Mailing List Archive

mythfrontend lip sync problems?
I have never had lip sync problems with mythfrontend until now. The reason
seems to be my FireTV Cube.

I do NOT have lip sync problems with mythfrontend on RPI4, FireTV 4K Stick,
Ubuntu PC, or Shield TV.

On all my Android devices, including the Cube I don't have problems with
lip sync on Leanfront or Kodi 18.8.

On the FireTV Cube only I have to edit the Audio Lip Sync to -400ms so the
picture and audio match. Some days it's -200ms. Since I've never
experienced this before, I'm wondering what could be the problem? Luckily,
I can adjust to fix it, but it makes me think the Cube isn't so good.

Is lip sync a common problem or is it just me and my Cube?

Jim A
Re: mythfrontend lip sync problems? [ In reply to ]
On Mon, Oct 19, 2020 at 8:21 AM James Abernathy <jfabernathy@gmail.com>
wrote:

> I have never had lip sync problems with mythfrontend until now. The reason
> seems to be my FireTV Cube.
>
> I do NOT have lip sync problems with mythfrontend on RPI4, FireTV 4K
> Stick, Ubuntu PC, or Shield TV.
>
> On all my Android devices, including the Cube I don't have problems with
> lip sync on Leanfront or Kodi 18.8.
>
> On the FireTV Cube only I have to edit the Audio Lip Sync to -400ms so the
> picture and audio match. Some days it's -200ms. Since I've never
> experienced this before, I'm wondering what could be the problem? Luckily,
> I can adjust to fix it, but it makes me think the Cube isn't so good.
>
> Is lip sync a common problem or is it just me and my Cube?
>
> Jim A
>

It's a definite problem with some hardware. My AT&T TV (formerly DirecTV
Now) box had a pretty large skew. Once I get the video performing the way
I like it with the playback profiles, I then match up the audio sync. I
never have to touch it afterward.

You are correct though - the leanback interfaces have always sync'ed with
no interaction.
Re: mythfrontend lip sync problems? [ In reply to ]
On 19/10/2020 14:26, Greg Oliver wrote:
> On Mon, Oct 19, 2020 at 8:21 AM James Abernathy <jfabernathy@gmail.com
> <mailto:jfabernathy@gmail.com>> wrote:
>
> I have never had lip sync problems with mythfrontend until now. The
> reason seems to be my FireTV Cube.
>
> I do NOT have lip sync problems with mythfrontend on RPI4, FireTV 4K
> Stick, Ubuntu PC, or Shield TV.
>
> On all my Android devices, including the Cube I don't have problems
> with lip sync on Leanfront or Kodi 18.8.
>
> On the FireTV Cube only I have to edit the Audio Lip Sync to -400ms
> so the picture and audio match.  Some days it's -200ms.  Since I've
> never experienced this before, I'm wondering what could be the
> problem?  Luckily, I can adjust to fix it, but it makes me think the
> Cube isn't so good.
>
> Is lip sync a common problem or is it just me and my Cube?
>
> Jim A
>
>
> It's a definite problem with some hardware.  My AT&T TV (formerly
> DirecTV Now) box had a pretty large skew.  Once I get the video
> performing the way I like it with the playback profiles, I then match up
> the audio sync.  I never have to touch it afterward.
>
> You are correct though - the leanback interfaces have always sync'ed
> with no interaction.

I have no experience of the FireTV Cube, but the spec for the 2019
device suggests that it should be OK. IIUC lipsync drift in recent
MythTV frontend has often resulted from frame dropping with greedy
high-spec deinterlacers, and perhaps not having all available cores
enabled. I'm not sure if that's what you are getting. Once set, again
IIUC, the offset is remembered.

https://developer.amazon.com/docs/fire-tv/device-specifications-fire-tv-cube.html

John P

_______________________________________________
mythtv-users mailing list
mythtv-users@mythtv.org
http://lists.mythtv.org/mailman/listinfo/mythtv-users
http://wiki.mythtv.org/Mailing_List_etiquette
MythTV Forums: https://forum.mythtv.org
Re: mythfrontend lip sync problems? [ In reply to ]
On 10/19/20 10:55 AM, John Pilkington wrote:
> On 19/10/2020 14:26, Greg Oliver wrote:
>> On Mon, Oct 19, 2020 at 8:21 AM James Abernathy
>> <jfabernathy@gmail.com <mailto:jfabernathy@gmail.com>> wrote:
>>
>>     I have never had lip sync problems with mythfrontend until now. The
>>     reason seems to be my FireTV Cube.
>>
>>     I do NOT have lip sync problems with mythfrontend on RPI4, FireTV 4K
>>     Stick, Ubuntu PC, or Shield TV.
>>
>>     On all my Android devices, including the Cube I don't have problems
>>     with lip sync on Leanfront or Kodi 18.8.
>>
>>     On the FireTV Cube only I have to edit the Audio Lip Sync to -400ms
>>     so the picture and audio match.  Some days it's -200ms. Since I've
>>     never experienced this before, I'm wondering what could be the
>>     problem?  Luckily, I can adjust to fix it, but it makes me think the
>>     Cube isn't so good.
>>
>>     Is lip sync a common problem or is it just me and my Cube?
>>
>>     Jim A
>>
>>
>> It's a definite problem with some hardware.  My AT&T TV (formerly
>> DirecTV Now) box had a pretty large skew.  Once I get the video
>> performing the way I like it with the playback profiles, I then match
>> up the audio sync.  I never have to touch it afterward.
>>
>> You are correct though - the leanback interfaces have always sync'ed
>> with no interaction.
>
> I have no experience of the FireTV Cube, but the spec for the 2019
> device suggests that it should be OK.  IIUC lipsync drift in recent
> MythTV frontend has often resulted from frame dropping with greedy
> high-spec deinterlacers, and perhaps not having all available cores
> enabled.  I'm not sure if that's what you are getting.  Once set,
> again IIUC, the offset is remembered.
>
> https://developer.amazon.com/docs/fire-tv/device-specifications-fire-tv-cube.html
>
>
> John P


I appreciate all the help on this, but I finally realized that all my
recent problems have been because I'm trying to make the Cube perform as
well as my Nvidia Shield TV 2017 model.  I never really had a problem
with the Nvidia on Mythtv-Frontend of Mythtv-leanfront. My only issues
were on non-MythTV apps like Hulu+ and Netflix frame rate on European
films. I solved those issue with beta fixes from Nvidia, so I really
have no issues with Shield TV.

I solved my FireTV Cube problem this morning by returning it to Amazon
for a full refund.

Jim A


_______________________________________________
mythtv-users mailing list
mythtv-users@mythtv.org
http://lists.mythtv.org/mailman/listinfo/mythtv-users
http://wiki.mythtv.org/Mailing_List_etiquette
MythTV Forums: https://forum.mythtv.org