Is where a way to smoothly seek playback to some position?
In other words, imagine that some track playing at 0:53 and I need it to play at 0:58 after 2 seconds. So I need it to smoothly increase rate (like using easing functions in animation) and smoothly decrease rate when playback time almost equal 0:58. (it should sound like rewind effect)
Simple seekToTime method is not an option since it just jumps to position.
Here is an illustration:
two________________________seconds_________________________to_seek
0:53__________________________________________________________0:58
|____________↑_________|__________=_________|__________↓__________|
rate=1______smoothly_rate=2.0_______________smoothly_rate=1_____rate=1
I've already tried to use easing methods to smoothly increase rate but looks like it's impossible - rate value changes right away to desired value without easing.
At least I know that it is actually possible. You can try Ampme app from Appstore. They're playing music synchronously on different devices and if there is some lag (buffering, etc) on one of the devices, it's playback smoothly corrects to right value without jumping.
Currently I'm using setRate:time:atHostTime: method and I think it's the right way, but I'm not able to make it work seeking smoothly.
Related
I use an avplayer instance to play a movie that plays forward and backward, depending on the device's roll. I use the rate at 1/-1 for that. Besides some lagging when rewinding, I have an awkward effect every some seconds. It seems as the movie is kind of reloaded and zoomed back into the view.
Observing status, rate and duration values show no additional execution of anything, memory consumption is stable, initialisation is not repeated either.
I didn't find anything, but does the avplayer has something like a sleep mode? auto reload?
Any ideas at what to look into would be much appreciated.
I am working on a kids ABC learning app which will be somewhat like this app.
Petting Zoo
The user can do these gestures... Swipe UP, DOWN, LEFT , RIGHT and TOUCH and each gesture has a small animation clip (approx duration 1 -3 secs each ) linked to it like the character jumping on Swipe UP, etc. There will also be an IDLE loopable movie which will be playing continuously when there is no input from user.
So I am trying to use videos in MP4 and M4V format for these gestures but the problem is that the videos are lagging just before playing. Means they dont play instantly upon doing a gesture but take a time of say micro second to load and play.
I am looking for output like the video above. You can see that the animations are so responsive and do not hang even for little time.
My developer once achieved such smooth output with the MP4 video clips but those clips didnt have audio embedded in them and then when he used videos with audio embedded in them, they were lagging again.
Can audio be the issue for lag here ? Or anything else you experts will like to suggest.
Please help guys. Yours inputs will be very valuable for me.
You can use - (void)replaceCurrentItemWithPlayerItem:(AVPlayerItem *)item of AVPlayer.
This methods helps you to load the new item to an existing AVPlayer.
Here is the important reference for playing multiple videos using single AVPlayer.
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!
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.
I know that you can easily set the volume property of the music player, but I want to do it smoothly like Google Maps does when they use the voiceover for navigation instructions.
I was wondering what the best way to do this is.
Thanks!
I would try using a repeating NSTimer. Every time the timer fires you lower the volume a bit. When it reaches the target value you invalidate the timer.
Other ways of getting a repeated event (so that you can do something in stages gradually over time) are DISPATCH_SOURCE_TYPE_TIMER and CADisplayLink. But I think a timer is probably the simplest way to get started.
If you have a pre-existing sound that you're playing, a completely different solution is to apply a fadeout to it before you start playing it (and then just play it all at the same volume, because the sound itself fades out, do you see). AVFoundation gives you the tools to do that (e.g. setVolumeRampFromStartVolume:toEndVolume:timeRange:).