How send to stream video from iOS device to server

问题:

I must send video in real-time from iPhone to server. I create capture session and use AVCaptureMovieFileOutput.

NSError *error = nil;

captureSession = [[AVCaptureSession alloc] init];
// find, attach devices
AVCaptureDevice *muxedDevice = [AVCaptureDevice defaultDeviceWithMediaType: AVMediaTypeMuxed];
if (muxedDevice) {
    NSLog (@"got muxedDevice");
    AVCaptureDeviceInput *muxedInput = [AVCaptureDeviceInput deviceInputWithDevice:muxedDevice
                                                                             error:&error];
    if (muxedInput) {
        [captureSession addInput:muxedInput];
    }
} else {
    AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType: AVMediaTypeVideo];
    if (videoDevice) {
        NSLog (@"got videoDevice");
        AVCaptureDeviceInput *videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice
                                                                                 error:&error];
        if (videoInput) {
            [captureSession addInput: videoInput];
        }
    }
    AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType: AVMediaTypeAudio];
    if (audioDevice) {
        NSLog (@"got audioDevice");
        AVCaptureDeviceInput *audioInput = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice
                                                                                 error:&error];
        if (audioInput) {
            [captureSession addInput: audioInput];
        }
    }
}

// create a preview layer from the session and add it to UI
AVCaptureVideoPreviewLayer *previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:captureSession];
previewLayer.frame = view.layer.bounds;
previewLayer.videoGravity = AVLayerVideoGravityResizeAspect;
previewLayer.orientation = AVCaptureVideoOrientationPortrait;
[view.layer addSublayer:previewLayer];

// create capture file output

captureMovieOutput = [[AVCaptureMovieFileOutput alloc] init];
if (! captureMovieURL) {
    captureMoviePath = [[self getMoviePathWithName:MOVIE_FILE_NAME] retain];
    captureMovieURL = [[NSURL alloc] initFileURLWithPath:captureMoviePath];
}
NSLog (@"recording to %@", captureMovieURL);
[captureSession addOutput:captureMovieOutput];

I use AVAssetExportSession to get videos with duration 10 seconds.

     AVURLAsset *asset = [AVURLAsset URLAssetWithURL:captureMovieURL options:[NSDictionary  dictionaryWithObject:@"YES" forKey:AVURLAssetPreferPreciseDurationAndTimingKey]];


AVMutableComposition *composition = [AVMutableComposition composition];

CMTime endTime;
CMTime duration = CMTimeMake(6000, 600);
if (asset.duration.value - startFragment.value < 6000)
{
    endTime = asset.duration;
}
else
{
    endTime = CMTimeMake(startFragment.value + 6000, 600);        
}
CMTimeRange editRange = CMTimeRangeMake(startFragment, duration);
startFragment = CMTimeMake(endTime.value, 600);
  NSError *editError = nil;
// and add into your composition 


[composition insertTimeRange:editRange ofAsset:asset atTime:composition.duration error:&editError];

 AVAssetExportSession *exportSession = [AVAssetExportSession exportSessionWithAsset:composition presetName:AVAssetExportPresetPassthrough];

exportSession.shouldOptimizeForNetworkUse = YES;
NSString *name = [NSString stringWithFormat:MOVUE_SEGMENT_NAME, countMovies];
NSString *path = [NSString stringWithFormat:@"file://localhost%@", [self getMoviePathWithName:name]];
NSURL *url = [NSURL URLWithString:path];
NSLog(@"urlsegment = %@", url);
exportSession.outputFileType = AVFileTypeMPEG4;
exportSession.outputURL = url;
[exportSession exportAsynchronouslyWithCompletionHandler:^{

    if (AVAssetExportSessionStatusCompleted == exportSession.status) 
    {
        countMovies++;

        NSLog(@"AVAssetExportSessionStatusCompleted");

    } 
    else if (AVAssetExportSessionStatusFailed == exportSession.status) 
    {                    
         NSLog(@"AVAssetExportSessionStatusFailed: %@", [exportSession.error localizedDescription]);

    } 
    else 
    {
        NSLog(@"Export Session Status: %d", exportSession.status);
    }
}];  

I send video to server if export session status is completed. But it is very slow. To get movie with duration 10 seconds and then it send to server necessary 15 seconds. If the size of the film is less than 10 seconds then nothing changes. How can I solve this problem? What is the best way to do this? How can I solve this problem? What better use for streaming video on the server?

回答1:

using ffmpeg to encode the metadata,it maybe better than AVAssetExportSession.But ffmpeg encoding is much more difficult than AVAssetExportSession;