mpeg2 4:2:2 >15Mbps

Warren Hedges wrote on 10/14/2007, 5:41 PM
Is there any way to render to a mpeg program stream using high profile / main level @4:2:2 greater than 15Mbps.

Interim file interchange format for broadcast in Australia recommends a minimum 15Mbps 4:2:2 mpeg file however the MainConcept encoder in Vegas 7 only seems to produce a max of 15Mbps @ 4:2:2. Is there a way around this?

Warren

Comments

Laurence wrote on 10/14/2007, 5:51 PM
Weird. I use 25mbps all the time with the stock Main Concepts mpeg 2 encoder. You've got to be doing something wrong if you can't. Are you sure you aren't using the mpeg4 encoder?
Warren Hedges wrote on 10/14/2007, 6:17 PM
Sorry for the confusion. I was referring to the built-in mpeg encoder in Vegas(File...Render As). When you select "custom" and set it to high profile on the video tab and 4:2:2 on the Advanced tab, the Maximum, Average and minimum combo boxes in the variable bit rate area only allow a maximum value of 15,000,000.
4eyes wrote on 10/14/2007, 9:06 PM
Try clicking directly on bit-rates settings and type in the absolute full bit-rate (no abbreviations)
Warren Hedges wrote on 10/14/2007, 9:21 PM
You can directly enter any value into the combo box fields (bit rate) eg. 20,000,000 (with or without comas) but the software will automatically reduce it to a maximum of 15,000,000 (15Mbps). It seems to be set as the highest possible value - much like 9.8Mbps is maximum for DVD. I am unaware of there being such a theoretic limit to mpeg high profile (4:2:2 profile)
4eyes wrote on 10/14/2007, 10:17 PM
Mpeg2 does have a max 15MBS for standard definintion.
If broadcast shouldn't that be the ATSC setting (drop down box mpeg2/hdv/d-vhs ect) with the correct framesize. I thought the other formats (HDV / D-VHS / ATSC ect) were extensions of the original Standard Def Mpeg2 spec which as far as I remember does have a 15MBS limit.

Warren Hedges wrote on 10/14/2007, 10:48 PM
I could be wrong but I thought main profile (MP@ML) mpeg2 has a limit of 15Mbps and High Profile (inc 4:2:2@ML) has a theoretical limit of 50Mbps