Audio/Video Sync

[takeajourney]

I'm trying to broadcast my video to livestream, but at the same time use it in-house as an IMAG feed to two projectors. In order to get non-lagging video on IMAG I have to run at 60fps, but this creates a problem with livestreaming because I know I can't run at that high a frame rate without having audio/video sync issues.

Here's my setup:

Camera
Canon XL H1
Frame Rate: 59.94fps
Output: HD-SDI

the camera runs into a...

Video Mixer
Panasonic AV-HS400
Frame Rate: 59.94fps
Input: HD-SDI
Output: HD-SDI

from the video mixer the video travels to a...

Mac Pro
Video Input: Blackmagic Decklink Duo Input Card

an audio feed is coming from a Yahama LS9 into the...

Mac Pro
Audio Input: Lexicon Alpha USB Interface

So the audio and video meet up at the Mac Pro. I'm using Procaster with a FPS setting of 30fps. It doesn't take terribly long before the audio and video get out of sync.

Here are my Internet speeds:

speedtest.net
Download: 10.17 Mb/s
Upload: 1.91 Mb/s

pingtest.net
B*
Ping: 34ms
Jitter: 6ms

Any thoughts of what I could try? Is there any type of down conversion for frame rate?

Thanks,

Matt

[coryfrans]

Originally Posted by takeajourney

I'm trying to broadcast my video to livestream, but at the same time use it in-house as an IMAG feed to two projectors. In order to get non-lagging video on IMAG I have to run at 60fps, but this creates a problem with livestreaming because I know I can't run at that high a frame rate without having audio/video sync issues.

Here's my setup:

Camera
Canon XL H1
Frame Rate: 59.94fps
Output: HD-SDI

the camera runs into a...

Video Mixer
Panasonic AV-HS400
Frame Rate: 59.94fps
Input: HD-SDI
Output: HD-SDI

from the video mixer the video travels to a...

Mac Pro
Video Input: Blackmagic Decklink Duo Input Card

an audio feed is coming from a Yahama LS9 into the...

Mac Pro
Audio Input: Lexicon Alpha USB Interface

So the audio and video meet up at the Mac Pro. I'm using Procaster with a FPS setting of 30fps. It doesn't take terribly long before the audio and video get out of sync.

Here are my Internet speeds:

speedtest.net
Download: 10.17 Mb/s
Upload: 1.91 Mb/s

pingtest.net
B*
Ping: 34ms
Jitter: 6ms

Any thoughts of what I could try? Is there any type of down conversion for frame rate?

Thanks,

Matt

Hello Matt,

The audio sync you are having is due to the fact that the video and audio are both hitting your Mac at different times. I suggest finding a way to have your audio go into the video mixer. That way they are joined together and set out via HD-SDI cable in sync. Currently Procaster does not support an audio delay feature, but it is something planed for the future. If you have any questions about this work flow, please contact us at procaster@livestream.com

[cseeman]

Telestream Wirecast Pro has an Audio Sync Delay feature. It's $995 though but given it's a mixer in software and support Blackmagic cards it might be worthwhile.

http://www.telestream.net/wire-cast/overview.htm
Wirecast Pro specifically
http://www.telestream.net/wire-cast/wirecast-pro.htm

[takeajourney]

Thanks for the feedback. Would I be able to pick up an audio delay box to fix the sync issue? Something like the Datavideo AD-100?

--
Matt Keith

[coryfrans]

Originally Posted by takeajourney

Thanks for the feedback. Would I be able to pick up an audio delay box to fix the sync issue? Something like the Datavideo AD-100?

--
Matt Keith

That could work. I would also suggest this http://www.behringer.com/EN/Products/DSP110.aspx

It is what our production team uses in situations like this.