| Summary: | Volumes in dB for artsshell and artsd | ||
|---|---|---|---|
| Product: | [Unmaintained] arts | Reporter: | Benedikt Gollatz <benedikt> |
| Component: | general | Assignee: | Arnold Krille <arnold> |
| Status: | RESOLVED FIXED | ||
| Severity: | wishlist | ||
| Priority: | NOR | ||
| Version: | unspecified | ||
| Target Milestone: | --- | ||
| Platform: | Compiled Sources | ||
| OS: | Linux | ||
| Latest Commit: | Version Fixed In: | ||
| Sentry Crash Report: | |||
While I am currently working on artscontrol and its volumeslider/levelmeter and therefor messin around with volume: Are you aware that your formular is the one for intensity? The formular used in artscontrol untill now is the one for the acoustic pressure is 20*log( volume ). So I am wondering how this could be made configurable... Arnold Apllied your patch, but it isn't working with negative dB-values since these get "eaten up" by the getopt-function... Arnold :S/apllied/applied/g Using negative dB-volumes in artsd is no problem since getopt() doesn't "eat"
multiple character command line options ("-XdB"). To use negative values with
artsshell you have to call "artsshell -- volumedb -X" instead of "artsshell
volumedb -X"; getopt() will ignore the (false) "-X" command line option now.
Maybe there should be a warning in the "usage" display.
AFAIK the 20*log(volume) formula is for calculating the absolute dB(A) volume
[volume_in_dBA = 20*log(acoustic_pressure / 0.00002 Pa)], not for calculating
the relative dB volume. Since on every mixing console, compressor or amplifier
increasing the volume 3 dB means approximately doubling the volume, I think my
formula is right because:
2 = 10^(volume_dB / 10) | log()
log 2 = volume_dB / 10 | * 10
10 * log 2 = volume_dB
3.0103 = volume_dB
Subject: Re: Volumes in dB for artsshell and artsd On Saturday 26 July 2003 17:35, benedikt@gollatz.net wrote: > ------- Using negative dB-volumes in artsd is no problem since getopt() > doesn't "eat" multiple character command line options ("-XdB"). To use > negative values with artsshell you have to call "artsshell -- volumedb -X" > instead of "artsshell volumedb -X"; getopt() will ignore the (false) "-X" > command line option now. Maybe there should be a warning in the "usage" > display. I will investigate on this... > AFAIK the 20*log(volume) formula is for calculating the absolute dB(A) > volume [volume_in_dBA = 20*log(acoustic_pressure / 0.00002 Pa)], not for > calculating the relative dB volume. Since on every mixing console, > compressor or amplifier increasing the volume 3 dB means approximately > doubling the volume, I think my formula is right because: But it would be a change for everyone used to the display in artscontrol and I think it should be consistent all over aRts. Thats why I finally used factor 20. But I will ask the experts on kde-multimedia on this... Arnold |
Version: CVS 20030712 (using KDE Devel) Installed from: Compiled sources Compiler: gcc version 3.2.1 OS: Linux I thought it were a nice feature if you could get and set the output volume in artsshell and with the command-line option of artsd in decibel and not with these unwieldy floating point values. The first of the following two patches allows to give something like "-V -6dB" as command-line option to artsd; the second adds the command "volumedb" to artsshell, so "artsshell -- volumedb -6" is possible. _____ --- arts/soundserver/artsd.cc 2003-07-02 20:36:47.000000000 +0200 +++ arts/soundserver/artsd.cc 2003-07-12 18:45:15.000000000 +0200 @@ -68,5 +68,5 @@ fprintf(stderr,"-b <bits> set number of bits (8 or 16)\n"); fprintf(stderr,"-d enable full duplex operation\n"); - fprintf(stderr,"-V <volume> set output volume\n"); + fprintf(stderr,"-V <volume>[dB] set output volume\n"); fprintf(stderr,"-D <devicename> audio device (usually /dev/dsp)\n"); fprintf(stderr,"-F <fragments> number of fragments\n"); @@ -166,5 +166,16 @@ case 'f': cfgForceStart = true; break; - case 'V': cfgVolume = atof(optarg); + case 'V': + if(strstr(optarg, "dB") && + strlen(strstr(optarg, "dB")) == 2) + { + // last two chars of optarg are "dB" + char *val = + (char *)calloc(strlen(optarg) - 1, sizeof(char)); + strncpy(val, optarg, strlen(optarg) - 2); + cfgVolume = pow(10, atof(val) / 10.0); + free(val); + } else + cfgVolume = atof(optarg); break; case 'h': _____ --- arts/soundserver/artsshell.cc 2003-03-07 23:07:30.000000000 +0100 +++ arts/soundserver/artsshell.cc 2003-07-12 19:13:30.000000000 +0200 @@ -121,4 +121,5 @@ #include "tradercheck.h" #include <stdio.h> +#include <math.h> bool quiet = false; @@ -146,4 +147,5 @@ networkbuffers <n> - increase network buffers by a factor of <n>\n\ volume [<volume>] - display/set the volume of the soundserver\n\ + volumedb [<volume>] - display/set the volume in dB (decibel)\n\ stereoeffect insert [top|bottom] <name> - insert stereo effect\n\ stereoeffect remove <id> - remove stereo effect\n\ @@ -324,4 +326,16 @@ } +// set the output volume in dB +void setDeciBelVolume(Arts::SoundServerV2 server, float volume) +{ + setVolume(server, pow(10, volume / 10)); +} + +// get the output volume in dB +float getDeciBelVolume(Arts::SoundServerV2 server) +{ + return 10 * log10(getVolume(server)); +} + // stereoeffect command void stereoEffect(Arts::SoundServerV2 server, int argc, char **argv) @@ -473,4 +487,5 @@ networkbuffers <n> - increase network buffers by a factor of <n>\n\ volume [<volume>] - display/set the volume of the soundserver\n\ + volumedb [<volume>] - display/set the volume in dB (decibel)\n\ stereoeffect insert [top|bottom] <name> - insert stereo effect\n\ stereoeffect remove <id> - remove stereo effect\n\ @@ -521,4 +536,13 @@ } + if(!strcmp(argv[0], "volumedb") && (argc == 2)) { + setDeciBelVolume(server,atof(argv[1])); + return 0; + } + if(!strcmp(argv[0], "volumedb") && (argc == 1)) { + cout << getDeciBelVolume(server) << endl; + return 0; + } + if(!strcmp(argv[0], "cpuusage") && (argc == 1)) { printf("%.1f\n",server.cpuUsage());