The pre-releases just keep getting cooler, thanks Rob! The auto attenuation is fantastic. On one track I have, ZZ Top's 'La Grange', taken from the Armageddon soundtrack (which has incredible amounts of clipping on the CD itself), and compressed into a VBR file by LAME, on MAD's default clipping setting it went from 32661 clipped samples to a mere 31 clipped samples with -1.1dB attenuation (23 at the Most setting, but still -1.1dB attenuation). On another track, this time by Christina Aguilera, there was a point in the song where she goes to stratospheric heights with her vocals, and it always seemed to distort with speakers and even with my good headphones, but after attenuation, smooth as silk. The top end scratchiness during loud segments were decidedly smoother, which is the whole point of attenuation I suppose. Well, it works!
I have a question though, how does the gradual attenuation work? How about something that clips yet isn't continuous, like a cymbal crash? And are all those graduations for the setting necessary? I think instead of this, a self-adjusting attenuation would be even better. It should work at an aggressive level however, and step back or un-attenuate as soon as the clipping stops. What I'm thinking is something like the concept of variable bitrate MP3 encoding. When the decoder sees the first instance of a clipped sample, it automatically attenuates the full level, but after so many samples of no clipping, it steps back to no attenuation. And so on. What I fear is that a large spike could occur in the beginning or middle of a file, setting a high attenuation level, and then muffling the rest of the song which might not clip at all.
And the Joint Stereo pie graph is very neat. There's just so much to look at now. The MAD plug-in is becoming a tweaker's dream come true. Is all this pre-releasing building up to a Christmas day present for all the devoted good little MAD users out there? If so, reading Xing VBR headers is on top of my Santa list!
:)
Thanks,
naw
Rob Leslie wrote:
The third installment in the pre-release series...
http://www.mars.org/home/rob/proj/mpeg/mad-plugin/in_mad-0.12.3b-pre3.zip
This version adds configurability to the automatic attenuation, and also fixes the problem with the joint stereo pie graph.
I decided it might be better to control the sensitivity of the auto attenuation rather than use a simple hard limit. The default is somewhat less aggressive than it was before (which would correspond to the "Most" setting.) The idea is to control how gradually the attenuation is increased. If only a few isolated samples clip, a less sensitive setting will attenuate less than a more sensitive setting would. Continuous clipping will continuously increase the attenuation until the signal no longer clips; the sensitivity controls how fast this occurs.
Let me know what you think.
Cheers, -rob