20:56 <tortoise> On first attempt, I'm not able to get the v4l2 decoder to work with FFmpeg 4.2's libavcodec on ubuntu on a radxa-zero board. All I get is this error message on stderr

20:56 <tortoise> [h264_v4l2m2m @ 0xaaab0ebcd180] output POLLERR

20:57 <tortoise> Is there a specific version of ffmpeg I should be using?

20:57 <tortoise> I thought I read somewhere that the vdec driver was tested by using ffmpeg? Where does the testing associated stuff live? that is test cases or test runner or what have you?

21:01 <tortoise> Oh wait, in dmesg I see a more an informative error message which looks like its the deal:

21:01 <tortoise> meson-vdec ff620000.video-decoder: Direct firmware load for meson/vdec/g12a_h264.bin failed with error -2

21:14 <tortoise> not sure why thats not in the radxa-zero ubuntu image. But I just copied that bin from the LibreELEC repo and it did get a bit further.

21:14 <tortoise> [ 2431.489602] meson-vdec ff620000.video-decoder: esparser_pad_start_code: unable to pad start code

21:14 <tortoise> [ 2431.692078] meson-vdec ff620000.video-decoder: esparser: input parsing error

21:15 <tortoise> I assume that it's ok to just copy the firmware bin from LibreElec like that. Or am I deranged?

21:36 <tortoise> So it'd be this check failing: https://elixir.bootlin.com/linux/v5.10.69/source/drivers/staging/media/meson/vdec/esparser.c#L201

21:36 <tortoise> Which just brings me back to my first question. Could it be that a specific version of ffmpeg is needed to do the correct dance with the kernel driver/hardware decoder? I'm guessing that this vb2_plane_size wasn't initialized or to the right size by my ffmpeg's v4l2 code

22:08 <tortoise> Nevermind, I figured out the problem was with the bitstream itself and not the driver or ffmpeg.