/* $Id$ */

/***
  This file is part of polypaudio.
 
  polypaudio is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published
  by the Free Software Foundation; either version 2 of the License,
  or (at your option) any later version.
 
  polypaudio 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 Lesser General Public License
  along with polypaudio; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <stdlib.h>

#include "sample-util.h"

struct pa_memblock *pa_silence_memblock(struct pa_memblock* b, const struct pa_sample_spec *spec) {
    assert(b && b->data && spec);
    pa_silence_memory(b->data, b->length, spec);
    return b;
}

void pa_silence_memchunk(struct pa_memchunk *c, const struct pa_sample_spec *spec) {
    assert(c && c->memblock && c->memblock->data && spec && c->length);
    pa_silence_memory((uint8_t*) c->memblock->data+c->index, c->length, spec);
}

void pa_silence_memory(void *p, size_t length, const struct pa_sample_spec *spec) {
    uint8_t c = 0;
    assert(p && length && spec);

    switch (spec->format) {
        case PA_SAMPLE_U8:
            c = 0x80;
            break;
        case PA_SAMPLE_S16LE:
        case PA_SAMPLE_S16BE:
        case PA_SAMPLE_FLOAT32:
            c = 0;
            break;
        case PA_SAMPLE_ALAW:
        case PA_SAMPLE_ULAW:
            c = 80;
            break;
        default:
            assert(0);
    }
                
    memset(p, c, length);
}

size_t pa_mix(struct pa_mix_info channels[], unsigned nchannels, void *data, size_t length, const struct pa_sample_spec *spec, pa_volume_t volume) {
    assert(channels && data && length && spec);
    
    if (spec->format == PA_SAMPLE_S16NE) {
        size_t d;
        
        for (d = 0;; d += sizeof(int16_t)) {
            unsigned c;
            int32_t sum = 0;
            
            if (d >= length)
                return d;
            
            for (c = 0; c < nchannels; c++) {
                int32_t v;
                pa_volume_t cvolume = channels[c].volume;
                
                if (d >= channels[c].chunk.length)
                    return d;
                
                if (cvolume == PA_VOLUME_MUTED)
                    v = 0;
                else {
                    v = *((int16_t*) ((uint8_t*) channels[c].chunk.memblock->data + channels[c].chunk.index + d));
                    
                    if (cvolume != PA_VOLUME_NORM) {
                        v *= cvolume;
                        v /= PA_VOLUME_NORM;
                    }
                }
                
                sum += v;
            }
            
            if (volume == PA_VOLUME_MUTED)
                sum = 0;
            else if (volume != PA_VOLUME_NORM) {
                sum *= volume;
                sum /= PA_VOLUME_NORM;
            }
            
            if (sum < -0x8000) sum = -0x8000;
            if (sum > 0x7FFF) sum = 0x7FFF;
            
            *((int16_t*) data) = sum;
            data = (uint8_t*) data + sizeof(int16_t);
        }
    } else if (spec->format == PA_SAMPLE_U8) {
        size_t d;
        
        for (d = 0;; d ++) {
            int32_t sum = 0;
            unsigned c;
            
            if (d >= length)
                return d;
            
            for (c = 0; c < nchannels; c++) {
                int32_t v;
                pa_volume_t cvolume = channels[c].volume;
                
                if (d >= channels[c].chunk.length)
                    return d;
                
                if (cvolume == PA_VOLUME_MUTED)
                    v = 0;
                else {
                    v = (int32_t) *((uint8_t*) channels[c].chunk.memblock->data + channels[c].chunk.index + d) - 0x80;
                    
                    if (cvolume != PA_VOLUME_NORM) {
                        v *= cvolume;
                        v /= PA_VOLUME_NORM;
                    }
                }
                
                sum += v;
            }
            
            if (volume == PA_VOLUME_MUTED)
                sum = 0;
            else if (volume != PA_VOLUME_NORM) {
                sum *= volume;
                sum /= PA_VOLUME_NORM;
            }
            
            if (sum < -0x80) sum = -0x80;
            if (sum > 0x7F) sum = 0x7F;
            
            *((uint8_t*) data) = (uint8_t) (sum + 0x80);
            data = (uint8_t*) data + 1;
        }
        
    } else if (spec->format == PA_SAMPLE_FLOAT32NE) {
        size_t d;
        
        for (d = 0;; d += sizeof(float)) {
            float_t sum = 0;
            unsigned c;
            
            if (d >= length)
                return d;
            
            for (c = 0; c < nchannels; c++) {
                float v;
                pa_volume_t cvolume = channels[c].volume;
                
                if (d >= channels[c].chunk.length)
                    return d;
                
                if (cvolume == PA_VOLUME_MUTED)
                    v = 0;
                else {
                    v = *((float*) ((uint8_t*) channels[c].chunk.memblock->data + channels[c].chunk.index + d));
                    
                    if (cvolume != PA_VOLUME_NORM)
                        v = v*cvolume/PA_VOLUME_NORM;
                }
                
                sum += v;
            }
            
            if (volume == PA_VOLUME_MUTED)
                sum = 0;
            else if (volume != PA_VOLUME_NORM)
                sum = sum*volume/PA_VOLUME_NORM;
            
            if (sum < -1) sum = -1;
            if (sum > 1) sum = 1;
            
            *((float*) data) = sum;
            data = (uint8_t*) data + sizeof(float);
        }
    } else {
        abort();
    }
}


void pa_volume_memchunk(struct pa_memchunk*c, const struct pa_sample_spec *spec, pa_volume_t volume) {
    assert(c && spec && (c->length % pa_frame_size(spec) == 0));

    if (volume == PA_VOLUME_NORM)
        return;

    if (volume == PA_VOLUME_MUTED) {
        pa_silence_memchunk(c, spec);
        return;
    }

    if (spec->format == PA_SAMPLE_S16NE) {
        int16_t *d;
        size_t n;
        
        for (d = (int16_t*) ((uint8_t*) c->memblock->data+c->index), n = c->length/sizeof(int16_t); n > 0; d++, n--) {
            int32_t t = (int32_t)(*d);
            
            t *= volume;
            t /= PA_VOLUME_NORM;
            
            if (t < -0x8000) t = -0x8000;
            if (t > 0x7FFF) t = 0x7FFF;
            
            *d = (int16_t) t;
        }
    } else if (spec->format == PA_SAMPLE_U8) {
        uint8_t *d;
        size_t n;

        for (d = (uint8_t*) c->memblock->data + c->index, n = c->length; n > 0; d++, n--) {
            int32_t t = (int32_t) *d - 0x80;

            t *= volume;
            t /= PA_VOLUME_NORM;

            if (t < -0x80) t = -0x80;
            if (t > 0x7F) t = 0x7F;

            *d = (uint8_t) (t + 0x80);
            
        }
    } else if (spec->format == PA_SAMPLE_FLOAT32NE) {
        float *d;
        size_t n;

        for (d = (float*) ((uint8_t*) c->memblock->data+c->index), n = c->length/sizeof(float); n > 0; d++, n--) {
            float t = *d;

            t *= volume;
            t /= PA_VOLUME_NORM;

            if (t < -1) t = -1;
            if (t > 1) t = 1;

            *d = t;
        }
        
    } else {
        abort();
    }
}