SCRecordSession.h

//
//  SCSession.h
//  SCAudioVideoRecorder
//
//  Created by Simon CORSIN on 27/03/14.
//  Copyright (c) 2014 rFlex. All rights reserved.
//

#import <Foundation/Foundation.h>
#import <AVFoundation/AVFoundation.h>
#import "SCFilterGroup.h"

#define kRecordSessionDefaultVideoCodec AVVideoCodecH264
#define kRecordSessionDefaultVideoScalingMode AVVideoScalingModeResizeAspectFill
#define kRecordSessionDefaultOutputBitPerPixel 12
#define kRecordSessionDefaultAudioBitrate 128000
#define kRecordSessionDefaultAudioFormat kAudioFormatMPEG4AAC

extern const NSString *SCRecordSessionSegmentFilenamesKey;
extern const NSString *SCRecordSessionDurationKey;
extern const NSString *SCRecordSessionIdentifierKey;
extern const NSString *SCRecordSessionDateKey;
extern const NSString *SCRecordSessionDirectoryKey;

extern const NSString *SCRecordSessionTemporaryDirectory;
extern const NSString *SCRecordSessionCacheDirectory;

@class SCRecordSession;
@class SCRecorder;

@interface SCRecordSession : NSObject

//////////////////
// GENERAL SETTINGS
////

/**
 An unique identifier generated when creating this record session.
 */
@property (readonly, nonatomic) NSString *identifier;

/**
 The date when this record session was created.
 */
@property (readonly, nonatomic) NSDate *date;

/**
 The directory to which the record segments will be saved.
 Can be either SCRecordSessionTemporaryDirectory or an arbritary directory.
 Default is SCRecordSessionTemporaryDirectory.
 */
@property (copy, nonatomic) NSString *recordSegmentsDirectory;

/**
 The output file type used for the AVAssetWriter.
 If null, AVFileTypeMPEG4 will be used for a video file, AVFileTypeAppleM4A for an audio file
 */
@property (copy, nonatomic) NSString *fileType;

/**
 The extension of every record segments.
 If null, the SCRecordSession will figure out one depending on the fileType.
 */
@property (copy, nonatomic) NSString *fileExtension;

/**
 The output url based on the identifier, the recordSegmentsDirectory and the fileExtension
 */
@property (readonly, nonatomic) NSURL *outputUrl;

/**
 Contains every record segment as NSURL.
 If shouldTrackRecordSegments is true, every pause/record actions
 will result in a new entry in this array.
 If shouldTrackRecordSegments is false, it will contains at most one segment
 */
@property (readonly, nonatomic) NSArray *recordSegments;

/**
 The current record duration including the duration of
 the current recording segment, if any.
 */
@property (readonly, nonatomic) CMTime currentRecordDuration;

/**
 The duration of the recorded record segments.
 */
@property (readonly, atomic) CMTime segmentsDuration;

/**
 The duration of the current recording segment.
 */
@property (readonly, atomic) CMTime currentSegmentDuration;

/**
 True if a recordSegment has began
 */
@property (readonly, nonatomic) BOOL recordSegmentBegan;

/**
 The recorder that is managing this SCRecordSession
 */
@property (readonly, nonatomic, weak) SCRecorder *recorder;

//////////////////
// PUBLIC METHODS
////

- (instancetype)init;

- (instancetype)initWithDictionaryRepresentation:(NSDictionary *)dictionaryRepresentation;

/**
 Create a SCRecordSession
 */
+ (instancetype)recordSession;

/**
 Create a SCRecordSession based on dictionary representation
 */
+ (instancetype)recordSession:(NSDictionary *)dictionaryRepresentation;

/**
 Start a new record segment.
 This method is automatically called by the SCRecorder
 */
- (void)beginRecordSegment:(NSError**)error;

/**
 End the current record segment.
 This method is automatically called by the SCRecorder
 when calling [SCRecorder pause] if necessary.
 segmentIndex contains the index of the segment recorded accessible
 in the recordSegments array. If error is not null, if will be -1
 If you don't remove the SCRecordSession from the SCRecorder while calling this method,
 The SCRecorder might create a new recordSegment right after automatically if it is not paused.
 */
- (void)endRecordSegment:(void(^)(NSInteger segmentIndex, NSError *error))completionHandler;

/**
 Remove the record segment at the given index and delete the associated file if asked
 Unexpected behavior can occur if you call this method if
 recordSegmentBegan is true
 */
- (void)removeSegmentAtIndex:(NSInteger)segmentIndex deleteFile:(BOOL)deleteFile;

/**
 Manually add a record segment.
 */
- (void)addSegment:(NSURL *)fileUrl;

/**
 Manually insert a record segment.
 */
- (void)insertSegment:(NSURL *)fileUrl atIndex:(NSInteger)segmentIndex;

/**
 Remove all the record segments and their associated files.
 */
- (void)removeAllSegments;

/**
 Remove all the record segments and their associated files if deleteFiles is true.
 */
- (void)removeAllSegments:(BOOL)deleteFiles;

/**
 Remove the last segment safely. Does not do anything if no segments were recorded.
 */
- (void)removeLastSegment;

/**
 Cancel the session.
 End the current recordSegment (if any) and call removeAllSegments
 If you don't want a segment to be automatically added when calling this method,
 you should remove the SCRecordSession from the SCRecorder
 */
- (void)cancelSession:(void(^)())completionHandler;

/**
 Merge the recorded record segments using the given AVAssetExportSessionPreset.
 */
- (void)mergeRecordSegmentsUsingPreset:(NSString *)exportSessionPreset completionHandler:(void(^)(NSURL *outputUrl, NSError *error))completionHandler;

/**
 Returns an asset representing all the record segments
 from this record session. This can be called anytime.
 */
- (AVAsset *)assetRepresentingRecordSegments;

/**
 Append all the record segments to a given AVMutableComposition.
 */
- (void)appendRecordSegmentsToComposition:(AVMutableComposition *)composition;

/**
 Stop the current segment and deinitialize the video and the audio.
 This can be usefull if the input video or audio profile changed.
 */
- (void)deinitialize;

/**
 Returns a dictionary that represents this SCRecordSession
 This will only contains strings and can be therefore safely serialized
 in any text format
 */
- (NSDictionary *)dictionaryRepresentation;

/**
 Returns a record segment URL for a filename and a directory.
 */
+ (NSURL *)recordSegmentURLForFilename:(NSString *)filename andDirectory:(NSString *)directory;

@end