audio::mixer(3pm) [debian man page]
Mixer(3pm) User Contributed Perl Documentation Mixer(3pm) NAME
Audio::Mixer - Perl extension for Sound Mixer control SYNOPSIS
use Audio::Mixer; $volume = Audio::Mixer::get_cval('vol'); if (Audio::Mixer::set_cval('vol', 50, 40)) { die("Can't set volume..."); } DESCRIPTION
Library to query / set various sound mixer parameters. This is just a very simple Perl interface which allows to set various sound mixer parameters. The most important probably 'vol' (volume). The list of all mixer parameters can be obtained using get_mixer_params() function. All values (lcval, rcval) are numbers in 0-100 range. FUNCTIONS
get_cval(cntrl) - Get parameter value Parameters: cntrl - name of parameter Returns: in array context: (lcval, rcval), where: lcval - left channel value rcval - right channel value in scalar context returns value of get_param_val() (see below) set_cval(cntrl, lcval, rcval) - Set parameter value Parameters: cntrl - name of parameter lcval - left channel value rcval - right channel value (optional, if not supplied will be equal to lcval) Returns: 0 if Ok, -1 if failed set_source(cntrl) - set record source Parameters: cntrl - name of channel to record from Returns: 0 if Ok, -1 if failed get_source(cntrl) - get record source Returns: name of channel to record from set_mixer_dev(fname) - Set mixer device name (optional), /dev/mixer is used by default fname - device name Returns: 0 if Ok init_mixer() - Initialize mixer (open it) set_cval() / get_cval() opens / closes the mixer each time they called unless init_mixer() called before. In case if init_mixer() called before all other functions will use already opened device instead of opening it each time. close_mixer() - Close device. Should be called only if init_mixer() was used. get_mixer_params() - Get list of mixer parameters Returns: list of parameters names. LOW LEVEL FUNCTIONS: get_param_val(cntrl) - Get parameter value Parameter: cntrl - name of parameter Returns: integer value, which will be constructed as follows: lower byte (x & 0xff) - value of the left channel (or whole value) next byte (x & 0xff00) - value of the right channel third byte (x & 0xff0000) - flags (if x & 0x10000 then 2 channels exist) or -1 in case of failure. set_param_val(cntrl, lcval, rcval) - Set parameter value. Here all parameters are mandatory (in contrast to set_cval()). Parameters: cntrl - name of parameter lcval - left channel value rcval - right channel value Returns: 0 if Ok, -1 if failed AUTHOR
Sergey Gribov, sergey@sergey.com LICENSE
Copyright (c) 2001 Sergey Gribov. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. SEE ALSO
perl(1). perl v5.14.2 2003-03-27 Mixer(3pm)
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pods::SDL::Mixer::Effects(3pm) User Contributed Perl Documentation pods::SDL::Mixer::Effects(3pm) NAME
SDL::Mixer::Effects - sound effect functions CATEGORY
Mixer METHODS
register SDL::Mixer::Effects::register( $channel, $effect_callback, $done_callback, $arg ); Hook a processor function into a channel for post processing effects. You may just be reading the data and displaying it, or you may be altering the stream to add an echo. Most processors also have state data that they allocate as they are in use, this would be stored in the $arg data space. When a processor is finished being used, any function passed into $done_callback will be called. The effects are put into a linked list, and always appended to the end, meaning they always work on previously registered effects output. Returns: Zero on errors, such as a nonexisting channel. Note: Passing MIX_CHANNEL_POST will register the $effect_callback as an postmix effect. Note: Do not use this on a threaded perl. This will crash. Example: use SDL; use SDL::Mixer; use SDL::Mixer::Channels; use SDL::Mixer::Effects; use SDL::Mixer::Samples; my @last_stream = (); my $echo_effect_func = sub { my $channel = shift; my $samples = shift; my $position = shift; my @stream = @_; my @stream2 = @stream; my $offset = $samples / 2; for(my $i = 0; $i < $samples; $i+=2) { if($i < $offset) { if(scalar(@last_stream) == $samples) { $stream2[$i] = $stream[$i] * 0.6 + $last_stream[$samples + $i - $offset] * 0.4; # left $stream2[$i + 1] = $stream[$i + 1] * 0.6 + $last_stream[$samples + $i - $offset + 1] * 0.4; # right } } else { $stream2[$i] = $stream[$i] * 0.6 + $stream[$i - $offset] * 0.4; # left $stream2[$i + 1] = $stream[$i + 1] * 0.6 + $stream[$i - $offset + 1] * 0.4; # right } } @last_stream = @stream; return @stream2; }; my $effect_done = sub { # you may do something here }; SDL::Mixer::open_audio( 44100, SDL::Constants::AUDIO_S16, 2, 1024 ); my $playing_channel = SDL::Mixer::Channels::play_channel( -1, SDL::Mixer::Samples::load_WAV('test/data/sample.wav'), -1 ); SDL::Mixer::Effects::register($playing_channel, $echo_effect_func, $effect_done, 0); SDL::delay(2000); SDL::Mixer::Effects::unregister($playing_channel, $echo_effect_func); SDL::Mixer::close_audio(); SDL::quit(); unregister SDL::Mixer::Effects::unregister( $channel, $effect_callback ); Remove the registered effect function from the effect list for channel. If the channel is active the registered effect will have its $done_callback function called, if it was specified in SDL::Mixer::Effects::register. Returns: Zero on errors, such as invalid channel, or effect function not registered on channel. Note: Do not use this on a threaded perl. This will crash. unregister_all SDL::Mixer::Effects::unregister_all( $channel ); This removes all effects registered to $channel. If the channel is active all the registered effects will have their $done_callback functions called, if they were specified in SDL::Mixer::Effects::register. Returns: Zero on errors, such as channel not existing. Note: Do not use this on a threaded perl. This will crash. set_post_mix SDL::Mixer::Effects::set_post_mix( $effect_callback, $arg ); Hook a processor function to the postmix stream for post processing effects. You may just be reading the data and displaying it, or you may be altering the stream to add an echo. This processor is never really finished, until you call it without arguments. There can only be one postmix function used at a time through this method. Use SDL::Mixer::Effects::register with MIX_CHANNEL_POST to use multiple postmix processors. This postmix processor is run AFTER all the registered postmixers set up by SDL::Mixer::Effects::register. Note: Do not use this on a threaded perl. This will crash. set_distance SDL::Mixer::Effects::set_distance( $channel, $distance ); This effect simulates a simple attenuation of volume due to distance. The volume never quite reaches silence, even at max distance(255). NOTE: Using a distance of 0 will cause the effect to unregister itself from channel. You cannot unregister it any other way, unless you use SDL::Mixer::Effects::unregister_all on the channel. Returns: Zero on errors, such as an invalid channel, or if Mix_RegisterEffect failed. set_panning SDL::Mixer::Effects::set_panning( $channel, $left, $right ); This effect will only work on stereo audio. Meaning you called SDL::Mixer::open_audio with 2 channels. Note: Setting both left and right to 255 will unregister the effect from channel. You cannot unregister it any other way, unless you use SDL::Mixer::Effects::unregister_all on the channel. Note: Using this function on a mono audio device will not register the effect, nor will it return an error status. Returns: Zero on errors, such as bad channel, or if SDL::Mixer::Effects::register failed. set_position SDL::Mixer::Effects::set_position( $channel, $angle, $distance ); This effect emulates a simple 3D audio effect. It's not all that realistic, but it can help improve some level of realism. By giving it the angle and distance from the camera's point of view, the effect pans and attenuates volumes. $angle is the direction in relation to forward from 0 to 360 degrees. Larger angles will be reduced to this range using angles % 360. o 0 = directly in front. o 90 = directly to the right. o 180 = directly behind. o 270 = directly to the left. So you can see it goes clockwise starting at directly in front. $distance is 0(close/loud) to 255(far/quiet). Note: Using angle and distance of 0, will cause the effect to unregister itself from channel. You cannot unregister it any other way, unless you use SDL::Mixer::Effects::unregister_all on the channel. Returns: Zero on errors, such as an invalid channel, or if SDL::Mixer::Effects::register failed. set_reverse_stereo SDL::Mixer::Effects::set_reverse_stereo( $channel, $flip ); If you pass 1 to $flip it simple reverse stereo, swaps left and right channel sound. Note: Using a flip of 0, will cause the effect to unregister itself from channel. You cannot unregister it any other way, unless you use SDL::Mixer::Effects::register on the channel. AUTHORS
See "AUTHORS" in SDL. perl v5.14.2 2012-05-28 pods::SDL::Mixer::Effects(3pm)