_rate
the average bitrate
Definition: avcodec.h:1204
ret
Definition: avfilter.c:961
vorbis_info vi
vorbis_info used during init
Definition: libvorbisenc.c:45
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
static char buffer[20]
Definition: seek-test.c:31
vorbis_comment vc
VorbisComment info.
Definition: libvorbisenc.c:51
#define AV_CH_FRONT_CENTER
int eof
end-of-file flag
Definition: libvorbisenc.c:49
#define AV_CH_LAYOUT_5POINT1_BACK
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:1893
AVSampleFormat
Audio Sample Formats.
Definition: samplefmt.h:49
const uint8_t ff_vorbis_encoding_channel_layout_offsets[8][8]
Definition: vorbis_data.c:36
int sample_rate
samples per second
Definition: avcodec.h:1873
static int ogg_packet(AVFormatContext *s, int *sid, int *dstart, int *dsize, int64_t *fpos)
find the next Ogg packet
Definition: oggdec.c:433
main external API structure.
Definition: avcodec.h:1146
static void close(AVCodecParserContext *s)
Definition: h264_parser.c:538
int extradata_size
Definition: avcodec.h:1255
unsigned int av_xiphlacing(unsigned char *s, unsigned int v)
Encode extradata length to a buffer.
Definition: utils.c:3119
Describe the class of an AVClass context structure.
Definition: log.h:50
uint8_t * data
Definition: avcodec.h:1063
AVFifoBuffer * av_fifo_alloc(unsigned int size)
Initialize an AVFifoBuffer.
Definition: fifo.c:27
#define AV_CH_LAYOUT_5POINT0_BACK
#define LIBAVCODEC_IDENT
Definition: version.h:43
int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, void(*func)(void *, void *, int))
Feed data from an AVFifoBuffer to a user-supplied callback.
Definition: fifo.c:127
void * priv_data
Definition: avcodec.h:1182
int global_quality
Global quality for codecs which cannot change it per frame.
Definition: avcodec.h:1220
#define AV_CH_BACK_CENTER
static int op(uint8_t **dst, const uint8_t *dst_end, GetByteContext *gb, int pixel, int count, int *x, int width, int linesize)
Perform decode operation.
Definition: anm.c:76
static int oggvorbis_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)
Definition: libvorbisenc.c:273
static int vorbis_error_to_averror(int ov_err)
Definition: libvorbisenc.c:74
common internal api header.
static double c[64]
static av_cold int oggvorbis_init_encoder(vorbis_info *vi, AVCodecContext *avctx)
Definition: libvorbisenc.c:84
#define AV_OPT_FLAG_ENCODING_PARAM
a generic parameter which can be set by the user for muxing or encoding
Definition: opt.h:283
int cutoff
Audio cutoff bandwidth (0 means &quot;automatic&quot;)
Definition: avcodec.h:1917
#define AVERROR_BUG
void ff_af_queue_remove(AudioFrameQueue *afq, int nb_samples, int64_t *pts, int *duration)
Remove frame(s) from the queue.
int channels
number of audio channels
Definition: avcodec.h:1874
AVFifoBuffer * pkt_fifo
output packet buffer
Definition: libvorbisenc.c:48
#define FF_QP2LAMBDA
factor to convert from H.263 QP to lambda
Definition: avcodec.h:2257
#define AVERROR(e)
float, planar
Definition: samplefmt.h:60
void ff_af_queue_close(AudioFrameQueue *afq)
Close AudioFrameQueue.
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:700
int avpriv_vorbis_parse_extradata(AVCodecContext *avctx, VorbisParseContext *s)
Initialize the Vorbis parser using headers in the extradata.
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
static av_always_inline int64_t ff_samples_to_time_base(AVCodecContext *avctx, int64_t samples)
Rescale from sample rate to AVCodecContext.time_base.
Definition: internal.h:181
int rc_min_rate
minimum bitrate
Definition: avcodec.h:2220
int av_fifo_space(AVFifoBuffer *f)
Return the amount of space in bytes in the AVFifoBuffer, that is the amount of data you can write int...
Definition: fifo.c:59
This structure stores compressed data.
Definition: avcodec.h:1040
int delay
Codec delay.
Definition: avcodec.h:1302
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:150
int64_t pts
Presentation timestamp in AVStream-&gt;time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1056
vorbis_block vb
vorbis_block used for analysis
Definition: libvorbisenc.c:47
#define OGGVORBIS_FRAME_SIZE
Definition: libvorbisenc.c:38
AudioFrameQueue afq
frame queue for timestamps
Definition: libvorbisenc.c:54
void av_get_channel_layout_string(char *buf, int buf_size, int nb_channels, uint64_t channel_layout)
Return a description of a channel layout.