Custom export preset does not honor audio rate control setting

[mcihelka]

Hi there. I have created a custom export preset that specifies libopus for the audio codec and Average Bitrate for rate control. On selecting the preset, the rate control setting is not honored and reverts to Quality-based VBR. The preset looks like this:

f=matroska
meta.preset.extension=mkv
vcodec=libx265
vb=256k
deinterlace_method=yadif
rescale=hyper
preset=veryslow
movflags=+faststart
threads=0
acodec=libopus
vbr=on
ab=64k

For me it’s a small inconvenience but a fix would be nice in any case. BTW I love Shotcut, couldn’t live without it =)

[shotcut]

OK, the bug here is that vbr should = constrained. The change I made for v19.07 is that when you choose audio codec libopus and set rate control to Average Bitrate, it will set the encoding parameter and any newly added custom presets with vbr=constrained.