Playing with movie tracks using AVFoundation in Swift (command line version)

movietracks.swift

#!/usr/bin/env swift

import Foundation
import AVFoundation


if Process.arguments.count != 2 {
  println("The first and only argument should be a full path to a movie or music file.")
  exit(1)
}

if let url = NSURL(fileURLWithPath:Process.arguments[1]) {
  let theOpts = [
    AVURLAssetPreferPreciseDurationAndTimingKey : true,
    AVURLAssetReferenceRestrictionsKey : 0 // AVAssetReferenceRestrictions.RestrictionForbidNone
  ]

  if let movie = AVURLAsset(URL:url, options:theOpts) {
    println("We have a movie")
    println("==============================")
    println("Getting the total number of tracks:")
    println("Movie has \(movie.tracks.count) tracks")
    println("==============================")
    println("Getting the number of tracks based on their characteristics")
    println("Movie has \(movie.tracksWithMediaCharacteristic(AVMediaCharacteristicVisual).count) visual tracks")
    println("Movie has \(movie.tracksWithMediaCharacteristic(AVMediaCharacteristicAudible).count) audible tracks")
    println("==============================")
    println("Getting the number of tracks based on their mediaType")
    println("Movie has \(movie.tracksWithMediaType(AVMediaTypeVideo).count) video tracks")
    println("Movie has \(movie.tracksWithMediaType(AVMediaTypeAudio).count) audio tracks")
    println("==============================")
    println("Now getting the CMPersistentTrackID for each track")
    var trackID:CMPersistentTrackID = CMPersistentTrackID(kCMPersistentTrackID_Invalid)
    for (index, track) in enumerate(movie.tracks) {
      trackID = track.trackID
      println("Track at index: \(index) has track ID: \(trackID)")
    }
    println("==============================")
    println("Now get the track with the last track ID")
    let track:AVAssetTrack = movie.trackWithTrackID(trackID)
    println("Track with trackID: \(trackID) is: \(track)")
    println()
    println("==============================")
    println("Lets get the track segments of one of the last track")
    for (index, segment) in enumerate(track.segments) {
      let sourceRange = CMTimeRangeCopyAsDictionary(segment.timeMapping.source, kCFAllocatorDefault)
      println("Segment \(index) time range for source: \(sourceRange)")
      let targetRange = CMTimeRangeCopyAsDictionary(segment.timeMapping.target, kCFAllocatorDefault)
      println("Segment \(index) time range for target: \(targetRange)")
    }
  }
}