FFmpeg
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"
25 #include "libavutil/fifo.h"
26 #include "libavutil/opt.h"
27 #include "avcodec.h"
28 #include "audio_frame_queue.h"
29 #include "codec_internal.h"
30 #include "encode.h"
31 #include "version.h"
32 #include "vorbis_parser.h"
33 
34 
35 /* Number of samples the user should send in each call.
36  * This value is used because it is the LCD of all possible frame sizes, so
37  * an output packet will always start at the same point as one of the input
38  * packets.
39  */
40 #define LIBVORBIS_FRAME_SIZE 64
41 
42 #define BUFFER_SIZE (1024 * 64)
43 
44 typedef struct LibvorbisEncContext {
45  AVClass *av_class; /**< class for AVOptions */
46  vorbis_info vi; /**< vorbis_info used during init */
47  vorbis_dsp_state vd; /**< DSP state used for analysis */
48  vorbis_block vb; /**< vorbis_block used for analysis */
49  AVFifo *pkt_fifo; /**< output packet buffer */
50  int eof; /**< end-of-file flag */
51  int dsp_initialized; /**< vd has been initialized */
52  vorbis_comment vc; /**< VorbisComment info */
53  double iblock; /**< impulse block bias option */
54  AVVorbisParseContext *vp; /**< parse context to get durations */
55  AudioFrameQueue afq; /**< frame queue for timestamps */
57 
58 static const AVOption options[] = {
59  { "iblock", "Sets the impulse block bias", offsetof(LibvorbisEncContext, iblock), AV_OPT_TYPE_DOUBLE, { .dbl = 0 }, -15, 0, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM },
60  { NULL }
61 };
62 
63 static const FFCodecDefault defaults[] = {
64  { "b", "0" },
65  { NULL },
66 };
67 
68 static const AVClass vorbis_class = {
69  .class_name = "libvorbis",
70  .item_name = av_default_item_name,
71  .option = options,
72  .version = LIBAVUTIL_VERSION_INT,
73 };
74 
75 static const uint8_t vorbis_encoding_channel_layout_offsets[8][8] = {
76  { 0 },
77  { 0, 1 },
78  { 0, 2, 1 },
79  { 0, 1, 2, 3 },
80  { 0, 2, 1, 3, 4 },
81  { 0, 2, 1, 4, 5, 3 },
82  { 0, 2, 1, 5, 6, 4, 3 },
83  { 0, 2, 1, 6, 7, 4, 5, 3 },
84 };
85 
86 static int vorbis_error_to_averror(int ov_err)
87 {
88  switch (ov_err) {
89  case OV_EFAULT: return AVERROR_BUG;
90  case OV_EINVAL: return AVERROR(EINVAL);
91  case OV_EIMPL: return AVERROR(EINVAL);
92  default: return AVERROR_UNKNOWN;
93  }
94 }
95 
96 static av_cold int libvorbis_setup(vorbis_info *vi, AVCodecContext *avctx)
97 {
99  int channels = avctx->ch_layout.nb_channels;
100  double cfreq;
101  int ret;
102 
103  if (avctx->flags & AV_CODEC_FLAG_QSCALE || !avctx->bit_rate) {
104  /* variable bitrate
105  * NOTE: we use the oggenc range of -1 to 10 for global_quality for
106  * user convenience, but libvorbis uses -0.1 to 1.0.
107  */
108  float q = avctx->global_quality / (float)FF_QP2LAMBDA;
109  /* default to 3 if the user did not set quality or bitrate */
110  if (!(avctx->flags & AV_CODEC_FLAG_QSCALE))
111  q = 3.0;
112  if ((ret = vorbis_encode_setup_vbr(vi, channels,
113  avctx->sample_rate,
114  q / 10.0)))
115  goto error;
116  } else {
117  int minrate = avctx->rc_min_rate > 0 ? avctx->rc_min_rate : -1;
118  int maxrate = avctx->rc_max_rate > 0 ? avctx->rc_max_rate : -1;
119 
120  /* average bitrate */
121  if ((ret = vorbis_encode_setup_managed(vi, channels,
122  avctx->sample_rate, maxrate,
123  avctx->bit_rate, minrate)))
124  goto error;
125 
126  /* variable bitrate by estimate, disable slow rate management */
127  if (minrate == -1 && maxrate == -1)
128  if ((ret = vorbis_encode_ctl(vi, OV_ECTL_RATEMANAGE2_SET, NULL)))
129  goto error; /* should not happen */
130  }
131 
132  /* cutoff frequency */
133  if (avctx->cutoff > 0) {
134  cfreq = avctx->cutoff / 1000.0;
135  if ((ret = vorbis_encode_ctl(vi, OV_ECTL_LOWPASS_SET, &cfreq)))
136  goto error; /* should not happen */
137  }
138 
139  /* impulse block bias */
140  if (s->iblock) {
141  if ((ret = vorbis_encode_ctl(vi, OV_ECTL_IBLOCK_SET, &s->iblock)))
142  goto error;
143  }
144 
145  if ((channels == 3 &&
147  (channels == 4 &&
150  (channels == 5 &&
153  (channels == 6 &&
156  (channels == 7 &&
158  (channels == 8 &&
160  if (avctx->ch_layout.order != AV_CHANNEL_ORDER_UNSPEC) {
161  char name[32];
162  av_channel_layout_describe(&avctx->ch_layout, name, sizeof(name));
163  av_log(avctx, AV_LOG_ERROR, "%s not supported by Vorbis: "
164  "output stream will have incorrect "
165  "channel layout.\n", name);
166  } else {
167  av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The encoder "
168  "will use Vorbis channel layout for "
169  "%d channels.\n", channels);
170  }
171  }
172 
173  if ((ret = vorbis_encode_setup_init(vi)))
174  goto error;
175 
176  return 0;
177 error:
179 }
180 
181 /* How many bytes are needed for a buffer of length 'l' */
182 static int xiph_len(int l)
183 {
184  return 1 + l / 255 + l;
185 }
186 
188 {
189  LibvorbisEncContext *s = avctx->priv_data;
190 
191  /* notify vorbisenc this is EOF */
192  if (s->dsp_initialized)
193  vorbis_analysis_wrote(&s->vd, 0);
194 
195  vorbis_block_clear(&s->vb);
196  vorbis_dsp_clear(&s->vd);
197  vorbis_info_clear(&s->vi);
198 
199  av_fifo_freep2(&s->pkt_fifo);
200  ff_af_queue_close(&s->afq);
201 
202  av_vorbis_parse_free(&s->vp);
203 
204  return 0;
205 }
206 
208 {
209  LibvorbisEncContext *s = avctx->priv_data;
210  ogg_packet header, header_comm, header_code;
211  uint8_t *p;
212  unsigned int offset;
213  int ret;
214 
215  vorbis_info_init(&s->vi);
216  if ((ret = libvorbis_setup(&s->vi, avctx))) {
217  av_log(avctx, AV_LOG_ERROR, "encoder setup failed\n");
218  goto error;
219  }
220  if ((ret = vorbis_analysis_init(&s->vd, &s->vi))) {
221  av_log(avctx, AV_LOG_ERROR, "analysis init failed\n");
223  goto error;
224  }
225  s->dsp_initialized = 1;
226  if ((ret = vorbis_block_init(&s->vd, &s->vb))) {
227  av_log(avctx, AV_LOG_ERROR, "dsp init failed\n");
229  goto error;
230  }
231 
232  vorbis_comment_init(&s->vc);
233  if (!(avctx->flags & AV_CODEC_FLAG_BITEXACT))
234  vorbis_comment_add_tag(&s->vc, "encoder", LIBAVCODEC_IDENT);
235 
236  if ((ret = vorbis_analysis_headerout(&s->vd, &s->vc, &header, &header_comm,
237  &header_code))) {
239  goto error;
240  }
241 
242  avctx->extradata_size = 1 + xiph_len(header.bytes) +
243  xiph_len(header_comm.bytes) +
244  header_code.bytes;
245  p = avctx->extradata = av_malloc(avctx->extradata_size +
247  if (!p) {
248  ret = AVERROR(ENOMEM);
249  goto error;
250  }
251  p[0] = 2;
252  offset = 1;
253  offset += av_xiphlacing(&p[offset], header.bytes);
254  offset += av_xiphlacing(&p[offset], header_comm.bytes);
255  memcpy(&p[offset], header.packet, header.bytes);
256  offset += header.bytes;
257  memcpy(&p[offset], header_comm.packet, header_comm.bytes);
258  offset += header_comm.bytes;
259  memcpy(&p[offset], header_code.packet, header_code.bytes);
260  offset += header_code.bytes;
261  av_assert0(offset == avctx->extradata_size);
262 
263  s->vp = av_vorbis_parse_init(avctx->extradata, avctx->extradata_size);
264  if (!s->vp) {
265  av_log(avctx, AV_LOG_ERROR, "invalid extradata\n");
266  return ret;
267  }
268 
269  vorbis_comment_clear(&s->vc);
270 
272  ff_af_queue_init(avctx, &s->afq);
273 
274  s->pkt_fifo = av_fifo_alloc2(BUFFER_SIZE, 1, 0);
275  if (!s->pkt_fifo) {
276  ret = AVERROR(ENOMEM);
277  goto error;
278  }
279 
280  return 0;
281 error:
282  libvorbis_encode_close(avctx);
283  return ret;
284 }
285 
287  const AVFrame *frame, int *got_packet_ptr)
288 {
289  LibvorbisEncContext *s = avctx->priv_data;
290  ogg_packet op;
291  int ret, duration;
292 
293  /* send samples to libvorbis */
294  if (frame) {
295  const int samples = frame->nb_samples;
296  float **buffer;
297  int c, channels = s->vi.channels;
298 
299  buffer = vorbis_analysis_buffer(&s->vd, samples);
300  for (c = 0; c < channels; c++) {
301  int co = (channels > 8) ? c :
303  memcpy(buffer[c], frame->extended_data[co],
304  samples * sizeof(*buffer[c]));
305  }
306  if ((ret = vorbis_analysis_wrote(&s->vd, samples)) < 0) {
307  av_log(avctx, AV_LOG_ERROR, "error in vorbis_analysis_wrote()\n");
309  }
310  if ((ret = ff_af_queue_add(&s->afq, frame)) < 0)
311  return ret;
312  } else {
313  if (!s->eof && s->afq.frame_alloc)
314  if ((ret = vorbis_analysis_wrote(&s->vd, 0)) < 0) {
315  av_log(avctx, AV_LOG_ERROR, "error in vorbis_analysis_wrote()\n");
317  }
318  s->eof = 1;
319  }
320 
321  /* retrieve available packets from libvorbis */
322  while ((ret = vorbis_analysis_blockout(&s->vd, &s->vb)) == 1) {
323  if ((ret = vorbis_analysis(&s->vb, NULL)) < 0)
324  break;
325  if ((ret = vorbis_bitrate_addblock(&s->vb)) < 0)
326  break;
327 
328  /* add any available packets to the output packet buffer */
329  while ((ret = vorbis_bitrate_flushpacket(&s->vd, &op)) == 1) {
330  if (av_fifo_can_write(s->pkt_fifo) < sizeof(ogg_packet) + op.bytes) {
331  av_log(avctx, AV_LOG_ERROR, "packet buffer is too small\n");
332  return AVERROR_BUG;
333  }
334  av_fifo_write(s->pkt_fifo, &op, sizeof(ogg_packet));
335  av_fifo_write(s->pkt_fifo, op.packet, op.bytes);
336  }
337  if (ret < 0) {
338  av_log(avctx, AV_LOG_ERROR, "error getting available packets\n");
339  break;
340  }
341  }
342  if (ret < 0) {
343  av_log(avctx, AV_LOG_ERROR, "error getting available packets\n");
345  }
346 
347  /* Read an available packet if possible */
348  if (av_fifo_read(s->pkt_fifo, &op, sizeof(ogg_packet)) < 0)
349  return 0;
350 
351  if ((ret = ff_get_encode_buffer(avctx, avpkt, op.bytes, 0)) < 0)
352  return ret;
353  av_fifo_read(s->pkt_fifo, avpkt->data, op.bytes);
354 
355  avpkt->pts = ff_samples_to_time_base(avctx, op.granulepos);
356 
357  duration = av_vorbis_parse_frame(s->vp, avpkt->data, avpkt->size);
358  if (duration > 0) {
359  /* we do not know encoder delay until we get the first packet from
360  * libvorbis, so we have to update the AudioFrameQueue counts */
361  if (!avctx->initial_padding && s->afq.frames) {
362  avctx->initial_padding = duration;
363  av_assert0(!s->afq.remaining_delay);
364  s->afq.frames->duration += duration;
365  if (s->afq.frames->pts != AV_NOPTS_VALUE)
366  s->afq.frames->pts -= duration;
367  s->afq.remaining_samples += duration;
368  }
369  ff_af_queue_remove(&s->afq, duration, &avpkt->pts, &avpkt->duration);
370  }
371 
372  *got_packet_ptr = 1;
373  return 0;
374 }
375 
377  .p.name = "libvorbis",
378  CODEC_LONG_NAME("libvorbis"),
379  .p.type = AVMEDIA_TYPE_AUDIO,
380  .p.id = AV_CODEC_ID_VORBIS,
381  .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY |
383  .caps_internal = FF_CODEC_CAP_NOT_INIT_THREADSAFE,
384  .priv_data_size = sizeof(LibvorbisEncContext),
387  .close = libvorbis_encode_close,
388  .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
390  .p.priv_class = &vorbis_class,
391  .defaults = defaults,
392  .p.wrapper_name = "libvorbis",
393 };
error
static void error(const char *err)
Definition: target_bsf_fuzzer.c:31
AVCodecContext::frame_size
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:1035
AV_SAMPLE_FMT_FLTP
@ AV_SAMPLE_FMT_FLTP
float, planar
Definition: samplefmt.h:66
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
name
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option name
Definition: writing_filters.txt:88
LibvorbisEncContext::vc
vorbis_comment vc
VorbisComment info
Definition: libvorbisenc.c:52
av_fifo_can_write
size_t av_fifo_can_write(const AVFifo *f)
Definition: fifo.c:94
av_vorbis_parse_free
void av_vorbis_parse_free(AVVorbisParseContext **s)
Free the parser and everything associated with it.
Definition: vorbis_parser.c:278
AVERROR
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
opt.h
LIBAVCODEC_IDENT
#define LIBAVCODEC_IDENT
Definition: version.h:43
ff_af_queue_remove
void ff_af_queue_remove(AudioFrameQueue *afq, int nb_samples, int64_t *pts, int64_t *duration)
Remove frame(s) from the queue.
Definition: audio_frame_queue.c:75
AVCodecContext::sample_rate
int sample_rate
samples per second
Definition: avcodec.h:1007
AVVorbisParseContext
Definition: vorbis_parser_internal.h:34
AVCodecContext::rc_min_rate
int64_t rc_min_rate
minimum bitrate
Definition: avcodec.h:1230
ff_af_queue_close
void ff_af_queue_close(AudioFrameQueue *afq)
Close AudioFrameQueue.
Definition: audio_frame_queue.c:36
AV_CODEC_FLAG_QSCALE
#define AV_CODEC_FLAG_QSCALE
Use fixed qscale.
Definition: avcodec.h:216
ff_af_queue_init
av_cold void ff_af_queue_init(AVCodecContext *avctx, AudioFrameQueue *afq)
Initialize AudioFrameQueue.
Definition: audio_frame_queue.c:28
AV_CHANNEL_LAYOUT_2_2
#define AV_CHANNEL_LAYOUT_2_2
Definition: channel_layout.h:376
vorbis_class
static const AVClass vorbis_class
Definition: libvorbisenc.c:68
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
AVPacket::data
uint8_t * data
Definition: packet.h:374
AVOption
AVOption.
Definition: opt.h:251
encode.h
libvorbis_setup
static av_cold int libvorbis_setup(vorbis_info *vi, AVCodecContext *avctx)
Definition: libvorbisenc.c:96
LIBVORBIS_FRAME_SIZE
#define LIBVORBIS_FRAME_SIZE
Definition: libvorbisenc.c:40
FF_CODEC_CAP_NOT_INIT_THREADSAFE
#define FF_CODEC_CAP_NOT_INIT_THREADSAFE
The codec is not known to be init-threadsafe (i.e.
Definition: codec_internal.h:34
FFCodec
Definition: codec_internal.h:119
version.h
av_vorbis_parse_frame
int av_vorbis_parse_frame(AVVorbisParseContext *s, const uint8_t *buf, int buf_size)
Get the duration for a Vorbis packet.
Definition: vorbis_parser.c:266
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:392
AVChannelLayout::order
enum AVChannelOrder order
Channel order used in this layout.
Definition: channel_layout.h:306
AVERROR_UNKNOWN
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:73
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:311
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:30
fifo.h
FFCodecDefault
Definition: codec_internal.h:89
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:123
AVCodecContext::ch_layout
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:2059
av_fifo_write
int av_fifo_write(AVFifo *f, const void *buf, size_t nb_elems)
Write data into a FIFO.
Definition: fifo.c:188
defaults
static const FFCodecDefault defaults[]
Definition: libvorbisenc.c:63
audio_frame_queue.h
AVCodecContext::initial_padding
int initial_padding
Audio only.
Definition: avcodec.h:1726
options
static const AVOption options[]
Definition: libvorbisenc.c:58
AVCodecContext::flags
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:478
FF_CODEC_ENCODE_CB
#define FF_CODEC_ENCODE_CB(func)
Definition: codec_internal.h:307
ff_af_queue_add
int ff_af_queue_add(AudioFrameQueue *afq, const AVFrame *f)
Add a frame to the queue.
Definition: audio_frame_queue.c:44
ogg_packet
static int ogg_packet(AVFormatContext *s, int *sid, int *dstart, int *dsize, int64_t *fpos)
find the next Ogg packet
Definition: oggdec.c:497
AV_CHANNEL_LAYOUT_SURROUND
#define AV_CHANNEL_LAYOUT_SURROUND
Definition: channel_layout.h:372
LibvorbisEncContext::av_class
AVClass * av_class
class for AVOptions
Definition: libvorbisenc.c:45
LibvorbisEncContext::vi
vorbis_info vi
vorbis_info used during init
Definition: libvorbisenc.c:46
libvorbis_encode_frame
static int libvorbis_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)
Definition: libvorbisenc.c:286
avassert.h
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
av_fifo_read
int av_fifo_read(AVFifo *f, void *buf, size_t nb_elems)
Read data from a FIFO.
Definition: fifo.c:240
duration
int64_t duration
Definition: movenc.c:64
av_channel_layout_describe
int av_channel_layout_describe(const AVChannelLayout *channel_layout, char *buf, size_t buf_size)
Get a human-readable string describing the channel layout properties.
Definition: channel_layout.c:778
float
float
Definition: af_crystalizer.c:122
AVCodecContext::extradata_size
int extradata_size
Definition: avcodec.h:500
AV_CHANNEL_LAYOUT_7POINT1
#define AV_CHANNEL_LAYOUT_7POINT1
Definition: channel_layout.h:390
s
#define s(width, name)
Definition: cbs_vp9.c:256
AVCodecContext::global_quality
int global_quality
Global quality for codecs which cannot change it per frame.
Definition: avcodec.h:464
AV_OPT_FLAG_ENCODING_PARAM
#define AV_OPT_FLAG_ENCODING_PARAM
a generic parameter which can be set by the user for muxing or encoding
Definition: opt.h:281
libvorbis_encode_close
static av_cold int libvorbis_encode_close(AVCodecContext *avctx)
Definition: libvorbisenc.c:187
AV_OPT_TYPE_DOUBLE
@ AV_OPT_TYPE_DOUBLE
Definition: opt.h:227
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
op
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
AV_CHANNEL_ORDER_UNSPEC
@ AV_CHANNEL_ORDER_UNSPEC
Only the channel count is specified, without any further information about the channel order.
Definition: channel_layout.h:112
AV_CHANNEL_LAYOUT_5POINT0_BACK
#define AV_CHANNEL_LAYOUT_5POINT0_BACK
Definition: channel_layout.h:380
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts_bsf.c:363
av_assert0
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
AudioFrameQueue
Definition: audio_frame_queue.h:32
channels
channels
Definition: aptx.h:31
AVCodecContext::rc_max_rate
int64_t rc_max_rate
maximum bitrate
Definition: avcodec.h:1223
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:264
AV_OPT_FLAG_AUDIO_PARAM
#define AV_OPT_FLAG_AUDIO_PARAM
Definition: opt.h:283
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
ff_samples_to_time_base
static av_always_inline int64_t ff_samples_to_time_base(const AVCodecContext *avctx, int64_t samples)
Rescale from sample rate to AVCodecContext.time_base.
Definition: encode.h:84
AVCodecContext::bit_rate
int64_t bit_rate
the average bitrate
Definition: avcodec.h:448
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:237
vorbis_parser.h
LibvorbisEncContext::afq
AudioFrameQueue afq
frame queue for timestamps
Definition: libvorbisenc.c:55
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:375
AVFifo
Definition: fifo.c:35
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:301
codec_internal.h
AV_SAMPLE_FMT_NONE
@ AV_SAMPLE_FMT_NONE
Definition: samplefmt.h:56
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
av_xiphlacing
unsigned int av_xiphlacing(unsigned char *s, unsigned int v)
Encode extradata length to a buffer.
Definition: utils.c:852
LibvorbisEncContext::vb
vorbis_block vb
vorbis_block used for analysis
Definition: libvorbisenc.c:48
LibvorbisEncContext::vp
AVVorbisParseContext * vp
parse context to get durations
Definition: libvorbisenc.c:54
header
static const uint8_t header[24]
Definition: sdr2.c:67
BUFFER_SIZE
#define BUFFER_SIZE
Definition: libvorbisenc.c:42
LibvorbisEncContext
Definition: libvorbisenc.c:44
xiph_len
static int xiph_len(int l)
Definition: libvorbisenc.c:182
offset
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
Definition: writing_filters.txt:86
vorbis_error_to_averror
static int vorbis_error_to_averror(int ov_err)
Definition: libvorbisenc.c:86
av_channel_layout_compare
int av_channel_layout_compare(const AVChannelLayout *chl, const AVChannelLayout *chl1)
Check whether two channel layouts are semantically the same, i.e.
Definition: channel_layout.c:932
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:367
AVCodecContext::extradata
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:499
LibvorbisEncContext::pkt_fifo
AVFifo * pkt_fifo
output packet buffer
Definition: libvorbisenc.c:49
AV_CHANNEL_LAYOUT_QUAD
#define AV_CHANNEL_LAYOUT_QUAD
Definition: channel_layout.h:377
AVCodecContext::cutoff
int cutoff
Audio cutoff bandwidth (0 means "automatic")
Definition: avcodec.h:1059
vorbis_encoding_channel_layout_offsets
static const uint8_t vorbis_encoding_channel_layout_offsets[8][8]
Definition: libvorbisenc.c:75
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:55
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:211
avcodec.h
ret
ret
Definition: filter_design.txt:187
AVClass::class_name
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:71
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
av_vorbis_parse_init
AVVorbisParseContext * av_vorbis_parse_init(const uint8_t *extradata, int extradata_size)
Allocate and initialize the Vorbis parser using headers in the extradata.
Definition: vorbis_parser.c:283
LibvorbisEncContext::eof
int eof
end-of-file flag
Definition: libvorbisenc.c:50
libvorbis_encode_init
static av_cold int libvorbis_encode_init(AVCodecContext *avctx)
Definition: libvorbisenc.c:207
av_fifo_alloc2
AVFifo * av_fifo_alloc2(size_t nb_elems, size_t elem_size, unsigned int flags)
Allocate and initialize an AVFifo with a given element size.
Definition: fifo.c:47
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: defs.h:40
AVCodecContext
main external API structure.
Definition: avcodec.h:398
channel_layout.h
LibvorbisEncContext::iblock
double iblock
impulse block bias option
Definition: libvorbisenc.c:53
buffer
the frame and frame reference mechanism is intended to as much as expensive copies of that data while still allowing the filters to produce correct results The data is stored in buffers represented by AVFrame structures Several references can point to the same frame buffer
Definition: filter_design.txt:49
ff_get_encode_buffer
int ff_get_encode_buffer(AVCodecContext *avctx, AVPacket *avpkt, int64_t size, int flags)
Get a buffer for a packet.
Definition: encode.c:79
AV_CODEC_CAP_DELAY
#define AV_CODEC_CAP_DELAY
Encoder or decoder requires flushing with NULL input at the end in order to give the complete and cor...
Definition: codec.h:82
samples
Filter the word “frame” indicates either a video frame or a group of audio samples
Definition: filter_design.txt:8
LibvorbisEncContext::dsp_initialized
int dsp_initialized
vd has been initialized
Definition: libvorbisenc.c:51
AV_CODEC_FLAG_BITEXACT
#define AV_CODEC_FLAG_BITEXACT
Use only bitexact stuff (except (I)DCT).
Definition: avcodec.h:288
ff_libvorbis_encoder
const FFCodec ff_libvorbis_encoder
Definition: libvorbisenc.c:376
AVPacket
This structure stores compressed data.
Definition: packet.h:351
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:425
AV_CHANNEL_LAYOUT_5POINT1_BACK
#define AV_CHANNEL_LAYOUT_5POINT1_BACK
Definition: channel_layout.h:381
AVERROR_BUG
#define AVERROR_BUG
Internal bug, also see AVERROR_BUG2.
Definition: error.h:52
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AV_CHANNEL_LAYOUT_6POINT1
#define AV_CHANNEL_LAYOUT_6POINT1
Definition: channel_layout.h:385
av_fifo_freep2
void av_fifo_freep2(AVFifo **f)
Free an AVFifo and reset pointer to NULL.
Definition: fifo.c:286
AV_CHANNEL_LAYOUT_5POINT0
#define AV_CHANNEL_LAYOUT_5POINT0
Definition: channel_layout.h:378
AV_CODEC_ID_VORBIS
@ AV_CODEC_ID_VORBIS
Definition: codec_id.h:440
FF_QP2LAMBDA
#define FF_QP2LAMBDA
factor to convert from H.263 QP to lambda
Definition: avutil.h:227
AV_CODEC_CAP_SMALL_LAST_FRAME
#define AV_CODEC_CAP_SMALL_LAST_FRAME
Codec can be fed a final frame with a smaller size.
Definition: codec.h:87
AV_CHANNEL_LAYOUT_5POINT1
#define AV_CHANNEL_LAYOUT_5POINT1
Definition: channel_layout.h:379
LibvorbisEncContext::vd
vorbis_dsp_state vd
DSP state used for analysis
Definition: libvorbisenc.c:47