Streaming Video to Multiple Receivers use Case

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JoãoMSM's picture
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Streaming Video to Multiple Receivers use Case

Hi all,

I found the Streaming Video example (https://www.rti.com/resources/usecases/streaming-video.html#) and tried to compile it after a few modifications but the example doesn't executed because a lack of "metadata compatibility" on the Subscriber side.

After a bit of investigation I found that in the pipeline initialization (Videooutput.cxx) was missing the pixel-aspect-ratio=(fraction)1/1 and the framerate=(fraction)1000/1 was different than the publisher side.

I also noticed that the frame buffer size was different in each write operation. I was expecting the same frame size. Does anyone knows why? 

Thanks in advance.

 

 

 

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Hello JoãoMSM, 

Thank you for posting!  Hopefully if anybody else sees this problem this will help.

I am guessing you are testing on Linux, since that is the platform that does not have the pixel-aspect-ratio set.  I have noticed that minor differences in the GStreamer framework (or the version of Linux it is running on) seem to have slightly different requirements in the properties you have to set on the pipeline – I'll try testing the pixel-aspect-ratio locally to see if that works on our test machines as well.  Also, we plan to update this code to a newer version of GStreamer, which should help with some of the compatibility issues.

The reason for the differences in the buffer size is due to the fact that the VP8 encoding format sends two types of frames: keyframes, and prediction frames.  The keyframes will be larger, and the prediction frames may vary in size.

Thank you!

Rose

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Hi Rose,

First of all sorry my late reply.

Yes, you guessed correctly. I was testing on Ubuntu LTS with gstreamer-0.10 in both machines.

Also, I came across another issue when I was trying to compile the code with the provided make file. Sincerely, I didn't search what was the real root cause, I just re-generate and replace them with the provided files within the 'Generated' directory.

Can you also try this and let me know if this is something I am doing uncorrectly?

If you need more information just let me know.

rose's picture
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Hello João MSM,

You are doing nothing wrong – in fact, our shipment process was accidentally shipping the generated files.  So, we are fixing that now.

Thank you!

Rose