49 int nb_samples, int64_t nb_samples_notify,
53 #define MAX_DURATION (24*3600*1000000LL) 54 #define OFFSET(x) offsetof(SilenceDetectContext, x) 55 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_AUDIO_PARAM 73 snprintf(key2,
sizeof(key2),
"lavfi.%s.%d", key, channel);
75 snprintf(key2,
sizeof(key2),
"lavfi.%s", key);
79 int is_silence,
int current_sample, int64_t nb_samples_notify,
84 if (s->
start[channel] == INT64_MIN) {
88 (
AVRational){ 1, s->last_sample_rate }, time_base);
89 set_meta(insamples, s->
mono ? channel + 1 : 0,
"silence_start",
98 if (s->
start[channel] > INT64_MIN) {
100 (
AVRational){ 1, s->last_sample_rate }, time_base)
104 set_meta(insamples, s->
mono ? channel + 1 : 0,
"silence_end",
106 set_meta(insamples, s->
mono ? channel + 1 : 0,
"silence_duration",
120 #define SILENCE_DETECT(name, type) \ 121 static void silencedetect_##name(SilenceDetectContext *s, AVFrame *insamples, \ 122 int nb_samples, int64_t nb_samples_notify, \ 123 AVRational time_base) \ 125 const type *p = (const type *)insamples->data[0]; \ 126 const type noise = s->noise; \ 129 for (i = 0; i < nb_samples; i++, p++) \ 130 update(s, insamples, *p < noise && *p > -noise, i, \ 131 nb_samples_notify, time_base); \ 155 s->
start[c] = INT64_MIN;
157 switch (inlink->format) {
161 s->
noise *= INT32_MAX;
165 s->
noise *= INT16_MAX;
192 s->
silencedetect(s, insamples, nb_samples, nb_samples_notify,
237 if (s->
start[c] > INT64_MIN)
262 .
name =
"silencedetect",
267 .
inputs = silencedetect_inputs,
268 .
outputs = silencedetect_outputs,
269 .priv_class = &silencedetect_class,
This structure describes decoded (raw) audio or video data.
Main libavfilter public API header.
int64_t frame_end
pts of the end of the current frame (used to compute duration of silence at EOS)
#define SILENCE_DETECT(name, type)
AVFilter ff_af_silencedetect
const char * name
Pad name.
static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
timestamp utils, mostly useful for debugging/logging purposes
static const AVFilterPad silencedetect_inputs[]
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
GLsizei GLboolean const GLfloat * value
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
AVDictionary * metadata
metadata.
A filter pad used for either input or output.
AVRational time_base
time_base
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
A link between two filters.
int sample_rate
samples per second
static const AVFilterPad silencedetect_outputs[]
static av_always_inline void update(SilenceDetectContext *s, AVFrame *insamples, int is_silence, int current_sample, int64_t nb_samples_notify, AVRational time_base)
#define av_ts2timestr(ts, tb)
Convenience macro, the return value should be used only directly in function arguments but never stan...
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
void * priv
private data for use by the filter
AVRational time_base
Define the time base used by the PTS of the frames/samples which will pass through this link...
int64_t duration
minimum duration of silence until notification
int64_t av_rescale(int64_t a, int64_t b, int64_t c)
Rescale a 64-bit integer with rounding to nearest.
#define AV_TIME_BASE
Internal time base represented as integer.
double noise
noise amplitude ratio
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
static int config_input(AVFilterLink *inlink)
static const AVFilterPad outputs[]
A list of supported channel layouts.
int channels
number of channels
void(* silencedetect)(struct SilenceDetectContext *s, AVFrame *insamples, int nb_samples, int64_t nb_samples_notify, AVRational time_base)
int independent_channels
number of entries in following arrays (always 1 in mono mode)
#define AV_LOG_INFO
Standard information.
int64_t * nb_null_samples
(array) current number of continuous zero samples
AVSampleFormat
Audio sample formats.
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 inputs
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
AVFILTER_DEFINE_CLASS(silencedetect)
int mono
mono mode : check each channel separately (default = check when ALL channels are silent) ...
Describe the class of an AVClass context structure.
Rational number (pair of numerator and denominator).
static int query_formats(AVFilterContext *ctx)
const char * name
Filter name.
AVFilterLink ** outputs
array of pointers to output links
enum MovChannelLayoutTag * layouts
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
channel
Use these values when setting the channel map with ebur128_set_channel().
int channels
Number of channels.
static const AVOption silencedetect_options[]
AVFilterContext * dst
dest filter
static av_cold void uninit(AVFilterContext *ctx)
static enum AVSampleFormat sample_fmts[]
static void set_meta(AVFrame *insamples, int channel, const char *key, char *value)
#define av_malloc_array(a, b)
int last_sample_rate
last sample rate to check for sample rate changes
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
int nb_samples
number of audio samples (per channel) described by this frame
int64_t * start
(array) if silence is detected, this value contains the time of the first zero sample (default/unset ...
void * av_mallocz_array(size_t nmemb, size_t size)