DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   AVCHD Format Discussion (https://www.dvinfo.net/forum/avchd-format-discussion/)
-   -   Transcoding Comparisons (https://www.dvinfo.net/forum/avchd-format-discussion/283496-transcoding-comparisons.html)

Chris Harding August 15th, 2009 09:30 PM

Transcoding Comparisons
 
Hi Guys

Ok a quick update for those also doing conversions to "easier to edit" formats. I have had lots of suggestions already but I had a trial version of Neo Scene, a purchased copy of Upshift and the MainConcept transcoder is free for Panasonic users.

I took 20 seconds of footage from a paper bark tree as it has a LOT of fine detail in it and did the following:

(1) Created a 1440x1080 HDV M2t clip at 50mps with Upshift
(2) Created a 1440x1080 HDV AVI clip with Cine Form Neo Scene
(3) Created a 720x576 16:9 AVI clip with Main Concept Transcoder

Each clip was then rendered to an SD 16:9 MPEG2 and then the set of 3 were compiled onto a DVD using DVDLab so I could watch it on both computers and TV's (the interlacing was not an issue as the tree never moved!!)

At the casual glance it really is not possible to differentiate between the clips!!! I watched the clips on a 27" TV and two widescreen computer monitors the second at 1680 x 1050 resolution.
As I do weddings the ultimate critic MUST be a woman so my wife checked them carefully! Her comments were that the M2t clip was "shinier" than the other two which were more "dull", so for her the Upshift converted file was "better" Even on a high res monitor it's pretty hard to say which is better!!!!!
Ronald here suggest Cine Form's Neo Scene so I figured that it was worth a try before buying it.

I would have thought that there would have been a marked improvement between rendering from a 1440x1080 source file to 720 x576 and a 720x576 file to 720x576 but it seems that visually you don't have any difference!!! Even doing a RAW avchd clip directly to SD doesn't seem to show any visual improvement although I'm sure technically it is superior!!!

Anyone else tried these routes for editing??

Chris

Bruce Foreman August 16th, 2009 08:16 AM

Chris,

If any of your friends have an HD TV with regular or "upconverting" DVD player connected, you need to see if you can carry that test disk over and see what it looks like there. The viewing results may be the same as on your TV or there may some differences there that may indicate which route is better for you to provide your clients.

Bruce

Robert Young August 16th, 2009 02:24 PM

I have found it to be difficult to do these "eyeball" comparisons of different encodings, and even different cameras (pro vs HD Prosumer/Consumer), particularly for a well shot, well lit scene.
Where I do notice the difference is over the course of an entire project involving lots of shots- some great, some marginal for various reasons- where significant amounts of CC and other filtering/tweaking is used. And then after final encoding to a high compression format for delivery- that's where I can see differences.
If you will be doing CC, filtering, effects, etc., the big, beefy, 10 bit Cineform .avi codec will make a noticable difference in the final product.

Chris Harding August 16th, 2009 07:01 PM

Hi Guys

Thanks and very true!!! Maybe on the next wedding I'll try maybe 30 mins worth of video in different formats on the biggest LCD TV I can find. Robert, what you also say is very true..I've seen domestic SD shots that look way better than pro shots purely because the lighting was perfect!!

I also think we tend to become obsessed with technical issues rather than content issues and we have to switch off our critical technical brains and just enjoy the content. Normal people watching a DVD are looking at content not resolution!! Bruce sent me an excellent DVD of movies he had shot with both SD and HD cameras and my wife enjoyed them all!! When I asked her about picture quality issues she said that all of them were great!!!

Yesterday I shot 20 secs of a newspaper page and comparing the 3 clips was also a waste of time. Desperately scanning the screen 3" away looking for signs of degradation surely means that I am getting way too technical!!!

Chris

Robert Young August 18th, 2009 03:43 PM

Quote:

Originally Posted by Chris Harding (Post 1231586)
Normal people watching a DVD are looking at content not resolution!! Bruce sent me an excellent DVD of movies he had shot with both SD and HD cameras and my wife enjoyed them all!! When I asked her about picture quality issues she said that all of them were great!!!

Absolutely true.
The average viewer will not register details about image quality if they get swept into the story.
This is not true of audio however. An amateur sounding audio track will brand the whole movie as amateur, no matter how good the video. Conversely, well edited, pro sounding audio will allow all sorts of video shortcomings to pass without notice. The audio track is a cheap & easy way of enhancing the overall production value. It pays big returns for the effort required.

Jeremy Dallek August 18th, 2009 05:24 PM

You mentioned that the tree never moved... seeing as there is no motion involved, I'm guessing you won't see the true strengths/weaknesses of the different compression schemes.

Chris Harding August 18th, 2009 07:01 PM

Hi Jeremy

I also did some comparison shots of a speed boat on the river with some closeup shots too and motion was fine with no image breakup. It seems cams with CMOS chips don't like fast pans..mine have CCD's

However a direct render from the raw AVCHD files to SD still seems to have a slight edge on the transcoded files. If the workflow permits I'll just skip the transcode and have longer render times!!! The only transcoded file that seemed to be just a tad better was the m2t!

Robert, you are 100% correct and I usually try to take the time to get really good audio ..it's just as important as the video!!!

Chris


All times are GMT -6. The time now is 03:42 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2020 The Digital Video Information Network