measuring av sync problem

[Carl Karsten]

On Sat, Jan 5, 2019 at 1:35 AM Carl Karsten <carl at personnelware.com> wrote:

> I'm trying to  provide tools and test scripts to diagnose and reproduce av
> sync problems in and around
> https://github.com/voc/voctomix
>
> I have a gst pipeline that sends in blip bop and can use my eyes and ears
> to observe the output, but I would rather have some code to the analysis.
>
> such a thing does exist, but I haven't been able to make it all work
> smoothly.
> create input file:
> https://www.mltframework.org/plugins/ProducerBlipflash/
> melt -profile hdv_720_30p blipflash out=90 -consumer avformat:blipflash.ts
> terminate_on_pause=1
> test:
> https://www.mltframework.org/plugins/ConsumerBlipflash/
> melt avformat:blipflash.ts -consumer blipflash:results.txt
> terminate_on_pause=1
> cat results.txt
> 0    0.00
> 30    0.00
> 60    0.00
> 90    0.00
>
> Each line is the frame the tone was detected, and how far off the flash is.
>
> does gst have anything like this?
>
> If one of the gst visualizers like spacescope could give me a full white
> frame on beep, that would get me most of the way there.
>
>
This gives me my white frame:
https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/merge_requests/130
but some of them get lost :(

quoting my MR:
"""I am seeing 46.88fps on a 30 fps stream, so I think many of the white
frames are getting lost.
I can make this work by playing with the new audiotestsrc parameters,
but maybe this blipbop generator should be written from scratch as a single
plugin that generates both.
"""

Can someone point me at some code that does a/v based on the system clock?



> --
> Carl K
>
>

-- 
Carl K
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/gstreamer-devel/attachments/20190106/77cdfb5c/attachment.html>