[FFmpeg-devel] CrystalHD and ffmpeg probe behaviour

[Philip Langdale]

Hi all,

The one last issue I need to sort out before you can reliably use the 
crystalhd
decoder for transcoding is that, as far as I can tell, unless you 
ensure the
crystalhd decoder is the default (first chosen) decoder for a given 
format, ffmpeg
will incorrectly identify the raw yuv format of the decoded stream, 
leading to
failures at actual transcode time.

If I make the crystalhd decoder the default one, then ffmpeg sees that 
the decoder
returns yuyv422 and automatically configures the scaler to do 
colourspace conversion
to yuv420p for the encoder, and everything works.

if it's not default, then it will do the probe with the default 
decoder, resulting in
it assuming the decoder outputs yuv420p and not setting up a filter. I 
tried fiddling
with the -pix_fmt options and manually adding a filter but I didn't 
find a way to force
the expected decoder format to change.

Is there some combination of options that will do this or is there a 
software limitation
I need to fix?

Thanks,

--phil