cog/Plugins/APL/APLDecoder.m

123 lines
2.6 KiB
Objective-C

#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 numberWithLong:trackLength] forKey:@"totalFrames"];
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;
if ([apl endBlock] > [apl startBlock])
trackEnd = [apl endBlock]; //([apl endBlock] / sampleRate) * 1000.0;
else
trackEnd = [[properties objectForKey:@"totalFrames"] doubleValue]; //!!? double?
trackStart = [apl startBlock];
trackLength = trackEnd - trackStart;
[self seek: 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;
}
}
- (long)seek:(long)frame
{
if (frame > trackEnd - trackStart) {
//need a better way of returning fail.
return -1;
}
frame += trackStart;
framePosition = [decoder seek:frame];
return framePosition;
}
- (int)readAudio:(void *)buf frames:(UInt32)frames
{
if (framePosition + frames > trackEnd)
frames = trackEnd - framePosition;
if (!frames) {
NSLog(@"APL readAudio Returning 0");
return 0;
}
int n = [decoder readAudio:buf frames:frames];
framePosition += n;
return n;
}
@end