cog/Plugins/playptmod/playptmod/ptmodDecoder.m

//
//  ptmodDecoder.m
//  playptmod
//
//  Created by Christopher Snowhill on 10/22/13.
//  Copyright 2013 __NoWork, Inc__. All rights reserved.
//

#import "ptmodDecoder.h"

#import "umx.h"
#import "mo3.h"

#import "Logging.h"

#import "PlaylistController.h"

@implementation ptmodDecoder

BOOL probe_length( void * ptmod, unsigned long * intro_length, unsigned long * loop_length, int test_vblank, const void * src, unsigned long size, unsigned int subsong )
{
    playptmod_Config( ptmod, PTMOD_OPTION_VSYNC_TIMING, test_vblank );
    
    playptmod_Play( ptmod, subsong );
    
    unsigned long length_total = 0;
    unsigned long length_saved;
    
    const long length_safety = 44100 * 60 * 30;
    
    while ( playptmod_LoopCounter( ptmod ) < 1 && length_total < length_safety )
    {
        playptmod_Render( ptmod, NULL, 512 );
        length_total += 512;
    }
    
    if ( playptmod_LoopCounter( ptmod ) < 1 )
    {
        *loop_length = 0;
        *intro_length = 44100 * 60 * 3;
        playptmod_Stop(ptmod);
        return YES;
    }
    
    length_saved = length_total;
    
    while ( playptmod_LoopCounter( ptmod ) < 2 )
    {
        playptmod_Render( ptmod, NULL, 512 );
        length_total += 512;
    }
    
    playptmod_Stop(ptmod);
    
    *loop_length = length_total - length_saved;
    *intro_length = length_saved - *loop_length;
    
    return YES;
}

- (BOOL)open:(id<CogSource>)s
{
    [s seek:0 whence:SEEK_END];
    size = [s tell];
    [s seek:0 whence:SEEK_SET];

    data = malloc(size);
    [s read:data amount:size];

    isMo3 = 0;
    char * try_data = unpackMo3( data, &size );
    if ( try_data ) {
        free( data );
        data = try_data;
        isMo3 = 1;
    }
    else {
        try_data = unpackUmx( data, &size );
        if ( try_data ) {
            free( data );
            data = try_data;
        }
    }
    
	if ([[[s url] fragment] length] == 0)
		track_num = 0;
	else
		track_num = [[[s url] fragment] intValue];
    
    void * mod = playptmod_Create( 44100 );
    if ( !mod ) return NO;
    
    if ( !playptmod_LoadMem(mod, data, size) )
    {
        playptmod_Free(mod);
        return NO;
    }
    
    int format = playptmod_GetFormat(mod);
    BOOL can_be_vblank = (format <= FORMAT_MK2);
    
    unsigned long normal_intro_length, normal_loop_length, vblank_intro_length, vblank_loop_length;
    
    if ( !probe_length(mod, &normal_intro_length, &normal_loop_length, 0, data, size, track_num) )
        return NO;
    if ( can_be_vblank )
    {
        if ( !probe_length(mod, &vblank_intro_length, &vblank_loop_length, 1, data, size, track_num) )
            return NO;
        if (vblank_loop_length == 0)
            can_be_vblank = NO;
    }
    else
    {
        vblank_intro_length = 0;
        vblank_loop_length = 0;
    }
    
    playptmod_Free(mod);

    isVblank = can_be_vblank && (( vblank_intro_length + vblank_loop_length ) < ( normal_intro_length + normal_loop_length ));

    unsigned long intro_length = isVblank ? vblank_intro_length : normal_intro_length;
    unsigned long loop_length = isVblank ? vblank_loop_length : normal_loop_length;

    framesLength = intro_length + loop_length * 2;
    totalFrames = framesLength + 44100 * 8;

    [self willChangeValueForKey:@"properties"];
	[self didChangeValueForKey:@"properties"];
    
	return YES;
}

- (BOOL)decoderInitialize
{
    ptmod = playptmod_Create( 44100 );
    if ( !ptmod )
        return NO;

    playptmod_Config( ptmod, PTMOD_OPTION_CLAMP_PERIODS, 0 );
    playptmod_Config( ptmod, PTMOD_OPTION_VSYNC_TIMING, isVblank );

    if ( !playptmod_LoadMem( ptmod, data, size ) )
        return NO;

    playptmod_Play( ptmod, track_num );

    framesRead = 0;
    
    return YES;
}

- (void)decoderShutdown
{
    if ( ptmod )
    {
        playptmod_Stop( ptmod );
        playptmod_Free( ptmod );
        ptmod = NULL;
    }
}

- (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
{
    BOOL repeat_one = IsRepeatOneSet();
    
    if ( !repeat_one && framesRead >= totalFrames )
        return 0;
    
    if ( !ptmod )
    {
        if ( ![self decoderInitialize] )
            return 0;
    }
    
    int total = 0;
    while ( total < frames ) {
        int framesToRender = 512;
        if ( !repeat_one && framesToRender > totalFrames - framesRead )
            framesToRender = (int)(totalFrames - framesRead);
        if ( framesToRender > frames - total )
            framesToRender = frames - total;

        int32_t * sampleBuf = ( int32_t * ) buf + total * 2;
        
        playptmod_Render( ptmod, sampleBuf, framesToRender );
    
        if ( !repeat_one && framesRead + framesToRender > framesLength ) {
            long fadeStart = ( framesLength > framesRead ) ? framesLength : framesRead;
            long fadeEnd = ( framesRead + framesToRender < totalFrames ) ? framesRead + framesToRender : totalFrames;
            const long fadeTotal = totalFrames - framesLength;
            for ( long fadePos = fadeStart; fadePos < fadeEnd; ++fadePos ) {
                const long scale = ( fadeTotal - ( fadePos - framesLength ) );
                const long offset = fadePos - framesRead;
                int32_t * samples = sampleBuf + offset * 2;
                samples[ 0 ] = (int32_t)(samples[ 0 ] * scale / fadeTotal);
                samples[ 1 ] = (int32_t)(samples[ 1 ] * scale / fadeTotal);
            }
            
            framesToRender = (int)(fadeEnd - framesRead);
        }

        if ( !framesToRender )
            break;
        
        total += framesToRender;
        framesRead += framesToRender;
    }
    
    for ( int i = 0; i < total; ++i )
    {
        int32_t * sampleIn = ( int32_t * ) buf + i * 2;
        float * sampleOut = ( float * ) buf + i * 2;
        sampleOut[ 0 ] = sampleIn[ 0 ] * (1.0f / 16777216.0f);
        sampleOut[ 1 ] = sampleIn[ 1 ] * (1.0f / 16777216.0f);
    }
    
    return total;
}

- (long)seek:(long)frame
{
    if ( frame < framesRead || !ptmod )
    {
        [self decoderShutdown];
        if ( ![self decoderInitialize] )
            return 0;
    }

    while ( framesRead < frame )
    {
        int frames_todo = INT_MAX;
        if ( frames_todo > frame - framesRead )
            frames_todo = (int)( frame - framesRead );
        playptmod_Render( ptmod, NULL, frames_todo );
        framesRead += frames_todo;
    }
    
    framesRead = frame;
    
    return frame;
}

- (void)close
{
    [self decoderShutdown];
	
    if (data) {
        if (isMo3) freeMo3( data );
        else free( data );
        data = NULL;
    }
}

- (void)dealloc
{
    [self close];
}

+ (NSArray *)fileTypes
{	
	return [NSArray arrayWithObjects:@"mod", @"mdz", @"stk", @"m15", @"fst", @"mo3", @"umx", nil];
}

+ (NSArray *)mimeTypes 
{	
	return [NSArray arrayWithObjects:@"audio/x-mod", nil];
}

+ (float)priority
{
    return 1.5;
}

@end