jack2/common/JackAudioPort.cpp

/*
Copyright (C) 2001-2003 Paul Davis
Copyright (C) 2004-2008 Grame

This program 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.

  This program 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 this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include "JackPortType.h"
#include <string.h>

#if defined (__APPLE__)
#include <Accelerate/Accelerate.h>
#elif defined (__SSE__)
#include <xmmintrin.h>
#endif

namespace Jack
{

static void AudioBufferInit(void* buffer, size_t buffer_size, jack_nframes_t)
{
    memset(buffer, 0, buffer_size);
}

static inline void MixAudioBuffer(float* mixbuffer, float* buffer, jack_nframes_t frames)
{
#ifdef __APPLE__
    // It seems that a vector mult only operation does not exist...
    float gain = 1.0f;
    vDSP_vsma(buffer, 1, &gain, mixbuffer, 1, mixbuffer, 1, frames);
#else
    jack_nframes_t frames_group = frames / 4;
    frames = frames % 4;

    while (frames_group > 0) {
#ifdef __SSE__
        __m128 vec = _mm_add_ps(_mm_load_ps(mixbuffer), _mm_load_ps(buffer));
        _mm_store_ps(mixbuffer, vec);

        mixbuffer += 4;
        buffer += 4;
        frames_group--;
#else
    register float mixFloat1 = *mixbuffer;
    register float sourceFloat1 = *buffer;
    register float mixFloat2 = *(mixbuffer + 1);
    register float sourceFloat2 = *(buffer + 1);
    register float mixFloat3 = *(mixbuffer + 2);
    register float sourceFloat3 = *(buffer + 2);
    register float mixFloat4 = *(mixbuffer + 3);
    register float sourceFloat4 = *(buffer + 3);

    buffer += 4;
    frames_group--;

    mixFloat1 += sourceFloat1;
    mixFloat2 += sourceFloat2;
    mixFloat3 += sourceFloat3;
    mixFloat4 += sourceFloat4;

    *mixbuffer = mixFloat1;
    *(mixbuffer + 1) = mixFloat2;
    *(mixbuffer + 2) = mixFloat3;
    *(mixbuffer + 3) = mixFloat4;

    mixbuffer += 4;
#endif
    }

    while (frames > 0) {
        register float mixFloat1 = *mixbuffer;
        register float sourceFloat1 = *buffer;
        buffer++;
        frames--;
        mixFloat1 += sourceFloat1;
        *mixbuffer = mixFloat1;
        mixbuffer++;
    }
#endif
}

static void AudioBufferMixdown(void* mixbuffer, void** src_buffers, int src_count, jack_nframes_t nframes)
{
    void* buffer;

    // Copy first buffer
    memcpy(mixbuffer, src_buffers[0], nframes * sizeof(float));

    // Mix remaining buffers
    for (int i = 1; i < src_count; ++i) {
        buffer = src_buffers[i];
        MixAudioBuffer(static_cast<float*>(mixbuffer), static_cast<float*>(buffer), nframes);
    }
}

const JackPortType gAudioPortType =
    {
        JACK_DEFAULT_AUDIO_TYPE,
        AudioBufferInit,
        AudioBufferMixdown
    };

} // namespace Jack