[CELT-dev] PLC Question & OPUS Migration?

Timothy B. Terriberry tterribe at xiph.org
Wed Jun 22 07:50:38 PDT 2011

> think). In older versions (0.7.1) a pointer to NULL did the trick, but
> with code from the tip of the GIT repository, this method causes the

This is the correct way to invoke PLC, not passing in an array of zeros.

> codec to crash on the C55x fixed point platform. I have not determined
> where the crash occurs.

This sounds like a bug. We'll try to track it down, but last I checked 
the C55x port didn't build with the free TI tools, and I was never able 
to get the code actually running on my C55x.

> Also, while I am here, I thought I would ask if any CELT enthusiasts are
> migrating over to the OPUS code base?  My main applications for the

We've migrated libcelt over to the Opus repository, so future bugfixes, 
etc., are all going to be over there, and not in the CELT git 
repository. This is a much better way of doing things than what we had 
before, where CELT, SILK, and Opus were all in different repositories 
and linked via git submodules.

You can still use the libcelt API with the Opus codebase. If you have a 
fixed frame size and audio bandwidth, you can even strip the first byte 
of the Opus packet produced on the encoder side and restore it on the 
receiver side, so you don't have to pay any of the overhead for Opus's 
flexibility (assuming you're willing to give up compatibility, but if 
you've got a fixed packet size, etc., you probably are).

I've also argued that the Opus repository should build a separate 
libcelt (with custom modes enabled by default) instead of just a libopus 
that exports the old libcelt API, but so far Jean-Marc has been 
resistant to that idea.

More information about the celt-dev mailing list