MPMoviePlayerController blank frame after seeking to particular time-line - ios

I am developing an iPhone application in which I play a video using MPMoviePlayerController. I use custom controls to play the video.
I have a slider that shows video time line. Using this user can seek the movie to any time-line of the movie.
When user continuously moves the slider:
Pause the video only for first time; [MPMoviePlayerController-obj pause]
MPMoviePlayerController-obj.currentPlaybackTime = slider.value
When slider action ends:
Play the video; [MPMoviePlayerController-obj play]
This plays the movie from the position where user had left the slider. But, it leads to blank frame when movie completes playing. This defect occurs randomly; i.e not for all the seek'd time.
What is the reason for getting the blank frame? How do I solve this?

I'm not sure if this will work, but try setting the initialPlaybackTime to either the slider.value or to currentPlaybackTime.

For being sure that your content is not flawed, hence possibly triggering that issue, you should try to replicate your faulty MPMoviePlayerController results using Apple's reference video content.
HTTP-Streaming: bipbop.m3u8
Progressive Download & Local
Playback: sample_mpeg4.mp4
I have personally observed many issues in connection with improper encoding. Weird things tend to happen when working with lossy compressed content. This is true for video (i-frames vs. p-frames) as well as audio (variable bitrate).
One being improper playback durations being reported. Such issue may result into an unexpected finished-state. I have seen cases where MPMoviePlayerController still shows a bunch of seconds to play even though the actual video has obviously finished. Those cases occur frequently once the user seeks around within the video.
Once you made sure that the issue occurs using the given sample files as well, you should file a bug-report.

Related

truncated sound clips on IOS

The essence of the problem is that on IOS only, playing
sound clips using
MediaManager.createMedia(clip, "audio/wav", null).play();
sometimes the playback is truncated. This is especially obvious
when the clip is several seconds long, but the point at which the
clip is truncated varies; occasionally the whole clip plays.
I've so far been unsuccessful creating a simple test case - in isolation
from my apps, the clip plays in full, so it seems like something in normal
background activity in the full app is interfering with audio playback.
I'm pretty sure I've found the root cause. MediaManager.createMedia creates an instance of Media, and when that object is garbage collected, it's finalize method is called, and a side effect of that causes the audio to be stopped.
A quick and dirty way to prevent this is to save a pointer to the media object.
This ought to be accomplished by internal bookkeeping in playaudio.

Cannot replay YouTube video on mobile twice when rel=0

The rel parameter in YouTube API dictates whether or not related videos are shown at the end. When rel=0 the video reverts back to the thumbnail with a play button.
However on mobile (tested on iPhone / iPad / Fire Tablet) when the video goes back to the thumbnail it cannot be played a second time. It just does nothing.
I reported the issue to Google but nothing yet after a few days.
I had to resort to destroying the video and recreating it but this makes for a kind of nasty flickering.
My experience with YouTube issues is they never seem to end up fixing anything related to iOS - so I was wondering if there was any other kind of trick to prevent this.
Test page
The trouble with refreshing a webpage at a specific interval is that you dont know exactly when the video ends so you need to develop a method which the video player sends a signal when the video ends, which would then start the script to refresh the page. Otherwise you end up restarting it in the middle of the video. so personally, I would not even mess with refreshing the page. For Audio players it works ok because audio is smaller and streams more quicker. Video dont.... they always stop to buffer.
So YouTube API uses "Events" and "Listeners", so in particular, you need to design around the Event: "onStateChange".
When onStateChange = "ended" (zero) the video has ended, so then you reload the video player with the same video and set it to its Ready State again.
In theory its very easy you basically need to setup and control the entire video player through javascript. And the API gives examples on that.
http://code.google.com/apis/youtube/js_api_reference.html
http://grizzlyweb.com/webmaster/javascripts/refresh.asp
http://code.google.com/apis/youtube/forum/
Have a look at loop and playlist parameters as well. You can set playlist parameter to video ID and same video can be replayed using this.
So, it will be something like:
http://www.youtube.com/embed/{VIDEO_ID}?wmode=opaque&loop=1&version=3&playlist={VIDEO_ID}
Hope this helps!
Appears to have been fixed by YouTube.
I can now play the video multiple times (on multiple devices) without it getting stuck. Was too busy wondering why my question was getting so little attention that I forgot to check again to see if it was fixed ;-)

Transitioning to background, AVPlayer Video has small audio gap

I have followed the many helpful previous questions to get my AVPlayer successfully streaming video when my app goes to the background. There are two methods described on Apple's QA1668 and they both work for my stream urls.
The problem is that there is a noticeable audio gap during the transition that is identical for both methods. On my iPhone 6 in release mode I would say the gap is less than 0.5 seconds, which may not seem terrible but if I'm playing something like a music video this is very distracting.
After more testing it looks like this gap actually occurs when I remove the AVPlayerLayer (or, if I am using the other method, when I disable the AVMediaCharacteristicVisual tracks) as I have determined it will still happen if I hook those actions up to a button rather than the backgrounding state.
My guess is that is has something to do with the audio re-syncing to the new video state of the AVPlayer but really I have no clue. Any help would be greatly appreciated!

AVPlayer setRate property create glitchy if we use setRate frequently

I have used AVPlayer to play videos in slow motion. I am using addPeriodicTimeObserverForInterval: message to get time at specific interval, and checking some condition according to current playback time. once condition is fulfilled, I am calculating rate and using setRate: message of AVPlayer. i.e I am setting rate frequently. but once I have done with this, video is not playing smoothly, it's glitchy.
Can anybody please let me know how can I set setRate: frequently.
Thanks
We were having kind of the same issue. We were using setRate:1 (or 1.5/2.0 depending on what the user chose) to play the video instead of calling play. We have changed to call play then setRate: and the video plays smoothly now.

AVComposition breaks on Airplay

I have a video composition which I'd like to play over Airplay (without mirroring). The app works as expected when using normal Airplay mirroring, but I'd like to get the speed, reliability, and resolution bump you get from using Airplay video instead.
The problem is that when I set
player.usesAirPlayVideoWhileAirPlayScreenIsActive = YES;
...the player goes blank.
Notes:
Since I don't create separate windows for each display, they are both trying to use the same AVPlayer.
My AVVideoComposition contains different files and adds opacity ramps between them.
This unanswered question suggests that the problem is more likely due to the fact that I'm playing an AVComposition than the use of a shared player: AVComposition doesn't play via Airplay Video
Two questions:
Do I have to get rid of the player on the iPad?
Can an AVVideoComposition ever be played over AirPlay?
I can't make comments so I had to post this as an answer although it might not fully respond to the questions.
I had similar issue and at the end I found out that when AVPlayer plays AVComposition it simply doesn't display anything on the external display. That's why I had to do it myself by listening to UIScreen connection notifications.
I have to say that all worked pretty perfect. I'm checking first if there are more than one screen and if there are I simply move the AVPlayer on that screen while displaying a simple message on the device's screen that content is played on... plus the name of AirPlay device. This way I can put whatever I want on the external display and is not very complicated. Same thing is when I receive UIScreenDidConnectNotification.
That was fine until I noticed that the composition plays really choppy on the the external display. Even if it consists of only one video without any complex edits or overlays. Same video plays perfectly if I save it to the Camera Roll or if I use MPMoviePlayerController.
I've tried many things like lowering resolutions, lowering renderScale and so on but with no success.
One thing bothers me more is how actually Apple do this in iMovie - if you have AirPlay enabled and you play a project (note it's still not rendered so it must use a composition in order to display it) right after tapping play button it opens a player that plays content really smoothly on the external monitor. If you however activate AirPlay from the player it closes and start rendering the project. After that it plays it I thing by using MPMoviePlayerController.
I'm still trying to find a solution and will post back if I have any success.
So for the two questions:
I don't see why you have to get rid.
Yes it can be played but with different technique and obviously issues.
in the app .plist create a new item called:
required background modes
add a new array element called:
App plays audio or streams audio/video using AirPlay
Not sure if you have already tried this, but you don't mention it in your post.
Cheers!

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