Mailing List Archive

On Friday 18 July 2003 06:28 pm, Larry Matter wrote:
> I have a remote Frontend client that works fine when I first start
> watching live-tv, but after I change the channel, it gets jerky. Not a
> lot, but enough to be noticed. I get only a few "Delaying to next
> trigger" messages. I'm using CVS from yesterday; problem also occurs in
> 0.10.
>
> Exiting and returning to Live TV fixes the problem (until the next channel
> change).
>
> Any suggestions on how to track this down?

I imagine pausing it a little helps as well?

> Not sure if it matters, but the frontend is a diskless Via EPIA M 10000
> (Nehemiah).

Kinda does, because the machine's slow enough to make drawing the OSD a chore
=) That's most likely not the issue here, though.

Isaac
_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

>> Any suggestions on how to track this down?
>
> I imagine pausing it a little helps as well?

Seems too. Do you have a theory as to what's causing it and/or what might
help?

>> Not sure if it matters, but the frontend is a diskless Via EPIA M 10000
>> (Nehemiah).
>
> Kinda does, because the machine's slow enough to make drawing the OSD a
> chore
> =) That's most likely not the issue here, though.

No, I was talking about well after the OSD fades away. During OSD
"transition" it's a real mess (and that may have been what generated the
Delaying to next trigger messages).

I recall reading (I think) that much of the MythTV encode/decode code is
written directly with MMX instructions which (again, I think) makes many
compiler optimization flags less effective. But are there optimizations
(like SSE) that will help with OSD drawing?

Since I also have an Ezra C3 system, I went with "-march=i586 -mmmx" to
ensure the same code works on both systems. But I would be willing to
optimize for nehemiah to get this working better.

Thanks,
Larry
_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

Quoting Larry Matter <mythtv@matter.net>:

> >> Any suggestions on how to track this down?
> >
> > I imagine pausing it a little helps as well?
>

I experience this same behavior too on a remote
athlon XP 2100+ frontend.

Seems that you have to do the little dance...

change channel, immediately hit pause, wait a second,
unpause.

If I dont do that, then audio and video get jerky and
sometimes the audio and video are out of sync.

It feels like a race between the incoming
data, and the active playing of the data.
Sometimes leaving the frontend starved for data.

Rick
_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

At 10:02 AM 7/19/2003 -0400, you wrote:
>Quoting Larry Matter <mythtv@matter.net>:
>
>> >> Any suggestions on how to track this down?
>> >
>> > I imagine pausing it a little helps as well?
>>
>
>I experience this same behavior too on a remote
>athlon XP 2100+ frontend.
>
>Seems that you have to do the little dance...
>
>change channel, immediately hit pause, wait a second,
>unpause.


I would occasionally get this too, but I changed a line in
NuppelVideoPlayer.h:
#define MAXVBUFFER 34

That seemed to fix it for me.



-WD
_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

> I experience this same behavior too on a remote
> athlon XP 2100+ frontend.

Interesting. I was thinking it was related to the CPU performance, but
your system should have plenty of CPU (I assume you're not compiling at
the same time :-)

> Seems that you have to do the little dance...
>
> change channel, immediately hit pause, wait a second,
> unpause.
>
> If I dont do that, then audio and video get jerky and
> sometimes the audio and video are out of sync.

I also sometimes see the audio/video sync problem, but IIRC that fixes
itself over time (like 10-20 seconds). The jerkiness does not correct
itself.

Larry
_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

> I would occasionally get this too, but I changed a line in
> NuppelVideoPlayer.h:
> #define MAXVBUFFER 34

Thanks for the tip; however, it didn't seem to correct the problem for me.

Larry

_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

On Saturday 19 July 2003 01:23 pm, Larry Matter wrote:
> > I would occasionally get this too, but I changed a line in
> > NuppelVideoPlayer.h:
> > #define MAXVBUFFER 34
>
> Thanks for the tip; however, it didn't seem to correct the problem for me.

Try editing NuppelVideoPlayer.cpp and changing the value of 'usepre' from 12
to something higher -- 18 or so. Or higher =) Up to 28 or so should work.
Lemme know if that helps any.

Isaac
_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

> Try editing NuppelVideoPlayer.cpp and changing the value of 'usepre' from
> 12
> to something higher -- 18 or so. Or higher =) Up to 28 or so should
> work.

I just tried setting it to 24 and that didn't help.

Silly question, but I'm not familiar with the code. On my frontend
machine I have only mythfrontend and libmyth (not libmythtv) and that is
enough myth code to run.

NuppleVideoPlayer.ccp is under libmythtv; so I am assuming I only need to
update the backend machine when I change it; since I'm not sure I did a
full build and updated both machines to try the value above but that is
time consuming. Any shortcuts I can take?

Thanks,
Larry
_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

On Thursday 24 July 2003 11:43 am, Larry Matter wrote:
> > Try editing NuppelVideoPlayer.cpp and changing the value of 'usepre' from
> > 12
> > to something higher -- 18 or so. Or higher =) Up to 28 or so should
> > work.
>
> I just tried setting it to 24 and that didn't help.
>
> Silly question, but I'm not familiar with the code. On my frontend
> machine I have only mythfrontend and libmyth (not libmythtv) and that is
> enough myth code to run.
>
> NuppleVideoPlayer.ccp is under libmythtv; so I am assuming I only need to
> update the backend machine when I change it; since I'm not sure I did a
> full build and updated both machines to try the value above but that is
> time consuming. Any shortcuts I can take?

The libmythtv section of code is statically compiled into mythfrontend. Only
the frontend would have to be updated to test this particular change.

Isaac
_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

On Friday 18 July 2003 06:28 pm, Larry Matter wrote:
> I have a remote Frontend client that works fine when I first start
> watching live-tv, but after I change the channel, it gets jerky. Not a
> lot, but enough to be noticed. I get only a few "Delaying to next
> trigger" messages. I'm using CVS from yesterday; problem also occurs in
> 0.10.
>
> Exiting and returning to Live TV fixes the problem (until the next channel
> change).
>
> Any suggestions on how to track this down?

Allright. This _should_ be fixed in CVS. Problem was the new audio output
layer -- it wasn't pausing the audio playback for prebuffering long enough on
channel changes. Could other people verify that I've fixed this for them?

Isaac
_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

I might give it a shot... My LiveTV sometimes goes jerky after a channel
change...


----- Original Message -----
From: "Isaac Richards" <ijr@po.cwru.edu>
To: "Discussion about mythtv" <mythtv-users@snowman.net>
Sent: Thursday, July 31, 2003 12:35 AM
Subject: Re: [mythtv-users] remote FE gets jerky after channel change


> On Friday 18 July 2003 06:28 pm, Larry Matter wrote:
> > I have a remote Frontend client that works fine when I first start
> > watching live-tv, but after I change the channel, it gets jerky. Not a
> > lot, but enough to be noticed. I get only a few "Delaying to next
> > trigger" messages. I'm using CVS from yesterday; problem also occurs in
> > 0.10.
> >
> > Exiting and returning to Live TV fixes the problem (until the next
channel
> > change).
> >
> > Any suggestions on how to track this down?
>
> Allright. This _should_ be fixed in CVS. Problem was the new audio
output
> layer -- it wasn't pausing the audio playback for prebuffering long enough
on
> channel changes. Could other people verify that I've fixed this for them?
>
> Isaac
> _______________________________________________
> mythtv-users mailing list
> mythtv-users@snowman.net
> http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

> On Friday 18 July 2003 06:28 pm, Larry Matter wrote:
>> I have a remote Frontend client that works fine when I first start
>> watching live-tv, but after I change the channel, it gets jerky. Not a
>> lot, but enough to be noticed. I get only a few "Delaying to next
>> trigger" messages. I'm using CVS from yesterday; problem also occurs in
>> 0.10.
>>
>> Exiting and returning to Live TV fixes the problem (until the next
>> channel
>> change).
>>
>> Any suggestions on how to track this down?
>
> Allright. This _should_ be fixed in CVS. Problem was the new audio
> output
> layer -- it wasn't pausing the audio playback for prebuffering long enough
> on
> channel changes. Could other people verify that I've fixed this for them?

I'll try it tonight.

BTW, in trying to track it down I have noticed two problems. One was the
jerkiness, the other was the audio/video getting out of sync. I would
sometimes get one or both or neither which was making it hard to see if
the usepre change really helped.

Do you think this fix will help with the sync issue as well?

Larry

_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

> Allright. This _should_ be fixed in CVS. Problem was the new audio
> output
> layer -- it wasn't pausing the audio playback for prebuffering long enough
> on
> channel changes. Could other people verify that I've fixed this for them?

I only had a few minutes to play with it, but this appears to have fixed
both the jerkiness and the audio/video sync issue.

Thanks!
Larry

_______________________________________________
mythtv-users mailing list
mythtv-users@mythtv.org
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users