Re: [Audacity-devel] Bug Report: Compressor Effect
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From: AndyB <An...@xe...> - 2005-06-29 12:38:06
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Hi Steve, Perhaps you could send me your Compressor code. I'll try to get the Compressor code in 1.2.3, and compare the two, at least for the control and math calculations. I'm still looking for who is considered to be "in charge" of this Effect. AndyB Steve Harris wrote: > * Replies will be sent through Spamex to sw...@sm... > * For additional info click -> http://www.spamex.com/i/?v=6863613 > > Did you ever get a reply to this? Its possible that the compressor is mine > (I wrote one which is in audacity, but I dont know if its this one). > > - Steve > > On Mon, Jun 27, 2005 at 05:28:29 -0400, AndyB wrote: > >>Version: AudaCity 1.2.3 >>OS: Win XP Home >>Function: Compression Effect >>Subfunction: Ratio slider bar >>Bug: The Ratio control works ** backwards ** >> >>First, is this the correct forum to report such bugs ? >> >>Summary >>-------------- >>Note that the slider bar provides for a selection of descrete ratios. >>The first four (left to right) are 1.5:1, 2.0:1, 2.5:1, and 3.0:1. >>The actual slopes achieved are reversed, specifically: >> >> Ratio setting: 1.5:1 2.0:1 2.5:1 3.0:1 >> Slope obtained: 3.0:1 2.0:1 5:3 1.5:1 >> >>The chart's slope agrees with the control ratio, but both are contrary to >>the test results achieved. (I'm interested in an actual slope of 2.5:1, >>which is not available.) >> >>Background >>------------------ >>I am primarily interested in the Compressor (& Amplify) functions; so as to >>compress the Dynamic Range of classical recordings from a peak level >>range of 0 to -50 dB to as much as 0 to -20 dB -- for listening in >>noisy >>environments (my car). >> >>Example results >>---------------------- >>Settings: Ratio: 1.5:1; Threshold: -36 dB; Delay 0.1 sec. >>After Compression, Amplify was used (whole track) so as to restore the >>first level to ~ 0 dB. >>Test waveform: >> A 400 Hz triangular wave WAV file, having 0.5 second steps of >> successive 6 dB attenuations: >> I.E.: Levels of 0, -6 -12 -18 -24 -30 >> -36 -42 -48 -54 dB >> Expected results: 0, -4, -8, -12, -16, -20, >> -24, -28, -32, - 36 >> Test results: 0, -2, -4, -6, -8, >> -10, -12, -14, -16, -18 >> => This is a linear slope (good) of 54/18 dB => 3.0:1 >> >>Note that the Compressor function -- apart from its control -- is nearly >>perfect. >> >>Additional >>======== >>I anyone is interested, I would be glad to discuss any of the following: >> o This issue further -- I have much more test results on this topic >> o My test methods >> o Why I would ever want to compress to as little as 0-20 dB from 0-50 >> o My results on Compressor transient response, e.g.: >> o Step increase overshoot and recovery time >> o Step decrease undershoot and recovery time >> >>In particular, I would like to "talk" to the developer of this function. >> >>AndyB at xemaps.com >> >> >> >> >> >> >> >> >> >> >>------------------------------------------------------- >>SF.Net email is sponsored by: Discover Easy Linux Migration Strategies >>from IBM. Find simple to follow Roadmaps, straightforward articles, >>informative Webcasts and more! Get everything you need to get up to >>speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click >>_______________________________________________ >>Audacity-devel mailing list >>Aud...@li... >>https://lists.sourceforge.net/lists/listinfo/audacity-devel > > > |