[Cin] Any chance of adding FFMPeg's 'atempo' filter ?

[gorge rankin]

For what it's worth, here on Ubuntu 21.04 :

ldd /usr/bin/ffmpeg |igrep rubber:
librubberband.so.2 => /lib/x86_64-linux-gnu/librubberband.so.2

dpkg -l ffmpeg:
Desired=Unknown/Install/Remove/Purge/Hold
|
Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name           Version                  Architecture Description
+++-==============-========================-============-================================================================
ii  ffmpeg         7:4.3.2-0+deb11u1ubuntu1 amd64        Tools for
transcoding, streaming and playing of multimedia files



On Sat, Jun 19, 2021 at 4:28 PM Andrew Randrianasulu via Cin <
cin at lists.cinelerra-gg.org> wrote:

>
>
> On Saturday, June 19, 2021, Andrew Randrianasulu <randrianasulu at gmail.com>
> wrote:
>
>>
>>
>> On Saturday, June 19, 2021, Phyllis Smith via Cin <
>> cin at lists.cinelerra-gg.org> wrote:
>>
>>> Gorge,
>>> About crashing:
>>>
>>> That's odd, it's a tweaked version
>>>>
>>> Not the main.cpp program but the F_atempo plugin inside of Cinelerra.
>>> Andrea is much more expert at testing the
>>> ffmpeg plugins and it did not crash for him as stated in his email.  I
>>> did get the plugin to not crash but I do not know
>>> what it is doing.
>>>
>>
>>
>> random internet search says:
>>
>> The parameter for atempo must be between 0.5 and 2.0. If you want to slow
>> it down even more, you can use the atempo filter more than once.
>> Eg. to slow it down by 4:
>> ffmpeg -i input.mp4 -filter:a "atempo=0.5,atempo=0.5" -vn output.aac
>>
>>
>>
>> https://muzso.hu/2015/04/25/how-to-speed-up-slow-down-an-audio-stream-with-ffmpeg
>>
>>
> more random internet search unearth those finds:
>
>
>
> https://patchwork.ffmpeg.org/project/ffmpeg/patch/20171202191342.25358-1-onemda@gmail.com/#21029
>
> adds scaletempo filter, probably not in mainstream due to discussion about
> how useful or not this new filter might be.
>
> for rubberband apparently you need librubberband installed and pass
> configuration flag to ffmpeg (cingg's build system allow this)
> ----
> Apply time-stretching and pitch-shifting with librubberband.
>
> To enable compilation of this filter, you need to configure FFmpeg with
> --enable-librubberband.
> ----
>
>
>>
>>
>>
>>
>>>
>>>> When it runs , a terminal comes up to show you the technical info.  But
>>>> the outfile is created.
>>>>
>>> I am still trying to compile the program because I have to put the
>>> include <libavcodec/avcodec.h>  in the right place.
>>> Then I will test it.  ...Phyllis
>>>
>> --
> Cin mailing list
> Cin at lists.cinelerra-gg.org
> https://lists.cinelerra-gg.org/mailman/listinfo/cin
>
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