MPEG-2 Render Questions

John Griffin wrote on 1/11/2011, 12:32 PM
Today I received specs for video to be delivered in mpeg-2 format. No big deal other than some of the settings I'm at a loss for finding in Vegas.

Format: MPEG 2 video
Format profile: MP@ML
Format Settings: BVOP: yes
Format Settings: GOP M=3, N=15
Bit Rate Constant: 8,000
Width: 720
Height: 480
Aspect: 4:3
Frame Rate: 29.97
Chroma: 4:2:0
Standard: NTSC
Scan: Interlaced
Scan Order: Top Field First

The BVOP? GOP i cannot get those settings. And the mpeg always want to default to lower field first, which I can change. This conversion will be coming from an HDV time line.

Thanks for some explanation on this.

John

Comments

John_Cline wrote on 1/11/2011, 1:10 PM
BVOP means “Bidirectional Video Object Plane” and is used for motion-compensated prediction processing. Unless you are rendering an "I-frame only" MPEG-2 stream, all encoders use BVOP and there is rarely a setting available to change it. GOP refers to "groups of pictures" and the MPEG-2 encoder in Vegas uses "M=3, N=15" by default for NTSC encoding. Vegas also defaults to "4:2:0" chroma sampling.

Just make sure you set the "Deinterlace Method" in the project properties to "interpolate" and "Render Quality" to "Best" in the custom render properties. Change the field order to "Upper Field First" and set the quality slider to "31" and render away.
John Griffin wrote on 1/11/2011, 2:42 PM
John,

Thanks so much for the response. I had read about most of this, but could find now way to edit some of these as you can in Adobe. As for the Deinterlace Method, where is a good source of info so i can better understand when to use what?

Thanks Again,

John
John_Cline wrote on 1/11/2011, 2:53 PM
Just leave the Deinterlace method set to "Interpolate" permanently unless you happen to be working with progressive footage.

In your case of resizing HDV to standard definition MPEG-2, setting it to anything other than "none" tells Vegas to split each interlaced frame into its separate fields, resize the fields individually and then reinterlace the fields back into frames. This is the correct/best method for resizing interlaced footage.
John Griffin wrote on 1/11/2011, 3:00 PM
Sorry John for not stating this in the beginning. All of my footage is shot 24p.
Am I missing a setting here where i can get notifications of post responses?


John