Opus 1.1a BABYEATER build Options

[NullC]

Ever mindful of the world's population problems, the Opus development team is excited to present a new highly experimental build of Opus which is expected to eat 100% more babies than prior editions. It is also expected have (potentially) improved transient handling performance:

https://people.xiph.org/~greg/opus-tools_ba...ater-deluxe.zip (Edit: replaced with updated version, see below)

What this does is adapts the frame-size dynamically based on transient analysis prior to encoding. Leave the opus-tools framesize knob alone (in this test build it controls the amount of look-ahead used for the analysis, and 60ms is the default and only tested value).

It would be super-helpful to compare this with the regular 1.1 alpha at various rates and point us to any interesting results you find (e.g. where it does obviously worse or better, or where it catches fire and/or eats household pets instead of babies). Obviously you shouldn't be encoding your music archives with this stuff yet.

This post has been edited by NullC: Feb 13 2013, 01:07

[RobertM]

Hello!
I have some files: original wav 16khz ultrasound - 48khz file and others recorded in aac, vorbis, mp3, opus. I know that it is not a real music, but opus sounds very bad here. Also it takes too much space unlike the others. There are 5 audio files and 5 spectrograms for each file. In cause of Spek doesn't support OPUS, I encoded it back to wav. What do you think about it? Is that a problem or not?

P.S.:Opus was encoded with the latest babyeater) and all the same is with 1.1.x

Managed to compile the latest opusenc.exe, so I'll attempt to answer your post.

I noticed that in the files you provided, the .opus file used the following options:

CODE

ENCODER_OPTIONS                : --bitrate 512 --vbr --ignorelength

That bitrate would inflate the file size unnecessarily. However, when I used the default settings (I think it defaults to --bitrate 64) the opus filesize came out to be 458KB, which is still a fair bit higher than your MP3 file. I'm putting that down to the codec finding it difficult to compress pure sine waves.

There didn't seem to be any quality loss with the opus file though - it didn't sound terrible to me. I was unable to tell the difference between playing the WAV, Opus and MP3 files. I'm no listening expert though - what kind of problems did you hear?