avfilter/af_apad: do not add infinite silence for zero pad_dur or whole_dur

Unfortunately pad_len and pad_dur behaviour was different if 0 was specified,
pad_dur handled 0 duration as infinity, for pad_len, infinity was -1.

Let's make the behaviour consistent by handling 0 duration for pad_dur and
whole_dur as indeed 0 duration. This somewhat changes the behaviour of the
filter if 0 was explicitly specified, but deprecating the old option and adding
a new for the corrected behaviour seemed a bit overkill. So let's document the
change instead.

Signed-off-by: Marton Balint <cus@passwd.hu>
This commit is contained in:
Marton Balint 2021-07-28 23:53:42 +02:00
parent 97c3053d59
commit 0a9edac48e
3 changed files with 10 additions and 7 deletions

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@ -2291,12 +2291,12 @@ with @option{pad_len}.
@item pad_dur
Specify the duration of samples of silence to add. See
@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
for the accepted syntax. Used only if set to non-zero value.
for the accepted syntax. Used only if set to non-negative value.
@item whole_dur
Specify the minimum total duration in the output audio stream. See
@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
for the accepted syntax. Used only if set to non-zero value. If the value is longer than
for the accepted syntax. Used only if set to non-negative value. If the value is longer than
the input audio length, silence is added to the end, until the value is reached.
This option is mutually exclusive with @option{pad_dur}
@end table
@ -2305,6 +2305,9 @@ If neither the @option{pad_len} nor the @option{whole_len} nor @option{pad_dur}
nor @option{whole_dur} option is set, the filter will add silence to the end of
the input stream indefinitely.
Note that for ffmpeg 4.4 and earlier a zero @option{pad_dur} or
@option{whole_dur} also caused the filter to add silence indefinitely.
@subsection Examples
@itemize

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@ -52,8 +52,8 @@ static const AVOption apad_options[] = {
{ "packet_size", "set silence packet size", OFFSET(packet_size), AV_OPT_TYPE_INT, { .i64 = 4096 }, 0, INT_MAX, A },
{ "pad_len", "set number of samples of silence to add", OFFSET(pad_len), AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, A },
{ "whole_len", "set minimum target number of samples in the audio stream", OFFSET(whole_len), AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, A },
{ "pad_dur", "set duration of silence to add", OFFSET(pad_dur), AV_OPT_TYPE_DURATION, { .i64 = 0 }, 0, INT64_MAX, A },
{ "whole_dur", "set minimum target duration in the audio stream", OFFSET(whole_dur), AV_OPT_TYPE_DURATION, { .i64 = 0 }, 0, INT64_MAX, A },
{ "pad_dur", "set duration of silence to add", OFFSET(pad_dur), AV_OPT_TYPE_DURATION, { .i64 = -1 }, -1, INT64_MAX, A },
{ "whole_dur", "set minimum target duration in the audio stream", OFFSET(whole_dur), AV_OPT_TYPE_DURATION, { .i64 = -1 }, -1, INT64_MAX, A },
{ NULL }
};
@ -138,9 +138,9 @@ static int config_output(AVFilterLink *outlink)
AVFilterContext *ctx = outlink->src;
APadContext *s = ctx->priv;
if (s->pad_dur)
if (s->pad_dur >= 0)
s->pad_len = av_rescale(s->pad_dur, outlink->sample_rate, AV_TIME_BASE);
if (s->whole_dur)
if (s->whole_dur >= 0)
s->whole_len = av_rescale(s->whole_dur, outlink->sample_rate, AV_TIME_BASE);
s->pad_len_left = s->pad_len;

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@ -31,7 +31,7 @@
#define LIBAVFILTER_VERSION_MAJOR 8
#define LIBAVFILTER_VERSION_MINOR 16
#define LIBAVFILTER_VERSION_MICRO 101
#define LIBAVFILTER_VERSION_MICRO 102
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \