Stuttering playback with 1080i mpeg2ts file about kxmovie

[kolyvan]

Just tested in on iPad 4.
In fact the problem in latest addition of avpicture_deinterlace. (
Try to comment it and will see difference.

[matzr]

Hi Konstantin,

I am going to test that straight away...
Mmmm, I might try to come up with a mechanism to evaluate how powerful the
device is, what the decoded resolution is and enable/disable deinterlacing
conditionally, then. It should be possible.
I will run some tests with lower end devices after that: iPad 2 / iPad 1
and see how they behave in regards to performance.
Again thank you for this amazing work.
Keep up the good work. I'll keep you updated to let you know how all this
goes.

Cheers,

Mathieu

On 15 January 2013 19:15, Konstantin Boukreev [email protected]:

Just tested in on iPad 4.
In fact the problem in latest addition of avpicture_deinterlace. (
Try to comment it and will see difference.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/15#issuecomment-12257342.

[matzr]

A bit more details about this perf issue.
It runs indeed fine without deinterlacing (even though it doesn't look great because of this line effect) on an iPhone 5 (A6 proc = 1.3 GHz Dual Core ARMv7s).
However, any device below these specs (that includes all iPad 1/2/3, iPhone 3/3gs/4/4s and all iPod to date) cannot playback these videos correctly, i.e. it stutters.

I have tried different compile flags for ffmpeg (especially enabling FPU through "--extra-cflags='-arch armv7 -mfpu=neon'") but it did not make any difference.

Now I am wondering how this can be achieved, given that I can play the same video file in other media players that seem to be using ffmpeg (iMediaPlayer for instance, which is available on the AppStore).

[kolyvan]

See 50cbe99 commit.
After build ffmpeg with neon support, the average performance increases about 30% for mpeg2 1440x1080 with enabled deinterlacing.
It almost enough for iPad 4.
But it's still unable to play this HD movie on iPhone 4S without stuttering.