GStreamer-devel

playback hangs with wallclock change

Classic

List

Threaded

3 messages Options

Babineau, Denis

playback hangs with wallclock change

Hi,

I’m thinking this might be a bug report but I thought I’d run it by the mailing list first. I’m having an issue where video stutters/freezes completely when the system clock is changed. I can cause this to happen by simply playing a video with playbin (in this case a theora stream) and moving the clock ahead and back. For example, if I move back the clock 1 minute, the video will hang for 1 minute. I have a callstack that looks something like so:

#0 0xffffe410 in __kernel_vsyscall ()

#1 0xb794ce50 in ppoll () from /lib/libc.so.6

#2 0xb7b50db3 in gst_poll_wait (set=0x8468af0, timeout=63569646) at gstpoll.c:1131

#3 0xb7b5e509 in gst_system_clock_id_wait_jitter_unlocked (clock=0x8647848, entry=0x863cbb8, jitter=0xb1fa2be0, restart=1)

at gstsystemclock.c:569

#4 0xb7b5ec73 in gst_system_clock_id_wait_jitter (clock=0x8647848, entry=0x863cbb8, jitter=0xb1fa2be0) at gstsystemclock.c:658

#5 0xb7b231ea in gst_clock_id_wait (id=0x863cbb8, jitter=0xb1fa2be0) at gstclock.c:381

#6 0xb612806f in gst_base_sink_wait_clock (sink=0x813a020, time=4733333333, jitter=0xb1fa2be0) at gstbasesink.c:1689

#7 0xb612ab07 in gst_base_sink_render_object (basesink=0x813a020, pad=0x8138850, obj=0x85abc10) at gstbasesink.c:1978

#8 0xb612c6b5 in gst_base_sink_queue_object_unlocked (basesink=0x813a020, pad=0x8138850, obj=0x85abc10, prerollable=1)

at gstbasesink.c:2558

#9 0xb61314dd in gst_base_sink_chain_unlocked (basesink=0x813a020, pad=0x8138850, buf=0x85abc10) at gstbasesink.c:2916

…

The timeout (nanoseconds) in frame 2 appears to be reasonable given the framerate, however it seems to be looping somewhere on those calls. I have yet to delve deep enough into the code to completely understand the clock synchronization but is there something that would easily allow me to change the clock to perhaps rely on the CLOCK_MONOTONIC time instead of CLOCK_REALTIME? (which appears to be the case)

Thanks

Denis

CONFIDENTIALITY NOTICE: The contents of this email are confidential
and for the exclusive use of the intended recipient. If you receive this
email in error, please delete it from your system immediately and 
notify us either by email, telephone or fax. You should not copy,
forward, or otherwise disclose the content of the email.

Wim Taymans

Re: playback hangs with wallclock change

On Fri, 2010-03-26 at 09:41 -0300, Babineau, Denis wrote:

> Hi,
>
>
>
> I’m thinking this might be a bug report but I thought I’d run it by
> the mailing list first. I’m having an issue where video
> stutters/freezes completely when the system clock is changed. I can
> cause this to happen by simply playing a video with playbin (in this
> case a theora stream) and moving the clock ahead and back. For
> example, if I move back the clock 1 minute, the video will hang for 1
> minute. I have a callstack that looks something like so:
>

What version of GStreamer is this? The clock has been using the
MONOTONIC clock by default since version 0.10.24 (and performance
counters on Windows since 0.10.25).

Wim

>
>
> #0 0xffffe410 in __kernel_vsyscall ()
>
> #1 0xb794ce50 in ppoll () from /lib/libc.so.6
>
> #2 0xb7b50db3 in gst_poll_wait (set=0x8468af0, timeout=63569646) at
> gstpoll.c:1131
>
> #3 0xb7b5e509 in gst_system_clock_id_wait_jitter_unlocked
> (clock=0x8647848, entry=0x863cbb8, jitter=0xb1fa2be0, restart=1)
>
> at gstsystemclock.c:569
>
> #4 0xb7b5ec73 in gst_system_clock_id_wait_jitter (clock=0x8647848,
> entry=0x863cbb8, jitter=0xb1fa2be0) at gstsystemclock.c:658
>
> #5 0xb7b231ea in gst_clock_id_wait (id=0x863cbb8, jitter=0xb1fa2be0)
> at gstclock.c:381
>
> #6 0xb612806f in gst_base_sink_wait_clock (sink=0x813a020,
> time=4733333333, jitter=0xb1fa2be0) at gstbasesink.c:1689
>
> #7 0xb612ab07 in gst_base_sink_render_object (basesink=0x813a020,
> pad=0x8138850, obj=0x85abc10) at gstbasesink.c:1978
>
> #8 0xb612c6b5 in gst_base_sink_queue_object_unlocked
> (basesink=0x813a020, pad=0x8138850, obj=0x85abc10, prerollable=1)
>
> at gstbasesink.c:2558
>
> #9 0xb61314dd in gst_base_sink_chain_unlocked (basesink=0x813a020,
> pad=0x8138850, buf=0x85abc10) at gstbasesink.c:2916
>
> …
>
>
>
> The timeout (nanoseconds) in frame 2 appears to be reasonable given
> the framerate, however it seems to be looping somewhere on those
> calls. I have yet to delve deep enough into the code to completely
> understand the clock synchronization but is there something that would
> easily allow me to change the clock to perhaps rely on the
> CLOCK_MONOTONIC time instead of CLOCK_REALTIME? (which appears to be
> the case)
>
>
>
> Thanks
>
> Denis
>
>
> CONFIDENTIALITY NOTICE: The contents of this email are confidential
> and for the exclusive use of the intended recipient. If you receive this
> email in error, please delete it from your system immediately and
> notify us either by email, telephone or fax. You should not copy,
> forward, or otherwise disclose the content of the email.
> ------------------------------------------------------------------------------
> Download Intel® Parallel Studio Eval
> Try the new software tools for yourself. Speed compiling, find bugs
> proactively, and fine-tune applications for parallel performance.
> See why Intel Parallel Studio got high marks during beta.
> http://p.sf.net/sfu/intel-sw-dev
> _______________________________________________ gstreamer-devel mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/gstreamer-devel

Babineau, Denis

Re: playback hangs with wallclock change

Ahhhh you're kidding me! I'm using version 0.10.23! haha! I had just found the attribute on the GstSystemClock that allowed me to change to MONOTONIC moments ago, and it works fine when I change the attribute.

Thanks Wim!

-----Original Message-----
From: Wim Taymans [mailto:[hidden email]]
Sent: Friday, March 26, 2010 11:02 AM
To: Discussion of the development of GStreamer
Subject: Re: [gst-devel] playback hangs with wallclock change

On Fri, 2010-03-26 at 09:41 -0300, Babineau, Denis wrote:

What version of GStreamer is this? The clock has been using the
MONOTONIC clock by default since version 0.10.24 (and performance
counters on Windows since 0.10.25).

Wim

------------------------------------------------------------------------------
Download Intel® Parallel Studio Eval
Try the new software tools for yourself. Speed compiling, find bugs
proactively, and fine-tune applications for parallel performance.
See why Intel Parallel Studio got high marks during beta.
http://p.sf.net/sfu/intel-sw-dev
_______________________________________________
gstreamer-devel mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/gstreamer-devel
CONFIDENTIALITY NOTICE: The contents of this email are confidential
and for the exclusive use of the intended recipient. If you receive this
email in error, please delete it from your system immediately and
notify us either by email, telephone or fax. You should not copy,
forward, or otherwise disclose the content of the email.
------------------------------------------------------------------------------
Download Intel® Parallel Studio Eval
Try the new software tools for yourself. Speed compiling, find bugs
proactively, and fine-tune applications for parallel performance.
See why Intel Parallel Studio got high marks during beta.
http://p.sf.net/sfu/intel-sw-dev
_______________________________________________
gstreamer-devel mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/gstreamer-devel