DeaDBeeF-Player
[Feature Request] De-emphasis of pre-emphasised audio sources
Steps to reproduce the problem
Playing back audio which has had pre-emphasis applied to the master
What's going on? Describe the problem in as much detail as possible.
Pre-emphasised audio (found on certain early CDs) sounds shrill unless it has been processed in a particular way.
One solution is to apply processing on the fly - for example, there is a plugin for foobar2000 called foo_deemph, which de-emphasises audio files that have been tagged PRE_EMPHASIS=1 or PRE-EMPHASIS=1
As far as I'm aware, there is as of yet no implementation of de-emphasis in DeaDBeeF.
More info on pre-emphasis, and what to do about it: https://wiki.hydrogenaud.io/index.php?title=Pre-emphasis
Information about the software:
Deadbeef version: OS: linux 1.8.8-1
Funny timing that you just opened this issue - I just started working on a little personal project which is a command-line CD player using libcdio/paranoia with on-the-fly de-emphasis (taking the filter design from SoX). I might be willing to give this a go, adding de-emphasis to the CDDA input plugin.
One issue I'm aware of is that the libcdio cdio_get_track_preemphasis API can only detect pre-emphasis if it's marked in the disc's table of contents. Some CDs with pre-emphasis only set the flags in the subcode and not the TOC, and as far as I know there's no way to read the subcode pre-emphasis flags using libcdio. But a good number (probably most?) CDs with pre-emphasis do flag it in the TOC as well as the subcode.
The only CD I have in my collection with pre-emphasis doesn't set the TOC flags, but I have one on the way that according to online info, does have TOC flags. So once that arrives I would be able to test the pre-emphasis detection.
It also might be nice to have a de-emphasis DSP plugin that can apply it on the fly to files as well. But I'd say that's quite lower priority b/c it has a workaround - using SoX or a similar tool to apply de-emphasis and re-encoding the files.