FFmpeg: libavfilter/af_aresample.c Source File

FFmpeg
af_aresample.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2011 Stefano Sabatini
3  * Copyright (c) 2011 Mina Nagy Zaki
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 /**
23  * @file
24  * resampling audio filter
25  */
26 
27 #include "libavutil/avstring.h"
28 #include "libavutil/channel_layout.h"
29 #include "libavutil/opt.h"
30 #include "libavutil/samplefmt.h"
31 #include "libavutil/avassert.h"
32 #include "libswresample/swresample.h"
33 #include "avfilter.h"
34 #include "audio.h"
35 #include "internal.h"
36 
37  typedef struct AResampleContext {
38   const AVClass *class;
39   int sample_rate_arg;
40   double ratio;
41   struct SwrContext *swr;
42   int64_t next_pts;
43   int more_data;
44 } AResampleContext;
45 
46  static av_cold int preinit(AVFilterContext *ctx)
47 {
48  AResampleContext *aresample = ctx->priv;
49 
50  aresample->next_pts = AV_NOPTS_VALUE;
51  aresample->swr = swr_alloc();
52  if (!aresample->swr)
53  return AVERROR(ENOMEM);
54 
55  return 0;
56 }
57 
58  static av_cold void uninit(AVFilterContext *ctx)
59 {
60  AResampleContext *aresample = ctx->priv;
61  swr_free(&aresample->swr);
62 }
63 
64  static int query_formats(AVFilterContext *ctx)
65 {
66  AResampleContext *aresample = ctx->priv;
67  enum AVSampleFormat out_format;
68  AVChannelLayout out_layout = { 0 };
69  int64_t out_rate;
70 
71  AVFilterLink *inlink = ctx->inputs[0];
72  AVFilterLink *outlink = ctx->outputs[0];
73 
74  AVFilterFormats *in_formats, *out_formats;
75  AVFilterFormats *in_samplerates, *out_samplerates;
76  AVFilterChannelLayouts *in_layouts, *out_layouts;
77  int ret;
78 
79  if (aresample->sample_rate_arg > 0)
80  av_opt_set_int(aresample->swr, "osr", aresample->sample_rate_arg, 0);
81  av_opt_get_sample_fmt(aresample->swr, "osf", 0, &out_format);
82  av_opt_get_int(aresample->swr, "osr", 0, &out_rate);
83 
84  in_formats = ff_all_formats(AVMEDIA_TYPE_AUDIO);
85  if ((ret = ff_formats_ref(in_formats, &inlink->outcfg.formats)) < 0)
86  return ret;
87 
88  in_samplerates = ff_all_samplerates();
89  if ((ret = ff_formats_ref(in_samplerates, &inlink->outcfg.samplerates)) < 0)
90  return ret;
91 
92  in_layouts = ff_all_channel_counts();
93  if ((ret = ff_channel_layouts_ref(in_layouts, &inlink->outcfg.channel_layouts)) < 0)
94  return ret;
95 
96  if(out_rate > 0) {
97  int ratelist[] = { out_rate, -1 };
98  out_samplerates = ff_make_format_list(ratelist);
99  } else {
100  out_samplerates = ff_all_samplerates();
101  }
102 
103  if ((ret = ff_formats_ref(out_samplerates, &outlink->incfg.samplerates)) < 0)
104  return ret;
105 
106  if(out_format != AV_SAMPLE_FMT_NONE) {
107  int formatlist[] = { out_format, -1 };
108  out_formats = ff_make_format_list(formatlist);
109  } else
110  out_formats = ff_all_formats(AVMEDIA_TYPE_AUDIO);
111  if ((ret = ff_formats_ref(out_formats, &outlink->incfg.formats)) < 0)
112  return ret;
113 
114  av_opt_get_chlayout(aresample->swr, "ochl", 0, &out_layout);
115  if (av_channel_layout_check(&out_layout)) {
116  const AVChannelLayout layout_list[] = { out_layout, { 0 } };
117  out_layouts = ff_make_channel_layout_list(layout_list);
118  } else
119  out_layouts = ff_all_channel_counts();
120  av_channel_layout_uninit(&out_layout);
121 
122  return ff_channel_layouts_ref(out_layouts, &outlink->incfg.channel_layouts);
123 }
124 
125 
126  static int config_output(AVFilterLink *outlink)
127 {
128  int ret;
129  AVFilterContext *ctx = outlink->src;
130  AVFilterLink *inlink = ctx->inputs[0];
131  AResampleContext *aresample = ctx->priv;
132  AVChannelLayout out_layout = { 0 };
133  int64_t out_rate;
134  enum AVSampleFormat out_format;
135  char inchl_buf[128], outchl_buf[128];
136 
137  ret = swr_alloc_set_opts2(&aresample->swr,
138  &outlink->ch_layout, outlink->format, outlink->sample_rate,
139  &inlink->ch_layout, inlink->format, inlink->sample_rate,
140  0, ctx);
141  if (ret < 0)
142  return ret;
143 
144  ret = swr_init(aresample->swr);
145  if (ret < 0)
146  return ret;
147 
148  av_opt_get_int(aresample->swr, "osr", 0, &out_rate);
149  av_opt_get_chlayout(aresample->swr, "ochl", 0, &out_layout);
150  av_opt_get_sample_fmt(aresample->swr, "osf", 0, &out_format);
151  outlink->time_base = (AVRational) {1, out_rate};
152 
153  av_assert0(outlink->sample_rate == out_rate);
154  av_assert0(!av_channel_layout_compare(&outlink->ch_layout, &out_layout));
155  av_assert0(outlink->format == out_format);
156 
157  av_channel_layout_uninit(&out_layout);
158 
159  aresample->ratio = (double)outlink->sample_rate / inlink->sample_rate;
160 
161  av_channel_layout_describe(&inlink ->ch_layout, inchl_buf, sizeof(inchl_buf));
162  av_channel_layout_describe(&outlink->ch_layout, outchl_buf, sizeof(outchl_buf));
163 
164  av_log(ctx, AV_LOG_VERBOSE, "ch:%d chl:%s fmt:%s r:%dHz -> ch:%d chl:%s fmt:%s r:%dHz\n",
165  inlink ->ch_layout.nb_channels, inchl_buf, av_get_sample_fmt_name(inlink->format), inlink->sample_rate,
166  outlink->ch_layout.nb_channels, outchl_buf, av_get_sample_fmt_name(outlink->format), outlink->sample_rate);
167  return 0;
168 }
169 
170  static int filter_frame(AVFilterLink *inlink, AVFrame *insamplesref)
171 {
172  AResampleContext *aresample = inlink->dst->priv;
173  const int n_in = insamplesref->nb_samples;
174  int64_t delay;
175  int n_out = n_in * aresample->ratio + 32;
176  AVFilterLink *const outlink = inlink->dst->outputs[0];
177  AVFrame *outsamplesref;
178  int ret;
179 
180  delay = swr_get_delay(aresample->swr, outlink->sample_rate);
181  if (delay > 0)
182  n_out += FFMIN(delay, FFMAX(4096, n_out));
183 
184  outsamplesref = ff_get_audio_buffer(outlink, n_out);
185 
186  if(!outsamplesref) {
187  av_frame_free(&insamplesref);
188  return AVERROR(ENOMEM);
189  }
190 
191  av_frame_copy_props(outsamplesref, insamplesref);
192  outsamplesref->format = outlink->format;
193 #if FF_API_OLD_CHANNEL_LAYOUT
194 FF_DISABLE_DEPRECATION_WARNINGS
195  outsamplesref->channels = outlink->ch_layout.nb_channels;
196  outsamplesref->channel_layout = outlink->channel_layout;
197 FF_ENABLE_DEPRECATION_WARNINGS
198 #endif
199  ret = av_channel_layout_copy(&outsamplesref->ch_layout, &outlink->ch_layout);
200  if (ret < 0)
201  return ret;
202  outsamplesref->sample_rate = outlink->sample_rate;
203 
204  if(insamplesref->pts != AV_NOPTS_VALUE) {
205  int64_t inpts = av_rescale(insamplesref->pts, inlink->time_base.num * (int64_t)outlink->sample_rate * inlink->sample_rate, inlink->time_base.den);
206  int64_t outpts= swr_next_pts(aresample->swr, inpts);
207  aresample->next_pts =
208  outsamplesref->pts = ROUNDED_DIV(outpts, inlink->sample_rate);
209  } else {
210  outsamplesref->pts = AV_NOPTS_VALUE;
211  }
212  n_out = swr_convert(aresample->swr, outsamplesref->extended_data, n_out,
213  (void *)insamplesref->extended_data, n_in);
214  if (n_out <= 0) {
215  av_frame_free(&outsamplesref);
216  av_frame_free(&insamplesref);
217  return 0;
218  }
219 
220  aresample->more_data = outsamplesref->nb_samples == n_out; // Indicate that there is probably more data in our buffers
221 
222  outsamplesref->nb_samples = n_out;
223 
224  ret = ff_filter_frame(outlink, outsamplesref);
225  av_frame_free(&insamplesref);
226  return ret;
227 }
228 
229  static int flush_frame(AVFilterLink *outlink, int final, AVFrame **outsamplesref_ret)
230 {
231  AVFilterContext *ctx = outlink->src;
232  AResampleContext *aresample = ctx->priv;
233  AVFilterLink *const inlink = outlink->src->inputs[0];
234  AVFrame *outsamplesref;
235  int n_out = 4096;
236  int64_t pts;
237 
238  outsamplesref = ff_get_audio_buffer(outlink, n_out);
239  *outsamplesref_ret = outsamplesref;
240  if (!outsamplesref)
241  return AVERROR(ENOMEM);
242 
243  pts = swr_next_pts(aresample->swr, INT64_MIN);
244  pts = ROUNDED_DIV(pts, inlink->sample_rate);
245 
246  n_out = swr_convert(aresample->swr, outsamplesref->extended_data, n_out, final ? NULL : (void*)outsamplesref->extended_data, 0);
247  if (n_out <= 0) {
248  av_frame_free(&outsamplesref);
249  return (n_out == 0) ? AVERROR_EOF : n_out;
250  }
251 
252  outsamplesref->sample_rate = outlink->sample_rate;
253  outsamplesref->nb_samples = n_out;
254 
255  outsamplesref->pts = pts;
256 
257  return 0;
258 }
259 
260  static int request_frame(AVFilterLink *outlink)
261 {
262  AVFilterContext *ctx = outlink->src;
263  AResampleContext *aresample = ctx->priv;
264  int ret;
265 
266  // First try to get data from the internal buffers
267  if (aresample->more_data) {
268  AVFrame *outsamplesref;
269 
270  if (flush_frame(outlink, 0, &outsamplesref) >= 0) {
271  return ff_filter_frame(outlink, outsamplesref);
272  }
273  }
274  aresample->more_data = 0;
275 
276  // Second request more data from the input
277  ret = ff_request_frame(ctx->inputs[0]);
278 
279  // Third if we hit the end flush
280  if (ret == AVERROR_EOF) {
281  AVFrame *outsamplesref;
282 
283  if ((ret = flush_frame(outlink, 1, &outsamplesref)) < 0)
284  return ret;
285 
286  return ff_filter_frame(outlink, outsamplesref);
287  }
288  return ret;
289 }
290 
291  static const AVClass *resample_child_class_iterate(void **iter)
292 {
293  const AVClass *c = *iter ? NULL : swr_get_class();
294  *iter = (void*)(uintptr_t)c;
295  return c;
296 }
297 
298  static void *resample_child_next(void *obj, void *prev)
299 {
300  AResampleContext *s = obj;
301  return prev ? NULL : s->swr;
302 }
303 
304  #define OFFSET(x) offsetof(AResampleContext, x)
305  #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
306 
307  static const AVOption options[] = {
308  {"sample_rate", NULL, OFFSET(sample_rate_arg), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS },
309  {NULL}
310 };
311 
312  static const AVClass aresample_class = {
313  .class_name = "aresample",
314  .item_name = av_default_item_name,
315  .option = options,
316  .version = LIBAVUTIL_VERSION_INT,
317  .child_class_iterate = resample_child_class_iterate,
318  .child_next = resample_child_next,
319 };
320 
321  static const AVFilterPad aresample_inputs[] = {
322  {
323  .name = "default",
324  .type = AVMEDIA_TYPE_AUDIO,
325  .filter_frame = filter_frame,
326  },
327 };
328 
329  static const AVFilterPad aresample_outputs[] = {
330  {
331  .name = "default",
332  .config_props = config_output,
333  .request_frame = request_frame,
334  .type = AVMEDIA_TYPE_AUDIO,
335  },
336 };
337 
338  const AVFilter ff_af_aresample = {
339  .name = "aresample",
340  .description = NULL_IF_CONFIG_SMALL("Resample audio data."),
341  .preinit = preinit,
342  .uninit = uninit,
343  .priv_size = sizeof(AResampleContext),
344  .priv_class = &aresample_class,
345  FILTER_INPUTS(aresample_inputs),
346  FILTER_OUTPUTS(aresample_outputs),
347  FILTER_QUERY_FUNC(query_formats),
348 };
ff_get_audio_buffer
AVFrame * ff_get_audio_buffer(AVFilterLink *link, int nb_samples)
Request an audio samples buffer with a specific set of permissions.
Definition: audio.c:100
FF_ENABLE_DEPRECATION_WARNINGS
#define FF_ENABLE_DEPRECATION_WARNINGS
Definition: internal.h:83
AVFilterChannelLayouts
A list of supported channel layouts.
Definition: formats.h:85
AVFilterFormatsConfig::samplerates
AVFilterFormats * samplerates
Lists of supported sample rates, only for audio.
Definition: avfilter.h:517
SwrContext::outpts
int64_t outpts
output PTS
Definition: swresample_internal.h:164
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
ff_make_format_list
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:380
AVFilterFormatsConfig::channel_layouts
AVFilterChannelLayouts * channel_layouts
Lists of supported channel layouts, only for audio.
Definition: avfilter.h:522
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:999
ff_channel_layouts_ref
int ff_channel_layouts_ref(AVFilterChannelLayouts *f, AVFilterChannelLayouts **ref)
Add *ref as a new reference to f.
Definition: formats.c:591
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
inlink
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
Definition: filter_design.txt:212
FLAGS
#define FLAGS
Definition: af_aresample.c:305
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:111
ff_all_channel_counts
AVFilterChannelLayouts * ff_all_channel_counts(void)
Construct an AVFilterChannelLayouts coding for any channel layout, with known or unknown disposition.
Definition: formats.c:566
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
AVFrame::pts
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:432
AVOption
AVOption.
Definition: opt.h:251
swr_alloc_set_opts2
int swr_alloc_set_opts2(struct SwrContext **ps, AVChannelLayout *out_ch_layout, enum AVSampleFormat out_sample_fmt, int out_sample_rate, AVChannelLayout *in_ch_layout, enum AVSampleFormat in_sample_fmt, int in_sample_rate, int log_offset, void *log_ctx)
Allocate SwrContext if needed and set/reset common parameters.
Definition: swresample.c:85
FILTER_QUERY_FUNC
#define FILTER_QUERY_FUNC(func)
Definition: internal.h:167
ff_request_frame
int ff_request_frame(AVFilterLink *link)
Request an input frame from the filter at the other end of the link.
Definition: avfilter.c:400
config_output
static int config_output(AVFilterLink *outlink)
Definition: af_aresample.c:126
AV_LOG_VERBOSE
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:196
preinit
static av_cold int preinit(AVFilterContext *ctx)
Definition: af_aresample.c:46
FFMAX
#define FFMAX(a, b)
Definition: macros.h:47
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:175
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:300
av_channel_layout_copy
int av_channel_layout_copy(AVChannelLayout *dst, const AVChannelLayout *src)
Make a copy of a channel layout.
Definition: channel_layout.c:637
AVFilterFormats
A list of supported formats for one end of a filter link.
Definition: formats.h:64
aresample_inputs
static const AVFilterPad aresample_inputs[]
Definition: af_aresample.c:321
samplefmt.h
AVFrame::ch_layout
AVChannelLayout ch_layout
Channel layout of the audio data.
Definition: frame.h:704
pts
static int64_t pts
Definition: transcode_aac.c:654
AVFrame::channels
attribute_deprecated int channels
number of audio channels, only used for audio.
Definition: frame.h:643
ff_all_formats
AVFilterFormats * ff_all_formats(enum AVMediaType type)
Return a list of all formats supported by FFmpeg for the given media type.
Definition: formats.c:480
swr_next_pts
int64_t swr_next_pts(struct SwrContext *s, int64_t pts)
Convert the next timestamp from input to output timestamps are in 1/(in_sample_rate * out_sample_rate...
Definition: swresample.c:1005
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:49
swr_get_delay
int64_t swr_get_delay(struct SwrContext *s, int64_t base)
Gets the delay the next input sample will experience relative to the next output sample.
Definition: swresample.c:955
options
static const AVOption options[]
Definition: af_aresample.c:307
avassert.h
resample_child_next
static void * resample_child_next(void *obj, void *prev)
Definition: af_aresample.c:298
av_cold
#define av_cold
Definition: attributes.h:90
AVFrame::channel_layout
attribute_deprecated uint64_t channel_layout
Channel layout of the audio data.
Definition: frame.h:510
swr_init
av_cold int swr_init(struct SwrContext *s)
Initialize context after user parameters have been set.
Definition: swresample.c:191
s
#define s(width, name)
Definition: cbs_vp9.c:256
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
ff_formats_ref
int ff_formats_ref(AVFilterFormats *f, AVFilterFormats **ref)
Add *ref as a new reference to formats.
Definition: formats.c:596
swr_alloc
av_cold struct SwrContext * swr_alloc(void)
Allocate SwrContext.
Definition: options.c:167
av_assert0
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
resample_child_class_iterate
static const AVClass * resample_child_class_iterate(void **iter)
Definition: af_aresample.c:291
ctx
AVFormatContext * ctx
Definition: movenc.c:48
av_get_sample_fmt_name
const char * av_get_sample_fmt_name(enum AVSampleFormat sample_fmt)
Return the name of sample_fmt, or NULL if sample_fmt is not recognized.
Definition: samplefmt.c:51
SwrContext
The libswresample context.
Definition: swresample_internal.h:95
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:190
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
av_frame_copy_props
int av_frame_copy_props(AVFrame *dst, const AVFrame *src)
Copy only "metadata" fields from src to dst.
Definition: frame.c:596
AResampleContext::sample_rate_arg
int sample_rate_arg
Definition: af_aresample.c:39
swr_get_class
const AVClass * swr_get_class(void)
Get the AVClass for SwrContext.
Definition: options.c:162
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVFilterContext::inputs
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:416
ROUNDED_DIV
#define ROUNDED_DIV(a, b)
Definition: common.h:48
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:237
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:930
av_opt_get_sample_fmt
int av_opt_get_sample_fmt(void *obj, const char *name, int search_flags, enum AVSampleFormat *out_fmt)
Definition: opt.c:1078
double
double
Definition: af_crystalizer.c:132
av_opt_get_int
int av_opt_get_int(void *obj, const char *name, int search_flags, int64_t *out_val)
Definition: opt.c:978
swresample.h
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_opt_set_int
int av_opt_set_int(void *obj, const char *name, int64_t val, int search_flags)
Definition: opt.c:624
av_channel_layout_uninit
void av_channel_layout_uninit(AVChannelLayout *channel_layout)
Free any allocated data in the channel layout and reset the channel count to 0.
Definition: channel_layout.c:630
uninit
static av_cold void uninit(AVFilterContext *ctx)
Definition: af_aresample.c:58
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
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:290
AVClass::child_next
void *(* child_next)(void *obj, void *prev)
Return next AVOptions-enabled child or NULL.
Definition: log.h:131
AVFrame::sample_rate
int sample_rate
Sample rate of the audio data.
Definition: frame.h:502
AV_SAMPLE_FMT_NONE
@ AV_SAMPLE_FMT_NONE
Definition: samplefmt.h:56
AResampleContext::ratio
double ratio
Definition: af_aresample.c:40
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
aresample_outputs
static const AVFilterPad aresample_outputs[]
Definition: af_aresample.c:329
swr_free
av_cold void swr_free(SwrContext **ss)
Free the given SwrContext and set the pointer to NULL.
Definition: swresample.c:173
swr_convert
int attribute_align_arg swr_convert(struct SwrContext *s, uint8_t **out_arg, int out_count, const uint8_t **in_arg, int in_count)
Convert audio.
Definition: swresample.c:800
AVFrame::format
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:412
AResampleContext
Definition: af_aresample.c:37
AResampleContext::swr
struct SwrContext * swr
Definition: af_aresample.c:41
internal.h
flush_frame
static int flush_frame(AVFilterLink *outlink, int final, AVFrame **outsamplesref_ret)
Definition: af_aresample.c:229
aresample_class
static const AVClass aresample_class
Definition: af_aresample.c:312
AVFrame::nb_samples
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:405
av_channel_layout_check
int av_channel_layout_check(const AVChannelLayout *channel_layout)
Check whether a channel layout is valid, i.e.
Definition: channel_layout.c:904
AVFrame::extended_data
uint8_t ** extended_data
pointers to the data planes/channels.
Definition: frame.h:386
OFFSET
#define OFFSET(x)
Definition: af_aresample.c:304
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:55
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *insamplesref)
Definition: af_aresample.c:170
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:55
av_rescale
int64_t av_rescale(int64_t a, int64_t b, int64_t c)
Rescale a 64-bit integer with rounding to nearest.
Definition: mathematics.c:129
AVFilter
Filter definition.
Definition: avfilter.h:171
AResampleContext::next_pts
int64_t next_pts
Definition: af_aresample.c:42
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
ff_all_samplerates
AVFilterFormats * ff_all_samplerates(void)
Definition: formats.c:551
channel_layout.h
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:225
avfilter.h
av_opt_get_chlayout
FF_ENABLE_DEPRECATION_WARNINGS int av_opt_get_chlayout(void *obj, const char *name, int search_flags, AVChannelLayout *cl)
Definition: opt.c:1104
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:776
AVFilterContext
An instance of a filter.
Definition: avfilter.h:408
FF_DISABLE_DEPRECATION_WARNINGS
#define FF_DISABLE_DEPRECATION_WARNINGS
Definition: internal.h:82
audio.h
AVFilterFormatsConfig::formats
AVFilterFormats * formats
List of supported formats (pixel or sample).
Definition: avfilter.h:512
query_formats
static int query_formats(AVFilterContext *ctx)
Definition: af_aresample.c:64
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:191
ff_af_aresample
const AVFilter ff_af_aresample
Definition: af_aresample.c:338
ff_make_channel_layout_list
AVFilterChannelLayouts * ff_make_channel_layout_list(const AVChannelLayout *fmts)
Definition: formats.c:389
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
request_frame
static int request_frame(AVFilterLink *outlink)
Definition: af_aresample.c:260
AResampleContext::more_data
int more_data
Definition: af_aresample.c:43
avstring.h
Generated on Wed Aug 24 2022 21:41:58 for FFmpeg by   doxygen 1.8.17

AltStyle によって変換されたページ (->オリジナル) /