SuperQ;444676 Wrote: > When I said implementation, I was talking about things like metaflac. I > guess I was wrong, metaflac will write tags that could clip tracks, but > provides a hint to newer software that there is a peak to consider. > > This seems to be a bad backwards compatibility design in the tag > system. If you designed the decoder before the peak tag existed, you're > kinda screwed. AFAIK the peak tag has always existed. Playback systems which implement the GAIN tag but ignore the PEAK tag are in principle broken.
It seems you would rather that there were no PEAK tags, but simply have GAIN tags that were scaled back at analysis time so as to avoid clipping. This achieves nothing other than to allow for lazy, broken implementations to get away with it. There are good reasons why this is not a good idea: Suppose the suggested boost would be +6dB, and the peak level is -2dB. I take it that you would prefer the GAIN tag to be set to +2dB so as to prevent clipping. What happens is that when played back, the file will be perceived as being 4dB quieter than others - and rightly so, because of course we do want to avoid clipping. But now suppose the playback system incorporates other digital volume control, and the listener happens to have set his digital control to -9dB. If the GAIN and PEAK tags are +6dB and -2dB (ie. the way that it does actually work in replaygain), we can see that within the context of an overall volume level of -9dB, we are able to apply the full +6dB adjustment. The perceived loudness of the track is now in line with other tracks. (As it happens, the Squeezebox system does have digital volume control but does NOT take advantage of this additional possibility, which is a shame. I decided not to push this issue in the bug report - getting the clipping fixed was far more important). There are other non-audiophile perspectives to consider. It may be that in a background listening environment, we really do want to have equal perceived loudness at all times, and in this case some kind of peak limiter can be applied to prevent hard clipping but still allow the full amount of overall boost. But under your desired approach, the playback system has no idea what the original boost would have been, and the track will remain 4dB quieter than other tracks in all circumstances. I hope you can now see why the way that replaygain tags work currently is actually the optimal solution. -- cliveb Transporter -> ATC SCM100A ------------------------------------------------------------------------ cliveb's Profile: http://forums.slimdevices.com/member.php?userid=348 View this thread: http://forums.slimdevices.com/showthread.php?t=65911 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
