Rockbox Technical Forums

Rockbox Development => Feature Ideas => Topic started by: pandora on May 24, 2016, 03:18:29 PM

Title: Codec2 audio format support? (better than Speex)
Post by: pandora on May 24, 2016, 03:18:29 PM
Hello, I tend to be an obsessive listener of audiobooks, radio show podcasts, and language tapes.  I like bringing massive archives with because I never know when i'll want to restudy something that I realize i'm forgetting or go looking for something I might have heard awhile ago but took notes on what show I heard it in.  So I am wondering if there has been other possible interest in very low bitrate codecs besides speex.

http://www.rowetel.com/blog/?page_id=452 Codec2 is designed for 700-3200bps rates and at 1200bps is surprisingly listenable, it's comparable to or possibly even better than MELPe which is considered the absolute state of the art currently but trapped up in patent law and for-profit licensing fees.  Codec2 is massively superior to Speex in quality and also open source. 

Nobody is even currently working on a realtime player so this might be pretty beta or alpha for awhile, but the more it's used in the real world, the more people can help the codec develop by finding it's strengths and weaknesses, offering samples to the developers of challenging to encode passages they found from their private listening.  I know i'd be happy to crunch down and listen for flaws to help but need a portable player to support it.  I've no clue how demanding it is vs speex or other encoders obviously.
Title: Re: Codec2 audio format support? (better than Speex)
Post by: saratoga on May 24, 2016, 04:02:08 PM
So I am wondering if there has been other possible interest in very low bitrate codecs besides speex.

Given how cheap storage is these days, probably not a huge amount.  A 128GB card would store over 11 years of audio at 3000 bps. 

http://www.rowetel.com/blog/?page_id=452 Codec2 is designed for 700-3200bps rates and at 1200bps is surprisingly listenable, it's comparable to or possibly even better than MELPe which is considered the absolute state of the art currently but trapped up in patent law and for-profit licensing fees.  Codec2 is massively superior to Speex in quality and also open source. 

If there is a fixed point decoder available, you could do it.  But I don't see a fixed point decoder listed there, so that might be quite painful to port if you had to convert to fixed point.
Title: Re: Codec2 audio format support? (better than Speex)
Post by: butrus on October 28, 2016, 04:01:42 PM
Well, the main problem with Codec2 is that it has no defined file format and that it changes frequently (new modes - which are NOT signalled in the bitstream - given the low speed! - are beeing added all the time!).
Title: Re: Codec2 audio format support? (better than Speex)
Post by: korvin on July 06, 2022, 07:27:15 PM

Given how cheap storage is these days, probably not a huge amount.  A 128GB card would store over 11 years of audio at 3000 bps. 


yes, right... 11 years... OMG..
with 512 Gb card you could use 12 kbps and for 11 years..
or almost 3 years with 48 kbps I am using for audio books (ogg and aac)