sample-convert: Can't convert video/x-raw GL memory to RGBA
Totem screenshot feature stopped working after being ported to gtkglsink:
https://gitlab.gnome.org/GNOME/totem/-/issues/508
GStreamer HEAD is 52c07630.
Reproducer: totem-video-thumbnailer.c.txt
$ gcc -o thumb-test totem-video-thumbnailer.c.txt `pkg-config --libs --cflags gstreamer-1.0 gstreamer-video-1.0 gtk+-3.0`
$ ./thumb-test ~/Videos/Welcome\ to\ my\ channel\ dingus-VFh8WubLzYY.mp4
** Message: 17:09:29.280: Opened video file: '/home/hadess/Videos/Welcome to my channel dingus-VFh8WubLzYY.mp4'
** Message: 17:09:29.291: managed to capture frame
$ gcc -DGLSINK=1 -o thumb-test totem-video-thumbnailer.c `pkg-config --libs --cflags gstreamer-1.0 gstreamer-video-1.0 gtk+-3.0`
$ ./thumb-test ~/Videos/Welcome\ to\ my\ channel\ dingus-VFh8WubLzYY.mp4
** Message: 17:10:06.528: Opened video file: '/home/hadess/Videos/Welcome to my channel dingus-VFh8WubLzYY.mp4'
0:00:00.294566271 101529 0x16cf890 ERROR default convertframe.c:377:gst_video_convert_sample: Could not convert video frame: Internal data stream error.
0:00:00.294759829 101529 0x16cf890 ERROR playsink gstplaysink.c:4183:gst_play_sink_convert_sample: Error converting frame: Internal data stream error.
** Message: 17:10:06.545: totem-video-thumbnailer couldn't get a picture from '/home/hadess/Videos/Welcome to my channel dingus-VFh8WubLzYY.mp4': Failed to retrieve or convert video frame