I’m trying to attach some XMP metadata to a QuickTime video I'm exporting using AVAssetExportSession.
AVFoundation does support writing metadata (AVMetadataItem) and I’ve managed to export simple values which can subsequently be examined using exiftool:
AVMutableMetadataItem *item = [AVMutableMetadataItem metadataItem];
item.identifier = [AVMetadataItem identifierForKey:AVMetadataCommonKeyTitle keySpace:AVMetadataKeySpaceCommon];
item.value = #"My Title";
exportSession.metadata = #[item];
But I’m having trouble configuring my AVMetadataItem’s to correctly encode XMP. According to the Adobe XMP spec, XMP in QuickTime videos should be under the moov / udta / XMP_ atoms but I can’t see a way to make hierarchical metadata using the AVFoundation API, or any key space that corresponds to this part of the metadata.
I also need to write XMP metadata to images, and Image I/O does have direct support for this (CGImageMetadataCreateFromXMPData), but I can't find anything equivalent in AVFoundation.
If it's not possible using AVFoundation (or similar), I'll probably look at integrating XMP-Toolkit-SDK but this feels like a clunky solution when AVFoundation almost seems to do what I need.
I finally managed to figure this after trying lots of variations of keys/key spaces and other attributes of AVMetadataItem:
Use a custom XMP_ key in the AVMetadataKeySpaceQuickTimeUserData key space
Set the value not as an NSString but as an NSData containing UTF-8 data for the payload
Set the dataType to raw data
This results in XMP attributes that can be read by exiftool as expected.
NSString *payload =
#"<x:xmpmeta xmlns:x=\"adobe:ns:meta/\" x:xmptk=\"MyAppXMPLibrary\">"
"<rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\">"
"<rdf:Description rdf:about=\"\" xmlns:xmp=\"http://ns.adobe.com/xap/1.0/\">"
"<xmp:CreatorTool>My App</xmp:CreatorTool>"
"</rdf:Description>"
"</rdf:RDF>"
"</x:xmpmeta>";
NSData *data = [payload dataUsingEncoding:kCFStringEncodingUTF8];
AVMutableMetadataItem *item = [AVMutableMetadataItem metadataItem];
item.identifier = [AVMetadataItem identifierForKey:#"XMP_"
keySpace:AVMetadataKeySpaceQuickTimeUserData];
item.dataType = (NSString *)kCMMetadataBaseDataType_RawData;
item.value = data;
exportSession.metadata = #[item];
We have videos encoded via bitmovin.com and provided as HTTP Live Streams (Fairplay HLS), but subtitles although in WebVTT format are exposed separately as direct URLs for the whole file, not individual segments and are not part of the HLS m3u8 playlist.
I am looking for the way how an external .vtt file downloaded separately can still be included in the HLS stream and be available as a subtitle in AVPlayer.
I know Apple's recommendation is to include segmented VTT subtitles into the HLS playlist, but I can't change the server implementation right now, so I want to clarify if it is even possible to provide the subtitle to AVPlayer to play along with the HLS stream.
The only valid post on this subject claiming it is possible is this: Subtitles for AVPlayer/MPMoviePlayerController. However, the sample code loads local mp4 file from bundle and I am struggling to make it work for m3u8 playlist via AVURLAsset. Actually, I am having problem to get videoTrack from the remote m3u8 stream as the asset.tracks(withMediaType: AVMediaTypeVideo) returns empty array. Any ideas if this approach can work for real HLS stream? Or is there any other way to play separate WebVTT subtitle with HLS stream without including them into HLS playlist on the server? Thanks.
func playFpsVideo(with asset: AVURLAsset, at context: UIViewController) {
let composition = AVMutableComposition()
// Video
let videoTrack = composition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: kCMPersistentTrackID_Invalid)
do {
let tracks = asset.tracks(withMediaType: AVMediaTypeVideo)
// ==> The code breaks here, tracks is an empty array
guard let track = tracks.first else {
Log.error("Can't get first video track")
return
}
try videoTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, asset.duration), of: track, at: kCMTimeZero)
} catch {
Log.error(error)
return
}
// Subtitle, some test from the bundle..
guard let subsUrl = Bundle.main.url(forResource: "subs", withExtension: "vtt") else {
Log.error("Can't load subs.vtt from bundle")
return
}
let subtitleAsset = AVURLAsset(url: subsUrl)
let subtitleTrack = composition.addMutableTrack(withMediaType: AVMediaTypeText, preferredTrackID: kCMPersistentTrackID_Invalid)
do {
let subTracks = subtitleAsset.tracks(withMediaType: AVMediaTypeText)
guard let subTrack = subTracks.first else {
Log.error("Can't get first subs track")
return
}
try subtitleTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, asset.duration), of: subTrack, at: kCMTimeZero)
} catch {
Log.error(error)
return
}
// Prepare item and play it
let item = AVPlayerItem(asset: composition)
let player = AVPlayer(playerItem: item)
let playerViewController = AVPlayerViewController()
playerViewController.player = player
self.playerViewController = playerViewController
context.present(playerViewController, animated: true) {
playerViewController.player?.play()
}
}
I figured this out. It took forever and I hated it. I'm putting my explanation and source code on Github but I'll put stuff here too incase the link dies for whatever reason: https://github.com/kanderson-wellbeats/sideloadWebVttToAVPlayer
I'm dropping this explanation here to try to save some future people a lot of pain. Lots of stuff I found online was wrong, or left out confusing pieces, or had a bunch of extra irrelevant information, or a mixture of all three. On top of that, I saw lots of people asking for help and trying to do the same thing with nobody providing any clear answers.
So to begin I'll describe what I'm trying to do. My backend server is Azure Media Services, and it's been really great for streaming different resolution video as needed but it just doesn't really support WebVtt. Yeah you can host a file on there, but it seems it cannot give us a master playlist that includes a reference to the subtitles playlist (as Apple requires). It seems both Apple and Microsoft decided what they were going to do with subtitles back in like 2012 and haven't touched it since. At that time they either didn't talk to each other or deliberately went opposite directions, but they happen to have poor intercompatibilty, and now devs like us are forced to stretch the gap between the behemoths. Many of the resources online covering this topic are addressing things like optimized caching of arbitrary streamed data, but I found those resources to be more confusing than helpful. All I'm wanting to do is add subtitles to on-demand videos played in AVPlayer being served by Azure Media Services with the HLS protocol when I have a hosted WebVtt file - nothing more, nothing less. I'll start by describing everything in words, then I'll put the actual code at the end.
Here is the extremely condensed version of what you need to do:
Intercept the requests for the master playlist and return an edited version of it that references the subtitle playlists (multiple for multiple languages, or just one for one language)
Select a subtitle to show (well documented on https://developer.apple.com/documentation/avfoundation/media_playback_and_selection/selecting_subtitles_and_alternative_audio_tracks )
Intercept requests to the subtitle playlists that will come through (after you've selected a subtitle to show) and return playlists you've built on the fly that reference the WebVtt files on the server
That's it. Not too much, except there are many complications that get in the way that I had to discover myself. I'll describe them each first briefly and then in greater detail.
Brief complication explanations:
Many requests will be coming through, but you should only (and can only) handle a couple of them yourself, the others need to be allowed to pass through untouched. I will describe which ones need handling and which ones don't and how to handle them.
Apple decided a simple HTTP request was not good enough and decided to obscure things by translating it into a weird double-identity AVAssetResourceLoadingRequest thing that has a DataRequest property (AVAssetResourceLoadingDataRequest) and a ContentInformationRequest property (AVAssetResourceLoadingContentInformationRequest). I still don't understand why this was necessary or what benefit it brings, but what I've done here with them is working. Some promising blogs/resources seem to suggest you have to mess with the ContentInformationRequest but I find that you can simply ignore the ContentInformationRequest, and in fact messing with it more often than not just breaks things.
Apple suggests you segment your VTT file into small pieces, but you simply can't do this client-side (Apple disallows this), but luckily it also seems you don't actually have to do it, it's merely a suggestion.
INTERCEPTING REQUESTS
To intercept requests, you have to subclass/extend AVAssetResourceLoaderDelegate and the method of interest is the ShouldWaitForLoadingOfRequestedResource method. To make use of the delegate, instantiate your AVPlayer by handing it an AVPlayerItem but hand the AVPlayerItem an AVUrlAsset which has a delegate property you assign the delegate to. All the requests will come through the ShouldWaitForLoadingOfRequestedResource method so that's where all the business will happen, except for one sneaky complication - the method will only be invoked if requests begin with something other than http/https, so my advice is to stick a constant string at the front of the Url you're using to create your AVUrlAsset, which you can then just shave off after the requests comes in to your delegate - let's call that "CUSTOMSCHEME". This part is described in a couple of places online, but it can be super frustrating if you don't know you have to do it because it will seem like nothing is happening at all.
INTERCEPTING - TYPE A) redirecting
Ok so now we're intercepting requests, but you don't want to (/can't) handle them all yourself. Some of the requests you just want to allow to pass through. You do this by doing the following:
create a new NSUrlRequest to the CORRECTED Url (shave off that "CUSTOMSCHEME" part from earlier) and set it to the Redirect property on the LoadingRequest
create a new NSHttpUrlResponse with that same corrected Url and a 302 code and set it to the Response property on the LoadingRequest
call FinishLoading on the LoadingRequest
return true
With those steps you can add in breakpoints and stuff to debug and inspect all the requests that will come through, but they'll proceed normally so you won't break anything. However, this approach isn't just for debugging, it's also a necessary thing to do for several requests even in the finished project.
INTERCEPTING - TYPE B) editing/faking response
When some requests come in, you'll want to do a request of your own so the response to your request (with some tweaking) can be used to fulfill the LoadingRequest. So do the following:
create an NSUrlSession and call the CreateDataTask method on the session (with a corrected URL - remove the "CUSTOMSCHEME")
call Resume on the DataTask (outside of the callback on the DataTask)
return true
up in the DataTask's callback you'll have data, so (after doing your edits) you call Respond on the LoadingRequest's DataRequest property with that (edited) data, followed by calling FinishLoading on the LoadingRequest
INTERCEPTING - which requests get which type of treatment
Lots of requests will come in, some need to be redirected, some need to be given manufactured/altered data responses. Here are the types of requests you'll see in the order they'll come in and what to do with each:
a request to the master playlist, but the DataRequest's RequestedLength is 2 - just redirect (TYPE A)
a request to the master playlist, but the DataRequest's RequestedLength matches the (unedited) length of the master playlist - do your own request to the master playlist so you can edit it and return the edited result (TYPE B)
a request to the master playist, but the DataRequest's RequestedLength is humongous - do the same thing as you did for the previous one (TYPE B)
lots of requests will come through for fragments of audio and video - all these requests need to be redirected (TYPE A)
once you get the master playlist edited correctly (and a subtitle selected) a request will come through for the subtitle playlist - edit this one to return a manufactured subtitle playlist (TYPE B)
HOW TO EDIT THE PLAYLISTS - master playlist
The master playlist is easy to edit. The change is two things:
each video resource has its own line and they all need to be told about the subtitle group (for each line that starts with #EXT-X-STREAM-INF I'm adding ,SUBTITLES="subs" on the end)
new lines need to be added for each subtitle language/type, all belonging to the subtitle group with their own URL (so for each type, add a line like #EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="subs",LANGUAGE="!!!yourLanguageHere!!!",NAME="!!!yourNameHere!!!",AUTOSELECT=YES,URI="!!!yourCustomUrlHere!!!"
The !!!yourCustomUrlHere!!! you use in step 2 will have to be detected by you when it's used for a request so you can return the manufactured subtitle playlist as part of the response, so set it to something unique. That Url will also have to use the "CUSTOMSCHEME" thing so that it comes to the delegate. You can also check out this streaming example to see how the manifest should look: https://developer.apple.com/streaming/examples/basic-stream-osx-ios5.html (sniff the network traffic with the browser debugger to see it).
HOW TO EDIT THE PLAYLISTS - subtitle playlist
The subtitle playlist is a little more complicated. You have to make the whole thing yourself. The way I've done it is to actually grab the WebVtt file myself inside the DataTask callback, then parse the thing down to find the end of the very last timestamp sequence, convert that to an integer number of seconds, and then insert that value in a couple places in a big string. Again, you can use the example listed above and sniff network traffic to see a real example for yourself. So it looks like this:
#EXTM3U
#EXT-X-TARGETDURATION:!!!thatLengthIMentioned!!!
#EXT-X-VERSION:3
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-PLAYLIST-TYPE:VOD
#EXTINF:!!!thatLengthIMentioned!!!
!!!absoluteUrlToTheWebVttFileOnTheServer!!!
#EXT-X-ENDLIST
Note that the playlist does NOT segment the vtt file as Apple recommends because this can't be done client-side (source: https://developer.apple.com/forums/thread/113063?answerId=623328022#623328022 ). Also note that I do NOT put a comma at the end of the "EXTINF" line even though Apple's example here says to do that, because it seems to break it: https://developer.apple.com/videos/play/wwdc2012/512/
Now the actual code:
public class CustomResourceLoaderDelegate : AVAssetResourceLoaderDelegate
{
public const string LoaderInterceptionWorkaroundUrlPrefix = "CUSTOMSCHEME"; // a scheme other than http(s) needs to be used for AVUrlAsset's URL or ShouldWaitForLoadingOfRequestedResource will never be called
private const string SubtitlePlaylistBoomerangUrlPrefix = LoaderInterceptionWorkaroundUrlPrefix + "SubtitlePlaylist";
private const string SubtitleBoomerangUrlSuffix = "m3u8";
private readonly NSUrlSession _session;
private readonly List<SubtitleBundle> _subtitleBundles;
public CustomResourceLoaderDelegate(IEnumerable<WorkoutSubtitleDto> subtitles)
{
_subtitleBundles = subtitles.Select(subtitle => new SubtitleBundle {SubtitleDto = subtitle}).ToList();
_session = NSUrlSession.FromConfiguration(NSUrlSessionConfiguration.DefaultSessionConfiguration);
}
public override bool ShouldWaitForLoadingOfRequestedResource(AVAssetResourceLoader resourceLoader,
AVAssetResourceLoadingRequest loadingRequest)
{
var requestString = loadingRequest.Request.Url.AbsoluteString;
var dataRequest = loadingRequest.DataRequest;
if (requestString.StartsWith(SubtitlePlaylistBoomerangUrlPrefix))
{
var uri = new Uri(requestString);
var targetLanguage = uri.Host.Split(".").First();
var targetSubtitle = _subtitleBundles.FirstOrDefault(s => s.SubtitleDto.Language == targetLanguage);
Debug.WriteLine("### SUBTITLE PLAYLIST " + requestString);
if (targetSubtitle == null)
{
loadingRequest.FinishLoadingWithError(new NSError());
return true;
}
var subtitlePlaylistTask = _session.CreateDataTask(NSUrlRequest.FromUrl(NSUrl.FromString(targetSubtitle.SubtitleDto.CloudFileURL)),
(data, response, error) =>
{
if (error != null)
{
loadingRequest.FinishLoadingWithError(error);
return;
}
if (data == null || !data.Any())
{
loadingRequest.FinishLoadingWithError(new NSError());
return;
}
MakePlaylistAndFragments(targetSubtitle, Encoding.UTF8.GetString(data.ToArray()));
loadingRequest.DataRequest.Respond(NSData.FromString(targetSubtitle.Playlist));
loadingRequest.FinishLoading();
});
subtitlePlaylistTask.Resume();
return true;
}
if (!requestString.ToLower().EndsWith(".ism/manifest(format=m3u8-aapl)") || // lots of fragment requests will come through, we're just going to fix their URL so they can proceed normally (getting bits of video and audio)
(dataRequest != null &&
dataRequest.RequestedOffset == 0 && // this catches the first (of 3) master playlist requests. the thing sending out these requests and handling the responses seems unable to be satisfied by our handling of this (just for the first request), so that first request is just let through. if you mess with request 1 the whole thing stops after sending request 2. although this means the first request doesn't get the same edited master playlist as the second or third, apparently that's fine.
dataRequest.RequestedLength == 2 &&
dataRequest.CurrentOffset == 0))
{
Debug.WriteLine("### REDIRECTING REQUEST " + requestString);
var redirect = new NSUrlRequest(new NSUrl(requestString.Replace(LoaderInterceptionWorkaroundUrlPrefix, "")));
loadingRequest.Redirect = redirect;
var fakeResponse = new NSHttpUrlResponse(redirect.Url, 302, null, null);
loadingRequest.Response = fakeResponse;
loadingRequest.FinishLoading();
return true;
}
var correctedRequest = new NSMutableUrlRequest(new NSUrl(requestString.Replace(LoaderInterceptionWorkaroundUrlPrefix, "")));
if (dataRequest != null)
{
var headers = new NSMutableDictionary();
foreach (var requestHeader in loadingRequest.Request.Headers)
{
headers.Add(requestHeader.Key, requestHeader.Value);
}
correctedRequest.Headers = headers;
}
var masterPlaylistTask = _session.CreateDataTask(correctedRequest, (data, response, error) =>
{
Debug.WriteLine("### REQUEST CARRIED OUT AND RESPONSE EDITED " + requestString);
if (error == null)
{
var dataString = Encoding.UTF8.GetString(data.ToArray());
var stringWithSubsAdded = AddSubs(dataString);
dataRequest?.Respond(NSData.FromString(stringWithSubsAdded));
loadingRequest.FinishLoading();
}
else
{
loadingRequest.FinishLoadingWithError(error);
}
});
masterPlaylistTask.Resume();
return true;
}
private string AddSubs(string dataString)
{
var tracks = dataString.Split("\r\n").ToList();
for (var ii = 0; ii < tracks.Count; ii++)
{
if (tracks[ii].StartsWith("#EXT-X-STREAM-INF"))
{
tracks[ii] += ",SUBTITLES=\"subs\"";
}
}
tracks.AddRange(_subtitleBundles.Select(subtitle => "#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID=\"subs\",LANGUAGE=\"" + subtitle.SubtitleDto.Language + "\",NAME=\"" + subtitle.SubtitleDto.Title + "\",AUTOSELECT=YES,URI=\"" + SubtitlePlaylistBoomerangUrlPrefix + "://" + subtitle.SubtitleDto.Language + "." + SubtitleBoomerangUrlSuffix + "\""));
var finalPlaylist = string.Join("\r\n", tracks);
return finalPlaylist;
}
private void MakePlaylistAndFragments(SubtitleBundle subtitle, string vtt)
{
var noWhitespaceVtt = vtt.Replace(" ", "").Replace("\n", "").Replace("\r", "");
var arrowIndex = noWhitespaceVtt.LastIndexOf("-->");
var afterArrow = noWhitespaceVtt.Substring(arrowIndex);
var firstColon = afterArrow.IndexOf(":");
var period = afterArrow.IndexOf(".");
var timeString = afterArrow.Substring(firstColon - 2, period /*(+ 2 - 2)*/);
var lastTime = (int)TimeSpan.Parse(timeString).TotalSeconds;
var resultLines = new List<string>
{
"#EXTM3U",
"#EXT-X-TARGETDURATION:" + lastTime,
"#EXT-X-VERSION:3",
"#EXT-X-MEDIA-SEQUENCE:0",
"#EXT-X-PLAYLIST-TYPE:VOD",
"#EXTINF:" + lastTime,
subtitle.SubtitleDto.CloudFileURL,
"#EXT-X-ENDLIST"
};
subtitle.Playlist = string.Join("\r\n", resultLines);
}
private class SubtitleBundle
{
public WorkoutSubtitleDto SubtitleDto { get; set; }
public string Playlist { get; set; }
}
public class WorkoutSubtitleDto
{
public int WorkoutID { get; set; }
public string Language { get; set; }
public string Title { get; set; }
public string CloudFileURL { get; set; }
}
}
If using a streaming service where you can edit the streaming manifest and upload other files where your encoded media is, then with a little bit of manual work (which could be scripted out), you can put the subtitles in the manifest in the way that iOS expects it to be. I was able to get this to work with Azure Media Services, although it is a little hacky.
Since Azure Media Services—which I'll call AMS from now on—streaming endpoints create the streaming manifest on the fly, I couldn't just add the necessary changes to a file. Instead, I created a new master playlist based off of AMS' generated playlist. #SomeXamarinDude explains in his answer the changes that are needed in the master playlist, but I'm going to include an example for completeness.
Let's say the AMS generated master playlist from a streaming endpoint with the URL:
https://mediaservicename-use2.streaming.media.azure.net/d36754c2-c8cf-4f0f-b73f-dafd21fff50f/YOUR-ENCODED-ASSET.ism/manifest\(format\=m3u8-aapl\)
Looks like this:
#EXTM3U
#EXT-X-VERSION:4
#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="aac_eng_2_128079_2_1",LANGUAGE="eng",DEFAULT=YES,AUTOSELECT=YES,URI="QualityLevels(128079)/Manifest(aac_eng_2_128079_2_1,format=m3u8-aapl)"
#EXT-X-STREAM-INF:BANDWIDTH=623543,RESOLUTION=320x180,CODECS="avc1.640015,mp4a.40.2",AUDIO="audio"
QualityLevels(466074)/Manifest(video,format=m3u8-aapl)
#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=623543,RESOLUTION=320x180,CODECS="avc1.640015",URI="QualityLevels(466074)/Manifest(video,format=m3u8-aapl,type=keyframes)"
#EXT-X-STREAM-INF:BANDWIDTH=976825,RESOLUTION=480x270,CODECS="avc1.64001e,mp4a.40.2",AUDIO="audio"
QualityLevels(811751)/Manifest(video,format=m3u8-aapl)
...
Then, the manually created playlist—which I'll name manually-created-playlist.m3u8—will need to look like this:
#EXTM3U
#EXT-X-VERSION:4
#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="subs",NAME="English",LANGUAGE="en",AUTOSELECT=YES,URI="https://mediaservicename-use2.streaming.media.azure.net/d36754c2-c8cf-4f0f-b73f-dafd21fff50f/subtitle-playlist.m3u8"
#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="aac_eng_2_128079_2_1",LANGUAGE="eng",DEFAULT=YES,AUTOSELECT=YES,URI="YOUR-ENCODED-ASSET.ism/QualityLevels(128079)/Manifest(aac_eng_2_128079_2_1,format=m3u8-aapl)"
#EXT-X-STREAM-INF:SUBTITLES="subs",BANDWIDTH=623543,RESOLUTION=320x180,CODECS="avc1.640015,mp4a.40.2",AUDIO="audio"
YOUR-ENCODED-ASSET.ism/QualityLevels(466074)/Manifest(video,format=m3u8-aapl)
#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=623543,RESOLUTION=320x180,CODECS="avc1.640015",URI="YOUR-ENCODED-ASSET.ism/QualityLevels(466074)/Manifest(video,format=m3u8-aapl,type=keyframes)"
#EXT-X-STREAM-INF:SUBTITLES="subs",BANDWIDTH=976825,RESOLUTION=480x270,CODECS="avc1.64001e,mp4a.40.2",AUDIO="audio"
YOUR-ENCODED-ASSET.ism/QualityLevels(811751)/Manifest(video,format=m3u8-aapl)
...
Note that the path changes I had to make to the various bitrate playlists.
This manual playlist will then need to be uploaded to the same Azure Storage Container that contains the rest of your encoded media assets.
I also had to create and upload a file called subtitle-playlist.m3u8 and a transcript.vtt to the same Azure Storage Container. My subtitle playlist looked like this:
#EXTM3U
#EXT-X-TARGETDURATION:61
#EXT-X-ALLOW-CACHE:YES
#EXT-X-PLAYLIST-TYPE:VOD
#EXT-X-VERSION:3
#EXT-X-MEDIA-SEQUENCE:1
#EXTINF:61.061000
https://mediaservicename-use2.streaming.media.azure.net/d36754c2-c8cf-4f0f-b73f-dafd21fff50f/transcript.vtt
#EXT-X-ENDLIST
Note that some of the subtitle playlist values depend on the length of the WebVTT file.
At this point, you should be able to point a HLS player to the following URL and be able to enable closed captions:
https://mediaservicename-use2.streaming.media.azure.net/d36754c2-c8cf-4f0f-b73f-dafd21fff50f/manually-created-master-playlist.m3u8
I hope this helps someone. Apparently there is a ticket in the works for fixing this on AMS' side.
Thank you to #SomeXamarinDude for your answer; I would have been totally lost with this issue if it weren't for all the groundwork you put in.
I am a developer in an IpTV. We have developed our application in Android and now we want to move on IOS devices. Akamai is our CDN.
At the moment we have a simple IOS application which is able to play HLS streams. We can navigate through each channel and all streams are played correctly.
To protect our streams we planned to use token. We already have implemented the token on android but I am now experiencing some difficulties on IOS. Streams protected with token won't play, the screen remains black.
Here is an example of my stream
http://this_is_my_stream_protected_with_token.m3u8?token=exp=1432902926~acl=*~hmac=1e1d2afa7e7fbca72b0da6f5820ba1063446631e75fea80093c8183b619c0acc
If i try to play this stream in my application,screen remains black in the other hand if i open with VLC or a player in webbrowser (http://www.flashls.org/latest/examples/chromeless/) it playes correctly.
I have created a function that makes a http request on that link and server response is:
#EXTM3U
#EXT-X-VERSION:3
#EXT-X-STREAM-INF:BANDWIDTH=1629884,CODECS="avc1.77.31,mp4a.40.2",RESOLUTION=640x360
chunklist.m3u8?__token__=exp%3D1432902926%7Eacl%3D*%7Ehmac%3D1e1d2afa7e7fbca72b0da6f5820ba1063446631e75fea80093c8183b619c0acc
To make sure my application generate correctly the token, i made it hardcoded and i still have the same problem.
Since this is not an Akamai problem neither token generation problem, it makes me believe that perhaps i need to encode the stream somehow in the player. I have read everywhere about this problem and still don't have a working solution
Here is my player code:
var param = ["auth":encryption.Token()] as Dictionary<String,String>;
WebHelper().httpPostNSString(currentChannel.channelTokenUrl, params: param, consumeData: { (nsstring) -> () in
//this is a custom method. it makes a post HttpRequest. It takes Token Url path and Dictionary with parameters and it returns the respnse data converted to String.
token = nsstring;
_URL_ += token;
_URL_ = _URL_.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet());
//remove spaces just in case (this is a 'MUST' in Android)
var address = "http://this_is_my_stream_protected_with_token.m3u8?__token__=exp=1432902926~acl=*~hmac=1e1d2afa7e7fbca72b0da6f5820ba1063446631e75fea80093c8183b619c0acc"
let url = NSURL(string: address)
self.moviePlayer = MPMoviePlayerController(contentURL: url)
self.moviePlayer?.controlStyle = MPMovieControlStyle.None;
if(self.db.select.getStringValue(forKey: self.db.STRING_VALUE_CURRENT_CHANNEL) == nil){
self.db.insert.CoreData_Insert(value: "-1", coreDataKey: self.db.STRING_VALUE_CURRENT_CHANNEL)
}
Logs().sendHit(currentChannel.channelNumber, accessway: self.access_way, lastchannel: self.db.select.getStringValue(forKey: self.db.STRING_VALUE_CURRENT_CHANNEL).value, username: self.db.select.getStringValue(forKey: self.db.STRING_VALUE_USERNAME).value);
self.db.delete.deleteEntityFromCore(entityName: "StringValue", field_Name: "key", field_Value: self.db.STRING_VALUE_CURRENT_CHANNEL);
self.db.insert.CoreData_Insert(value: currentChannel.channelNumber, coreDataKey: self.db.STRING_VALUE_CURRENT_CHANNEL);
//we save some data and than proceed to play selected channel.
if let player = self.moviePlayer{
//save the new channel
player.view.frame = self.view.bounds
player.prepareToPlay()
player.scalingMode = .AspectFill
self.view.addSubview(player.view)
self.view.bringSubviewToFront(self.two_way_channel);
player.play();
//send hits
}
})
Thank You
I'm implementing an AVAssetResourceLoaderDelegate, and I'm having a bit of trouble getting to to behave correctly. My goal is to intercept any requests made by the AVPlayer, make the request myself, write the data out to a file, then respond to the AVPlayer with the file data.
The issue I'm seeing: I can intercept the first request, which is only asking for two bytes, and respond to it. After that, I'm not getting any more requests hitting my AVAssetResourceLoaderDelegate.
When I intercept the very first AVAssetResourceLoadingRequest from the AVPlayer it looks like this:
<AVAssetResourceLoadingRequest: 0x17ff9e40,
URL request = <NSMutableURLRequest: 0x17f445a0> { URL: fakeHttp://blah.com/blah/blah.mp3 },
request ID = 1,
content information request = <AVAssetResourceLoadingContentInformationRequest: 0x17ff9f30,
content type = "(null)",
content length = 0,
byte range access supported = NO,
disk caching permitted = NO>,
data request = <AVAssetResourceLoadingDataRequest: 0x17e0d220,
requested offset = 0,
requested length = 2,
current offset = 0>>
As you can see, this is only a request for the first two bytes of data. I'm taking the fakeHttp protocol in the URL, replacing it with just http, and making the request myself.
Then, here's how I'm responding to the request once I have some data:
- (BOOL)resourceLoader:(AVAssetResourceLoader *)resourceLoader shouldWaitForLoadingOfRequestedResource:(AVAssetResourceLoadingRequest *)loadingRequest {
//Make the remote URL request here if needed, omitted
CFStringRef contentType = UTTypeCreatePreferredIdentifierForTag(kUTTagClassMIMEType, (__bridge CFStringRef)([self.response MIMEType]), NULL);
loadingRequest.contentInformationRequest.byteRangeAccessSupported = YES;
loadingRequest.contentInformationRequest.contentType = CFBridgingRelease(contentType);
loadingRequest.contentInformationRequest.contentLength = [self.response expectedContentLength];
//Where responseData is the appropriate NSData to respond with
[loadingRequest.dataRequest respondWithData:responseData];
[loadingRequest finishLoading];
return YES;
}
I've stepped through this and verified that everything in the contentInformationRequest is filled in correctly, and that the data I'm sending is NSData with the appropriate length (in this case, two bytes).
No more requests get sent to my delegate, and the player does not play (presumably because it only has two bytes of data, and hasn't requested any more).
Does anyone have experience with this to point me toward an area where I may be doing something wrong? I'm running iOS 7.
Edit: Here's what my completed request looks like, after I call finishedLoading:
<AVAssetResourceLoadingRequest: 0x16785680,
URL request = <NSMutableURLRequest: 0x166f4e90> { URL: fakeHttp://blah.com/blah/blah.mp3 },
request ID = 1,
content information request = <AVAssetResourceLoadingContentInformationRequest: 0x1788ee20,
content type = "public.mp3",
content length = 7695463,
byte range access supported = YES,
disk caching permitted = NO>,
data request = <AVAssetResourceLoadingDataRequest: 0x1788ee60,
requested offset = 0,
requested length = 2,
current offset = 2>>
- (BOOL)resourceLoader:(AVAssetResourceLoader *)resourceLoader shouldWaitForLoadingOfRequestedResource:(AVAssetResourceLoadingRequest *)loadingRequest
{
loadingRequest.contentInformationRequest.contentType = #"public.aac-audio";
loadingRequest.contentInformationRequest.contentLength = [self.fileData length];
loadingRequest.contentInformationRequest.byteRangeAccessSupported = YES;
NSData *requestedData = [self.fileData subdataWithRange:NSMakeRange((NSUInteger)loadingRequest.dataRequest.requestedOffset,
(NSUInteger)loadingRequest.dataRequest.requestedLength)];
[loadingRequest.dataRequest respondWithData:requestedData];
[loadingRequest finishLoading];
return YES;
}
This implementation works for me. It always asks for the first two bytes and then for the whole data. If you don't get another callback it means that there was something wrong with the first response you have made. I guess the problem is that you are using MIME content type instead of UTI.
Circling back to answer my own question in case anyone was curious.
The issue boiled down to threading. Though it's not explicitly documented anywhere, AVAssetResourceLoaderDelegate does some weird stuff with threads.
Essentially, my issue was that I was creating the AVPlayerItem and AVAssetResourceLoaderDelegate on the main thread, but responding to delegate calls on a background thread (since they were the result of network calls). Apparently, AVAssetResourceLoader just completely ignores responses coming in on a different thread than it was expecting.
I solved this by just doing everything, including AVPlayerItem creation, on the same thread.