Hydrogenaudio Forums

Lossy Audio Compression => Opus => Topic started by: sean darcy on 2018-01-27 21:22:23

Title: opus 1.3 beta v ffmpeg native opus
Post by: sean darcy on 2018-01-27 21:22:23
I see the beta for libopus 1.3. I know there's been work on a native ffmpeg opus encoder. I need to transcode a lot of voice, to be played while driving. It doesn't have to have great quality, but easily intelligible and highly compressed. Maybe as low as 12 kbps ?

Does it make any difference which encoder to use ?  Has anybody compared them ?

Title: Re: opus 1.3 beta v ffmpeg native opus
Post by: 2012 on 2018-01-27 22:06:22
Not only FFmpeg's encoder is still experimental, but it also only implements the CELT part of the codec as of now. So, encoding at 12kbps currently produces terrible results (you would know if you tried it).

I would always stick with the latest stable release. The current latest beta apparently still has issues.
Title: Re: opus 1.3 beta v ffmpeg native opus
Post by: sean darcy on 2018-01-27 22:30:25
Ok, Thanks for the quick response.
sean
Title: Re: opus 1.3 beta v ffmpeg native opus
Post by: Nikaki on 2018-01-28 05:26:46
Why does ffmpeg want their own encoder to begin with? Why not just use the official one?
Title: Re: opus 1.3 beta v ffmpeg native opus
Post by: 2012 on 2018-01-28 14:30:16
Why not just use the official one?

The official encoder(libopus) is the default. Using the experimental native encoder requires passing -strict -2 -c:a opus.

Quote
Why does ffmpeg want their own encoder to begin with?

FFmpeg is an open-source project that accepts contributions. And this particular encoder was actually contributed by a Mozilla employee. It's a good encoder. It just does not have the low-bitrate optimized-for-voice SILK part of Opus yet.

The existence of multiple independent implementations of a codec is a good thing. As long as no one opts to use one of them insensibly*.

* IIRC, for some reason, YouTube opted to use FFmpeg's experimental Vorbis encoder when they started supporting HTML5 video. But they promptly stopped after being contacted by Xiph people. That was the last time I came across a story bout a major insensible encoder choice.
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