10 Jun
2012
10 Jun
'12
3:19 p.m.
I've made a bit of progress. It appears that the phase calculation in
software_imbe_decoder::synth_voiced is not correct in the "fine transition"
case, resulting in abrupt phase shifts between the 20ms frames. I'm not sure yet how
to correct it, but by commenting out the "fine transition" case completely so
that the "coarse transition" case always runs instead, I've eliminated most
of the warble.
Another problem I noticed is that the audio output is sometimes greater than 1.0,
resulting in clipping if connected directly to an audio sink. I corrected this by
changing the "sample /= 16384.0;" line at the end of
software_imbe_decoder::decode_audio back to "sample /= 32768.0;".
- Clayton
--- In op25-dev(a)yahoogroups.com, "argilo314" <argilo@...> wrote:
I'm getting the same issue with the sound: speech is intelligible but with a strong
warble that makes it sound like talking through a fan. I had a quick look at the waveform
and spectrum of the output but didn't spot any obvious problems there. Not knowing
IMBE, I couldn't get far with the code. Any ideas?
- Clayton
--- In op25-dev(a)yahoogroups.com, "rrgsti" <bobrich@> wrote:
Basically looking at bit 113 (only) seems to indicate whether or not it's a voice
frame of some sort. The audio still sounds like everyone is talking through a fan, but
there are no dropouts, no clicks, no stutters, etc.
I could not find anything resembling a DUID or NAC in the headers. If anyone has a
suggestion to de-warble the audio, I would greatly appreciate it.