Hello Imran, What mode are you using? There isn't much frame-frame memory in Codec 2 (e.g. prediction), in modes like 1300 there is none.
Are you sure the bit-alignment remains correct when you remove frames? - David On 20/07/16 05:51, Imran wrote: > Hi All, > > I've been experimenting with Codec2 for voice reconstruction. I've > found something odd. > > I have a ~2 second long wav file, 8 Khz, 16 bit pcm, mono. I can encode > this file into codec2 no problem. > The first 1.3 seconds is silence. The mic is on, but in a quiet room > with no noise. The wav file spectogram shows a flat line, near 0, with > just a little white noise, for these 1.3 seconds, followed by a quiet > envelope of speech sounds. > > So, I encode the wav file into codec2, decode it and playback. Sounds > fine. > Then, I start deleting frames at the head of the encoding. So, I delete > frame 0, then frame 1 .. frame 15. That's about 300 ms of sound I've > removed that has no human sounds in it -- just mic whitenoise. > > Then, something weird happens. > While there's still a lot of silence in the playback, when playback > reaches the speech, the voice is noticeably degraded. > > I can delete 10 frames, no problem. When I delete more than 10, > degradation starts, and increases as I delete more frames. > > Anyone have any hints on why? > > Thanks, > Imran > ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports.http://sdm.link/zohodev2dev _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
