audiostreamer.h

////  AudioStreamer.h//  StreamingAudioPlayer////  Created by Matt Gallagher on 27/09/08.//  Copyright 2008 Matt Gallagher. All rights reserved.////  Permission is given to use this source code file, free of charge, in any//  project, commercial or otherwise, entirely at your risk, with the condition//  that any redistribution (in part or whole) of source code must retain//  this copyright and permission notice. Attribution in compiled projects is//  appreciated but not required.//#ifdef TARGET_OS_IPHONE#import <UIKit/UIKit.h>#else#import <Cocoa/Cocoa.h>#endif TARGET_OS_IPHONE#include <pthread.h>#include <AudioToolbox/AudioToolbox.h>#define LOG_QUEUED_BUFFERS 0#define kNumAQBufs 16// Number of audio queue buffers we allocate.// Needs to be big enough to keep audio pipeline// busy (non-zero number of queued buffers) but// not so big that audio takes too long to begin// (kNumAQBufs * kAQBufSize of data must be// loaded before playback will start).//// Set LOG_QUEUED_BUFFERS to 1 to log how many// buffers are queued at any time -- if it drops// to zero too often, this value may need to// increase. Min 3, typical 8-24.#define kAQDefaultBufSize 2048// Number of bytes in each audio queue buffer// Needs to be big enough to hold a packet of// audio from the audio file. If number is too// large, queuing of audio before playback starts// will take too long.// Highly compressed files can use smaller// numbers (512 or less). 2048 should hold all// but the largest packets. A buffer size error// will occur if this number is too small.#define kAQMaxPacketDescs 512// Number of packet descriptions in our arraytypedef enum{AS_INITIALIZED = 0,AS_STARTING_FILE_THREAD,AS_WAITING_FOR_DATA,AS_FLUSHING_EOF,AS_WAITING_FOR_QUEUE_TO_START,AS_PLAYING,AS_BUFFERING,AS_STOPPING,AS_STOPPED,AS_PAUSED} AudioStreamerState;typedef enum{AS_NO_STOP = 0,AS_STOPPING_EOF,AS_STOPPING_USER_ACTION,AS_STOPPING_ERROR,AS_STOPPING_TEMPORARILY} AudioStreamerStopReason;typedef enum{AS_NO_ERROR = 0,AS_NETWORK_CONNECTION_FAILED,AS_FILE_STREAM_GET_PROPERTY_FAILED,AS_FILE_STREAM_SEEK_FAILED,AS_FILE_STREAM_PARSE_BYTES_FAILED,AS_FILE_STREAM_OPEN_FAILED,AS_FILE_STREAM_CLOSE_FAILED,AS_AUDIO_DATA_NOT_FOUND,AS_AUDIO_QUEUE_CREATION_FAILED,AS_AUDIO_QUEUE_BUFFER_ALLOCATION_FAILED,AS_AUDIO_QUEUE_ENQUEUE_FAILED,AS_AUDIO_QUEUE_ADD_LISTENER_FAILED,AS_AUDIO_QUEUE_REMOVE_LISTENER_FAILED,AS_AUDIO_QUEUE_START_FAILED,AS_AUDIO_QUEUE_PAUSE_FAILED,AS_AUDIO_QUEUE_BUFFER_MISMATCH,AS_AUDIO_QUEUE_DISPOSE_FAILED,AS_AUDIO_QUEUE_STOP_FAILED,AS_AUDIO_QUEUE_FLUSH_FAILED,AS_AUDIO_STREAMER_FAILED,AS_GET_AUDIO_TIME_FAILED,AS_AUDIO_BUFFER_TOO_SMALL} AudioStreamerErrorCode;extern NSString * const ASStatusChangedNotification;@interface AudioStreamer : NSObject{NSURL *url;//// Special threading consideration://The audioQueue property should only ever be accessed inside a//synchronized(self) block and only *after* checking that ![self isFinishing]//AudioQueueRef audioQueue;AudioFileStreamID audioFileStream;// the audio file stream parserAudioStreamBasicDescription asbd;// description of the audioNSThread *internalThread;// the thread where the download and// audio file stream parsing occursAudioQueueBufferRef audioQueueBuffer[kNumAQBufs];// audio queue buffersAudioStreamPacketDescription packetDescs[kAQMaxPacketDescs];// packet descriptions for enqueuing audiounsigned int fillBufferIndex;// the index of the audioQueueBuffer that is being filledUInt32 packetBufferSize;size_t bytesFilled;// how many bytes have been filledsize_t packetsFilled;// how many packets have been filledbool inuse[kNumAQBufs];// flags to indicate that a buffer is still in useNSInteger buffersUsed;NSDictionary *httpHeaders;AudioStreamerState state;AudioStreamerStopReason stopReason;AudioStreamerErrorCode errorCode;OSStatus err;bool discontinuous;// flag to indicate middle of the streampthread_mutex_t queueBuffersMutex;// a mutex to protect the inuse flagspthread_cond_t queueBufferReadyCondition;// a condition varable for handling the inuse flagsCFReadStreamRef stream;NSNotificationCenter *notificationCenter;UInt32 bitRate;// Bits per second in the fileNSInteger dataOffset;// Offset of the first audio packet in the streamNSInteger fileLength;// Length of the file in bytesNSInteger seekByteOffset;// Seek offset within the file in bytesUInt64 audioDataByteCount;  // Used when the actual number of audio bytes in// the file is known (more accurate than assuming// the whole file is audio)UInt64 processedPacketsCount;// number of packets accumulated for bitrate estimationUInt64 processedPacketsSizeTotal;// byte size of accumulated estimation packetsdouble seekTime;BOOL seekWasRequested;double requestedSeekTime;double sampleRate;// Sample rate of the file (used to compare with// samples played by the queue for current playback// time)double packetDuration;// sample rate times frames per packetdouble lastProgress;// last calculated progress point}@property AudioStreamerErrorCode errorCode;@property (readonly) AudioStreamerState state;@property (readonly) double progress;@property (readonly) double duration;@property (readwrite) UInt32 bitRate;@property (readonly) NSDictionary *httpHeaders;- (id)initWithURL:(NSURL *)aURL;- (void)start;- (void)stop;- (void)pause;- (BOOL)isPlaying;- (BOOL)isPaused;- (BOOL)isWaiting;- (BOOL)isIdle;- (void)seekToTime:(double)newSeekTime;- (double)calculatedBitRate;@end