Opened 12 years ago

Closed 12 years ago

Last modified 11 years ago

#3690 closed defect (fixed)

Prebuffering pauses with ivtv since ffmpeg resync

Reported by: Hadley Rich <hads@…> Owned by: Anduin Withers
Priority: minor Milestone: unknown
Component: mythtv Version: head
Severity: medium Keywords:
Cc: Ticket locked: no

Description

Since the ffmpeg resync - [13655] - one of my frontends has had issues playing back recordings from the PVR150 in the backend. If I roll back to 13654 playback is smooth but on 13655 it's unwatchable (prebuffering pauses every 2 seconds or so). This only occurs with recordings from the PVR150, playing from the DVB cards is fine.

I have three networked myth boxes;

BE/FE - Intel E6300/2GB RAM FE 1 - Intel E6320/2GB RAM (the one with the problem) FE 2 - VIA MiniITX 1Ghz/512MB RAM

both remote FEs are using myth streaming. Strangely enough FE 1 is the only one having issues. The other two are fine on any revision.

I'm not quite sure what I can provide to assist in debugging this. If logs or anything will help then please let me know and I will provide them.

hads

Attachments (1)

3690.patch (594 bytes) - added by Anduin Withers 12 years ago.
quick nop seeks

Download all attachments as: .zip

Change History (15)

comment:1 Changed 12 years ago by skd5aner@…

I too, am experiencing prebuffer pauses after 13655 and had to roll back. I've included some logs here:

http://www.gossamer-threads.com/lists/mythtv/users/276818?#276818

I have dvb and ivtv recordings, but I believe I only tested on the ivtv ones. I experienced the same issues as the original reporter.

comment:2 Changed 12 years ago by dave@…

Seems adding noapic to the kernel command line fixed this for me.

-Dave

comment:3 Changed 12 years ago by william

I needed to use both noapic and nolapic to get best video performance. Video jitter is down on pvr-250 captured material. HDHR still plays smoothly.

comment:4 Changed 12 years ago by skd5aner@…

I still would have to say that this is due to the ffmpeg sync and not due to kernel configurations. I had no pre-buffer pauses at all with HD or SD material prior to the sync on the same kernel. After the sync, bam... issues.

comment:5 Changed 12 years ago by dave@…

Same here -- worked fine till after the sync.

But -- noapic fixed it for me on my frontend. My diskless frontend with no hardware. So -- this shouldn't be related to iptv -- it's something to do with playback only.

comment:6 Changed 12 years ago by skd5aner@…

I have just put the "noapic" in my kernel boot command line and it made no difference. I still have just as many prebuffer pauses as before. I am running SVN 14021. I'm going to have to roll back (again).

Until this is fixed, I'm stuck at the pre-ffmpeg sync version. It seems many people are experiencing this issue, so maybe the priority/severity should be increased. I'm not sure why adding "noapic" worked for some people, but logically that shouldn't really make any difference anyway.

Seems to happen with all of my SD recordings, especially when using any form of time stretch (but also at 1.0x). However, interesting enough, I haven't noticed it with HD. After 5 mins of HD, there were no (noticeable) prebuffer pauses. However, after 5 minutes of SD, there are a ton of pre-buffer pauses.

Changed 12 years ago by Anduin Withers

Attachment: 3690.patch added

quick nop seeks

comment:7 Changed 12 years ago by skd5aner@…

Wow! Night and day difference. I'm testing right now with 14158 and I can now watch recordings again. I tested with 10 minutes at 1.0x and 20 minutes at 1.4x. No pre-buffer pauses. Thank you Anduin! Thank goodness another dev finally experienced the symptoms. I'm sure as Anduin could attest that it was simply unusable after the ffmpeg sync.

Please apply this patch to trunk. I'd highly recommend getting this in especially before people are forced to upgrade to accomodate for the scheduling changes.

comment:8 in reply to:  7 Changed 12 years ago by skd5aner@…

Replying to skd5aner@gmail.com:

Wow! Night and day difference. I'm testing right now with 14158 and I can now watch recordings again. I tested with 10 minutes at 1.0x and 20 minutes at 1.4x. No pre-buffer pauses. Thank you Anduin! Thank goodness another dev finally experienced the symptoms. I'm sure as Anduin could attest that it was simply unusable after the ffmpeg sync.

Please apply this patch to trunk. I'd highly recommend getting this in especially before people are forced to upgrade to accomodate for the scheduling changes.

Just to clarify, I meant I've tested the patch that Anduin provided attached to this ticket by applying it to 14158, not that 14158 alone solves the issue. :)

comment:9 Changed 12 years ago by Anduin Withers

Owner: changed from Isaac Richards to Anduin Withers

comment:10 Changed 12 years ago by Anduin Withers

Resolution: fixed
Status: newclosed

(In [14159]) Closes #3690

Make RingBuffer::Seek handle seeks to the current position better.

The ffmpeg sync in [13655] caused seeks to the current position every PES header read. Prior to this patch that meant the read buffer was cleared, data was reread, and some had trouble with playback.

comment:11 Changed 12 years ago by wiz561@…

Resolution: fixed
Status: closedreopened

I just upgraded to rev 14169 of mythtv. I checked the ringbuff file and it does have the patched code in it. Unfortunately though, I'm still getting prebuffer pauses...


2007-08-12 17:22:00.968 /usr/local/share/mythtv/mythweather/scripts/ndfd.pl -u ENG -d /home/mythtv/.mythtv/MythWeather/NDFD-6_day +41.47,-087.45 has exited
2007-08-12 17:22:01.145 TV: Changing from None to WatchingLiveTV
2007-08-12 17:22:01.147 Realtime priority would require SUID as root.
2007-08-12 17:22:01.276 Video timing method: SGI OpenGL
2007-08-12 17:22:03.011 NVP: prebuffering pause
2007-08-12 17:22:04.685 XMLParse::LoadTheme using /usr/local/share/mythtv/themes/G.A.N.T./ui.xml
2007-08-12 17:22:06.095 NVP: prebuffering pause
2007-08-12 17:22:07.612 NVP: prebuffering pause
2007-08-12 17:22:08.696 NVP: prebuffering pause
2007-08-12 17:22:10.180 NVP: prebuffering pause
2007-08-12 17:22:12.098 NVP: prebuffering pause
[mpeg2video @ 0x2b218c01eb90]warning: first frame is no keyframe
2007-08-12 17:22:15.833 NVP: prebuffering pause
2007-08-12 17:22:16.600 NVP: prebuffering pause
2007-08-12 17:22:18.200 NVP: prebuffering pause
2007-08-12 17:22:19.402 NVP: prebuffering pause
2007-08-12 17:22:21.218 NVP: prebuffering pause
2007-08-12 17:22:23.037 NVP: prebuffering pause
2007-08-12 17:22:24.004 NVP: prebuffering pause
2007-08-12 17:22:25.354 NVP: prebuffering pause
2007-08-12 17:22:28.373 NVP: prebuffering pause
2007-08-12 17:22:52.267 NVP: prebuffering pause
2007-08-12 17:23:20.780 NVP: prebuffering pause
2007-08-12 17:30:06.180 NVP: prebuffering pause
2007-08-12 17:30:06.878 RingBuf(/data/myth/live/2003_20070812173000.mpg): Waited 1.0 seconds for data to become available...
2007-08-12 17:30:06.878 Checking to see if there's a new livetv program to switch to..
2007-08-12 17:30:07.670 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:07.902 RingBuf(/data/myth/live/2003_20070812173000.mpg): Waited 2.0 seconds for data to become available...
2007-08-12 17:30:07.902 Checking to see if there's a new livetv program to switch to..
2007-08-12 17:30:09.170 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:09.950 RingBuf(/data/myth/live/2003_20070812173000.mpg): Waited 4.0 seconds for data to become available...
2007-08-12 17:30:09.950 Checking to see if there's a new livetv program to switch to..
2007-08-12 17:30:10.674 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:12.174 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:13.674 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:14.046 RingBuf(/data/myth/live/2003_20070812173000.mpg): Waited 8.0 seconds for data to become available...
2007-08-12 17:30:14.046 Checking to see if there's a new livetv program to switch to..
2007-08-12 17:30:15.177 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:16.677 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:18.181 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:19.681 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:21.181 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:21.981 RingBuf(/data/myth/live/2003_20070812173000.mpg) Error: Waited 16 seconds for data, aborting.
2007-08-12 17:30:22.685 NVP: Prebuffer wait timed out 10 times.
[mpeg2video @ 0x2b218c01eb90]ac-tex damaged at 40 19
[mpeg2video @ 0x2b218c01eb90]Warning MVs not available
2007-08-12 17:30:24.185 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:25.685 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:27.188 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:28.689 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:30.193 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:31.693 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:33.193 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:34.697 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:36.197 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:37.701 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:39.201 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:40.701 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:42.205 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:43.705 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:45.205 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:46.709 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:48.209 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:49.714 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:51.213 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:52.714 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:54.218 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:55.718 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:57.222 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:30:58.722 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:31:00.222 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:31:01.726 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:31:03.226 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:31:04.726 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:31:06.230 NVP: Prebuffer wait timed out 10 times.
2007-08-12 17:31:07.730 NVP: Prebuffer wait timed out 10 times.

comment:12 Changed 12 years ago by Anduin Withers

Resolution: fixed
Status: reopenedclosed

Reopen this ticket if you can verify it was the 13655 changes that caused it.

comment:13 Changed 11 years ago by Nigel

(In [18297]) Remove unused bDefaultPixmap vars, inspired by patch from Erik Hovland. Lightly tested (recordings page in MythWeb). Closes #3690.

comment:14 Changed 11 years ago by Nigel

Oops. That last checkin was for #5690, not #3690

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