Support key-frame accurate seeking in HLS

[mohammed-atif]

SimpleExoPlayer.seekTo(int millis) issue

I have seen several issues requesting the same feature of smoother seeking in Exoplayer

At one thread I have seen your reply mentioning about the decoder but Android's VideoView default seeking is much more smoother when compared to ExoPlayer or MediaPlayer

Here is my code for reference

@Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
        long seekTo = (long) (mPlayer.getCurrentPosition() - distanceX);
        Log.d(TAG, "current scroll position "+seekTo);
        mPlayer.seekTo(seekTo);
        return true;
    }

I am using locally stored mp4 file to play using Exoplayer with TextureView

current exoplayer version - r2.4.1
com.google.android.exoplayer:exoplayer-core:r2.4.1

Are there any configurations that I have to change for smoother seeking?

[ojw28]

The reason behavior is different is that ExoPlayer does frame-accurate seeking (in all cases). I think VideoView does key-frame accurate seeking, which is faster but less accurate. We can use this issue to track supporting key-frame accurate seeking as an option, but it's low priority.

[mohammed-atif]

@ojw28 , In other players, we have a callback which notifies about the successful seeking. If I make multiple calls for seek using onScroll method, I can ignore the inputs if seek is in progress, but in case of ExoPlayer there is no such callback and due to multiple seek requests, the performance of seeking further goes down. It would be really good if ExoPlayer too provides the callbacks for seek completion.

Apart from that, as you mentioned about the key-frame seeking, can you provide me details about the class which I can look into to do minor tweaks at my end for better seeking?

[goffioul]

@atifmohammed Not sure this will help you, but I also needed some callback after seek completion. What I come up with was to drop a flag in my app when starting the seek operation, then listen to state change in onPlayerStateChanged. If my flag was set and the player state was STATE_READY, then I fired my callback. That seemed to work for my use case.

[mohammed-atif]

@goffioul Thanks for the response, I figured it out few days ago but couldn't update here. While seeking the state goes to Buffer and after seek it shifts to ready.

@ojw28 forward seek works good after adding the callbacks. But when I seek backwards, player's current time is not updated.

int currentTime =  mSimpleExoPlayer.getCurrentTime();
int seekToMillis = currentTime - 45; //seek duration is very small in the range of 30 to 60 milliseconds
mSimpleExoPlayer.seekTo(seekToMillis);

if seekToMillis is currentTime + duration then everything works good, but when seeking back, in STATE_READY, currentTime remains same after every seek action which causes back and forth jerk to the video. Is it avoidable by making any changes?

[ojw28]

You shouldn't rely on the player reporting exactly your seek position back through getCurrentTime. The reported position may be adjusted slightly. If you want to seek in tiny increments like this, you should find a way to keep track of the last position that you performed a seek in your own code, and subtract 45 from that value each time. With that approach each position you pass to seekTo really will be 45 less than the previous value passed.

If we could keep this issue on topic, which is to support seeking to the nearest key-frame, that would be good. Thanks.