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stereo to mono

Posted: 23 Jun 2009 12:29
by marwan.khoury
Hi Guys,

I am trying to transcode and stream my output using the following command:

/usr/bin/vlc -vvvvv http://east.streamguys.com/radioone ":sout=#transcode{acodec=alaw,samplerate=8000,channels=1,ab=64}:standard{mux=raw,dst=brazil:2050,access=http}"

I should note that I am using 0.8.6i since transcoding is completely broken in 0.9.*
The problem is that VLC isn't transcoding the output to mono, although its working for other formats, it seems that for this one, its failing.
I have notice in vlc output the following:
[00000413] main decoder debug: using decoder module "ffmpeg"
[00000414] main encoder debug: looking for encoder module: 9 candidates
[00000414] araw encoder debug: samplerate:8000Hz channels:1 bits/sample:8
[00000414] main encoder debug: using encoder module "araw"
[00000423] main private debug: looking for audio filter2 module: 4 candidates
[00000423] audio_format private debug: s16l->fl32, bits per sample: 16
[00000423] main private debug: using audio filter2 module "audio_format"
[00000431] main private debug: looking for audio filter2 module: 4 candidates
[00000431] linear_resampler private debug: fl32/44100KHz/2->s16l/8000KHz/1
[00000431] main private debug: using audio filter2 module "linear_resampler"
[00000432] main private debug: looking for audio filter2 module: 4 candidates
[00000432] audio_format private debug: fl32->s16l, bits per sample: 32
[00000432] main private debug: using audio filter2 module "audio_format"
[00000433] main private debug: looking for audio filter2 module: 4 candidates
[00000414] main encoder debug: removing module "araw"
[00000370] stream_out_transcode private debug: number of audio channels for mixing changed, trying to reopen the encoder for mixing 2 to 2 channels
[00000414] main encoder debug: looking for encoder module: 9 candidates
[00000414] araw encoder debug: samplerate:8000Hz channels:2 bits/sample:8
[00000414] main encoder debug: using encoder module "araw"
[00000376] main private debug: adding a new input
[00000376] mux_dummy private debug: adding input

vlc considers first transcoding to mono
[00000414] araw encoder debug: samplerate:8000Hz channels:1 bits/sample:8
and then it seems that its considering as stereo
[00000414] araw encoder debug: samplerate:8000Hz channels:2 bits/sample:8

I don't know if downmixing is broken for some formats.

Can anyone help and does anyone know if transcoding will be fixed in release 1.0?

I really need your help on this, I hit a brick wall.

Thanks and Regards,
Marwan