XBMC Stuttering Only While Using HDMI

So I have bought one of these devices and I wonder if anyone else is having this issue using android and xbmc 13.2.

I am able to play HD movies on the tablet perfectly it seems however when I plug in a mini hdmi to connect to a tv, I get a slight stutter every few seconds.

Hardware acceleration is enabled (libstagefright & MediaCodec). In playback I have ticked adjust display refresh rate to match video & have ticked sync playback to display. However I still get stuttering only when using the HDMI. Looking at the debug log it seems the cpu is maxing out once the hdmi is connected. Reading around I wonder if an overclocked kernel may help. Any ideas please or should I assume this device although able to play HD movies will not be able to power the same video over HDMI. I have read that many android are unable to play HD movies as they are not powerful enough.


Brand PolaTab
Item model number Q97RETINA
Color Black Front
Screen Size 9.70 inches
Screen Resolution 2048 X 1536 RETINA DISPLAY
Processor Speed 1.6 GHz
Processor Count 4
RAM Size 2 GB
Computer Memory Type DDR3 SDRAM
Hard Drive Size 16 GB

Kindda answered my own question with the cpu however I was only looking into xbmc settings when I also needed to do was go to android settings > HDMI and reduce the resolution to 720p when using the HDMI connector. It plays perfectly.

I had this problem but on my media pc so hope its the same but what i had to do believe it or not was change the sound source.It was a weird one as it took me a couple of hours to work what the problem was then i changed the sound source and it was all perfect.

Interesting, that is one thing I did not try and change as it was working. Thanks, Ill give this a go, I assume you mean the XBMC settings in Video > Playback & Under System > Audio Output right

skinz said:

Interesting, that is one thing I did not try and change as it was working. Thanks, Ill give this a go, I assume you mean the XBMC settings in Video > Playback & Under System > Audio Output right

Click to expand...

Yes mate as it was a weird one tbh it was something i didn't even think about.

roachieuk said:

Yes mate as it was a weird one tbh it was something i didn't even think about.

Click to expand...

Thanks for the idea, It dint work though. I guess although powerful the tablet is not powerful enough.Maybe the next generation tablets should be able to stream HDMI. These rockchips seem to have this issue, anyways I'm more than happy with this tablet for the price and what it does, it does well.

roachieuk said:

I had this problem but on my media pc so hope its the same but what i had to do believe it or not was change the sound source.It was a weird one as it took me a couple of hours to work what the problem was then i changed the sound source and it was all perfect.

Click to expand...

I had the same issue and solution there. Shame it didn't work for this problem though. Have you asked over at xbmc?

No I have not however over at freektab it seems that these tablets have some issues with 720p & 1080p as the cpu is not powerful enough. However let me do that now

Libstagefright and mediacodec can clash when used together.
Try just libstagefright and use a custom advanced.xml file to acheive better buffering times.

skinz said:

No I have not however over at freektab it seems that these tablets have some issues with 720p & 1080p as the cpu is not powerful enough. However let me do that now

Click to expand...

Its not about CPU, as long as you have a HD acceleration AND a compatible codec then you will be fine. I can play back high bit rate HD MKV (50GB file) on the Pi and that has a 700MHz single core CPU. The key is that it has a HD GPU (not even a powerful one) and ROM with the correct drivers and codecs.

Problem with android devices is though there is a Android APK for XBMC it only covers a limited number of GPU. Most of the Android XBMC STB use custom ROM with drivers for their device. There is a list of tested chipsets here,

Android hardware - Kodi

Having said all that, it looks like that tablet comes with RK3188 chip which is a quad core 1.6GHz with Mali GPU which is on the supported list and should definitely support 1080p. I think I did read that was the chip used for the original Android port.

Saying that there seems there was an issue with that chip and libstagefright http://tabletrepublic.com/forum/android-mini-pc/xbmc-libstagefright-working-hw-decoding-rockchip-4239.html

Also could be that the tablet does not have a optimised android GPU driver. Is there is a newer ROM available for the tablet ?

I use a rockchip 3188 and mali 400 here with no issues. Also running a true 1080p kernel not upscaled like most. It is all down to the rom abd xbmc setup.

Should probably ask why OP is using libstagefright as it was merged into Android port last year ?