NSFileHandleReadCompletionNotification不張貼

我在與NSFileHandleReadCompletionNotification不張貼的問題。我將一個NSTask的結果輸入另一個。無論出於什麼原因，我的getData方法都不會被調用。有任何想法嗎？這兩項任務都正常工作，因爲我正在將預期的文件寫入我的硬盤。只是沒有通知。NSFileHandleReadCompletionNotification不張貼

- (void) encodeVideo:(NSString*)path 
{ 
    NSString* ffmpegPath = [[NSBundle mainBundle] pathForResource:@"ffmpeg" ofType:@""]; 
    NSString* presetFile = [[NSBundle mainBundle] pathForResource:@"128" ofType:@"ffpreset"]; 

    NSTask* encodeTask = [[NSTask alloc] init]; 

    NSMutableArray* arguments = [[NSMutableArray alloc] init]; 
    [arguments addObject:@"-y"]; 
    [arguments addObject:@"-i"]; 
    [arguments addObject:path]; 
    [arguments addObject:@"-f"]; 
    [arguments addObject:@"mpegts"]; 
    [arguments addObject:@"-ac"]; 
    [arguments addObject:@"2"]; 
    [arguments addObject:@"-fpre"]; 
    [arguments addObject:presetFile]; 
    [arguments addObject:@"-s"]; 
    [arguments addObject:@"320x240"]; 
    [arguments addObject:@"-aspect"]; 
    [arguments addObject:@"320:240"]; 
    [arguments addObject:@"-async"]; 
    [arguments addObject:@"2"]; 
    [arguments addObject:@"-"]; 

    [encodeTask setLaunchPath: ffmpegPath]; 
    [encodeTask setArguments: arguments]; 
    [encodeTask setStandardOutput:[NSPipe pipe]]; 

    NSMutableArray* segmentArguments = [[NSMutableArray alloc] init]; 
    [segmentArguments addObject:@"-t"]; 
    [segmentArguments addObject:@"10"]; 
    [segmentArguments addObject:@"-f"]; 
    [segmentArguments addObject:@"/Users/Morgan/Desktop/LiveStreamServer/video"]; 
    [segmentArguments addObject:@"-S"]; 
    [segmentArguments addObject:@"1"]; 

    NSString* segmenterPath = [[NSBundle mainBundle] pathForResource:@"mediastreamsegmenter" ofType:@""]; 
    NSLog(@"%@", segmenterPath); 
    NSTask* segmentTask = [[NSTask alloc] init]; 

    [segmentTask setLaunchPath: segmenterPath]; 
    [segmentTask setArguments: segmentArguments]; 

    [segmentTask setStandardInput:[encodeTask standardOutput]]; 
    [segmentTask setStandardOutput:[NSPipe pipe]]; 
    [segmentTask setStandardError:[NSPipe pipe]]; 

    NSFileHandle *file = [[segmentTask standardOutput] fileHandleForReading]; 
    [file readInBackgroundAndNotify]; 

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(getData:) name:NSFileHandleReadCompletionNotification object:file]; 

    [segmentTask launch]; 
    [encodeTask launch]; 

    [arguments release]; 
    [segmentArguments release]; 
} 

- (void) getData: (NSNotification *)aNotification 
{ 
    NSData *data = [[aNotification userInfo] objectForKey:@"NSFileHandleNotificationDataItem"]; 
    NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]; 

    NSLog(@"%@", string); 
    [[aNotification object] readInBackgroundAndNotify]; 
}

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2011-10-22 Morgan

我知道你已經解決了這個問題。我只是想添加評論，因爲這是很多人犯的常見錯誤。你應該總是使用系統提供的定義，所以這是一個好主意，用NSFileHandleNotificationDataItem代替@‘NSFileHandleNotificationDataItem’的，因爲如果你拼錯一個字符串，你會碰到一些難以發現的問題。如果拼寫頭文件中提供的定義拼寫錯誤，您只會收到編譯錯誤，並可以立即發現它。 – 2013-12-09 07:05:40

需要在後臺讀取stdError。如果它輸出到一個管道，但沒有讀取它，所以緩衝區填滿了。

來源

2011-10-26 04:31:45 Morgan

NSFileHandleReadCompletionNotification不張貼

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