NSTask problem with --audio-format

[WiS3]

I'm using Objective-C NSTask to start youtube-dl.

Here is the code i'm currently using:

    NSString *URL = [NSString stringWithFormat:@"'%@'", _URLInput.stringValue]; // _URLInput = NSTextField with a YouTube URL
    NSArray *args = [NSArray arrayWithObjects: @"--extract-audio", @"-f 22", @"--audio-format m4a", @"-o '~/Downloads/%(extractor_key)s/%(title)s.%(ext)s'", URL, nil];
    NSOperationQueue *queue = [[NSOperationQueue alloc] init];
    [queue addOperationWithBlock:^(void) {
        NSString* youtube_dl_Path = @"/usr/local/bin/youtube-dl";

        NSTask *task = [[NSTask alloc] init];
        NSPipe *standardOutputPipe = [NSPipe pipe];
        NSPipe *standardErrorPipe = [NSPipe pipe];
                NSString* stringOutput; 
        [[standardOutputPipe fileHandleForReading]setReadabilityHandler:^(NSFileHandle *file) {
            NSData *data = [file availableData]; // this will read to EOF, so call only once
            NSLog(@"Task output! %@", [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding]);
        }];

        NSFileHandle * readError = [standardErrorPipe fileHandleForReading];

        [task setLaunchPath: youtube_dl_Path];
        [task setArguments: args];
        [task setStandardError: standardErrorPipe];

        [task launch];
        [task waitUntilExit];
        NSData* errorData = [readError readDataToEndOfFile];
        NSString* stringError = [[NSString alloc] initWithData:errorData encoding:NSASCIIStringEncoding];

        if(stringError.length > 0){
            NSLog(@"ERROR: %@",stringError);
        }else{
            NSLog(@"DONE");
        }
    }];

And i get this error:

ERROR: Usage: youtube-dl [OPTIONS] URL [URL...]
youtube-dl: error: no such option: --audio-format m4a

If i remove --audio-format m4a from the args array, it is working.
If i run directly in the terminal with the same arguments, it is working.
Only with NSTask i get this issue.
I have latest youtube-dl.

[yan12125]

I guess you need: @"--audio-format", @"m4a"

[WiS3]

Thank you! It is working now!