2012-09-30, 10:27
A call for Testing
While doing extensive testing for the release of Openelec 2.0, we have discovered some issues that are not clear to us at all wether this is pure hardware or also some software problem.
When connecting htpc setups (nvidia, AMD, e.g.) a strange "global sync delay" when running 24p can be seen. This means that Audio is ahead of the movie by a specific time t > 0. You can easily see this when somebody is speaking. His/her speech is already done, but you can still see lips moving or mouth closing - this is called Lip Sync. In order to work-around this for user affected, we need you to do some tests on different hardware to gather some values, so that we can make it work for everybody out of the box.
We are currently not searching for issues that sync is lost or changing within a movie. To help us, you and your hardware must meet the following constraint:
- Your Setup must be able to do 24.0 hz respectively 23.976 hz
- Xbmc must be up and running (Frodo, Eden, OE, never mind)
Preconditions:
- Vertical Blank Sync must be enabled (System -> System -> Video output)
- Also enable Adjust Refresh Rate to match Video (System -> Video -> Playback)
- Download Iron Man trailer for testing: http://www.hdtv-praxis.de/downloads/IronManTrailer.zip
- Download Tears of steel for testing: http://www.fsmpi.uni-bayreuth.de/~pw/man..._1080p.mkv
- Both videos should be stored locally on the HTPC's harddisk.
- Always watch the movie beginning from the start, if you seek you might lose sync, this is to minimize the variations of the results.
We have four testcases:
a) Play the Iron Man trailer. Your TV should switch to 23.98hz. No follow some dialogs. Use the Audio Offset Slider to adjust the offset so the lips are in sync with audio. Take your time and get it as close to perfect as you can. Write down the offset.
b) Play the Tears of steel video. Your TV should switch to 24hz. No follow some dialogs. Use the Audio Offset Slider to adjust the offset so the lips are in sync with audio. Take your time and get it as close to perfect as you can. Write down the offset.
c) Disable Adjust RefreshRate to match Video. Set your Display to 60hz (System->System->Video output). Start both videos again. It should now run at 60hz. Make it Lip Sync again and write down the offset.
d) Disable Adjust RefreshRate to match Video. Set your Display to 50hz. Start both videos again and make it lip sync. Write down the offset.
How to adjust the audio offset:
We need the following output:
Thank you very much. In the longterm we want to use HDMI 1.3 spec to auto sync between hardware and TV, but for now we want to deliver reasonable defaults by using the given xbmc video delay infrastructure.
Btw. cause of the importance keep this thread on topic: We will silently ignore everything else that has nothing to do with this issue.
While doing extensive testing for the release of Openelec 2.0, we have discovered some issues that are not clear to us at all wether this is pure hardware or also some software problem.
When connecting htpc setups (nvidia, AMD, e.g.) a strange "global sync delay" when running 24p can be seen. This means that Audio is ahead of the movie by a specific time t > 0. You can easily see this when somebody is speaking. His/her speech is already done, but you can still see lips moving or mouth closing - this is called Lip Sync. In order to work-around this for user affected, we need you to do some tests on different hardware to gather some values, so that we can make it work for everybody out of the box.
We are currently not searching for issues that sync is lost or changing within a movie. To help us, you and your hardware must meet the following constraint:
- Your Setup must be able to do 24.0 hz respectively 23.976 hz
- Xbmc must be up and running (Frodo, Eden, OE, never mind)
Preconditions:
- Vertical Blank Sync must be enabled (System -> System -> Video output)
- Also enable Adjust Refresh Rate to match Video (System -> Video -> Playback)
- Download Iron Man trailer for testing: http://www.hdtv-praxis.de/downloads/IronManTrailer.zip
- Download Tears of steel for testing: http://www.fsmpi.uni-bayreuth.de/~pw/man..._1080p.mkv
- Both videos should be stored locally on the HTPC's harddisk.
- Always watch the movie beginning from the start, if you seek you might lose sync, this is to minimize the variations of the results.
We have four testcases:
a) Play the Iron Man trailer. Your TV should switch to 23.98hz. No follow some dialogs. Use the Audio Offset Slider to adjust the offset so the lips are in sync with audio. Take your time and get it as close to perfect as you can. Write down the offset.
b) Play the Tears of steel video. Your TV should switch to 24hz. No follow some dialogs. Use the Audio Offset Slider to adjust the offset so the lips are in sync with audio. Take your time and get it as close to perfect as you can. Write down the offset.
c) Disable Adjust RefreshRate to match Video. Set your Display to 60hz (System->System->Video output). Start both videos again. It should now run at 60hz. Make it Lip Sync again and write down the offset.
d) Disable Adjust RefreshRate to match Video. Set your Display to 50hz. Start both videos again and make it lip sync. Write down the offset.
How to adjust the audio offset:
We need the following output:
Quote:Xbmc-Version: OpenELEC 12.0-ALPHA6 Git:bbce68b (this is found by going to System->System info, also specify what distrobution you are on, as in Ubuntu, XBMCbuntu, OpenELEC, GeeXboX)
GFX Driver: NVIDIA 304.51
Hardware Configuration: ION2 - Asus EEE Box EB1501P (Fusion E-450, ION-2, Nvidia GT520 with Celeron 1700 e.g.)
Speaker TV Conncection: HTPC to AVR via HDMI and HDMI out of AVR to TV (e.g. HTPC to AVR via HDMI and HDMI out of AVR to TV, or TV directly connected to HDMI while using Optical Out to Receiver)
Receiver: Onkyo TX-SR607
TV Model: Samsung UE40C6715 40" led tv
Xbmc Audio Configuration:
(Just take a screenshot)
Results:
Audio offset @ 23.976hz: Delayed by: 0.175sec
Audio offset @ 24hz: Delayed by: 0.175sec
Audio offset @ 50hz: 0.000sec
Audio offset @ 60hz: 0.000sec
Thank you very much. In the longterm we want to use HDMI 1.3 spec to auto sync between hardware and TV, but for now we want to deliver reasonable defaults by using the given xbmc video delay infrastructure.
Btw. cause of the importance keep this thread on topic: We will silently ignore everything else that has nothing to do with this issue.