cog/Plugins/Opus/Opus/OpusDecoder.m

//
//  OpusDecoder.m
//  Opus
//
//  Created by Christopher Snowhill on 10/4/13.
//  Copyright 2013 __NoWork, Inc__. All rights reserved.
//

#import "Plugin.h"

#import "OpusDecoder.h"

#import "Logging.h"

@implementation OpusFile

static const int MAXCHANNELS = 8;
static const int chmap[MAXCHANNELS][MAXCHANNELS] = {
    { 0, },                    // mono
    { 0, 1, },                 // l, r
    { 0, 2, 1, },              // l, c, r -> l, r, c
    { 0, 1, 2, 3, },           // l, r, bl, br
    { 0, 2, 1, 3, 4, },        // l, c, r, bl, br -> l, r, c, bl, br
    { 0, 2, 1, 5, 3, 4 },      // l, c, r, bl, br, lfe -> l, r, c, lfe, bl, br
    { 0, 2, 1, 6, 5, 3, 4 },   // l, c, r, sl, sr, bc, lfe -> l, r, c, lfe, bc, sl, sr
    { 0, 2, 1, 7, 5, 6, 3, 4 } // l, c, r, sl, sr, bl, br, lfe -> l, r, c, lfe, bl, br, sl, sr
};

int sourceRead(void *_stream, unsigned char *_ptr, int _nbytes)
{
	id source = (__bridge id)_stream;

	return (int) [source read:_ptr amount:_nbytes];
}

int sourceSeek(void *_stream, opus_int64 _offset, int _whence)
{
	id source = (__bridge id)_stream;
	return ([source seek:_offset whence:_whence] ? 0 : -1);
}

int sourceClose(void *_stream)
{
	return 0;
}

opus_int64 sourceTell(void *_stream)
{
	id source = (__bridge id)_stream;

	return [source tell];
}

- (id)init
{
    self = [super init];
    if (self)
    {
        opusRef = NULL;
    }
    return self;
}

- (BOOL)open:(id<CogSource>)s
{
	source = s;
	
	OpusFileCallbacks callbacks = {
		.read =  sourceRead,
		.seek =  sourceSeek,
		.close =  sourceClose,
		.tell =  sourceTell
	};
    
    int error;
    opusRef = op_open_callbacks((__bridge void *)source, &callbacks, NULL, 0, &error);
	
	if (!opusRef)
	{
		DLog(@"FAILED TO OPEN OPUS FILE");
		return NO;
	}

    currentSection = lastSection = op_current_link( opusRef );
    
	bitrate = (op_bitrate(opusRef, currentSection )/1000.0);
	channels = op_channel_count( opusRef, currentSection );
	
	seekable = op_seekable(opusRef);
	
	totalFrames = op_pcm_total(opusRef, -1);

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

- (int)readAudio:(void *)buf frames:(UInt32)frames
{
	int numread;
	int total = 0;
	
	if (currentSection != lastSection) {
		bitrate = (op_bitrate(opusRef, currentSection)/1000.0);
		channels = op_channel_count(opusRef, currentSection);
		
		[self willChangeValueForKey:@"properties"];
		[self didChangeValueForKey:@"properties"];
	}
	
    int size = frames * channels;
    
    do {
        float *out = ((float*)buf) + total;
        float tempbuf[512 * channels];
		lastSection = currentSection;
        int toread = size - total;
        if (toread > 512) toread = 512;
        numread = op_read_float( opusRef, (channels < MAXCHANNELS) ? tempbuf : out, toread, NULL );
        if (numread > 0 && channels < MAXCHANNELS) {
            for (int i = 0; i < numread; ++i) {
                for (int j = 0; j < channels; ++j) {
                    out[i * channels + j] = tempbuf[i * channels + chmap[channels - 1][j]];
                }
            }
        }
        currentSection = op_current_link( opusRef );
		if (numread > 0) {
			total += numread * channels;
		}
	
		if (currentSection != lastSection) {
			break;
		}
		
    } while (total != size && numread != 0);

    return total/channels;
}

- (void)close
{
    op_free(opusRef);
    opusRef = NULL;
}

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

- (long)seek:(long)frame
{
    op_pcm_seek(opusRef, frame);
	
	return frame;
}

- (NSDictionary *)properties
{
	return [NSDictionary dictionaryWithObjectsAndKeys:
		[NSNumber numberWithInt:channels], @"channels",
		[NSNumber numberWithInt:32], @"bitsPerSample",
        [NSNumber numberWithBool:YES], @"floatingPoint",
		[NSNumber numberWithFloat:48000], @"sampleRate",
		[NSNumber numberWithDouble:totalFrames], @"totalFrames",
		[NSNumber numberWithInt:bitrate], @"bitrate",
		[NSNumber numberWithBool:([source seekable] && seekable)], @"seekable",
        @"Opus", @"codec",
        @"host", @"endian",
		nil];
}


+ (NSArray *)fileTypes
{
	return @[@"opus",@"ogg"];
}

+ (NSArray *)mimeTypes
{
	return @[@"audio/x-opus+ogg", @"application/ogg"];
}

+ (float)priority
{
    return 1.0;
}

+ (NSArray *)fileTypeAssociations
{
    return @[
        @[@"Opus Audio File", @"ogg.icns", @"opus"],
        @[@"Ogg Audio File", @"ogg.icns", @"ogg"]
    ];
}

@end