On 03/08/2016 05:53 PM, David Rowe wrote: > Yes I've noticed that too. It still sounds "coded", but the wideband > presence is def there. Be nice to do that over narrow band HF channels :-)
It wouldn't actually be so costly to scale codec2 to wideband. Back in 2000, I was taking narrowband audio and encoding wideband from it with just 500 bps: https://jmvalin.ca/papers/scw2000.pdf The result was pretty decent and if you reduce the rate a bit further, you might be able to make it an overall quality/intelligibility improvement over narrowband codec2 at the same rate. Cheers, Jean-Marc > - David > >> >> glen >> >> >> >> On 9/03/2016 9:31 AM, David Rowe wrote: >>> Another intriguing possibility is add another few samples and do >>> wideband, but still low bit rate coding. For example a 6 kHz audio >>> bandwidth at a channel bit rate of 1000 bit/s, and a RF bandwidth of say >>> 500Hz (QSPK with tones spaced at Rs). >>> >>> It takes very few bits to represent the higher frequencies, as the ear >>> has a log(f) response. The extra cues may give us a performance advantage. >>> >>> Sort of "out of the box" thinking we can do with open source. AFAIK the >>> rest of the low bit rate would is constrained to 300-3300Hz type audio. >>> >>> - David >>> >>> On 09/03/16 08:27, glen english wrote: >>>> "The 4th freq frequency histogram has a mean of 3.2kHz." >>>> >>>> I think we need the high frequency support- it adds , i think , to the >>>> intelligibility in a high noise listening environment. Especially for >>>> younger ears. There is a significant intel difference between 2700 and >>>> 3300 Hz band limited speech. >>>> >>>> glen >>>> >>>> >>>> On 8/03/2016 12:42 PM, David Rowe wrote: >>>>> Hello Lists, >>>>> >>>>> I'm working on some new ideas for Codec 2. The aim is to get quality >>>>> similar to FreeDV 1600 (which uses Codec 2 at 1300 bit/s) at 700 bit/s. >>>>> >>>> >>>> ------------------------------------------------------------------------------ >>>> Transform Data into Opportunity. >>>> Accelerate data analysis in your applications with >>>> Intel Data Analytics Acceleration Library. >>>> Click to learn more. >>>> http://makebettercode.com/inteldaal-eval >>>> >>>> >>>> >>>> _______________________________________________ >>>> Freetel-codec2 mailing list >>>> Freetel-codec2@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >>>> >>> ------------------------------------------------------------------------------ >>> Transform Data into Opportunity. >>> Accelerate data analysis in your applications with >>> Intel Data Analytics Acceleration Library. >>> Click to learn more. >>> http://makebettercode.com/inteldaal-eval >>> _______________________________________________ >>> Freetel-codec2 mailing list >>> Freetel-codec2@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >>> >> > > ------------------------------------------------------------------------------ > Transform Data into Opportunity. > Accelerate data analysis in your applications with > Intel Data Analytics Acceleration Library. > Click to learn more. > http://makebettercode.com/inteldaal-eval > _______________________________________________ > Freetel-codec2 mailing list > Freetel-codec2@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785111&iu=/4140 _______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2
