Frame-accurate seekingin FFplay?

classic Classic list List threaded Threaded
2 messages Options
Reply | Threaded
Open this post in threaded view
|

Frame-accurate seekingin FFplay?

Stuart Bruce
Hello

I've been tasked with making a Python-based, cross-platform application
that centres around (but which is not limited to) a central video player
window. As a regular user of FFmpeg, I want to use FFplay, via the
ffpyplayer library.

However the problem I'm having is that while FFmpeg has had frame-accurate
seeking for some time, and I can accurately pull images or conversions of a
MOV file from FFmpeg, it seems that FFplay's seek is not frame accurate,
even on the same MOV file. Frame accuracy is absolutely essential to my
application, as users need to be able to jump or step to specific frames
with confidence. Presently, using ffpyplayer's seek function, or the Kivy
video library which is essentially a front end for ffpyplayer it seems,
tends to land me on the keyframe prior to the frame that I want- sometimes
up to 4 seconds out.

This question is likely to be out of my league, but how difficult would it
be to make FFplay frame accurate on the same principles as FFmpeg? I don't
imagine it's as simple as just lifting code from one into the other? Is
there a reason why this discrepancy between FFmpeg's ability and FFplay's
ability still exists?

This application is a rebuild of software that was using the QuickTime API
and then Microsoft's MediaElement, both of which are frame-accurate when
setting a position on the same MOV file.

If FFplay cannot work frame accurately, can anyone recommend an alternative
Pythonable video player library with frame-accurate control playback and
MOV support? (I've already tried VLC, but it is nowhere near frame accurate
either.)

Thanks

Stuart

--
Stuart Bruce - [hidden email] - www.stuartbruce.co.uk
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: Frame-accurate seekingin FFplay?

Paul B Mahol
On 9/23/19, Stuart Bruce <[hidden email]> wrote:

> Hello
>
> I've been tasked with making a Python-based, cross-platform application
> that centres around (but which is not limited to) a central video player
> window. As a regular user of FFmpeg, I want to use FFplay, via the
> ffpyplayer library.
>
> However the problem I'm having is that while FFmpeg has had frame-accurate
> seeking for some time, and I can accurately pull images or conversions of a
> MOV file from FFmpeg, it seems that FFplay's seek is not frame accurate,
> even on the same MOV file. Frame accuracy is absolutely essential to my
> application, as users need to be able to jump or step to specific frames
> with confidence. Presently, using ffpyplayer's seek function, or the Kivy
> video library which is essentially a front end for ffpyplayer it seems,
> tends to land me on the keyframe prior to the frame that I want- sometimes
> up to 4 seconds out.
>
> This question is likely to be out of my league, but how difficult would it
> be to make FFplay frame accurate on the same principles as FFmpeg? I don't
> imagine it's as simple as just lifting code from one into the other? Is
> there a reason why this discrepancy between FFmpeg's ability and FFplay's
> ability still exists?
>
> This application is a rebuild of software that was using the QuickTime API
> and then Microsoft's MediaElement, both of which are frame-accurate when
> setting a position on the same MOV file.
>
> If FFplay cannot work frame accurately, can anyone recommend an alternative
> Pythonable video player library with frame-accurate control playback and
> MOV support? (I've already tried VLC, but it is nowhere near frame accurate
> either.)

Try mpv.

>
> Thanks
>
> Stuart
>
> --
> Stuart Bruce - [hidden email] - www.stuartbruce.co.uk
> _______________________________________________
> ffmpeg-user mailing list
> [hidden email]
> https://ffmpeg.org/mailman/listinfo/ffmpeg-user
>
> To unsubscribe, visit link above, or email
> [hidden email] with subject "unsubscribe".
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".