Youtube Iframe API says the following"
player.setPlaybackQuality(suggestedQuality:String):Void This function
sets the suggested video quality for the current video. The function
causes the video to reload at its current position in the new quality.
If the playback quality does change, it will only change for the video
being played. Calling this function does not guarantee that the
playback quality will actually change. However, if the playback
quality does change, the onPlaybackQualityChange event will fire, and
your code should respond to the event rather than the fact that it
called the setPlaybackQuality function.
I am working with the API and realize that for a video the default quality picked up was "large". Using the API, I am unable to set it to "hd720". Setting to any other quality fails. Also after the quality is set to "hd720", re-setting it to "large" also fails.
So can someone please explain me why this can happen?
Thanks.
Related
I am building an app that streams video content, something like TikTok. So you can swipe videos in table, and when new cell becomes visible the video starts playing. And it works great, except when you compare it to TikTok or Instagram or ect. My video starts streaming pretty fast but not always, it is very sensible to network quality, and sometimes even when network is great it still buffering too long. When comparing to TikTok, Instagram ... in same conditions they don't seam to have that problem. I am using JWPlayer as video hosting service, and AVPlayer as player. I am also doing async preload of assets before assigning them to PlayerItem. So my question is what else can I do to speed up video start. Do I need to do some special video preparations before uploading it to streaming service. (also I stream m3U8 files). Is there some set of presets that enables optimum streaming quality and start speed. Thanks in advance.
So theres a few things you can do.
HLS is apples preferred method of streaming to an apple device. So try to get that as much as possible for iOS devices.
The best practices when it comes to mobile streaming is offering multiple resolutions. The trick is to start with the lowest resolution available to get the video started. Then switch to a higher resolution once the speed is determined to be capable of higher resolutions. Generally this can be done quickly that the user doesn't really notice. YouTube is the best example of this tactic. HLS automatically does this, not sure about m3U8.
Assuming you are offering a UICollectionView or UITableView, try to start low resolution streams of every video on the screen in the background every time the scrolling stops. Not only does this allow you to do some cool preview stuff based off the buffer but when they click on it the video is already established. If thats too slow try just the middle video.
Edit the video in the background before upload to only be at the max resolution you expected it to be played at. There is no 4k resolution screen resolutions on any iOS device and probably never will be so cut down the amount of data.
Without getting more specifics this is all I got for now. Hope I understood your question correctly. Good luck!
The app I’m working on loops a video a specified # of times by adding the same AVAssetTrack (created from the original video url) multiple times to the same AVComposition at successive intervals. The app similarly inserts a new video clip into an existing composition by 'removing' the time range from the composition's AVMutableCompositionTrack (for AVMediaTypeVideo) and inserting the new clip's AVAssetTrack into the previously removed time range.
However, occasionally and somewhat rarely, after inserting a new clip as described above into a time range within a repeat of the original looping video, there are resulting blank frames which only appear at the video loop’s transition points (within the composition), but only during playback - the video exports correctly without gaps.
This leads me to believe the issue is with the AVPlayer or AVPlayerItem and how the frames are currently buffered for playback, rather than how I'm inserting/ looping the clips or choosing the correct CMTime stamps to do so. The app is doing a bunch of things at once (loop visualization in the UI via an NSTimer, audio playback via Amazing Audio Engine) - could my issue be a result of competition for resources?
One more note: I understand that discrepancies between audio and video in an asset can cause glitches (i.e. the underlying audio is a little bit longer than the video length), but as I'm not adding an audioEncodingTarget to the GPUImageWriter that I'm using to record and save the video, the videos have no audio components.
Any thoughts or directions you can point me in would be greatly appreciated! Many thanks in advance.
Update: the flashes coincide with the "Had to drop a video frame" error logged by the GPUImage library, which according to the creator has to do with the phone not being able to process video fast enough. Can multi-threading solving this?
Update 2: So the flashes actually don't always correspond to the had to drop a video frame error. I have also disabled all of the AVRecorder/Amazing Audio Engine code and the issue still persists making it not a problem of resource competition between those engines. I have been logging properties of AVPlayer item and notice that the 'isPlayBackLikelyToKeepUp' which is always NO, and 'isPlaybackBufferFull' which is always yes.
So problem is solved - sort of frustrating how brutally simple the fix is. I just used a time range a frame shorter for adding the videos to the composition rather than the AVAssetTrack's time range. No more flashes. Hopefully the users won't miss that 30th of a second :)
shortened_duration = CMTimeSubtract(originalVideoAssetTrack.timeRange.duration, CMTimeMake(1,30));
I am recording videos and playing them back using AVFoundation. Everything is perfect except the hissing which is there in the whole video. You can hear this hissing in every video captured from any iPad. Even videos captured from Apple's inbuilt camera app has it.
To hear it clearly, you can record a video in a place as quiet as possible without speaking anything. It can be very easily detected through headphones and keeping volume to maximum.
After researching, I found out that this hissing is made by preamplifier of the device and cannot be avoided while recording.
Only possible solution is to remove it during post processing of audio. Low frequency noise can be removed by implementing low pass filter and noise gates. There are applications and software like Adobe Audition which can perform this operation. This video shows how it is achieved using Adobe Audition.
I have searched Apple docs and found nothing which can achieve this directly. So I want to know if there exists any library, api or open source project which can perform this operation. If not, then how can I start going in right direction because it does looks like a complex task.
I am currently working on one application in which I am supposed to display the recording time while video recording is going on. Whats more interesting is that this recording time should also be there in the recorded video.
So I think I have two things to consider :
1.) Show recording time overlay while recording video
2.) Recording time should also be shown in the recorded video.
I know we can do the static text overlay while recording the video and then we add one text layer in recorded video. But in my case, this time value should be changed on every second.
I have searched a lot on google and stake overflow. Tried different solutions. By using GPUImage, By using AVMutableVideoComposition and CALayer. But they all are for static value.
May be I am nearer to my solution but not able to find it. So can anyone guide me on how can I achieve it?
Any help would be greatly appreciated.
Thanks
Use AVAssetReader for recorded video. Get the CMSampleBufferRef, get it timestamp, draw time on sample buffer, write buffer to AVAssetWriterInputPixelBufferAdaptor. Similar approach for video being recorded.
I have been using MPMovieplayer and the playableDuration to check the available duration of a movie.
The duration always seems to be ~1 second further than my current duration and basically I would like to increase this.
I have tried to use the prepareToPlay but this seems to do nothing noticeable to the playable Duration.
I have tried to set as many parameters as possible to attempt to try and change the value via setting the defaults pre-emptively such as the MPMovieSourceType, MediaType and alike, but all to no avail.
Just to clear a few things up firstly: I am using both MPMoviePlayer and AVplayer which both play different streams simultaneously as the video/audio I am using is split.
EDIT
Seems like I overlooked the file size affecting the stream and should have read more in the apple resources then elsewhere, but as far as I can tell the issue is: the file size is too large and therefore a server side media segmenter has to be implemented.
Apple Resource on Media Segmenting