问题
i'm developing an app that export audio file stored in the iPod library, but i should verify the file size before export and upload (server has a fixed max upload size):
- i know that after exporting file, the size will not be the same: is there any method to estimate the new size ?
- main question : can i know the original file size before export (using MPMediaItem or something else), so i can tell user that this file can't be uploaded (the export can take a while). thanks.
回答1:
I have not tested but AVAssetExportSession can help you with this.
MPMediaItem *curItem = musicPlayer.nowPlayingItem;
NSURL *url = [curItem valueForProperty: MPMediaItemPropertyAssetURL];
AVURLAsset *songAsset = [AVURLAsset URLAssetWithURL: url options:nil];
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset: songAsset
presetName: AVAssetExportPresetPassthrough];
exporter.estimatedOutputFileLength will give you size in bytes.
回答2:
I'm not sure, but i think you could use:
MPMediaItem *item = [[collection items] objectAtIndex:0];
NSURL *url = [item valueForProperty:MPMediaItemPropertyAssetURL];
NSData *data = [NSData dataWithContentsOfURL:url];
NSLog(@"length %d",[data length]);
Regards,
Mariano
来源:https://stackoverflow.com/questions/20684800/get-audio-file-size-without-export