[FFmpeg-cvslog] avfilter/asrc_anullsrc: add support to set output duration
Paul B Mahol
git at videolan.org
Fri Sep 4 20:46:11 EEST 2020
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Fri Sep 4 18:30:46 2020 +0200| [615d75f291c6cc3057074245ab83cbd48187dfbc] | committer: Paul B Mahol
avfilter/asrc_anullsrc: add support to set output duration
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=615d75f291c6cc3057074245ab83cbd48187dfbc
---
doc/filters.texi | 7 +++++++
libavfilter/asrc_anullsrc.c | 7 +++++++
2 files changed, 14 insertions(+)
diff --git a/doc/filters.texi b/doc/filters.texi
index ebe0d3301e..d0ff3d470f 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -6076,6 +6076,13 @@ Specifies the sample rate, and defaults to 44100.
@item nb_samples, n
Set the number of samples per requested frames.
+ at item duration, d
+Set the duration of the sourced audio. See
+ at ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
+
+If not specified, or the expressed duration is negative, the audio is
+supposed to be generated forever.
@end table
@subsection Examples
diff --git a/libavfilter/asrc_anullsrc.c b/libavfilter/asrc_anullsrc.c
index 7093f08275..ab56d84424 100644
--- a/libavfilter/asrc_anullsrc.c
+++ b/libavfilter/asrc_anullsrc.c
@@ -40,6 +40,7 @@ typedef struct ANullContext {
uint64_t channel_layout;
char *sample_rate_str;
int sample_rate;
+ int64_t duration;
int nb_samples; ///< number of samples per requested frame
int64_t pts;
} ANullContext;
@@ -54,6 +55,8 @@ static const AVOption anullsrc_options[]= {
{ "r", "set sample rate", OFFSET(sample_rate_str) , AV_OPT_TYPE_STRING, {.str = "44100"}, 0, 0, FLAGS },
{ "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 0, INT_MAX, FLAGS },
{ "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 0, INT_MAX, FLAGS },
+ { "duration", "set the audio duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = -1}, -1, INT64_MAX, FLAGS },
+ { "d", "set the audio duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = -1}, -1, INT64_MAX, FLAGS },
{ NULL }
};
@@ -108,6 +111,10 @@ static int request_frame(AVFilterLink *outlink)
ANullContext *null = outlink->src->priv;
AVFrame *samplesref;
+ if (null->duration >= 0 &&
+ av_rescale_q(null->pts, outlink->time_base, AV_TIME_BASE_Q) >= null->duration)
+ return AVERROR_EOF;
+
samplesref = ff_get_audio_buffer(outlink, null->nb_samples);
if (!samplesref)
return AVERROR(ENOMEM);
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