Edit Sony DVD Cam mpeg2 files

dvd300man wrote on 2/20/2006, 7:00 PM
What is the best way to edit the MPEG2 files created using a sony DCR-DVD300 with minimal losses and minimal decoding/encoding? I would like to edit these files in VMS-plat6 and then render them for use in DVD-arch3 . These mpeg-2 files have the following format when recorded in SP mode: 704x480, 29.97fps, 4:2:0 chroma format, VBR, Average video bitrate=5000Kbps, Audio: AC3, 48000hz, 2-ch, 256 kbps.

These mpeg2 files import directly into VMS but I have not found the best way to render them after editing (forced to increase to 720x480 and bitrates reduce after render). Also I am not sure if it would be better to convert them to AVI of something before I edit them.

Any ideas?

Thanks

Phil

Comments

rustier wrote on 2/21/2006, 7:26 AM
I believe whatever "losses" you may have are already there since mpeg2 is a compressed format (lossy I think is the term). I also believe every time you convert the file into another lossy format thats exactly what happens - you lose a little bit. VMS works with mpeg2 no problem so I would suggest you use it as it is.

I believe the avi format offers the ablity to use the fit to disk option for those who have a big project trying to get it onto a single DVD. But if you use this you do exactly what you say you don't want to do - lose something. It makes space by reducing the bit rates - sometimes recompressing the audio. The picture quality will diminish as these rates reduce - which may or may not be a problem.

As far as re-rendering goes I believe DVDA doesn't recompress anything it doesn't have to, so there should be no additional loss there. If you are changing the dimensions of the video I believe that is called resampling - but I am not sure why you are concerned about the bit rate. To be honest I haven't played much with the formats , but I was under the impression you had a multitude of options for setting up the project. We are gonna have to pull a guru over here to answer that one. I bet Chein would know.

Hey Chein! Stop playing with your mixer board for second and answer ths man's question please! B-)
dvd300man wrote on 2/21/2006, 7:13 PM
I did some rendering tests and used the MPEGValidator program to check the resulting MPEG2 files:

Source file:
MPEG2, 704x480, avg bitrate 7830kbps, Peak 7946kbps

Render video with MainConcept -> DVDA NTSC video stream
MPEG2, 720x480, avg bitrate 5148kbps, Peak 6964kbps

Render with MainConcept -> MPEG2 Default Template
MPEG2, 704x480, avg bitrate 3250kbps, Peak 4739kbps

Both rendered files had noticable reduction in quality. (motion not as crisp as original) but could not see much difference in the two files.

Still not sure what is the best method. Sure would be nice to have a little control over the bitrate of MPEG2 encoding. The only way that I can find to render to the 704x480 resolution is to used the "Default template" which also forces MPEG layer II audio. Would also be nice if DVDA encoded audio in either MPEG layer II or AC3. I did notice that the MPEG2 files that have AC3 audio are compliant in DVDA which is a plus (these would get converted to PCM if they needed to be re-compressed).

Is there any way to add MPEG Layer II audio or AC3 audio to DVDA without upgrading to the full version? Might have to continue to use my old junky SONIC program to burn DVD's.

THanks