AUD_ChannelMapperReader.cpp

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/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * Copyright 2009-2011 Jörg Hermann Müller
 *
 * This file is part of AudaSpace.
 *
 * Audaspace is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * AudaSpace is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Audaspace; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <cmath>

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

#ifndef M_PI_2
#define M_PI_2 1.57079632679489661923
#endif

#include "AUD_ChannelMapperReader.h"

AUD_ChannelMapperReader::AUD_ChannelMapperReader(AUD_Reference<AUD_IReader> reader,
                                                 AUD_Channels channels) :
        AUD_EffectReader(reader), m_target_channels(channels),
    m_source_channels(AUD_CHANNELS_INVALID), m_mapping(0), m_map_size(0), m_mono_angle(0)
{
}

AUD_ChannelMapperReader::~AUD_ChannelMapperReader()
{
    delete[] m_mapping;
}

void AUD_ChannelMapperReader::setChannels(AUD_Channels channels)
{
    m_target_channels = channels;
    calculateMapping();
}

void AUD_ChannelMapperReader::setMonoAngle(float angle)
{
    if(angle != angle)
        angle = 0;
    m_mono_angle = angle;
    if(m_source_channels == AUD_CHANNELS_MONO)
        calculateMapping();
}

float AUD_ChannelMapperReader::angleDistance(float alpha, float beta)
{
    alpha = fabs(alpha - beta);

    if(alpha > M_PI)
        alpha = fabs(alpha - 2 * M_PI);

    return alpha;
}

void AUD_ChannelMapperReader::calculateMapping()
{
    if(m_map_size < m_source_channels * m_target_channels)
    {
        delete[] m_mapping;
        m_mapping = new float[m_source_channels * m_target_channels];
        m_map_size = m_source_channels * m_target_channels;
    }

    for(int i = 0; i < m_source_channels * m_target_channels; i++)
        m_mapping[i] = 0;

    const AUD_Channel* source_channels = CHANNEL_MAPS[m_source_channels - 1];
    const AUD_Channel* target_channels = CHANNEL_MAPS[m_target_channels - 1];

    int lfe = -1;

    for(int i = 0; i < m_target_channels; i++)
    {
        if(target_channels[i] == AUD_CHANNEL_LFE)
        {
            lfe = i;
            break;
        }
    }

    const float* source_angles = CHANNEL_ANGLES[m_source_channels - 1];
    const float* target_angles = CHANNEL_ANGLES[m_target_channels - 1];

    if(m_source_channels == AUD_CHANNELS_MONO)
        source_angles = &m_mono_angle;

    int channel_min1, channel_min2;
    float angle_min1, angle_min2, angle;

    for(int i = 0; i < m_source_channels; i++)
    {
        if(source_channels[i] == AUD_CHANNEL_LFE)
        {
            if(lfe != -1)
                m_mapping[lfe * m_source_channels + i] = 1;

            continue;
        }

        channel_min1 = channel_min2 = -1;
        angle_min1 = angle_min2 = 2 * M_PI;

        for(int j = 0; j < m_target_channels; j++)
        {
            if(j == lfe)
                continue;
            angle = angleDistance(source_angles[i], target_angles[j]);
            if(angle < angle_min1)
            {
                channel_min2 = channel_min1;
                angle_min2 = angle_min1;

                channel_min1 = j;
                angle_min1 = angle;
            }
            else if(angle < angle_min2)
            {
                channel_min2 = j;
                angle_min2 = angle;
            }
        }

        angle = angle_min1 + angle_min2;
        if(channel_min2 == -1 || angle == 0)
        {
            m_mapping[channel_min1 * m_source_channels + i] = 1;
        }
        else
        {
            m_mapping[channel_min1 * m_source_channels + i] = cos(M_PI_2 * angle_min1 / angle);
            m_mapping[channel_min2 * m_source_channels + i] = cos(M_PI_2 * angle_min2 / angle);
        }
    }

    /* AUD_XXX for(int i = 0; i < m_source_channels; i++)
    {
        for(int j = 0; j < m_target_channels; j++)
        {
            std::cout << m_mapping[i * m_source_channels + j] << " ";
        }
        std::cout << std::endl;
    }*/
}

AUD_Specs AUD_ChannelMapperReader::getSpecs() const
{
    AUD_Specs specs = m_reader->getSpecs();
    specs.channels = m_target_channels;
    return specs;
}

void AUD_ChannelMapperReader::read(int& length, bool& eos, sample_t* buffer)
{
    AUD_Channels channels = m_reader->getSpecs().channels;
    if(channels != m_source_channels)
    {
        m_source_channels = channels;
        calculateMapping();
    }

    if(m_source_channels == m_target_channels)
    {
        m_reader->read(length, eos, buffer);
        return;
    }

    m_buffer.assureSize(length * channels * sizeof(sample_t));

    sample_t* in = m_buffer.getBuffer();

    m_reader->read(length, eos, in);

    sample_t sum;

    for(int i = 0; i < length; i++)
    {
        for(int j = 0; j < m_target_channels; j++)
        {
            sum = 0;
            for(int k = 0; k < m_source_channels; k++)
                sum += m_mapping[j * m_source_channels + k] * in[i * m_source_channels + k];
            buffer[i * m_target_channels + j] = sum;
        }
    }
}

const AUD_Channel AUD_ChannelMapperReader::MONO_MAP[] =
{
    AUD_CHANNEL_FRONT_CENTER
};

const AUD_Channel AUD_ChannelMapperReader::STEREO_MAP[] =
{
    AUD_CHANNEL_FRONT_LEFT,
    AUD_CHANNEL_FRONT_RIGHT
};

const AUD_Channel AUD_ChannelMapperReader::STEREO_LFE_MAP[] =
{
    AUD_CHANNEL_FRONT_LEFT,
    AUD_CHANNEL_FRONT_RIGHT,
    AUD_CHANNEL_LFE
};

const AUD_Channel AUD_ChannelMapperReader::SURROUND4_MAP[] =
{
    AUD_CHANNEL_FRONT_LEFT,
    AUD_CHANNEL_FRONT_RIGHT,
    AUD_CHANNEL_REAR_LEFT,
    AUD_CHANNEL_REAR_RIGHT
};

const AUD_Channel AUD_ChannelMapperReader::SURROUND5_MAP[] =
{
    AUD_CHANNEL_FRONT_LEFT,
    AUD_CHANNEL_FRONT_RIGHT,
    AUD_CHANNEL_FRONT_CENTER,
    AUD_CHANNEL_REAR_LEFT,
    AUD_CHANNEL_REAR_RIGHT
};

const AUD_Channel AUD_ChannelMapperReader::SURROUND51_MAP[] =
{
    AUD_CHANNEL_FRONT_LEFT,
    AUD_CHANNEL_FRONT_RIGHT,
    AUD_CHANNEL_FRONT_CENTER,
    AUD_CHANNEL_LFE,
    AUD_CHANNEL_REAR_LEFT,
    AUD_CHANNEL_REAR_RIGHT
};

const AUD_Channel AUD_ChannelMapperReader::SURROUND61_MAP[] =
{
    AUD_CHANNEL_FRONT_LEFT,
    AUD_CHANNEL_FRONT_RIGHT,
    AUD_CHANNEL_FRONT_CENTER,
    AUD_CHANNEL_LFE,
    AUD_CHANNEL_REAR_CENTER,
    AUD_CHANNEL_REAR_LEFT,
    AUD_CHANNEL_REAR_RIGHT
};

const AUD_Channel AUD_ChannelMapperReader::SURROUND71_MAP[] =
{
    AUD_CHANNEL_FRONT_LEFT,
    AUD_CHANNEL_FRONT_RIGHT,
    AUD_CHANNEL_FRONT_CENTER,
    AUD_CHANNEL_LFE,
    AUD_CHANNEL_REAR_LEFT,
    AUD_CHANNEL_REAR_RIGHT,
    AUD_CHANNEL_SIDE_LEFT,
    AUD_CHANNEL_SIDE_RIGHT
};

const AUD_Channel* AUD_ChannelMapperReader::CHANNEL_MAPS[] =
{
    AUD_ChannelMapperReader::MONO_MAP,
    AUD_ChannelMapperReader::STEREO_MAP,
    AUD_ChannelMapperReader::STEREO_LFE_MAP,
    AUD_ChannelMapperReader::SURROUND4_MAP,
    AUD_ChannelMapperReader::SURROUND5_MAP,
    AUD_ChannelMapperReader::SURROUND51_MAP,
    AUD_ChannelMapperReader::SURROUND61_MAP,
    AUD_ChannelMapperReader::SURROUND71_MAP
};

const float AUD_ChannelMapperReader::MONO_ANGLES[] =
{
    0.0f * M_PI / 180.0f
};

const float AUD_ChannelMapperReader::STEREO_ANGLES[] =
{
    -90.0f * M_PI / 180.0f,
     90.0f * M_PI / 180.0f
};

const float AUD_ChannelMapperReader::STEREO_LFE_ANGLES[] =
{
   -90.0f * M_PI / 180.0f,
    90.0f * M_PI / 180.0f,
     0.0f * M_PI / 180.0f
};

const float AUD_ChannelMapperReader::SURROUND4_ANGLES[] =
{
     -45.0f * M_PI / 180.0f,
      45.0f * M_PI / 180.0f,
    -135.0f * M_PI / 180.0f,
     135.0f * M_PI / 180.0f
};

const float AUD_ChannelMapperReader::SURROUND5_ANGLES[] =
{
     -30.0f * M_PI / 180.0f,
      30.0f * M_PI / 180.0f,
       0.0f * M_PI / 180.0f,
    -110.0f * M_PI / 180.0f,
     110.0f * M_PI / 180.0f
};

const float AUD_ChannelMapperReader::SURROUND51_ANGLES[] =
{
      -30.0f * M_PI / 180.0f,
       30.0f * M_PI / 180.0f,
       0.0f * M_PI / 180.0f,
       0.0f * M_PI / 180.0f,
    -110.0f * M_PI / 180.0f,
     110.0f * M_PI / 180.0f
};

const float AUD_ChannelMapperReader::SURROUND61_ANGLES[] =
{
      -30.0f * M_PI / 180.0f,
       30.0f * M_PI / 180.0f,
       0.0f * M_PI / 180.0f,
       0.0f * M_PI / 180.0f,
     180.0f * M_PI / 180.0f,
    -110.0f * M_PI / 180.0f,
     110.0f * M_PI / 180.0f
};

const float AUD_ChannelMapperReader::SURROUND71_ANGLES[] =
{
      -30.0f * M_PI / 180.0f,
       30.0f * M_PI / 180.0f,
       0.0f * M_PI / 180.0f,
       0.0f * M_PI / 180.0f,
    -110.0f * M_PI / 180.0f,
     110.0f * M_PI / 180.0f,
    -150.0f * M_PI / 180.0f,
     150.0f * M_PI / 180.0f
};

const float* AUD_ChannelMapperReader::CHANNEL_ANGLES[] =
{
    AUD_ChannelMapperReader::MONO_ANGLES,
    AUD_ChannelMapperReader::STEREO_ANGLES,
    AUD_ChannelMapperReader::STEREO_LFE_ANGLES,
    AUD_ChannelMapperReader::SURROUND4_ANGLES,
    AUD_ChannelMapperReader::SURROUND5_ANGLES,
    AUD_ChannelMapperReader::SURROUND51_ANGLES,
    AUD_ChannelMapperReader::SURROUND61_ANGLES,
    AUD_ChannelMapperReader::SURROUND71_ANGLES
};