• Compression Techniques

  Compressor – No CBR for DVCPro HD to MPEG2 720p

  Posted by Jack Updyke on November 4, 2007 at 8:07 pm

  I have been trying for days to fiqure out how to do a Constant Bit Rate compression of DVCPro HD footage to 720p MPEG 2. Compressor only allows VBR in this catagory. I have five programs of the same length that need to be synced up on 5 servers. The files neded to be the same size according to Adtec, who makes the servers. The only way to do that is with CBR but compressor does not allow CBR encoding unless downconverting to standard def NTSC. I have tried in vain to locate other compression tools that will do it but have been unsuccessful. Anyone have any idea how to do this or how to hack compressor so it allows CBR compression from DVCProHD to MPEG2 HD?

  Jack Updyke replied 18 years, 6 months ago 2 Members · 4 Replies
• 4 Replies

• 

  Jeff Greenberg

  November 9, 2007 at 1:07 pm

  Create an MPEG 2 setting in compressor. Switch the stream usage to Generic. On the Quality tab, set the Mode to One pass CBR.

  Best,

  Jeff G
  Principal Instructor
  Future Media Concepts

  FMCTraining.com
  Editorsretreat.com
• 

  Jack Updyke

  November 10, 2007 at 6:41 pm

  Unfortunately, this only works for NTSC material. When trying to compress HD material, the CBR option is not available.
• 

  Jeff Greenberg

  November 13, 2007 at 7:25 pm

  Dammit, Jack, you’re dead right. I only tried NTSC.

  I will tell you I fired up Squeeze and Episode and both allowed me to do so in HD.

  Best,

  Jeff G
  Principal Instructor
  Future Media Concepts

  FMCTraining.com
  Editorsretreat.com
• 

  Jack Updyke

  November 16, 2007 at 3:03 pm

  Jeff,
  I had considered Episode Pro but the cost was about $900 and I only needed it this one time. Seemed a little excessive. I had checked out versions of Pro Coder and Cleaner but neither one did what I needed to do.

  As it turned out, I compressed them in Compressor using VBR and then multiplexed them with a AC3 audio track into transport streams using Manzanita. While the video tracks were diffrent sizes, the AC3 audio track was the same for all five versions. Turned out the final muxed tracks were identical in size. Go figure. I guess the multiplexer took its cue from the audio and not the video.

  The tracks worked perfectly once loaded on the servers and synced.

  Subsequently, Adtec retracted there recommendation of needing CBR and stated that VBR would work..so problem solved.

  How has your experience with Episode Pro been? I understand it works with Final Cut from the timeline and is supposed to be much faster than Compressor. What about the quality?

  Thanks for the input.
  Jack

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