[FFmpeg-user] intel hd4000 h264 encoding with vaapi for quicktime - yuv420p possible?

[Kevin Smallman]

Hi there,

I have an old powerpc mac that can play h264 mp4 files, but they seem
to need to be in yuv420p pixel format so as not to get a black screen.

I can encode them successfully on my linux laptop with libx264 cpu
encoding and -pix_fmt yuv420p option.  The cpu is ivybridge, so the
gpu can do h264 encode and decode which plays fine in vlc on linux,
but not in quicktime on the old imac.

My question is:  is there a set of options so that the hardware
accelerated ffmpeg encoding/decoding/both can output a mp4 file with
yuv420p pixel format that is compatible with the quicktime standards?

So far, I haven't been able to find one from here:
https://trac.ffmpeg.org/wiki/Hardware/VAAPI

To get hardware encoding to work I seem to need to use this option
with the h264_vaapi encoder:
-vf 'hwupload,format=nv12'

which seems to be causing the problem.  I can't specify the same
-pix_fmt option as I can with libx264, because it just doesn't work.