cog/Plugins/APL/APLDecoder.m

137 lines
3.0 KiB
Objective-C

//
// CueSheetDecoder.m
// CueSheet
//
// Created by Zaphod Beeblebrox on 10/8/07.
// Copyright 2007 __MyCompanyName__. All rights reserved.
//
#import "APLDecoder.h"
#import "APLFile.h"
@implementation APLDecoder
+ (NSArray *)fileTypes {
return [NSArray arrayWithObject:@"apl"];
}
+ (NSArray *)mimeTypes {
return [NSArray arrayWithObjects:@"application/x-apl", nil];
}
- (NSDictionary *)properties {
NSMutableDictionary *properties = [[decoder properties] mutableCopy];
//Need to alter length
[properties setObject:[NSNumber numberWithDouble:trackLength] forKey:@"length"];
return [properties autorelease];
}
- (BOOL)open:(id<CogSource>)s
{
NSLog(@"Loading apl...");
if (![[s url] isFileURL])
return NO;
NSURL *url = [s url];
[s close];
apl = [APLFile createWithFile:[url path]];
[apl retain];
//Kind of a hackish way of accessing outside classes.
source = [NSClassFromString(@"AudioSource") audioSourceForURL:[apl file]];
[source retain];
if (![source open:[apl file]]) {
NSLog(@"Could not open source for file '%@' referenced in apl", [apl file]);
return NO;
}
decoder = [NSClassFromString(@"AudioDecoder") audioDecoderForSource:source];
[decoder retain];
if (![decoder open:source]) {
NSLog(@"Could not open decoder for source for apl");
return NO;
}
NSDictionary *properties = [decoder properties];
int bitsPerSample = [[properties objectForKey:@"bitsPerSample"] intValue];
int channels = [[properties objectForKey:@"channels"] intValue];
float sampleRate = [[properties objectForKey:@"sampleRate"] floatValue];
bytesPerFrame = (bitsPerSample/8) * channels;
bytesPerSecond = (int)(bytesPerFrame * sampleRate);
if ([apl endBlock] > [apl startBlock])
trackEnd = ([apl endBlock] / sampleRate) * 1000.0;
else
trackEnd = [[properties objectForKey:@"length"] doubleValue];
trackStart = ([apl startBlock]/sampleRate) * 1000.0;
trackLength = trackEnd - trackStart;
[self seekToTime: 0.0];
//Note: Should register for observations of the decoder, but laziness consumes all.
[self willChangeValueForKey:@"properties"];
[self didChangeValueForKey:@"properties"];
return YES;
}
- (void)close {
if (decoder) {
[decoder close];
[decoder release];
decoder = nil;
}
if (source) {
[source release];
source = nil;
}
if (apl) {
[apl release];
apl = nil;
}
}
- (double)seekToTime:(double)time //milliseconds
{
if (time > trackLength || time < 0) {
//need a better way of returning fail.
return -1.0;
}
time += trackStart;
bytePosition = (time/1000.0) * bytesPerSecond;
NSLog(@"Before: %li", bytePosition);
bytePosition -= bytePosition % bytesPerFrame;
NSLog(@"After: %li", bytePosition);
return [decoder seekToTime:time];
}
- (int)fillBuffer:(void *)buf ofSize:(UInt32)size
{
long trackByteEnd = (trackEnd/1000.0) * bytesPerSecond;
trackByteEnd -= trackByteEnd % (bytesPerFrame);
if (bytePosition + size > trackByteEnd)
size = trackByteEnd - bytePosition;
if (!size)
return 0;
int n = [decoder fillBuffer:buf ofSize:size];
bytePosition += n;
return n;
}
@end