rtph264depay should translate "a-framerate (string)" attribute to "framerate (fraction)" on certain cameras
Submitted by Jan Spurny
When playing h264 streams from Sony SNC-VB600 and FLIR FC-690-PAL cameras, the rtph264depay will receive caps containing "a-framerate" attribute, which contains string value, for example "12.0", but rtph264depay does not recognize it and reports "framerate=(fraction)0/1" on src pad, so the whole pipeline downstream has "0/1" framerate, which means "variable bitrate" according to documentation.
I believe that rtph264depay could translate the nonstandard "a-framerate" to "framerate", so the caps downstream would report correct framerate when it is in fact known, instead of reporting a variable framerate (0/1), which is not true.
If someone has access to cameras mentioned above (and I think it's safe to assume that probably all contemporary Sony and FLIR cameras will exhibit the same behaviour), you can check using simple pipeline:
gst-launch-1.0 rtspsrc location=rtsp://`<addr>` ! decodebin ! xvimagesink
This is the log record where "a-framerate" is first mentioned:
DEBUG rtspsrc gstrtspsrc.c:1892:gst_rtspsrc_sdp_attributes_to_caps: adding caps: a-framerate=12.0
and from there, every other element has "framerate=0/1" in caps.
For additional info, see bug 758023