liffy99 wrote: > I'm interested in analysing some audio CDs to see if clipping is present > in their recording. Can anyone recommend software that will allow me to > analyse this (Mac) ? > I have tried Audacity which has an 'Analyze Clipping' function which > identifies possible culprit peaks. On the waveform graph however none of > the waveform exceeds the +1 or -1 levels - so I'm not quite sure what > I'm looking at. Should, for example, the +1 level equate to 0db (the max > level CD can be recorded at without clipping) ? > Thanks As others have pointed out, you'll never see any sample greater than 0dB. And since in principle samples at 0dB might be genuine (ie. not clips), then any analysis of a CD for clipping can only use some kind of rule to determine whether a section of waveform is likely to be a clip. A common rule-of-thumb is that 4 consecutive full-scale samples represent a clip. But in fact many CDs are clipped below full scale. Moreover, many clips on CDs are not absolute flat-tops, but are either slightly "ragged" (indicating subsequent processing after clipping) or sloped (indicating EQ after clipping). Audacity's clipping detection is actually pretty primitive. It only notices full scale clips, so will often miss clipping on CDs.
Here is not the place for me to advertise my own software, but I do have a program (Windows only, unfortunately) that does some pretty sophisticated clipping analysis of 16 bit PCM WAV files (ie. the sort you get from CDs). PM me if you are interested. ------------------------------------------------------------------------ cliveb's Profile: http://forums.slimdevices.com/member.php?userid=348 View this thread: http://forums.slimdevices.com/showthread.php?t=98180 _______________________________________________ discuss mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/discuss
