m2v files

GatorBait wrote on 5/14/2010, 11:27 AM
Hi everyone,

I kinda saw this topic in the search but it was for DVDA.

I have HDV files (JVC 720p camera) that I captured with Liquid and fused out of the timeline into a .m2v file. I have converted it to .m2ts using tsMuxer. I imported the file into Vegas to to render out as .m2t but it will not smart render. It is recompressing the video even at the standard settings for the file format. What is the issue in this situation? Is it the container or is the contents in it different that is preventing vegas from smart rendering it out? The main reason I want to do this is to separate the clips in the video file. Note, that I do not have the original tapes to recapture in Vegas as this was done long ago.

-alan

Comments

jabloomf1230 wrote on 5/14/2010, 12:58 PM
Make sure that the bit rate on the input files and the output bit rate are identical (among other things). An .m2t file should smart render with no problem, as long as the input properties and output settings match.

But for example, an AVCHD file (which technically should also smart render in Vegas Pro 9) may not, because the bit rate on the input file(s) is usually higher than what the built-in encoder can export.
GatorBait wrote on 5/14/2010, 10:22 PM
Thanks for the info!

but my mission still kinda continues..lol. I checked the bit rate of the file .m2v file and for some reason Liquid exports it out at 25Mbs..even though its in HD1 format. So i was able to dump it back into Liquid and then i exported it out as an .mpg (and i put the bitrate at a constant 18.3) The quality looked pretty good as it is...not much off at all from the original. I took that exported file and dropped it into vegas. when i rendered out...anything without motion did not re-render...but any movement in the video recompressed. I also tried other compression programs (TMPGEnc) and vegas recompressed the video..even though it was at the 18.3 bitrate. The exported mpeg2 file from Liquid is the only one that did not recompress...but only the still videos. Is it possible that Liquid changed the bitrate as it saw movement in the video? Or will Vegas detect the movement and make that change as it rendered out?

This isnt that big of a deal I guess sicne I can just mux the files into .m2t at the higher bitrate...but its turning into a curiousity so I can learn something out of this. I'm only using this as archiving the files. They probably wont get used except for on my reel. I hope this reply made sense since it is really late and my head is spinning from all these tests I did...lol
musicvid10 wrote on 5/14/2010, 10:28 PM
The critical factors to smart render an mpeg file in Vegas are:
-- Frame size
-- Aspect ratio
-- Field order
-- Maximum bitrate
-- Average bitrate

These all being equal, if a file still re-encodes in Vegas, it's probably not going to happen.
GatorBait wrote on 5/15/2010, 11:22 AM
Since its a constant bitrate at 18.3...the max and avg arent applied. I set everything at what it should be at. I exported the file from Liquid as and mpg2 in constant 18.3 with the gop size at 6. dropping that file into the time caused any frame with lots of movement to get recompressed..but the less movement frames rendered out without recompression. Does anyone know why it did that? Obviously it liked the settings of the file since it didnt recompress most of the frames at all...but i thought it would do that to the entire file. Could it be that Liquid changed the B or P frames for the fast moving frames? Or did Vegas decide to make that change?