Mp3 on Michael’s Domain

Changing sound volume or bitrate of mp3 files with lame

Wed, 23 May 2007 00:00:00 +0000

Sometimes the recording level of mp3 files is very low. If I do some jogging next to a busy road, I cannot hear anything even when the sound volume is on the max. Therefore I have to increase the volume of the mp3 file. Using lame you can do it with the following script: #!/bin/bashwhile [ $# -ge 1 ]; doinfn=$1outfn="${infn%%.mp3}_3x.mp3"echo $outfnlame --mp3input -v --scale=3 $infn $outfnshift 1doneThe only problem is that filnames with blank spaces make this script to collapse. Have to figure out something else. Also the bitrate can be modified in this way:#!/bin/bashwhile [ $# -ge 1 ]; doinfn=$1outfn="${infn%%.mp3}_LQ.mp3"echo $outfnlame --mp3input -V 9 $infn $outfnshift 1done-V 9 is the lowest bitrate/quality -V 0 is the highest.

Grip configuration (%) switches for file formats

Wed, 04 Apr 2007 00:00:00 +0000

Grip is a GTK-based CD-player and CD-ripper / MP3 encoder. Here is a list of the ‘%’ switches used in command-lines.

Re-encoding mp3 files into smaller files with lame

Tue, 06 Mar 2007 00:00:00 +0000

My old mp3 player broke quite a while ago and now I am using a very primitive one that has only 128 MB and which refused to play some mp3s. In order to fit more podcasts into the memory and to play back those unplayable mp3 files I re-encode them with lame:lame --mp3input -V 3 --strictly-enforce-ISO --resample 12 original.mp3 reencoded.mp3

Shell script to downsample podcasts

Sat, 23 Dec 2006 00:00:00 +0000

I have a very basic mp3 player with only 128 MB memory. I mostly listen to podcasts which are automatically downloaded by Amarok into the folder ~/.kde/share/apps/amarok/podcasts/data. In order to fit many of them to the limited memory and to have them available from anywhere, I have been writing a script that automatically downsamples them as they arrive and puts them online to my web server. The script is executed hourly by the crontab. The two relevant files look like this:

Using lame to create mp3s from wavs

Tue, 24 Oct 2006 00:00:00 +0000

Using Audacity I converted one of the ripped WAVs into an MP3. However there was no possibility to batch convert WAV files. Thus I started to use lame from the command line. I created a shell script (encode.sh):while [ $ -ge 1 ]; do infn=$1 outfn="${infn%%.wav}.mp3" echo $outfn lame -v $infn $outfn shift 1done It does the batch converting:encode.sh *.wav The -v switch cause lame to encode using variable bitrate. -h would do fixed bitrate at 128, for other bitrates use e.g. -b 160. The -V 0 switch uses variable bitrate encoding with highest quality, while -V uses the lowest quality.