> On Thu, 15 Nov 2012 12:03:31 -0800 > "Richard C. Steffens" <[email protected]> wrote: > > Anyway, does anyone have any ideas about why the sound on my Linux > machines show this noise while the sound on two Winders machines does > not? And more important, is there anything I can do about it, other > than listening on XP while typing on Ubuntu?
> <...> On 11/15/2012 04:23 PM, Dale Snell wrote: > Hard to say what this might be. The only thing I can think of off > the top of my head is that you've got clipping somewhere. Try > loading one of the errant files into Audacity and check for > clipping. If it's there, use Audacity reduce the audio amplitude; > that should clear up the problem. Bingo. I had to check the box, "Show Clipping" in the View menu, and it was obvious. Clipping was present every time one of the speakers spoke. I used the amplify effect to reduce the amplitude from 0.0 to -1.4 and the clipping disappeared. However, while quieter, the noise was still present in the saved mp3 file. On 11/15/2012 06:40 PM, King Beowulf wrote: > Rich, what linux audio player are you using? I'm using a program called a python program called Transcribe. I get the same noise when using Movie Player. I'm guessing it uses the same underlying sound library as Transcribe, which uses gstreamer. Interestingly, though, the noise is not present when I play the audio with Audacity. > You said you "clean up" the > mp3 in audacity so is the sound quality bad in audacity or just another > player? I gave a wrong impression. I did not use Audacity to "clean up" this particular mp3. I have used Audacity for that purpose in the past, but not this time. It didn't occur to me to try since the noise sounds like an effect I get sometimes when filtering with Audacity. > As Dale mentioned, clipping could be a reason. Also, if you > didn't set up the noise filter properly you can have introduced some > static that depends on the mp3 codec and player (Fraunhofer licensed vs. > LAME for example). LAME is what's installed here -- at least for exporting mp3s from Audacity. > Also, you may wish to convert to a lossless format > (wav or flac) before editing in audacity. Also, consider mp3 bit rate, > CBR vs VBR.... This proved very useful. I imported the mp3 into Audacity at the beginning of this exercise (responding to these e-mails). Since it was already there, I exported the file as flac -- after the amplitude reduction. Now it plays nice and quiet in Transcribe and Movie Player. Thanks to both of you for your helpful ideas. -- Regards, Dick Steffens _______________________________________________ PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
