"decreasing DTS value" error with `nleurisource`s

[amindfv at mailbox.org]

On Sun, Aug 07, 2022 at 03:06:04AM -0700, amindfv--- via gstreamer-devel wrote:
> To answer my specific question about "commit," I found some details here: https://gitlab.freedesktop.org/gstreamer/gstreamer/-/blob/main/subprojects/gst-editing-services/ges/ges-timeline.c#L60-65
> 
> I'd still appreciate any links to docs on nlecomposition/GES documentation, though!
> 

Following up on this a while later, by far the best GES documentation I've found is reading the source itself, which is quite well documented.

I've come across something a bit confusing in the docs, though. In gst-editing-services/ges/ges-timeline.c it says:


     * Most usage of a timeline will likely only need a single #GESAudioTrack
     * and/or a single #GESVideoTrack. You can create such a timeline with
     * ges_timeline_new_audio_video(). After this, you are unlikely to need to
     * work with the tracks directly.


However, information about default framerate and frame size is in gst-editing-services/ges/ges-video-track.c, which seems to imply you actually _do_ want to work directly with tracks:


     * By default, a video track will have its #GESTrack:restriction-caps
     * set to "video/x-raw" with the following properties:
     *
     * - width: 1280
     * - height: 720
     * - framerate: 30/1
     *
     * These fields are needed for negotiation purposes, but you can change
     * their values if you wish. It is advised that you do so using
     * ges_track_update_restriction_caps() with new values for the fields you
     * wish to change [...]

It seems like wanting to change framerate or width/height is a pretty common case; is there a better way to do this than on the track level, or is the "you are unlikely to need to work with the tracks directly" only in the cases where you're okay with defaults?

Thanks!
Tom