AVAssetExportSession Trim & Download - ios

Question

I'm trying to trim and download online video using AVExportSession.
code:
FileMove *fileMove = (FileMove*)data;
NSString *url = #"http://download.wavetlan.com/SVV/Media/HTTP/H264/Talkinghead_Media/H264_test1_Talkinghead_mp4_480x360.mp4";
NSURL *videoURL = [NSURL URLWithString:[url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSLog(#"VideoURL: %#",videoURL);
AVAsset *anAsset = [AVURLAsset URLAssetWithURL:videoURL options:nil];
NSArray *compatiblePresets = [AVAssetExportSession exportPresetsCompatibleWithAsset:anAsset];
if ([compatiblePresets containsObject:AVAssetExportPresetLowQuality]) {
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc]
initWithAsset:anAsset presetName:AVAssetExportPresetLowQuality];
NSURL *outputURL = [NSURL fileURLWithPath:fileMove.dst];
NSLog(#"outputURL: %#",outputURL);
exportSession.outputURL = outputURL;
exportSession.outputFileType = AVFileTypeQuickTimeMovie;
CMTime start = CMTimeMakeWithSeconds(1.0, 600);
CMTime duration = CMTimeMakeWithSeconds(3.0, 600);
CMTimeRange range = CMTimeRangeMake(start, duration);
exportSession.timeRange = range;
if ([[NSFileManager defaultManager] fileExistsAtPath:fileMove.dst])
[[NSFileManager defaultManager] removeItemAtPath:fileMove.dst error:nil];
[exportSession exportAsynchronouslyWithCompletionHandler:^{
switch ([exportSession status]) {
case AVAssetExportSessionStatusFailed:
NSLog(#"Export failed: %#", [[exportSession error]description ]);
break;
case AVAssetExportSessionStatusCancelled:
NSLog(#"Export canceled");
break;
default:
break;
}
}];
}
Error:
Export failed: Error Domain=AVFoundationErrorDomain Code=-11800 "The
operation could not be completed" UserInfo=0x635a820
{NSLocalizedDescription=The operation could not be completed,
NSUnderlyingError=0x1ff4240 "The operation couldn’t be completed.
(OSStatus error -12780.)", NSLocalizedFailureReason=An unknown error
occurred (-12780)}
Do you guys see any issue in the code ? Is there any limitation in AVExportSession accessing online video ?

Answer 1

I've managed to trim remote video using AVFoundation. Here is the sample code which is written in Swift:
let range: CMTimeRange
let sourceURL: NSURL
let targetFileURL: NSURL
let requiredKeys = [ "exportable", "tracks" ]
let asset = AVAsset(URL: sourceURL)
asset.loadValuesAsynchronouslyForKeys(requiredKeys) {
// Error handling code here
precondition(asset.statusOfValueForKey("exportable", error: nil) == .Loaded)
precondition(asset.statusOfValueForKey("tracks", error: nil) == .Loaded)
precondition(asset.exportable)
let composition = AVMutableComposition()
do {
try composition.insertTimeRange(range, ofAsset: asset, atTime: kCMTimeZero)
} catch {
// Error handling code here
return
}
let finalComposition = composition.copy() as! AVComposition
guard let export = AVAssetExportSession(asset: finalComposition, presetName: AVAssetExportPresetPassthrough) else {
// Error handling code here
return
}
export.outputURL = targetFileURL
export.outputFileType = AVFileTypeMPEG4
export.exportAsynchronouslyWithCompletionHandler {
switch export.status {
case .Completed:
// Alright!
break
case .Cancelled, .Failed:
// Error handling code here
break
default:
fatalError("Shouldn't be called")
}
}
}

Answer 2

The URL used for creating an AVAsset needs to be a local file that you have access to. You will need to download it onto the device before creating the AVAsset like so

Answer 3

I think we are not able to export online videos
see here:
Unable to export AVPlayerItem
So I guess, you can download video first locally and then trim,save and use it.