ProRes Confusion at DVinfo.net

Alex Hawt · January 4th, 2010, 01:08 PM

I keep hearing people talk about ProRes. I have have a raw 6 second video shot with my 5d that is a file size of 35 megabytes. I use compressor 3.5 to convert that clip to ProRes. My new ProRes Version of the clip is 124.6 megabytes...

Isn't compressing your raw video to ProRes 422 suposed to make your file smaller? The ProRes file seems to have a slightly better image quality however. Im sorry if I sound like a video N00B, but can someone please shed some light on this for me?

Raymond Tsang · January 4th, 2010, 01:15 PM

You are not compressing the video - In fact, ProRes is decompressing it (not sure if that's the correct term). And yes, transcoding to ProRes will make your file sizes considerably larger.

Raymond Tsang · January 4th, 2010, 01:17 PM

On that note, the h.264 files straight out of the 5D Mark II is a highly compressed format and generally not ideal for editing.

Mike Watson · January 4th, 2010, 01:46 PM

I say "uncompress".

Furthermore, a directly converted video clip will not look any different (theoretically) after conversion than before. You can't get MORE information from a compressed clip, you can only uncompress the information that is there. However, once you start to edit it, if you apply filters (e.g. color correction), the color correction is done in the greater color space of ProRes 422, rather than H.264.

Also, editing in ProRes will be infinitely easier than H.264. Less processor stress leads to less dropped frames and shorter render times.

Alex Hawt · January 4th, 2010, 02:10 PM

Thank you for clearing that up for me.

Steve Maller · January 5th, 2010, 10:29 AM

The most significant difference with respect to editability between H.264 (what comes out of the camera) and ProRes (and other, similar formats) is that ProRes compresses the individual frames as separate frames, whereas H.264 uses an "inter-frame" method which makes it complicated for editing software to work in a frame-accurate mode. For example, playing an H.264 clip backwards is an amazingly complicated thing (read: processor-intensive).

Alex Hawt · January 5th, 2010, 10:48 AM

you guys are awesome. thanks.

Perrone Ford · January 5th, 2010, 11:03 AM

Quote:

Originally Posted by Alex Hawt

I keep hearing people talk about ProRes. I have have a raw 6 second video shot with my 5d that is a file size of 35 megabytes. I use compressor 3.5 to convert that clip to ProRes. My new ProRes Version of the clip is 124.6 megabytes...

Isn't compressing your raw video to ProRes 422 suposed to make your file smaller? The ProRes file seems to have a slightly better image quality however. Im sorry if I sound like a video N00B, but can someone please shed some light on this for me?

You were not the target audience. The target audience were professionals who were faced with dealing with uncompressed HD, like they had been dealing with uncompressed SD. Uncompressed SD clocks in around 80Mbps. Uncompressed HD clocks in at 1500Mbps. ProResHQ is 220Mbps and this was a GODSEND to people who were looking at 2.5 hours per Terabyte for uncompressed HD. Back then, 1TB drives were $1k each.

Your 5D shoots 40Mbps. AVCHD is 24Mbps. HDV is 25Mbps, the GH1 is 17Mbps.

You're playing in a different league.

January 4th, 2010, 01:08 PM	#1
Alex Hawt New Boot Join Date: Oct 2009 Location: Richmond Virginia Posts: 23	ProRes Confusion I keep hearing people talk about ProRes. I have have a raw 6 second video shot with my 5d that is a file size of 35 megabytes. I use compressor 3.5 to convert that clip to ProRes. My new ProRes Version of the clip is 124.6 megabytes... Isn't compressing your raw video to ProRes 422 suposed to make your file smaller? The ProRes file seems to have a slightly better image quality however. Im sorry if I sound like a video N00B, but can someone please shed some light on this for me?

January 5th, 2010, 10:29 AM	#6
Steve Maller Major Player Join Date: Sep 2006 Location: Burlingame, CA USA Posts: 285	The most significant difference with respect to editability between H.264 (what comes out of the camera) and ProRes (and other, similar formats) is that ProRes compresses the individual frames as separate frames, whereas H.264 uses an "inter-frame" method which makes it complicated for editing software to work in a frame-accurate mode. For example, playing an H.264 clip backwards is an amazingly complicated thing (read: processor-intensive). __________________ me@facebook: http://facebook.com/stevemallerphotography

January 4th, 2010, 01:15 PM	#2
Raymond Tsang Regular Crew Join Date: Dec 2008 Location: san francisco, ca Posts: 90	You are not compressing the video - In fact, ProRes is decompressing it (not sure if that's the correct term). And yes, transcoding to ProRes will make your file sizes considerably larger.

January 4th, 2010, 01:17 PM	#3
Raymond Tsang Regular Crew Join Date: Dec 2008 Location: san francisco, ca Posts: 90	On that note, the h.264 files straight out of the 5D Mark II is a highly compressed format and generally not ideal for editing.

January 4th, 2010, 01:46 PM	#4
Mike Watson Trustee Join Date: Aug 2006 Location: San Diego, CA Posts: 1,082	I say "uncompress". Furthermore, a directly converted video clip will not look any different (theoretically) after conversion than before. You can't get MORE information from a compressed clip, you can only uncompress the information that is there. However, once you start to edit it, if you apply filters (e.g. color correction), the color correction is done in the greater color space of ProRes 422, rather than H.264. Also, editing in ProRes will be infinitely easier than H.264. Less processor stress leads to less dropped frames and shorter render times.

January 4th, 2010, 02:10 PM	#5
Alex Hawt New Boot Join Date: Oct 2009 Location: Richmond Virginia Posts: 23	Thank you for clearing that up for me.

January 5th, 2010, 10:48 AM	#7
Alex Hawt New Boot Join Date: Oct 2009 Location: Richmond Virginia Posts: 23	you guys are awesome. thanks.