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"
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 LIBVORBIS_FRAME_SIZE 64
39 
40 #define BUFFER_SIZE (1024 * 64)
41 
42 typedef struct LibvorbisEncContext {
43  AVClass *av_class; /**< class for AVOptions */
44  vorbis_info vi; /**< vorbis_info used during init */
45  vorbis_dsp_state vd; /**< DSP state used for analysis */
46  vorbis_block vb; /**< vorbis_block used for analysis */
47  AVFifoBuffer *pkt_fifo; /**< output packet buffer */
48  int eof; /**< end-of-file flag */
49  int dsp_initialized; /**< vd has been initialized */
50  vorbis_comment vc; /**< VorbisComment info */
51  double iblock; /**< impulse block bias option */
52  AVVorbisParseContext *vp; /**< parse context to get durations */
53  AudioFrameQueue afq; /**< frame queue for timestamps */
55 
56 static const AVOption options[] = {
57  { "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 },
58  { NULL }
59 };
60 
61 static const AVCodecDefault defaults[] = {
62  { "b", "0" },
63  { NULL },
64 };
65 
66 static const AVClass vorbis_class = {
67  .class_name = "libvorbis",
68  .item_name = av_default_item_name,
69  .option = options,
70  .version = LIBAVUTIL_VERSION_INT,
71 };
72 
74  { 0 },
75  { 0, 1 },
76  { 0, 2, 1 },
77  { 0, 1, 2, 3 },
78  { 0, 2, 1, 3, 4 },
79  { 0, 2, 1, 4, 5, 3 },
80  { 0, 2, 1, 5, 6, 4, 3 },
81  { 0, 2, 1, 6, 7, 4, 5, 3 },
82 };
83 
84 static int vorbis_error_to_averror(int ov_err)
85 {
86  switch (ov_err) {
87  case OV_EFAULT: return AVERROR_BUG;
88  case OV_EINVAL: return AVERROR(EINVAL);
89  case OV_EIMPL: return AVERROR(EINVAL);
90  default: return AVERROR_UNKNOWN;
91  }
92 }
93 
94 static av_cold int libvorbis_setup(vorbis_info *vi, AVCodecContext *avctx)
95 {
97  double cfreq;
98  int ret;
99 
100  if (avctx->flags & AV_CODEC_FLAG_QSCALE || !avctx->bit_rate) {
101  /* variable bitrate
102  * NOTE: we use the oggenc range of -1 to 10 for global_quality for
103  * user convenience, but libvorbis uses -0.1 to 1.0.
104  */
105  float q = avctx->global_quality / (float)FF_QP2LAMBDA;
106  /* default to 3 if the user did not set quality or bitrate */
107  if (!(avctx->flags & AV_CODEC_FLAG_QSCALE))
108  q = 3.0;
109  if ((ret = vorbis_encode_setup_vbr(vi, avctx->channels,
110  avctx->sample_rate,
111  q / 10.0)))
112  goto error;
113  } else {
114  int minrate = avctx->rc_min_rate > 0 ? avctx->rc_min_rate : -1;
115  int maxrate = avctx->rc_max_rate > 0 ? avctx->rc_max_rate : -1;
116 
117  /* average bitrate */
118  if ((ret = vorbis_encode_setup_managed(vi, avctx->channels,
119  avctx->sample_rate, maxrate,
120  avctx->bit_rate, minrate)))
121  goto error;
122 
123  /* variable bitrate by estimate, disable slow rate management */
124  if (minrate == -1 && maxrate == -1)
125  if ((ret = vorbis_encode_ctl(vi, OV_ECTL_RATEMANAGE2_SET, NULL)))
126  goto error; /* should not happen */
127  }
128 
129  /* cutoff frequency */
130  if (avctx->cutoff > 0) {
131  cfreq = avctx->cutoff / 1000.0;
132  if ((ret = vorbis_encode_ctl(vi, OV_ECTL_LOWPASS_SET, &cfreq)))
133  goto error; /* should not happen */
134  }
135 
136  /* impulse block bias */
137  if (s->iblock) {
138  if ((ret = vorbis_encode_ctl(vi, OV_ECTL_IBLOCK_SET, &s->iblock)))
139  goto error;
140  }
141 
142  if (avctx->channels == 3 &&
144  avctx->channels == 4 &&
145  avctx->channel_layout != AV_CH_LAYOUT_2_2 &&
146  avctx->channel_layout != AV_CH_LAYOUT_QUAD ||
147  avctx->channels == 5 &&
150  avctx->channels == 6 &&
153  avctx->channels == 7 &&
155  avctx->channels == 8 &&
157  if (avctx->channel_layout) {
158  char name[32];
160  avctx->channel_layout);
161  av_log(avctx, AV_LOG_ERROR, "%s not supported by Vorbis: "
162  "output stream will have incorrect "
163  "channel layout.\n", name);
164  } else {
165  av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The encoder "
166  "will use Vorbis channel layout for "
167  "%d channels.\n", avctx->channels);
168  }
169  }
170 
171  if ((ret = vorbis_encode_setup_init(vi)))
172  goto error;
173 
174  return 0;
175 error:
177 }
178 
179 /* How many bytes are needed for a buffer of length 'l' */
180 static int xiph_len(int l)
181 {
182  return 1 + l / 255 + l;
183 }
184 
186 {
187  LibvorbisEncContext *s = avctx->priv_data;
188 
189  /* notify vorbisenc this is EOF */
190  if (s->dsp_initialized)
191  vorbis_analysis_wrote(&s->vd, 0);
192 
193  vorbis_block_clear(&s->vb);
194  vorbis_dsp_clear(&s->vd);
195  vorbis_info_clear(&s->vi);
196 
197  av_fifo_freep(&s->pkt_fifo);
198  ff_af_queue_close(&s->afq);
199  av_freep(&avctx->extradata);
200 
201  av_vorbis_parse_free(&s->vp);
202 
203  return 0;
204 }
205 
207 {
208  LibvorbisEncContext *s = avctx->priv_data;
209  ogg_packet header, header_comm, header_code;
210  uint8_t *p;
211  unsigned int offset;
212  int ret;
213 
214  vorbis_info_init(&s->vi);
215  if ((ret = libvorbis_setup(&s->vi, avctx))) {
216  av_log(avctx, AV_LOG_ERROR, "encoder setup failed\n");
217  goto error;
218  }
219  if ((ret = vorbis_analysis_init(&s->vd, &s->vi))) {
220  av_log(avctx, AV_LOG_ERROR, "analysis init failed\n");
222  goto error;
223  }
224  s->dsp_initialized = 1;
225  if ((ret = vorbis_block_init(&s->vd, &s->vb))) {
226  av_log(avctx, AV_LOG_ERROR, "dsp init failed\n");
228  goto error;
229  }
230 
231  vorbis_comment_init(&s->vc);
232  if (!(avctx->flags & AV_CODEC_FLAG_BITEXACT))
233  vorbis_comment_add_tag(&s->vc, "encoder", LIBAVCODEC_IDENT);
234 
235  if ((ret = vorbis_analysis_headerout(&s->vd, &s->vc, &header, &header_comm,
236  &header_code))) {
238  goto error;
239  }
240 
241  avctx->extradata_size = 1 + xiph_len(header.bytes) +
242  xiph_len(header_comm.bytes) +
243  header_code.bytes;
244  p = avctx->extradata = av_malloc(avctx->extradata_size +
246  if (!p) {
247  ret = AVERROR(ENOMEM);
248  goto error;
249  }
250  p[0] = 2;
251  offset = 1;
252  offset += av_xiphlacing(&p[offset], header.bytes);
253  offset += av_xiphlacing(&p[offset], header_comm.bytes);
254  memcpy(&p[offset], header.packet, header.bytes);
255  offset += header.bytes;
256  memcpy(&p[offset], header_comm.packet, header_comm.bytes);
257  offset += header_comm.bytes;
258  memcpy(&p[offset], header_code.packet, header_code.bytes);
259  offset += header_code.bytes;
260  av_assert0(offset == avctx->extradata_size);
261 
262  s->vp = av_vorbis_parse_init(avctx->extradata, avctx->extradata_size);
263  if (!s->vp) {
264  av_log(avctx, AV_LOG_ERROR, "invalid extradata\n");
265  return ret;
266  }
267 
268  vorbis_comment_clear(&s->vc);
269 
271  ff_af_queue_init(avctx, &s->afq);
272 
273  s->pkt_fifo = av_fifo_alloc(BUFFER_SIZE);
274  if (!s->pkt_fifo) {
275  ret = AVERROR(ENOMEM);
276  goto error;
277  }
278 
279  return 0;
280 error:
281  libvorbis_encode_close(avctx);
282  return ret;
283 }
284 
286  const AVFrame *frame, int *got_packet_ptr)
287 {
288  LibvorbisEncContext *s = avctx->priv_data;
289  ogg_packet op;
290  int ret, duration;
291 
292  /* send samples to libvorbis */
293  if (frame) {
294  const int samples = frame->nb_samples;
295  float **buffer;
296  int c, channels = s->vi.channels;
297 
298  buffer = vorbis_analysis_buffer(&s->vd, samples);
299  for (c = 0; c < channels; c++) {
300  int co = (channels > 8) ? c :
302  memcpy(buffer[c], frame->extended_data[co],
303  samples * sizeof(*buffer[c]));
304  }
305  if ((ret = vorbis_analysis_wrote(&s->vd, samples)) < 0) {
306  av_log(avctx, AV_LOG_ERROR, "error in vorbis_analysis_wrote()\n");
308  }
309  if ((ret = ff_af_queue_add(&s->afq, frame)) < 0)
310  return ret;
311  } else {
312  if (!s->eof && s->afq.frame_alloc)
313  if ((ret = vorbis_analysis_wrote(&s->vd, 0)) < 0) {
314  av_log(avctx, AV_LOG_ERROR, "error in vorbis_analysis_wrote()\n");
316  }
317  s->eof = 1;
318  }
319 
320  /* retrieve available packets from libvorbis */
321  while ((ret = vorbis_analysis_blockout(&s->vd, &s->vb)) == 1) {
322  if ((ret = vorbis_analysis(&s->vb, NULL)) < 0)
323  break;
324  if ((ret = vorbis_bitrate_addblock(&s->vb)) < 0)
325  break;
326 
327  /* add any available packets to the output packet buffer */
328  while ((ret = vorbis_bitrate_flushpacket(&s->vd, &op)) == 1) {
329  if (av_fifo_space(s->pkt_fifo) < sizeof(ogg_packet) + op.bytes) {
330  av_log(avctx, AV_LOG_ERROR, "packet buffer is too small\n");
331  return AVERROR_BUG;
332  }
333  av_fifo_generic_write(s->pkt_fifo, &op, sizeof(ogg_packet), NULL);
334  av_fifo_generic_write(s->pkt_fifo, op.packet, op.bytes, NULL);
335  }
336  if (ret < 0) {
337  av_log(avctx, AV_LOG_ERROR, "error getting available packets\n");
338  break;
339  }
340  }
341  if (ret < 0) {
342  av_log(avctx, AV_LOG_ERROR, "error getting available packets\n");
344  }
345 
346  /* check for available packets */
347  if (av_fifo_size(s->pkt_fifo) < sizeof(ogg_packet))
348  return 0;
349 
350  av_fifo_generic_read(s->pkt_fifo, &op, sizeof(ogg_packet), NULL);
351 
352  if ((ret = ff_alloc_packet2(avctx, avpkt, op.bytes, 0)) < 0)
353  return ret;
354  av_fifo_generic_read(s->pkt_fifo, avpkt->data, op.bytes, NULL);
355 
356  avpkt->pts = ff_samples_to_time_base(avctx, op.granulepos);
357 
358  duration = av_vorbis_parse_frame(s->vp, avpkt->data, avpkt->size);
359  if (duration > 0) {
360  /* we do not know encoder delay until we get the first packet from
361  * libvorbis, so we have to update the AudioFrameQueue counts */
362  if (!avctx->initial_padding && s->afq.frames) {
363  avctx->initial_padding = duration;
364  av_assert0(!s->afq.remaining_delay);
365  s->afq.frames->duration += duration;
366  if (s->afq.frames->pts != AV_NOPTS_VALUE)
367  s->afq.frames->pts -= duration;
368  s->afq.remaining_samples += duration;
369  }
370  ff_af_queue_remove(&s->afq, duration, &avpkt->pts, &avpkt->duration);
371  }
372 
373  *got_packet_ptr = 1;
374  return 0;
375 }
376 
378  .name = "libvorbis",
379  .long_name = NULL_IF_CONFIG_SMALL("libvorbis"),
380  .type = AVMEDIA_TYPE_AUDIO,
381  .id = AV_CODEC_ID_VORBIS,
382  .priv_data_size = sizeof(LibvorbisEncContext),
384  .encode2 = libvorbis_encode_frame,
385  .close = libvorbis_encode_close,
387  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
389  .priv_class = &vorbis_class,
390  .defaults = defaults,
391  .wrapper_name = "libvorbis",
392 };
error
static void error(const char *err)
Definition: target_bsf_fuzzer.c:30
AVCodecContext::frame_size
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:1216
AVCodec
AVCodec.
Definition: codec.h:197
AV_SAMPLE_FMT_FLTP
@ AV_SAMPLE_FMT_FLTP
float, planar
Definition: samplefmt.h:69
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:200
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:50
AV_CH_LAYOUT_5POINT0_BACK
#define AV_CH_LAYOUT_5POINT0_BACK
Definition: channel_layout.h:102
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
av_vorbis_parse_free
void av_vorbis_parse_free(AVVorbisParseContext **s)
Free the parser and everything associated with it.
Definition: vorbis_parser.c:276
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
av_xiphlacing
unsigned int av_xiphlacing(unsigned char *s, unsigned int v)
Encode extradata length to a buffer.
Definition: utils.c:883
LIBAVCODEC_IDENT
#define LIBAVCODEC_IDENT
Definition: version.h:42
AVCodecContext::channel_layout
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:1247
av_fifo_generic_write
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:122
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:1196
AVVorbisParseContext
Definition: vorbis_parser_internal.h:34
AVCodecContext::rc_min_rate
int64_t rc_min_rate
minimum bitrate
Definition: avcodec.h:1423
defaults
static const AVCodecDefault defaults[]
Definition: libvorbisenc.c:61
ff_af_queue_close
void ff_af_queue_close(AudioFrameQueue *afq)
Close AudioFrameQueue.
Definition: audio_frame_queue.c:36
sample_fmts
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:925
AV_CODEC_FLAG_QSCALE
#define AV_CODEC_FLAG_QSCALE
Use fixed qscale.
Definition: avcodec.h:275
ff_af_queue_init
av_cold void ff_af_queue_init(AVCodecContext *avctx, AudioFrameQueue *afq)
Initialize AudioFrameQueue.
Definition: audio_frame_queue.c:28
vorbis_class
static const AVClass vorbis_class
Definition: libvorbisenc.c:66
av_get_channel_layout_string
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.
Definition: channel_layout.c:217
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:318
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:369
AVOption
AVOption.
Definition: opt.h:248
libvorbis_setup
static av_cold int libvorbis_setup(vorbis_info *vi, AVCodecContext *avctx)
Definition: libvorbisenc.c:94
LIBVORBIS_FRAME_SIZE
#define LIBVORBIS_FRAME_SIZE
Definition: libvorbisenc.c:38
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:264
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:387
av_fifo_generic_read
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:213
AVERROR_UNKNOWN
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:71
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:31
AVFifoBuffer
Definition: fifo.h:31
fifo.h
audio_frame_queue.h
AVCodecContext::initial_padding
int initial_padding
Audio only.
Definition: avcodec.h:2062
options
static const AVOption options[]
Definition: libvorbisenc.c:56
AVCodecContext::flags
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:616
ff_libvorbis_encoder
AVCodec ff_libvorbis_encoder
Definition: libvorbisenc.c:377
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:498
AV_CH_LAYOUT_STEREO
#define AV_CH_LAYOUT_STEREO
Definition: channel_layout.h:91
LibvorbisEncContext::av_class
AVClass * av_class
class for AVOptions
Definition: libvorbisenc.c:43
LibvorbisEncContext::vi
vorbis_info vi
vorbis_info used during init
Definition: libvorbisenc.c:44
AV_CH_LAYOUT_QUAD
#define AV_CH_LAYOUT_QUAD
Definition: channel_layout.h:99
libvorbis_encode_frame
static int libvorbis_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)
Definition: libvorbisenc.c:285
avassert.h
ff_samples_to_time_base
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:277
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
av_fifo_space
int av_fifo_space(const 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:82
av_cold
#define av_cold
Definition: attributes.h:90
duration
int64_t duration
Definition: movenc.c:64
AVCodecContext::extradata_size
int extradata_size
Definition: avcodec.h:638
s
#define s(width, name)
Definition: cbs_vp9.c:257
AVCodecContext::global_quality
int global_quality
Global quality for codecs which cannot change it per frame.
Definition: avcodec.h:602
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:278
libvorbis_encode_close
static av_cold int libvorbis_encode_close(AVCodecContext *avctx)
Definition: libvorbisenc.c:185
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:75
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:33
AVCodecContext::rc_max_rate
int64_t rc_max_rate
maximum bitrate
Definition: avcodec.h:1416
AV_OPT_FLAG_AUDIO_PARAM
#define AV_OPT_FLAG_AUDIO_PARAM
Definition: opt.h:280
AVCodecDefault
Definition: internal.h:222
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:67
NULL
#define NULL
Definition: coverity.c:32
AVCodecContext::bit_rate
int64_t bit_rate
the average bitrate
Definition: avcodec.h:586
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
AV_CH_LAYOUT_5POINT1
#define AV_CH_LAYOUT_5POINT1
Definition: channel_layout.h:101
vorbis_parser.h
AV_CH_FRONT_CENTER
#define AV_CH_FRONT_CENTER
Definition: channel_layout.h:51
LibvorbisEncContext::afq
AudioFrameQueue afq
frame queue for timestamps
Definition: libvorbisenc.c:53
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
AVPacket::size
int size
Definition: packet.h:370
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
AV_SAMPLE_FMT_NONE
@ AV_SAMPLE_FMT_NONE
Definition: samplefmt.h:59
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
LibvorbisEncContext::vb
vorbis_block vb
vorbis_block used for analysis
Definition: libvorbisenc.c:46
LibvorbisEncContext::vp
AVVorbisParseContext * vp
parse context to get durations
Definition: libvorbisenc.c:52
header
static const uint8_t header[24]
Definition: sdr2.c:67
BUFFER_SIZE
#define BUFFER_SIZE
Definition: libvorbisenc.c:40
LibvorbisEncContext
Definition: libvorbisenc.c:42
xiph_len
static int xiph_len(int l)
Definition: libvorbisenc.c:180
AV_CH_LAYOUT_5POINT1_BACK
#define AV_CH_LAYOUT_5POINT1_BACK
Definition: channel_layout.h:103
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:84
AVCodecContext::channels
int channels
number of audio channels
Definition: avcodec.h:1197
AV_CH_LAYOUT_5POINT0
#define AV_CH_LAYOUT_5POINT0
Definition: channel_layout.h:100
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:362
vorbis.h
AVCodecContext::extradata
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:637
AVCodecContext::cutoff
int cutoff
Audio cutoff bandwidth (0 means "automatic")
Definition: avcodec.h:1240
vorbis_encoding_channel_layout_offsets
static const uint8_t vorbis_encoding_channel_layout_offsets[8][8]
Definition: libvorbisenc.c:73
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
AV_CH_LAYOUT_7POINT1
#define AV_CH_LAYOUT_7POINT1
Definition: channel_layout.h:112
AV_CH_BACK_CENTER
#define AV_CH_BACK_CENTER
Definition: channel_layout.h:57
uint8_t
uint8_t
Definition: audio_convert.c:194
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:204
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:72
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:281
LibvorbisEncContext::eof
int eof
end-of-file flag
Definition: libvorbisenc.c:48
libvorbis_encode_init
static av_cold int libvorbis_encode_init(AVCodecContext *avctx)
Definition: libvorbisenc.c:206
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: avcodec.h:215
AVCodecContext
main external API structure.
Definition: avcodec.h:536
LibvorbisEncContext::iblock
double iblock
impulse block bias option
Definition: libvorbisenc.c:51
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
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:77
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:49
AV_CODEC_FLAG_BITEXACT
#define AV_CODEC_FLAG_BITEXACT
Use only bitexact stuff (except (I)DCT).
Definition: avcodec.h:333
av_fifo_size
int av_fifo_size(const 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:77
av_fifo_freep
void av_fifo_freep(AVFifoBuffer **f)
Free an AVFifoBuffer and reset pointer to NULL.
Definition: fifo.c:63
AVPacket
This structure stores compressed data.
Definition: packet.h:346
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:563
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
av_fifo_alloc
AVFifoBuffer * av_fifo_alloc(unsigned int size)
Initialize an AVFifoBuffer.
Definition: fifo.c:43
AVERROR_BUG
#define AVERROR_BUG
Internal bug, also see AVERROR_BUG2.
Definition: error.h:50
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AV_CODEC_ID_VORBIS
@ AV_CODEC_ID_VORBIS
Definition: codec_id.h:429
FF_QP2LAMBDA
#define FF_QP2LAMBDA
factor to convert from H.263 QP to lambda
Definition: avutil.h:227
LibvorbisEncContext::pkt_fifo
AVFifoBuffer * pkt_fifo
output packet buffer
Definition: libvorbisenc.c:47
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:82
ff_alloc_packet2
int ff_alloc_packet2(AVCodecContext *avctx, AVPacket *avpkt, int64_t size, int64_t min_size)
Check AVPacket size and/or allocate data.
Definition: encode.c:33
LibvorbisEncContext::vd
vorbis_dsp_state vd
DSP state used for analysis
Definition: libvorbisenc.c:45
AV_CH_LAYOUT_2_2
#define AV_CH_LAYOUT_2_2
Definition: channel_layout.h:98