John Stebbins

The code to look at is avresample_build_matrix in libav/libavresample. It should be constructing a matrix something like what is described here: https://en.wikipedia.org/wiki/Matrix_decoder#Dolby_Pro_Logic_II_matrix_(5:2:5) The thing to note is that signals from...

Yup, appears to be all kinds of broken. Their matrix multipliers seem all out of whack. e.g. using sqrt(3/2) instead of sqrt(3)/2. And they don't do proper phase shifting. In...

ffmpeg's swresample appears to be borked in the same way.

What's required to extract Ls and Rs from the matrixed L and R is that there be a 180 degree phase difference between the Rs that is encoded in L...

There really is no simple answer. This post sums up some of the problems with phase shifting https://forum.doom9.org/showpost.php?p=846869&postcount=143 FYI, I just rechecked the coefficients. They are actually correct when you...

I think we could do this relatively easily in HandBrake code (and gate it with an option so it can be enabled/disabled). We could do a +90º shift of Rs...

I had forgotten that the official presets used dpl2 :stuck_out_tongue: I think very few people even know how to properly set up their stereos for dpl2 playback. So yes, I...

Just a note about "Prefer highest channel count source". I've run across many sources where the feature audio is stereo (old movies and such) and there is a multi-channel "commentary"...

This is something I would like to implement and the necessary infrastructure for it has been started. But there's quite a lot of work left to do. So it's not...

Seems like the CLI would be relatively easy to parallelize. It already has an option to use a json queue file to process a queue of jobs. Not sure how...