OSDLAudio.cc

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#include "OSDLAudio.h"


#include "OSDLUtils.h"          // for getBackendLastError
#include "OSDLBasic.h"   // for OSDL::GetVersion


#include "SDL.h"


#include <list>
using std::list ;

using std::string ;



using namespace Ceylan::Log ;

using namespace OSDL::Audio ;


bool AudioModule::_AudioInitialized = false ;


/* untested code follows... 
Uint32 getChunkTimeMilliseconds(Mix_Chunk *chunk)
{
    Uint32 points = 0;
    Uint32 frames = 0;
    int freq = 0;
    Uint16 fmt = 0;
    int chans = 0;
    // Chunks are converted to audio device format... 
    if (!Mix_QuerySpec(&freq, &fmt, &chans))
        return 0;  //never called Mix_OpenAudio()?!

    // bytes / samplesize == sample points 
    points = (chunk->alen / ((fmt & 0xFF) / 8));

    // sample points / channels == sample frames 
    frames = (points / chans);

    // (sample frames * 1000) / frequency == play length in ms 
    return (frames * 1000) / freq);
}

*/


string AudioModule::SDLEnvironmentVariables[] = 
{
    
    "AUDIODEV",
    "SDL_AUDIODRIVER",
    "SDL_DISKAUDIOFILE",
    "SDL_DISKAUDIODELAY",
    "SDL_DSP_NOSELECT",
    "SDL_PATH_DSP"
    
} ;



AudioException::AudioException( const string & reason ) throw() :
    OSDL::Exception( reason )
{

}


AudioException::~AudioException() throw()
{

}


AudioModule::AudioModule() throw( AudioException ) :
    Ceylan::Module( 
        "OSDL Audio module",
        "This is the root audio module of OSDL",
        "http://osdl.sourceforge.net",
        "Olivier Boudeville",
        "olivier.boudeville@online.fr",
        OSDL::GetVersion(),
        "LGPL" )        
{

    send( "Initializing audio subsystem." ) ;

    if ( SDL_InitSubSystem( 
            CommonModule::UseAudio ) != CommonModule::BackendSuccess )
        throw AudioException( "AudioModule constructor : "
            "unable to initialize audio subsystem : " 
            + Utils::getBackendLastError() ) ;

    _AudioInitialized = true ;
    
    send( "Audio subsystem initialized." ) ;
    
    dropIdentifier() ;
    
}   


AudioModule::~AudioModule() throw()
{

    send( "Stopping audio subsystem." ) ;
    
    SDL_QuitSubSystem( CommonModule::UseAudio ) ;
    
    send( "Audio subsystem stopped." ) ;
    
}


const string AudioModule::toString( Ceylan::VerbosityLevels level ) 
    const throw()
{
    
    string res = "Audio module" ;
        
    if ( level == Ceylan::low )
        return res ;
                
    res += ". " + Ceylan::Module::toString() ;  
    
    return res ;
    
}


string AudioModule::DescribeEnvironmentVariables() throw()
{

    Ceylan::Uint16 varCount = 
        sizeof( SDLEnvironmentVariables ) / sizeof (char * ) ;
        
    string result = "Examining the " + Ceylan::toString( varCount )
        + " audio-related environment variables for SDL backend :" ;
    
    list<string> variables ;
        
    string var, value ;

    bool htmlFormat = Ceylan::TextDisplayable::GetOutputFormat() ;
    
    for ( Ceylan::Uint16 i = 0; i < varCount; i++ ) 
    {
        var = SDLEnvironmentVariables[ i ] ;
        value = Ceylan::System::getEnvironmentVariable( var ) ;
        
        if ( value.empty() )
        {
            if ( htmlFormat )
            {
                variables.push_back( "<em>" + var + "</em> is not set." ) ;
            }
            else
            {
                variables.push_back( var + " is not set." ) ;           
            }   
        }
        else
        {           
            if ( htmlFormat )
            {
                variables.push_back( "<b>" + var + "</b> set to [" 
                    + value + "]." ) ;
            }
            else
            {
                variables.push_back( var + " set to [" + value + "]." ) ;
            }   
        }   
    
    }
    
    return result + Ceylan::formatStringList( variables ) ;
    
}


bool AudioModule::IsAudioInitialized() throw()
{

    return _AudioInitialized ;
    
}

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