Down Rez recommendations?

cspvideo wrote on 6/2/2012, 10:18 AM

I do some work for a client who shoots on a SONY PDW 335L camera. He elected to shoot 25 weddings by down-rezing in the camera from HD to an SD format.

When I use the video from that camera shot in that way and apply slow motion to scenes I frequently see a great deal of jitter. Sometimes I see halo-like artifacting on shots.

The output form it a standard DVD for the end users.

Is there any combination of settings or workflow in Vegas 11 which might minimize this?

I've also noticed that video shot in HD from that same camera does not exhibit these issues even if the final form of the video will be SD.

Yes. I've asked him not to down rez in the camera from now on.

Thanks for any advice.

Paul Conti

Comments

Former user wrote on 6/2/2012, 1:22 PM

Make sure you are matching field order on your renders to the SD source material.

Dave T2

cspvideo wrote on 6/4/2012, 12:08 PM

Thanks. I will check that.

cspvideo wrote on 6/4/2012, 12:13 PM

I've tried all three:

None/Progressive
Lower
Upper

Lower looks best, but isn't perfect.

malowz wrote on 6/4/2012, 1:42 PM

i would recommend export and resize externally with avisynth.

interlaced resizing its not easy. best way is to deiterlace to double framerate. resize, then select fields.

i use yadif plugin for avisynth with great success.

Malcolm D wrote on 6/4/2012, 1:51 PM

Check the field order properties of the project media.
This is more important than setting it at render.
If it is wrong it will strobe.
You could try changing the properties to see if it helps and if not put it back to what it was.
I presume the down convert in camera was to DV so should be lower field first unless he shot in progressive.
Most other formats including HD are UFF.

Malcolm

amendegw wrote on 6/4/2012, 2:37 PM

"When I use the video from that camera shot in that way I wonder whether this could be a resampling issue? Can you tell us about how you apply the slow motion? Ctrl+drag? Velocity envelope? etc. and how slow?

Also, it might help if you furnished the properties of the source footage using MediaInfo. Are you using the "match media settings" wizard to set your project properties?

...Jerry

cspvideo wrote on 6/8/2012, 7:42 AM

Thanks for the help!

First, here is the information about the material (using Media Info).

General
Complete name : F:\Hutchinson\video\FE080A00515705C100F0080046020224\Clip\Play_00001.MXF
Format : MXF
Commercial name : DV
Format profile : OP-1a
Format settings : Closed / Complete
File size : 437 MiB
Duration : 1mn 53s
Overall bit rate mode : Constant
Overall bit rate : 32.4 Mbps
Encoded date : 2011-07-09 12:45:03.000
Writing application : SONY Opt 1.40
Writing library : SONY Opt 1.40

Video
ID : 2
Format : DV
Format_Settings_Wrapping : Frame
Duration : 1mn 53s
Bit rate mode : Constant
Bit rate : 24.4 Mbps
Encoded bit rate : 28.8 Mbps
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 fps
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:1:1
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Bottom Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 2.357
Stream size : 329 MiB (75%)
Encoded stream size : 388 MiB (89%)
Delay_SDTI : 0

Audio #1
ID : 3
Format : PCM
Format settings, Endianness : Little
Format_Settings_Wrapping : Frame (AES)
Duration : 1mn 53s
Bit rate mode : Constant
Bit rate : 768 Kbps
Channel(s) : 1 channel
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 10.4 MiB (2%)
Delay_SDTI : 0

Audio #2
ID : 4
Format : PCM
Format settings, Endianness : Little
Format_Settings_Wrapping : Frame (AES)
Duration : 1mn 53s
Bit rate mode : Constant
Bit rate : 768 Kbps
Channel(s) : 1 channel
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 10.4 MiB (2%)
Delay_SDTI : 0

Audio #3
ID : 5
Format : PCM
Format settings, Endianness : Little
Format_Settings_Wrapping : Frame (AES)
Duration : 1mn 53s
Bit rate mode : Constant
Bit rate : 768 Kbps
Channel(s) : 1 channel
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 10.4 MiB (2%)
Delay_SDTI : 0

Audio #4
ID : 6
Format : PCM
Format settings, Endianness : Little
Format_Settings_Wrapping : Frame (AES)
Duration : 1mn 53s
Bit rate mode : Constant
Bit rate : 768 Kbps
Channel(s) : 1 channel
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 10.4 MiB (2%)
Delay_SDTI : 0

To create slow motion I use a velocity envelope. I ordinarily slow it down to 50%. On a few shots it may be closer to 35%, like when it's champagne pouring into a glass. I do not see this issue on that specific shot because the camera is not in motion. I see the stuttering when the videographer pans.

The Match Media Settings box is checked on project properties.

Thanks again for the help.

Paul

amendegw wrote on 6/8/2012, 9:02 AM

Paul,

I'm not in a position to adequately reply as I'm @ a tablet rather than my computer, but it looks like you are not downrezzing (source is already SD). Also, make sure your project properties are set to match your source using the match media settings wizard

Maybe someone else (who has a real keyboard) can do a better job of explaining this.

...Jerry

Steve Mann wrote on 6/8/2012, 11:21 AM

"He elected to shoot 25 weddings by down-rezing in the camera from HD to an SD format."

Amateur.

If quality is important to him, then he should shoot and edit in the highest resolution possible and only downres at the last step - making the MPEG file for the DVD.

Frankly, I am surprised that Sony even offers the SD option on a professional camera.

cspvideo wrote on 6/8/2012, 12:53 PM

I agree that shooting the weddings in HD and letting the software take care of the encoding is a better option. The guy has 30 years in the business. Amateur might be a stretch. Clearly this was the wrong choice.

I own several, professional cameras. Some Sony. Some JVC. All allow the end user to switch to 480p. I never use that setting but some people do.

Anyway, he's been shooting this way for a couple of years and I didn't have a problem with it until version 11 of the software. I'm trying to resolve which settings are in need of a tweak to get these projects to render out the way they should.

Meanwhile I kept version 10 around for editing his projects.

Here's an odd clue, it renders out better on a system which does not have GPU capability regardless of whether or not the GPU feature is enabled on a system which does.

B.Verlik wrote on 6/8/2012, 1:03 PM

I don't have any recommendations, but I just happened to notice in the details of your video section, it says 720 X 480, then is says 16X9 aspect ratio. I doubt that's your problem, but that seems wrong to me.

cspvideo wrote on 6/8/2012, 1:26 PM

You can have a 16 by 9 aspect ration, DV video in 720 by 480. It's make believe HD. I don't like it, but it's what the client is using. It does seem wrong, but it isn't. Thanks.

Steve Mann wrote on 6/8/2012, 5:43 PM

"Here's an odd clue, it renders out better on a system which does not have GPU capability regardless of whether or not the GPU feature is enabled on a system which does"

I have suspected since Version 11 was introduced that the GPU and non-GPU instances of the CODECS are different. This is more support to that theory.

john_dennis wrote on 6/25/2012, 12:06 AM

"...it says 720 X 480, then is says 16X9 aspect ratio. I doubt that's your problem, but that seems wrong to me."

720x480 with a pixel aspect ratio of 1.2121 is a legitimate ~ 16x9 format (NTSC DV Widescreen). It's not HD, but it's wide.

If I could have been born 75 years later, maybe I could have missed that whole pixel aspect ratio nonsense. But, if I could have been born twenty years ealier I could have been a drummer with a big swing band.

As Sheldon on the Big Bang Theory says: "That's just wrong!"