[LAD] Normalize and Cut Wav

 Hi experts.
 I have started my small project - mp3 database for radio.
 http://martini.pudele.com/radio/mp3_database/mp3_database.html
 How do i normalize by peak [not RMS] and trim silences in begin and
 end of WAV files ?
 Silences somewhere in middle of file i wanna leave untouched.
 I wanna in first step detect MAX sample in whole WAV file.
  For example we gotta MAX sample 10 000, then Apmliefier_coefficient
 will be 32 000/10 000 = 3,2 .
 In second step i wanna trim silences at begin and below -80 dB [or 2
 bit noise]
  For this in same file each sample multiple by Apmliefier_coefficient
 , and see - result is over -80 dB or not.
 If not, then first N samples will not written in trimmed file, but
 first sample that is over -80 dB [in any channel] ,
 and all further samples written in new file.
 Now we must just follow which sample [in any channel] is over -80
 dB.
 After write is complete, we can just truncate after last sample that
 was over -80 dB, and write header.
 So far i have found SOX vanna reverse da file for end silence trim,
 and for each step produce tmp file.
   Is here C API , program, script, way to do so what without any
 temporary files ?
 I have written script for normalize, but what ir best way for
 normalize ?
 What about mp3 and ogg automatic normalize and frames trim ?
 Tnx in advance
 Alf
 ====
 #!/bin/bash
 for i in *.wav; do
  val=${i%.wav}
  echo "** Check peak for $i **"
   ampl=`sox "$i" -t wav /dev/null stat -v 2>&1`
   waveaus=${i%.wav}.wave
   wert1="1.1"; wert2=$ampl;
   wahr=$(echo "$wert1 > $wert2" | bc)
   if [ $wahr = 1 ]; then
     echo " $wert1 > $wert2 , Do Nuthin"
   else
     echo " $wert1 <= $wert2 , Do process"
     echo "** Amplifying volume by -=$ampl=- to fake a normalize
 $val.wav -- $waveaus"
     ampl2=$(echo $ampl*0.9995 | bc -l)
     echo "ampl2 = $ampl2"
     sox -v $ampl2 "$i" -t wav "$waveaus"
   fi
 echo ""
 done
  ----

_______________________________________________
Linux-audio-dev mailing list
Linux-audio-dev@email-addr-hidden
http://lists.linuxaudio.org/listinfo/linux-audio-dev
Received on Wed Mar 9 00:15:04 2011