downsampled avchd crappy

Rory Cooper wrote on 5/20/2008, 12:00 AM
Hi Guys

I filmed some stuff this weekend in avchd and downsampled those to mpeg 1024 x 596

Then in new project 1024 x 596 dumped those mpegs edited for tv ad but the quality was not as good as I was hoping for

The reason now please don’t spit at me for all this fuzzel and not go direct from original clips is because I edit in Vegas 7 which doesn’t do avchd

I used Vegas home video plat 8 to cut avchd to mpeg 1024 x 596 then did final mpeg cuts in vegas 7

{I am upgrading to pro 8 waiting for our IdioT DEPT to get move on so ] the fact that the clips were edited twice would this effect the final output quality?
Rory

Comments

farss wrote on 5/20/2008, 1:52 AM
Not so much that you did it twice but why oh why did you use a lossy codec like mpeg?

My advice and this is a bit of overkill.
Use Vegas to render from the horrid AVCHD to Sony YUV at 1920x1080. You've now got a decent master that's not too hard to edit although you'll eat up a lot of disk space but that's cheap.

Do all your editing in 1920x1080 HD. Then render out to SD.
IF you're working with interlaced footage you must specify a de-interlace method in your project properties when you downscale or the results will look really, really bad.

The reason for doing everything in HD and THEN downscaling is if you're adding text or graphics the final result maybe a little better.

Bob.
Rory Cooper wrote on 5/20/2008, 5:48 AM
thanks Bob

I will redo the project your method and give you some feed back

Shot some fantastic harly Davidson biggest run in Africa footage with my new canon hg10 so I want to keep the quality as best as I can
Compared with normal sd sony pro the footage looks more alive

Bikers useless lot I had to start the fights myself

oh yes if i work with progressive do you have any advice?

thanks

Rory


farss wrote on 5/20/2008, 6:20 AM
Don't do a lot of progressive as yet, 25p can be a devil to shoot. Fine for set pieces. You probably have the option of 30p which is easier to live with.
In post P is always less hassle than I.
About the only hassle you can have is some cameras in P deliver too much resolution causing aliasing and line twitter problems when downscaled but your hg10 shouldn't cause any grief.

Bob.
Rory Cooper wrote on 5/20/2008, 6:49 AM
ok but i am rendering for PAL and my cam is strictly PAL so you i dont have 30p option

so what you are saying is do 25 p rather than 50i?

i am scared of interlacing and deinterlacing its my fear factor scared because i dont fully understand it i know why its there and what it does its primarily for NTSC

so go safe pal progressive correct?


Rory
John_Cline wrote on 5/20/2008, 1:40 PM
Progressive cuts your temporal (time) resolution in half. Probably not a good idea for video with a lot of motion.

I'm curious, why did you choose 1024x596? That's not a "standard" video size and can cause potential interlace related issues when rescaling the image. If you need to resize the video to near 1024x596, then 960x540 would work out better.
farss wrote on 5/20/2008, 2:10 PM
As John said 25p is problematic with fast motion compared to 50i. Not saying it can't be done but outside of set pieces not easy at all.
I use 50i all the time without problems, you just need to be aware of how to make Vegas handle it properly.
I've also got to agree with John again, where did that wierd frame size come from. Seems to me you're going to be doing a lot of rescaling which is going to take more render time and certainly not a positive for image quality.
One extra word of caution. Shooting 24p in PAL countries can be a real problem with flicker from lights if your camera uses a CMOS imager. I don't think your current camera will shoot 24p anyway but good to keep it in mind.

Bob.
Rory Cooper wrote on 5/20/2008, 10:41 PM
Hi John

The 1024 x 596 is the requested format from the client to fit there internal plasmas I will try 960 x 540 and see how this fly’s

They want the content to fit the screen no letterbox or pillar boxing

Do you have any suggestions? Thanks


Hi farss

1 So the consensus is then to shoot 50i for better results higher quality and better rendering results
2 So if I convert the avchd to Sony YUV 1920 X 1080
3 Edit in and finalise in 1920 x 1080 with text graphics etc
4 down sample to 1024 x 596

This is correct

Thanks for all your positive input guys

johnmeyer wrote on 5/20/2008, 11:59 PM
I just Googled

"1024 x 596" plasma

and got zero hits. I was pretty sure that there was no device that has this resolution. This is not to say that the client didn't request this, but clients sometimes ask for something that they don't really want (e.g., they get some fact mixed up ...).

They want the content to fit the screen no letterbox or pillar boxing

We just went through this in another thread. I provided links to all sorts of sites that tell you how to re-size and scale video:

My 640 x 480 video is clipped (cropped)

But, before you spend too much time on this, I'd sure try to make sure that you have the correct info on their final display. Maybe this is for some sort of proprietary display or signage?


Rory Cooper wrote on 5/21/2008, 1:26 AM
Hi John

Yes I read that thread the solution for me was pixel aspect ratio sorted that problem

Stick with me on this most content here in South Africa is PAL SD now Montecasino my client have installed widescreen plasmas on property which I generate content for
they have developed a live scheduling system the guys who developed that system suggested 1024 x 596 now they are not video guys but are tech people
The requirements are also that the content be anamorphic so that you can resize content live and run a ticker [for example] so I produce the content at that spec
The system has only been developed for them and is unique

I also shoot my own video as well as develop the ads as I used to be an art director for one of our local ad agencies. Anyway my immediate objective is to set a template
for generating and producing all content, from graphics to video. Whereas before it was 720 x 576 easy, graphics video everything.Now I generate graphics at 1024 x 596
I need to find a way to resample AVCHD to 1024 x 596