Raw footage bitrates at DVinfo.net

Adam Chilton · October 23rd, 2009, 08:17 PM

Hi, I use a Canon XHA1 and capture footage with FCS2. I have a question about bitrates. When I capture, all of my raw clips are around 26.5mbps. My friend has an HV20 and captures with iMovie and he gets bitrates of 60, 90, and up to 110 for his raw files. Is there any ways to change bitrates with final cut. His footage from his HV20 is looking crisper on the computer than my XHA1. In the info it says his footage is an "Apple Intermediate Codec" whereas mine is "Apple HDV 1080i60". What's the difference and what's usually the best way to go when capturing? thanks.

Christopher Drews · October 23rd, 2009, 11:40 PM

Apple AIC vs Apple HDV.
Hmmm.

AIC is as it says - an intermediary codec, much like ProRes.
Used for editing, trans-coding and finishing.
The bit-rate details for AIC are user selectable whereas HDV is fixed on acquisition.
HDV is an acquisition codec used to capture and compress HD sources.
It's an MPEG-2 transport stream... Not the best for editing but seriously economical in terms of disk space. After all, it was developed to be recorded on standard DV tape.

AIC is 100 times better to be editing in than HDV, as again, HDV is an acquisition codec.
HDV is 4:2:0 and roughly 25 MBs @ 1080i (1440x1080).
AIC is anything you make it, much like ProRes. It uses temporal compression, will be less taxing on your CPU but takes up 4x the space of HDV.

But, as the adage goes, Garbage in - Garbage Out.
Since your cameras are HDV - there is no better quality to be gained by using a high quality 10-bit Uncompressed codec because your data is already 8-bit, 4:2:0 as acquired by your camera.

AIC is allowing for smoothness in the editing process and taking your HDV out of MPEG-2. No quality or crispness is to be had by using one or the other- it's already decided by your acquisition codec.

Compare instead the XHA1 vs the HV20. Or the Lenses used on the camera. Or the exposure level. These all have more bearing on "crispness."

Now, post workflow is a different ball of wax. You'll gain in color correction if you take your HDV out of HDV (use AIC or ProRes).

Hope this helps,
-C

October 23rd, 2009, 08:17 PM	#1
Adam Chilton New Boot Join Date: Sep 2009 Location: The West, Canada Posts: 5	Raw footage bitrates Hi, I use a Canon XHA1 and capture footage with FCS2. I have a question about bitrates. When I capture, all of my raw clips are around 26.5mbps. My friend has an HV20 and captures with iMovie and he gets bitrates of 60, 90, and up to 110 for his raw files. Is there any ways to change bitrates with final cut. His footage from his HV20 is looking crisper on the computer than my XHA1. In the info it says his footage is an "Apple Intermediate Codec" whereas mine is "Apple HDV 1080i60". What's the difference and what's usually the best way to go when capturing? thanks.

October 23rd, 2009, 11:40 PM	#2
Christopher Drews Major Player Join Date: Jul 2007 Location: Los Angeles, CA Posts: 628	Apple AIC vs Apple HDV. Hmmm. AIC is as it says - an intermediary codec, much like ProRes. Used for editing, trans-coding and finishing. The bit-rate details for AIC are user selectable whereas HDV is fixed on acquisition. HDV is an acquisition codec used to capture and compress HD sources. It's an MPEG-2 transport stream... Not the best for editing but seriously economical in terms of disk space. After all, it was developed to be recorded on standard DV tape. AIC is 100 times better to be editing in than HDV, as again, HDV is an acquisition codec. HDV is 4:2:0 and roughly 25 MBs @ 1080i (1440x1080). AIC is anything you make it, much like ProRes. It uses temporal compression, will be less taxing on your CPU but takes up 4x the space of HDV. But, as the adage goes, Garbage in - Garbage Out. Since your cameras are HDV - there is no better quality to be gained by using a high quality 10-bit Uncompressed codec because your data is already 8-bit, 4:2:0 as acquired by your camera. AIC is allowing for smoothness in the editing process and taking your HDV out of MPEG-2. No quality or crispness is to be had by using one or the other- it's already decided by your acquisition codec. Compare instead the XHA1 vs the HV20. Or the Lenses used on the camera. Or the exposure level. These all have more bearing on "crispness." Now, post workflow is a different ball of wax. You'll gain in color correction if you take your HDV out of HDV (use AIC or ProRes). Hope this helps, -C