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Topic: Problem with LAME with low bitrate (Read 4357 times) previous topic - next topic
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Problem with LAME with low bitrate

I have one specific MP3 file, stereo, 64kbps.  This is some monolog which I always convert to 24 kbps mono for archive.  However, this one file just can't be compressed.  I had success with any other files I tried.  The result for this file is very low volume and quality of sound.  I've convert it to WAV first and them use LAME directly.  Yet the result is the same.  I am a bit puzzled.

Is there any other encoder to try?  Or is there some way to find out what's going on?

thanks!

Problem with LAME with low bitrate

Reply #1 –
It sounds like you have a stereo file in which the two tracks are inverted from each other, so that when you convert to mono they nearly cancel. You should be able to extract just one track from the wav file and then compress that, or else invert one of the tracks and convert to mono.

Problem with LAME with low bitrate

Reply #2 –
Quote from: pdq on
It sounds like you have a stereo file in which the two tracks are inverted from each other, so that when you convert to mono they nearly cancel. You should be able to extract just one track from the wav file and then compress that, or else invert one of the tracks and convert to mono.


That makes sense.  Any tool you would recommend?

Thanks!

Problem with LAME with low bitrate

Reply #4 –
I found split track.  However, I don't seem to have a way to apply effect Invert on just one of them.  Any way to do it?

Thanks!
 

Problem with LAME with low bitrate

Reply #5 –
From your out-of-phase joint-mono source you might be able to scale one channel as "0" and the other as "1," then downmix to a single channel, like this:
Quote
lame -b 24 --cbr --scale-l 0 --scale-r 1 -a  <infile> <outfile.mp3>


    - M.