cog/Plugins/Hively/Hively/HVLDecoder.m

//
//  HVLDecoder.m
//  Hively
//
//  Created by Christopher Snowhill on 10/29/13.
//  Copyright 2013 __NoWork, Inc__. All rights reserved.
//

#import "HVLDecoder.h"

@implementation HVLDecoder

void oneTimeInit()
{
    static BOOL initialized = NO;
    if (!initialized)
    {
        hvl_InitReplayer();
        initialized = YES;
    }
}

+ (void)initialize
{
    if ([self class] == [HVLDecoder class])
        oneTimeInit();
}

- (BOOL)open:(id<CogSource>)s
{
    [s seek:0 whence:SEEK_END];
    long size = [s tell];
    [s seek:0 whence:SEEK_SET];
    
    if (size > UINT_MAX)
        return NO;
    
    void * data = malloc(size);
    [s read:data amount:size];
	
    tune = hvl_LoadTune( data, (uint32_t) size, 44100, 2 );
    free( data );
    if ( !tune )
        return NO;

    unsigned long safety = 2 * 60 * 60 * 50 * tune->ht_SpeedMultiplier;
    
    NSURL * url = [s url];
	if ([[url fragment] length] == 0)
		trackNumber = 0;
	else
		trackNumber = [[url fragment] intValue];

    hvl_InitSubsong( tune, trackNumber );
    
    unsigned long loops = 0;
    
    while ( loops < 2 && safety )
    {
        while ( !tune->ht_SongEndReached && safety )
        {
            hvl_play_irq( tune );
            --safety;
        }
        tune->ht_SongEndReached = 0;
        ++loops;
    }
    
    framesLength = tune->ht_PlayingTime * 44100 / (tune->ht_SpeedMultiplier * 50);
    framesFade = 44100 * 8;
    totalFrames = framesLength + framesFade;
    
    framesRead = 0;
    framesInBuffer = 0;
    
    buffer = malloc( sizeof(int32_t) * (44100 / 50) * 2 );
    
    hvl_InitSubsong( tune, trackNumber );

    [self willChangeValueForKey:@"properties"];
	[self didChangeValueForKey:@"properties"];

	return YES;
}

- (NSDictionary *)properties
{
	return [NSDictionary dictionaryWithObjectsAndKeys:
		[NSNumber numberWithInt:0], @"bitrate",
		[NSNumber numberWithFloat:44100], @"sampleRate",
		[NSNumber numberWithDouble:totalFrames], @"totalFrames",
		[NSNumber numberWithInt:32], @"bitsPerSample",
        [NSNumber numberWithBool:YES], @"floatingPoint",
		[NSNumber numberWithInt:2], @"channels",
		[NSNumber numberWithBool:YES], @"seekable",
		@"host", @"endian",
		nil];
}

- (int)readAudio:(void *)buf frames:(UInt32)frames
{
    if (framesRead >= totalFrames)
        return 0;
    
    int total = 0;
    while ( total < frames ) {
        if ( framesInBuffer )
        {
            float * outbuffer = (( float * ) buf) + total * 2;
            int framesToCopy = frames - total;
            if ( framesToCopy > framesInBuffer )
                framesToCopy = (int) framesInBuffer;
            for ( int i = 0; i < framesToCopy; ++i )
            {
                outbuffer[ 0 ] = buffer[ i * 2 + 0 ] * (1.0f / 16777216.0f);
                outbuffer[ 1 ] = buffer[ i * 2 + 1 ] * (1.0f / 16777216.0f);
                outbuffer += 2;
            }
            framesInBuffer -= framesToCopy;
            total += framesToCopy;
            if (framesInBuffer)
            {
                memcpy(buffer, buffer + framesToCopy * 2, sizeof(int32_t) * framesInBuffer * 2);
                break;
            }
        }
        hvl_DecodeFrame( tune, (int8_t *) buffer, ((int8_t *) buffer) + 4, 8 );
        framesInBuffer = 44100 / 50;
    }

    if ( framesRead + total > framesLength ) {
        long fadeStart = (framesLength > framesRead) ? framesLength : framesRead;
        long fadeEnd = (framesRead + total) > totalFrames ? totalFrames : (framesRead + total);
        long fadePos;
        
        float * buff = ( float * ) buf;
        
        float fadeScale = (float)(totalFrames - fadeStart) / (float)framesFade;
        float fadeStep = 1.0 / (float)framesFade;
        for (fadePos = fadeStart; fadePos < fadeEnd; ++fadePos) {
            buff[ 0 ] *= fadeScale;
            buff[ 1 ] *= fadeScale;
            buff += 2;
            fadeScale -= fadeStep;
            if (fadeScale <= 0.0) break;
        }
        total = (int)(fadePos - fadeStart);
    }
    
	framesRead += total;
    
    return total;
}

- (long)seek:(long)frame
{
    if (frame < framesRead) {
        hvl_InitSubsong( tune, trackNumber );
        framesRead = 0;
    }

    while (framesRead < frame) {
        hvl_play_irq( tune );
        framesRead += 44100 / 50;
    }
   
    return framesRead;
}

- (void)close
{
    if ( tune ) {
        hvl_FreeTune( tune );
        tune = NULL;
    }
    
    if ( buffer ) {
        free( buffer );
        buffer = NULL;
    }
}

+ (NSArray *)fileTypes 
{	
	return [NSArray arrayWithObjects:@"hvl", @"ahx", nil];
}

+ (NSArray *)mimeTypes 
{	
	return nil;
}

+ (float)priority
{
    return 1.0;
}

@end