Re: [LAD] [PlanetCCRMA] FIxed alsa-tools' envy24control missing peak level meters and "Reset Peaks"

On Fri, Jul 16, 2010 at 5:27 AM, Geoff King <gsking1(a)gmail.com> wrote: Geoff -- thank you for trying out the patch! (And, OT, thanks for working w/ Rui to help fix http://sourceforge.net/tracker/?func=detail&atid=733076&aid=3021645… :: "help fix qtractor crash on bus changing/configuration (3021645)" -- Envy24 and multichannel qtractor users, yes, it's time for a "svn up" ). FYI, to try out the new levelmeters "easy", if you're running Fedora x86_64, use the "envy24control" binary directly, or drop the levelmeters.c file into your build: http://nielsmayer.com/npm/Efficient-Meters-Envy24Control.tgz ( for details http://nielsmayer.com/npm/Efficient-Meters-Envy24Control.README ) ........ On a completely different "note" the envy 24 manual ( http://alsa.cybermirror.org/manuals/icensemble/envy24.pdf ) has interesting info on the envy24 digital mixer that I've snapshotted: Diagram: http://nielsmayer.com/npm/envy24mixer-architecture.png Note the way it truncates in the mixer: the more inputs you "mix" at once, the fewer bits each input source gets, and it's not clear what kind of dither, or it's a straight truncate of 24... ultimately the envy24 seems oriented towards producing a 16 bit, and not 24 bit master (which makes sense given that the chip is well over a decade old and HD audio production for "prosumer" was rare): .......... 4.5.5 Multi-Track Digital Monitoring The Envy24 integrates a 36-bit resolution digital hardware mixer. The width of the data path is strictly to ensure that during processing of all the channels, under any condition, no resolution is lost. The dynamic range of the end user system will be limited by the range of the physical output devices used. In order to maintain identical gain to the input stream (i.e. 0dB), the resulting 24-bit is not msb-aligned to the 36-bit. The overflow bits correspond to the analog distortion due to saturation. The user would need to reduce the overall attenuation of the inputs to avoid clipping. Insertion of the digital mixer adds only a single sample cycle delay with respect to the original data. This extremely low latency all digital mixer provides monitoring functionality and can replace a traditional external analog input mixer. There are 20 independent audio data streams to mix and control the volume. ... .............. --Niels http://nielsmayer.com