source: code/branches/FICN/src/audio/AudioStream.cc @ 414

#include "AudioStream.h"

namespace audio
{
        void AudioStream::open(string path)
        {
            int result;
            
            path = "audio/ambient/" + path + ".ogg"; 
            
            if(!(oggFile = fopen(path.c_str(), "rb")))
                throw std::string("Could not open Ogg file.");
        
            if((result = ov_open(oggFile, &oggStream, NULL, 0)) < 0)
            {
                fclose(oggFile);
                
                throw std::string("Could not open Ogg stream. ") + errorString(result);
            }
        
            vorbisInfo = ov_info(&oggStream, -1);
            vorbisComment = ov_comment(&oggStream, -1);
        
            if(vorbisInfo->channels == 1)
                format = AL_FORMAT_MONO16;
            else
                format = AL_FORMAT_STEREO16;
                
                
            alGenBuffers(2, buffers);
            check();
            alGenSources(1, &source);
            check();
            
            alSource3f(source, AL_POSITION,        0.0, 0.0, 0.0);
            alSource3f(source, AL_VELOCITY,        0.0, 0.0, 0.0);
            alSource3f(source, AL_DIRECTION,       0.0, 0.0, 0.0);
            alSourcef (source, AL_ROLLOFF_FACTOR,  0.0          );
            alSourcei (source, AL_SOURCE_RELATIVE, AL_TRUE      );
        }
        
        
        
        
        void AudioStream::release()
        {
            alSourceStop(source);
            empty();
            alDeleteSources(1, &source);
            check();
            alDeleteBuffers(1, buffers);
            check();
        
            ov_clear(&oggStream);
        }
        
        
        
        
        void AudioStream::display()
        {
            cout
                << "version         " << vorbisInfo->version         << "\n"
                << "channels        " << vorbisInfo->channels        << "\n"
                << "rate (hz)       " << vorbisInfo->rate            << "\n"
                << "bitrate upper   " << vorbisInfo->bitrate_upper   << "\n"
                << "bitrate nominal " << vorbisInfo->bitrate_nominal << "\n"
                << "bitrate lower   " << vorbisInfo->bitrate_lower   << "\n"
                << "bitrate window  " << vorbisInfo->bitrate_window  << "\n"
                << "\n"
                << "vendor " << vorbisComment->vendor << "\n";
                
            for(int i = 0; i < vorbisComment->comments; i++)
                cout << "   " << vorbisComment->user_comments[i] << "\n";
                
            cout << endl;
        }
        
        
        
        
        bool AudioStream::playback()
        {
            if(playing())
                return true;
                
            if(!stream(buffers[0]))
                return false;
                
            if(!stream(buffers[1]))
                return false;
            
            alSourceQueueBuffers(source, 2, buffers);
            alSourcePlay(source);
            
            return true;
        }
        
        
        
        
        bool AudioStream::playing()
        {
            ALenum state;
            
            alGetSourcei(source, AL_SOURCE_STATE, &state);
            
            return (state == AL_PLAYING);
        }
        
        
        
        
        bool AudioStream::update()
        {
            int processed;
            bool active = true;
        
            alGetSourcei(source, AL_BUFFERS_PROCESSED, &processed);
        
            while(processed--)
            {
                ALuint buffer;
                
                alSourceUnqueueBuffers(source, 1, &buffer);
                check();
        
                active = stream(buffer);
        
                alSourceQueueBuffers(source, 1, &buffer);
                check();
            }
        
            return active;
        }
        
        
        
        
        bool AudioStream::stream(ALuint buffer)
        {
            char pcm[BUFFER_SIZE];
            int  size = 0;
            int  section;
            int  result;
        
            while(size < BUFFER_SIZE)
            {
                result = ov_read(&oggStream, pcm + size, BUFFER_SIZE - size, 0, 2, 1, &section);
            
                if(result > 0)
                    size += result;
                else
                    if(result < 0)
                        throw errorString(result);
                    else
                        break;
            }
            
            if(size == 0)
                return false;
                
            alBufferData(buffer, format, pcm, size, vorbisInfo->rate);
            check();
            
            return true;
        }
        
        
        
        
        void AudioStream::empty()
        {
            int queued;
            
            alGetSourcei(source, AL_BUFFERS_QUEUED, &queued);
            
            while(queued--)
            {
                ALuint buffer;
            
                alSourceUnqueueBuffers(source, 1, &buffer);
                check();
            }
        }
        
        
        
        
        void AudioStream::check()
        {
                int error = alGetError();
        
                if(error != AL_NO_ERROR)
                        throw std::string("OpenAL error was raised.");
        }
        
        
        
        std::string AudioStream::errorString(int code)
        {
            switch(code)
            {
                case OV_EREAD:
                    return std::string("Read from media.");
                case OV_ENOTVORBIS:
                    return std::string("Not Vorbis data.");
                case OV_EVERSION:
                    return std::string("Vorbis version mismatch.");
                case OV_EBADHEADER:
                    return std::string("Invalid Vorbis header.");
                case OV_EFAULT:
                    return string("Internal logic fault (bug or heap/stack corruption.");
                default:
                    return std::string("Unknown Ogg error.");
            }
        }
}