Sim Sat audio

Ben Longden

Well-known member
I had to send a story I had shot back to my client via the satellite using SDI.

The vision went well, and the audio was recorded perfectly, BUT I have had to resend the files via FTP as the audio levels were too LOW to be usable.

The SDI facility has audio in, which is taken directly from the audio line out on the camera, and the vision is uploaded into the big wok via the SDI box.

Any ideas on the low audio level?
 

satpimp

Well-known member
Clarification

Was the SDI feed embedded or discreet audio? From the post it sounds like a seperate auio line waas run. Was it analog or AES?

"The SDI facility has audio in, which is taken directly from the audio line out on the camera, and the vision is uploaded into the big wok via the SDI box."

If audio was seperate, levels needed to be increased on the transmit. Did the intake facility check levels at the feed time? Embedded audio should have passed through as recorded unless it was being stipped (deembedded) for the ingest at which point the intake needed to increase levels.

At first glance, sounds like a problem at ingest or downlink record. But truck guys always say "your problem looks(sounds) good leaving here".

The SDI box you were using may also have some sort of limiter, pad or other such mess. Need a little more info on the problem to be of any real help...sorry.
 

Ben Longden

Well-known member
I had a chat with the guys using a similar uplink last night at the harness racing for Sky, and the consensus is that master control at Sky had the audio down too low.

His opinion was everything was done correctly at the playout....

This was the first time since I started shoot'n teevee news in 2003 that I have used the SDI.

The Blackmagic converter that I got (after a request from my client) features vision and audio in, but only one SDI out, so the audio was embedded.

On the test transmission, there was no audio, so a quick repatching saw the audio out on the camera connected directly to the sat box. As soon as this was done, both vision and audio were received in Melbourne, 600km away.

As it turns out, I had connected everything correctly in the end.

My clients master control said the vision was fine but audio a little low. it was not until later the CoS rang me and said to FTP the story as the audio was unusable.

The audio levels in camera were perfect.

I got an email from the senior editor, who said the FTP was fine, but noted the vision was a bit sharper with the FTP...

I have sent Sky an email, and think that my client might do the same, especially as the buggers charge $1000 per hour.
 
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