Codec Guide

Currently there are no support for playback m4a-alac files.
FFDShow don't have ALAC decoding while ALAC decoding is supported by libavcodec (why??). But DC-Bass Source Filter also supports ALAC decoding.
I installed K-Lite Mega and DC-Bass Source (full version) and after that I was able to playback m4a-alac files in MPC-HC but not in Windows Media Player.
Additionally I installed QT Lite and RiverPast's QuickTime DirectShow Filter (http://www.riverpast.com/en/prod/quicktime/) and finally got playlable m4a-alac in MPC-HC and WMP.

I'd like to suggest to incorporate my solution (at least DC-Bass part) in K-Lite.

DC-Bass is already included. But that only works for .alac files, not M4A.

DC-Bass don't work with M4A-ALAC in MPC-HC if DC-Bass installed by K-Lite.
MPC-HC able to play M4A-ALAC only if DC-Bass installed separately after installation of K-Lite.
May be some registry settings are different?

That should be fixable by adding a registry tweak to force usage of DC-Bass for handling .m4a.

I always thought it only supported AAC in M4A. I have one sample file and it does not work with that. Even when I use the offical DC-Bass installer.

Could you upload a sample file for me that worked for you?

Works with full DC-Bass and don't work with K-Lite only - just double checked.

M4A-ALAC is widely used by MacOS/iPod/iPhone(/iTunes?) as default lossless format as far as I know.
Uploading sample now.

Sample:
http://www.filefactory.com/file/a06g332 ... singer_m4a
http://www.filehosting.org/file/details ... singer.m4a

Here is GraphStudio's graph: "DC-Bass source" -> "Default DirectSound Device"

Thanks, I shall test it.

Another method for playing these files with MPC is to make it use the QT framework for decoding these files (MPC options -> Formats).

Your sample works, but another sample that I have doesn't. Both play with the tweak I mentioned above.

Forcing the use of DC-Bass is not something I consider a good idea if it only works with some files. I will have to think about that. Maybe it will be an option.

You can apply it manually with this registry script:

Code: Select all

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\Media Type\Extensions\.m4a]
"Source Filter"="{ABE7B1D9-4B3E-4ACD-A0D1-92611D3A4492}"


I don't use QT on my computer, so QT framework is not available in my case.

Forcing source filter don't work. Codec Tweak Tool detects broken source filter, MPC-HC and GraphStudio can't render file.
Manually constructed graph works fine.

Just double checked.
Registry tweak (force source filer) don't work, full DC-Bass install fix M4A-ALAC playback.

Another registry tweak is needed?

It works here. Next version of the pack will have an option to use DC-Bass for .m4a files.

Under Win7 x64 correct registry tweak is another one:

Code: Select all

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\Wow6432Node\Media Type\Extensions\.m4a]
"Source Filter"="{ABE7B1D9-4B3E-4ACD-A0D1-92611D3A4492}"

Tweak with "HKEY_CLASSES_ROOT\Media Type\Extensions\.m4a" don't work - triple checked.

I forgot you were using x64. In that case, the correct key is indeed the one you posted.

But don't worry, the pack will use the correct keys.

Next question is what to do to play M4A-ALAC in Windows Media Player (and Windows Media Center)?
I have one solution (QT + RiverPast's QuickTime DirectShow Filter), but I'd like have more elegant one.

DC-bass works with WMP as well.