path: root/src/replayGain.c

#include "replayGain.h"

#include "log.h"
#include "conf.h"

#include <string.h>
#include <math.h>
#include <stdlib.h>
 
/* Added 4/14/2004 by AliasMrJones */
static int replayGainState = REPLAYGAIN_OFF;

void initReplayGainState() {
	if(!getConf()[CONF_REPLAYGAIN]) return;

	if(strcmp(getConf()[CONF_REPLAYGAIN],"track")==0) {
		replayGainState = REPLAYGAIN_TRACK;
	}
	else if(strcmp(getConf()[CONF_REPLAYGAIN],"album")==0) {
		replayGainState = REPLAYGAIN_ALBUM;
	}
	else {
		ERROR("replaygain value \"%s\" is invalid\n",
				getConf()[CONF_REPLAYGAIN]);
		exit(EXIT_FAILURE);
	}
}

int getReplayGainState() {
	return replayGainState;
}

float computeReplayGainScale(float gain, float peak){
	float scale;

	if(gain == 0.0) return(1);
	scale = pow(10.0, gain/20.0);
	if(scale > 15.0) scale = 15.0;

	if (scale * peak > 1.0) {
		scale = 1.0 / peak;
	}
	return(scale);
}

void doReplayGain(char * buffer, int bufferSize, AudioFormat * format, 
		float scale) 
{
	mpd_sint16 * buffer16 = (mpd_sint16 *)buffer;
	mpd_sint8 * buffer8 = (mpd_sint8 *)buffer;
	mpd_sint32 temp32;

	if(scale == 1.0) return;
	switch(format->bits) {
		case 16:
			while(bufferSize > 0){
				temp32 = *buffer16;
				temp32 *= scale;
				*buffer16 = temp32>32767 ? 32767 : 
					(temp32<-32768 ? -32768 : temp32);
				buffer16++;
				bufferSize-=2;
			}
			break;
		case 8:
			while(bufferSize>0){
				temp32 = *buffer8;
				temp32 *= scale;
				*buffer8 = temp32>127 ? 127 : 
					(temp32<-128 ? -128 : temp32);
				buffer8++;
				bufferSize--;
			}
			break;
		default:
			ERROR("%i bits not supported by doReplaygain!\n", format->bits);
	}
}
/* End of added code */