| Message ID | 20180608021558.23862-1-pkoshevoy@gmail.com |
|---|---|
| State | Accepted |
| Commit | 29cddc99cd8302e462bbae572e885e88f63d6dc3 |
| Headers | show |
On Thu, Jun 7, 2018 at 8:16 PM Pavel Koshevoy <pkoshevoy@gmail.com> wrote: > > --- > doc/filters.texi | 17 ++++++++++++++--- > libavfilter/af_atempo.c | 6 +++--- > 2 files changed, 17 insertions(+), 6 deletions(-) > > diff --git a/doc/filters.texi b/doc/filters.texi > index 256ab42b00..6b98b04774 100644 > --- a/doc/filters.texi > +++ b/doc/filters.texi > @@ -1986,7 +1986,12 @@ Adjust audio tempo. > > The filter accepts exactly one parameter, the audio tempo. If not > specified then the filter will assume nominal 1.0 tempo. Tempo must > -be in the [0.5, 2.0] range. > +be in the [0.5, 100.0] range. > + > +Note that tempo greater than 2 will skip some samples rather than > +blend them in. If for any reason this is a concern it is always > +possible to daisy-chain several instances of atempo to achieve the > +desired product tempo. > > @subsection Examples > > @@ -1998,9 +2003,15 @@ atempo=0.8 > @end example > > @item > -To speed up audio to 125% tempo: > +To speed up audio to 300% tempo: > +@example > +atempo=3 > +@end example > + > +@item > +To speed up audio to 300% tempo by daisy-chaining two atempo instances: > @example > -atempo=1.25 > +atempo=sqrt(3),atempo=sqrt(3) > @end example > @end itemize > > diff --git a/libavfilter/af_atempo.c b/libavfilter/af_atempo.c > index 8b214bccd7..52f15f2769 100644 > --- a/libavfilter/af_atempo.c > +++ b/libavfilter/af_atempo.c > @@ -153,7 +153,7 @@ typedef struct ATempoContext { > > static const AVOption atempo_options[] = { > { "tempo", "set tempo scale factor", > - OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 2.0, > + OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 100.0, > AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM }, > { NULL } > }; > @@ -439,8 +439,8 @@ static int yae_load_data(ATempoContext *atempo, > return 0; > } > > - // samples are not expected to be skipped: > - av_assert0(read_size <= atempo->ring); > + // samples are not expected to be skipped, unless tempo is greater than 2: > + av_assert0(read_size <= atempo->ring || atempo->tempo > 2.0); > > while (atempo->position[0] < stop_here && src < src_end) { > int src_samples = (src_end - src) / atempo->stride; > -- > 2.16.4 > Any objections if I apply this? Pavel.
On 06/13/2018 07:39 AM, Pavel Koshevoy wrote: > On Thu, Jun 7, 2018 at 8:16 PM Pavel Koshevoy <pkoshevoy@gmail.com> wrote: >> --- >> doc/filters.texi | 17 ++++++++++++++--- >> libavfilter/af_atempo.c | 6 +++--- >> 2 files changed, 17 insertions(+), 6 deletions(-) >> >> diff --git a/doc/filters.texi b/doc/filters.texi >> index 256ab42b00..6b98b04774 100644 >> --- a/doc/filters.texi >> +++ b/doc/filters.texi >> @@ -1986,7 +1986,12 @@ Adjust audio tempo. >> >> The filter accepts exactly one parameter, the audio tempo. If not >> specified then the filter will assume nominal 1.0 tempo. Tempo must >> -be in the [0.5, 2.0] range. >> +be in the [0.5, 100.0] range. >> + >> +Note that tempo greater than 2 will skip some samples rather than >> +blend them in. If for any reason this is a concern it is always >> +possible to daisy-chain several instances of atempo to achieve the >> +desired product tempo. >> >> @subsection Examples >> >> @@ -1998,9 +2003,15 @@ atempo=0.8 >> @end example >> >> @item >> -To speed up audio to 125% tempo: >> +To speed up audio to 300% tempo: >> +@example >> +atempo=3 >> +@end example >> + >> +@item >> +To speed up audio to 300% tempo by daisy-chaining two atempo instances: >> @example >> -atempo=1.25 >> +atempo=sqrt(3),atempo=sqrt(3) >> @end example >> @end itemize >> >> diff --git a/libavfilter/af_atempo.c b/libavfilter/af_atempo.c >> index 8b214bccd7..52f15f2769 100644 >> --- a/libavfilter/af_atempo.c >> +++ b/libavfilter/af_atempo.c >> @@ -153,7 +153,7 @@ typedef struct ATempoContext { >> >> static const AVOption atempo_options[] = { >> { "tempo", "set tempo scale factor", >> - OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 2.0, >> + OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 100.0, >> AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM }, >> { NULL } >> }; >> @@ -439,8 +439,8 @@ static int yae_load_data(ATempoContext *atempo, >> return 0; >> } >> >> - // samples are not expected to be skipped: >> - av_assert0(read_size <= atempo->ring); >> + // samples are not expected to be skipped, unless tempo is greater than 2: >> + av_assert0(read_size <= atempo->ring || atempo->tempo > 2.0); >> >> while (atempo->position[0] < stop_here && src < src_end) { >> int src_samples = (src_end - src) / atempo->stride; >> -- >> 2.16.4 >> > > Any objections if I apply this? > > Pavel. Applied, pushed Pavel.
diff --git a/doc/filters.texi b/doc/filters.texi index 256ab42b00..6b98b04774 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -1986,7 +1986,12 @@ Adjust audio tempo. The filter accepts exactly one parameter, the audio tempo. If not specified then the filter will assume nominal 1.0 tempo. Tempo must -be in the [0.5, 2.0] range. +be in the [0.5, 100.0] range. + +Note that tempo greater than 2 will skip some samples rather than +blend them in. If for any reason this is a concern it is always +possible to daisy-chain several instances of atempo to achieve the +desired product tempo. @subsection Examples @@ -1998,9 +2003,15 @@ atempo=0.8 @end example @item -To speed up audio to 125% tempo: +To speed up audio to 300% tempo: +@example +atempo=3 +@end example + +@item +To speed up audio to 300% tempo by daisy-chaining two atempo instances: @example -atempo=1.25 +atempo=sqrt(3),atempo=sqrt(3) @end example @end itemize diff --git a/libavfilter/af_atempo.c b/libavfilter/af_atempo.c index 8b214bccd7..52f15f2769 100644 --- a/libavfilter/af_atempo.c +++ b/libavfilter/af_atempo.c @@ -153,7 +153,7 @@ typedef struct ATempoContext { static const AVOption atempo_options[] = { { "tempo", "set tempo scale factor", - OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 2.0, + OFFSET(tempo), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 0.5, 100.0, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM }, { NULL } }; @@ -439,8 +439,8 @@ static int yae_load_data(ATempoContext *atempo, return 0; } - // samples are not expected to be skipped: - av_assert0(read_size <= atempo->ring); + // samples are not expected to be skipped, unless tempo is greater than 2: + av_assert0(read_size <= atempo->ring || atempo->tempo > 2.0); while (atempo->position[0] < stop_here && src < src_end) { int src_samples = (src_end - src) / atempo->stride;