Encoding format string

[amindfv at mailbox.org]

On Wed, Oct 26, 2022 at 01:18:28AM -0700, amindfv at mailbox.org wrote:
> Hi Eslam - thank you very much for the information about GST_DEBUG_DUMP_DOT_DIR. I'd never used it before, and it's given me a ton of insight about what's going on (though unfortunately I still haven't fixed the issue).
> 
> A few things I notice from the pipeline, as rendered in the .dot files:
> 
>   - At some point in the pipeline, a GstVideoConvert element has a sink pad with format I420_10LE (good), but its source pad has format I420 (not good)
>   - Later in the same pipeline, a GstVideoRate element has a sink pad with framerate 24/1, but source pad with framerate 30/1 (also not good). Later, in the GstEncodeBin, the framerate is converted back to 24/1.
>   - In some .dot files, a GESSmartMixer (inside a NleOperation) downgrades the geometry from 4K to 1280x720 (definitely not good). Not sure what it means but the "interlace-mode: progressive" label also disappears.
> 
> This is after explicitly adding a framerate to my encoding profile, as in:
> 
>    ges-launch-1.0 [...] --format 'video/quicktime,variant=iso:video/x-raw(ANY),framerate=24/1,width=4096,height=2160->video/x-h264|element-properties,target-bitrate=200000'
> 


Just to follow up here, does anyone have an explanation for why this occurred? It seems so deeply wrong to me that GES would silently downgrade video geometry and change framerate in the middle of a pipeline (i.e. go 4K 24fps -> 720p 30 fps -> 4K 24fps) without a really good reason.

Thanks,
Tom