Bitrate compression for output of recorded conference

Compression Techniques

Bitrate compression for output of recorded conference

Posted by David Silvester on April 19, 2013 at 5:22 am

Hi guys,

I want some advice on what type of bit-rate I can get away with when outputting our project for compression. A friend and I are being hired to record and edit a conference. It is a pretty simple set-up: four cameras shooting 40 hours of video. It is a basic concept; recording each presentation and the end of each session having Q&A. The presenter’s slides will be brought in in post. For 25 – 30 of the recorded hours, we will be taking out the video of the presenters and only having the slides as video. For the other 10 – 15 hours we will show the presenter and their slides in video (and any Q&A in video too).

So, what I am wondering, is what types of bit-rates we should be going for in the output for 1) where there is only the presenter’s voice + their slides 2) the presenter’s voice and image + their slides.

This is all because I want to cut down on size (and therefore how many discs to author and output).

Any help is greatly appreciated.

Thanks,
David.

———
iMac: 2.8GHz i7 | 8GB RAM | 10.6.8 | ATI Radeon HD 4850 | 512MB VRAM
PC: 3.4GHz i5 | 16GB RAM | Win 7 SP1 | nVidia GeForce 660 OC II | 2GB VRAM

FCP 10.0.8
Compressor 4.0.7
DVD SP 4.2
Soundtrack 3

Photoshop 13.0.1.0
MPEG Streamclip 1.9.2

Jeff Greenberg replied 13 years ago 2 Members · 3 Replies
3 Replies

Jeff Greenberg
April 20, 2013 at 2:53 am

You neglect to tell us whether you’re working in SD for a DVD….or HD for blu-ray.

If the camera is on sticks and there’s not much action in general, you can go in at the bottom for MPEG-2 around 3-3.5 Mb/s and probably get away with much lower (towards 1-2) with good VBR encoding; you might get better results with something other than compressor which doesn’t have the best MPEG2 encoder.

Best,

Jeff I. Greenberg
Author/Master Instructor/Speaker/Consulting
My contact info and more
New! Come see me speak @ NAB/Post Production World!
David Silvester
April 21, 2013 at 2:11 am

Oh yeah, sorry about that. It will be for DVD.

So you are saying around 3.5 MB/s as a maximum and 1 – 2 MB/s as a minimum?
Okay, great. Thanks for the tip

I would like to not use Compressor, but as our workflow, where we will be outputting straight from FCP, I don’t think there is any other reasonable way of doing it.

Thanks,
Dave.

———
iMac: 2.8GHz i7 | 8GB RAM | 10.6.8 | ATI Radeon HD 4850 | 512MB VRAM
PC: 3.4GHz i5 | 16GB RAM | Win 7 SP1 | nVidia GeForce 660 OC II | 2GB VRAM

FCP 10.0.8
Compressor 4.0.7
DVD SP 4.2
Soundtrack 3

Photoshop 13.0.1.0
MPEG Streamclip 1.9.2
Jeff Greenberg
April 21, 2013 at 7:38 pm

You asked for a guideline, I’d really suggest just testing the footage with a very low data rate, because you claim that most of it is talking head/freezeframe on a slide.

[David Silvester] ” I would like to not use Compressor, but as our workflow, where we will be outputting straight from FCP, I don’t think there is any other reasonable way of doing it.”

Compressor is going to be better than the straight QuickTime export from FCP7.

The MPEG2 codec in QuickTime is fair at best (both of them use it.)

Best,

Jeff I. Greenberg
Author/Master Instructor/Speaker/Consulting
My contact info and more
New! Come see me speak @ NAB/Post Production World!

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