Page 1 of 1
WebM with VP9 SVC
Posted: 12 Feb 2024 20:55
by bkirnum
I have a WebM file which was generated by writing VP9 frames extracted from RTP streams. The VP9 frames have SVC enabled and contain several spatial layers. The lowest layer is 480x270, the largest is 1280x720. When played in VLC only the lowest spatial layer is rendered. Is this expected with SVC or am not generating the WebM properly? Thanks!
Re: WebM with VP9 SVC
Posted: 22 Feb 2024 19:03
by bkirnum
Based on debugging FFmpeg it seems the issue is not with the file but with the VP9 decoder. There are two VP9 codecs available, "Libvpx VP9" and "Google VP9". The former detects the dimension changes correctly and decodes SVC as desired using the highest spatial layer. The latter only decodes the lowest spatial layer. I assume VLC is using the "Google VP9" codec. Is there any way of forcing it to use "Libvpx VP9" (without having to rebuild)?
Re: WebM with VP9 SVC
Posted: 22 Feb 2024 20:00
by RĂ©mi Denis-Courmont
VLC uses either FFmpeg or libvpx. I don't know what you mean by Google VP9.