Audio and Video Timestamp or Offset Problems

William Metcalf wmetcalf at
Tue Jul 19 12:09:14 PDT 2011

-------- Original Message --------
Subject: 	Re: Audio and Video Timestamp or Offset Problems
Date: 	Tue, 19 Jul 2011 14:05:15 -0500
From: 	William Metcalf <wmetcalf at>
To: 	Wim Taymans <wim.taymans at>


Thank you very much for your quick response.  I have a few questions
about the min-latency property.  The gst-inspect of the appsrc element
shows the min-latency property, but it only shows that the property is
an int64.  Is the latency measured in microseconds, milliseconds, or
seconds?  Also, what does the min-latency property control?  The minimum
latency between sent buffers?

Thank you again for your help,

On 7/19/2011 1:58 PM, Wim Taymans wrote:
>  On 07/19/2011 08:50 PM, William Metcalf wrote:
>>  Hello all,
>>  I am reading in Raw Audio and Raw Video from capture cards, and then
>>  rendering them directly to my computer. I am able to do this fine, but
>>  the resulting video is ahead of the audio. My initial thought was to
>>  start the Audio pipeline, and then wait 2 seconds and start the video
>>  pipeline. When I executed this code the audio began playing sooner than
>>  the video as it should, but then the video just played faster until it
>>  was ahead of the audio again. I then tried pausing 5 seconds before I
>>  started the video pipeline just to see what would happen, and that time
>>  the video did the same thing. Because the video always plays ahead of
>>  the audio at the same rate, I am now thinking this problem is a
>>  timestamp or offset issue of some sort. Is there any way to adjust the
>>  Video/Audio offset, or is there a better way to delay the video so that
>>  it will not speed up and pass the audio?
>>  Here are my pipelines:
>>  video - appsrc max-bytes = 0 is-live=true typefind=true !
>>  "video/x-raw-yuv,format=UYVY,width=720,height=486,framerate=30/1" !
>>  autovideosink
>>  audio - appsrc max-bytes=0 is-live=true typefind=true ! audioparse !
>>  autoaudiosink
>  You forgot to configure the latency on the appsrc elements. Try
>  setting the min-latency property.
>  Wim
>>  Thank you for any help you can offer,
>>  William
>>  _______________________________________________
>>  gstreamer-devel mailing list
>>  gstreamer-devel at

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