what is sync=false?

[Daniel Drake-5]

Hi,

Google shows many examples of using the xvimagesink element with
sync=false but I can't find any explanation of what this actually does
and why someone might want to use it. The GstBaseSink documentation
only has 1 line on this property and it isn't very enlightening.

What does it do?

In OLPC's Record activity we use xvimagesink for a live video preview
of the photograph which is about to be taken, or for a live preview of
the video that we are currently recording to disk. Given that we're
only talking about a video preview, we're suspecting that sync=false
is something that we'd want, assuming that it results in xvimagesink
being able to display frames at times which are most convenient
without having to worry about the clock, resulting in less resource
usage on the system. Is there any truth here?

Thanks,
Daniel

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[michael smith-6-3]

On Tue, May 18, 2010 at 11:56 AM, Daniel Drake <[hidden email]> wrote:
> Hi,
>
> Google shows many examples of using the xvimagesink element with
> sync=false but I can't find any explanation of what this actually does
> and why someone might want to use it. The GstBaseSink documentation
> only has 1 line on this property and it isn't very enlightening.

It simply means that the sink ignores the timestamps on buffers and
the clock, and just displays the frame as soon as it arrives.

>
> What does it do?
>
> In OLPC's Record activity we use xvimagesink for a live video preview
> of the photograph which is about to be taken, or for a live preview of
> the video that we are currently recording to disk. Given that we're
> only talking about a video preview, we're suspecting that sync=false
> is something that we'd want, assuming that it results in xvimagesink
> being able to display frames at times which are most convenient
> without having to worry about the clock, resulting in less resource
> usage on the system. Is there any truth here?

Synchronisation doesn't intrinsically use any significant amount of resources.

Mike

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[Clark, Rob]

sync=false disables A/V sync..

in your case, you might get weirdness if you try and synchronize video
preview display to audio capture...   so you probably want sync=false,
and it should at least not hurt.

If you are getting messages about timestamping problems and xvimagesink
dropping frames, then try sync=false

BR,
-R

On 05/18/2010 01:56 PM, Daniel Drake wrote:

> Hi,
>
> Google shows many examples of using the xvimagesink element with
> sync=false but I can't find any explanation of what this actually does
> and why someone might want to use it. The GstBaseSink documentation
> only has 1 line on this property and it isn't very enlightening.
>
> What does it do?
>
> In OLPC's Record activity we use xvimagesink for a live video preview
> of the photograph which is about to be taken, or for a live preview of
> the video that we are currently recording to disk. Given that we're
> only talking about a video preview, we're suspecting that sync=false
> is something that we'd want, assuming that it results in xvimagesink
> being able to display frames at times which are most convenient
> without having to worry about the clock, resulting in less resource
> usage on the system. Is there any truth here?
>
> Thanks,
> Daniel
>
> ------------------------------------------------------------------------------
>
> _______________________________________________
> gstreamer-devel mailing list
> [hidden email]
> https://lists.sourceforge.net/lists/listinfo/gstreamer-devel
>    

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[AJAY GAUTAM]

You can use like this Example in my code:
gst-launch -v dvbsrc do-timestamp=true modulation=AUTO trans-mode=AUTO

bandwidth=AUTO frequency=586000000 code-rate-lp=AUTO  guard=AUTO

hierarchy=NONE pids=16:17:18:110:120:130:140 ! flutsdemux  name=demux
  program-number=257 !  queue max-size-buffers=0 max-size-time=0 !  mpeg2dec
  ! xvimagesink sync=true  demux. ! queue max-size-buffers=0 max-size-time=0
  ! mad ! alsasink sync=true

On Wed, May 19, 2010 at 12:39 AM, Rob Clark <[hidden email]> wrote:

sync=false disables A/V sync..

in your case, you might get weirdness if you try and synchronize video
preview display to audio capture...   so you probably want sync=false,
and it should at least not hurt.

If you are getting messages about timestamping problems and xvimagesink
dropping frames, then try sync=false

BR,
-R

On 05/18/2010 01:56 PM, Daniel Drake wrote:
> Hi,
>
> Google shows many examples of using the xvimagesink element with
> sync=false but I can't find any explanation of what this actually does
> and why someone might want to use it. The GstBaseSink documentation
> only has 1 line on this property and it isn't very enlightening.
>
> What does it do?
>
> In OLPC's Record activity we use xvimagesink for a live video preview
> of the photograph which is about to be taken, or for a live preview of
> the video that we are currently recording to disk. Given that we're
> only talking about a video preview, we're suspecting that sync=false
> is something that we'd want, assuming that it results in xvimagesink
> being able to display frames at times which are most convenient
> without having to worry about the clock, resulting in less resource
> usage on the system. Is there any truth here?
>
> Thanks,
> Daniel
>
> ------------------------------------------------------------------------------
>
> _______________________________________________
> gstreamer-devel mailing list
> [hidden email]
> https://lists.sourceforge.net/lists/listinfo/gstreamer-devel
>


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--
Thanx & Regards
Ajay Gautam
[phone]

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