[Live-devel] H265 elementary stream plays at half speed

[Paul Westlund]

Hi,

I am new to Live555 and am trying to get the testOnDemandRTSPServer running correctly with an H265 encoded video. The video plays correctly when opened directly from VLC. However when I access it through the testOnDemandRTSPServer, it plays at half the frame rate.

Looking into the code and referencing these two threads (http://lists.live555.com/pipermail/live-devel/2019-August/021257.html and http://lists.live555.com/pipermail/live-devel/2014-December/019007.html), this appears to be related to DeltaTfiDivisor having a default value of 2 in H264or5VideoStreamParser. The video does not contain any SEI packets, so analyze_sei_payload is never called (which appears to be the only place that DeltaTfiDivisor changes its value).

I just recently started digging into the details of H264/H265 codecs so I could easily be missing something, but I would think that with the frame_field_info_present_flag=0, num_units_in_tick=1, and time_scale=60, the output frame rate should be 60 fps not 30.

I have attached the test video to help you recreate the issue (I am using the build from May 17, 2021).

Any help/clarification would be greatly appreciated.

Paul

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.live555.com/pipermail/live-devel/attachments/20210624/c926980a/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: video.zip
Type: application/x-zip-compressed
Size: 292332 bytes
Desc: video.zip
URL: <http://lists.live555.com/pipermail/live-devel/attachments/20210624/c926980a/attachment-0001.bin>