Unable to decode AV1 stream generated by NVENC on sunshine linux in capable hardware

[ghost]

No description provided.

[cgutman]

I think I narrowed down the problem to the presence of Padding OBUs. It seems like Qualcomm did not test their decoder with AV1 bitstreams containing padding OBUs (common for CBR encoding, but not otherwise).

We don't have control of padding OBUs for all encoders (notably not FFmpeg NVENC or VAAPI), but we might be able to strip them off after each encoded frame.

[cgutman]

Does padding obus are also present when a stream is created in the windows app?

No, because our standalone NVENC implementation used on Windows disables padding OBUs. The bitstream produced in both cases is completely valid, but Qualcomm's decoder does not properly implement the AV1 specification and fails to decode a valid bitstream if it contains padding OBUs.

I confirmed the issue was only the padding OBUs by patching FFmpeg to avoid setting NV_ENC_CONFIG_AV1::enableBitstreamPadding = 1. This was enough to enable my Fold 6 to decode the stream successfully.

[ReenigneArcher]

Great!, should i add something to the sunshine.conf file?

There's no config option for this. It will be fixed in a future release.