• Compression Techniques

  mpeg2 VOD field question

  Posted by Paul Allman on October 21, 2005 at 7:16 pm

  Hi — I am creating mpeg2 transport streams to CableLabs specs. The specs call for upper field, but the source video is a combo of DVCPRO50 (lower field) and graphics. The question: does switching field dominance in Mpeg encoder damage image quality? Bit rate is 3.75. BTW, I have tested all encoders mentioned here (except Procoder) and I have gotten best results exporting mpeg2 directly out of QTPro(!).

  Thanks in advance.

  Ben Waggoner replied 20 years, 7 months ago 2 Members · 3 Replies
• 3 Replies

• 

  Ben Waggoner

  October 21, 2005 at 7:23 pm

  I did exactly that project last week!

  I used Carbon (pro-ProCoder), but I imagine ProCoder could do it just fine itself.

  My Book: https://www.benwaggoner.com/books.htm
  Squeeze and ProCoder tutorials: https://www.classondemand.net/benwaggoner/
  Compression Class at Stanford: https://www.digitalmediaacademy.org/compression.html
• 

  Paul Allman

  October 21, 2005 at 8:01 pm

  Hi Ben – does that mean the the field switching is a non-issue? I haven’t seen any problems but I cannot preview on the VOD server. Best I can do is cook a dvd with source mpg and watch it that way.

  I thought Procoder was PC only. I’ll have to check it out.

  thanks
• 

  Ben Waggoner

  October 21, 2005 at 8:16 pm

  I believe the VOD spec can handle either field order. I’ve done my VOD in lower-field without a hitch.

  My Book: https://www.benwaggoner.com/books.htm
  Squeeze and ProCoder tutorials: https://www.classondemand.net/benwaggoner/
  Compression Class at Stanford: https://www.digitalmediaacademy.org/compression.html

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