[Libav-user] Reducing Decoding Delay with h264_v4l2m2m on Raspberry Pi Zero 2: Seeking Solutions

[Alessandro Longobardi]

Hi,
I am using the h264_v4l2m2m decoder with libavcodec on a Raspberry Pi Zero 2 running Bookworm OS. My codec has the AV_CODEC_CAP_DELAY capability set, which means "The decoder has a non-zero delay" (reference: https://ffmpeg.org/doxygen/6.0/group__l ... 95028855e6<https://ffmpeg.org/doxygen/6.0/group__lavc__core.html#ga3f55f5bcfbb12e06c7cb1195028855e6>). I have observed that the decoder stores N encoded frames before outputting a decoded frame, and the value of N varies depending on the resolution, with higher resolution leading to a larger N. It means i have a delay in decoding about N*time_per_frame (e.g., at 25 fps, time_per_frame=40 milliseconds).

Is there a way to reduce this N value?

Thanks,
Alessandro

Inviato da Outlook per Android<https://aka.ms/AAb9ysg>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://ffmpeg.org/pipermail/libav-user/attachments/20240507/c5b1d605/attachment.htm>