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-   -   EX1 on a shoot (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/104915-ex1-shoot.html)

Thomas Smet October 4th, 2007 09:22 AM

Quote:

Originally Posted by Simon Wyndham (Post 753879)
A note on NLE's, Vegas 8 is great for the XDCAM format, especially if you don't perform any grading process. Vegas 8 is the only NLE to my knowledge that can take HDV and XDCAM HD and only render out the portions of the video that have changed (ie transitions been added or filters applied). If you have performed a cuts only edit then Vegas can render out an HDV or XDCAM HD file without any recompression at all! Nada, zilch. Thats zero recompression, and zero quality loss. Neat huh?
.


Avid Liquid has been a native mpeg editor for years. It "was" the first NLE to have native HDV or any type of mpeg2 editing.

Simon Wyndham October 4th, 2007 04:37 PM

I'm not talking about the ability to edit HDV or XDCAM HD. I'm talking about the ability to edit it and then create a final edited file for output back to tape or disc without needing to recompress the footage. AFAIK Vegas is the only NLE out there that can currently do this. Though I'll put my hands up if I'm wrong.

Travis Binkle October 18th, 2007 06:00 PM

Simon: Could you tell me how long the EX is?

It looks like it is nearly identical in size as the Z1 in these photos from:
http://www.dvuser.co.uk/content.php?CID=171

But the specs say the EX is 2" shorter.

Can you confirm any thing either way? Thanks

Steven Thomas October 18th, 2007 10:29 PM

I like the looks of the EX. It has less of the HVX200 toaster shape. LOL

Greg Boston October 18th, 2007 11:41 PM

Quote:

Originally Posted by Simon Wyndham (Post 754487)
I'm not talking about the ability to edit HDV or XDCAM HD. I'm talking about the ability to edit it and then create a final edited file for output back to tape or disc without needing to recompress the footage. AFAIK Vegas is the only NLE out there that can currently do this. Though I'll put my hands up if I'm wrong.

Am I not getting the same from FCP by sticking to the native XDCAM HD codec and exporting the sequence back to disc? If so, please explain. I'm talking cuts only editing like you mentioned.

-gb-

Alex Leith October 19th, 2007 06:26 AM

I was under the impression that even cuts-only GOP mpeg had to have some recompression when layed out as unless you only ever cut on the I frames the GOP structure changes and needs to be "reassembled"... (which I would assume means recompressed)

Greg Boston October 19th, 2007 07:00 AM

Quote:

Originally Posted by Alex Leith (Post 761294)
I was under the impression that even cuts-only GOP mpeg had to have some recompression when layed out as unless you only ever cut on the I frames the GOP structure changes and needs to be "reassembled"... (which I would assume means recompressed)

Re-conforming the GOP is not recompressing the material. It should just be going back to frame one of the sequence and labeling the frames according to the GOP length. I'm going to look into it further.

-gb-

Alex Leith October 19th, 2007 07:13 AM

Quote:

Originally Posted by Greg Boston (Post 761309)
Re-conforming the GOP is not recompressing the material. It should just be going back to frame one of the sequence and labeling the frames according to the GOP length. I'm going to look into it further.

-gb-

I don't think that would work... Isn't the GOP is always a set number of frames?

Data-wise an I frame is quite different to a P frame... So surely any edited sequence would actually need recompressing to create new I frames and P frames, as they don't work interchangeably.

Greg Boston October 19th, 2007 07:38 AM

Quote:

Originally Posted by Alex Leith (Post 761318)
I don't think that would work... Isn't the GOP is always a set number of frames?

Data-wise an I frame is quite different to a P frame... So surely any edited sequence would actually need recompressing to create new I frames and P frames, as they don't work interchangeably.

You may be right, but using that logic, no software, not even Vegas 8 as Simon mentioned, could work without re-compression after editing.

BTW, GOP length in XDCAM HD changes, not within a sequence, but based on frame rate. When shooting 24P, the GOP length is 12, as opposed to 15 in 30p or 60i.

I just re-read the XDCAM Whitepaper for FCP. It states that if the sequence is a native XDCAM HD format, no re-compression is required. However, a couple pages later, it states that 'minor' re-compression may occur around edit points to ensure group of pictures and data rate meet MPEG2 compliancy.

-gb-

Alex Leith October 19th, 2007 08:20 AM

Quote:

Originally Posted by Greg Boston (Post 761332)
I just re-read the XDCAM Whitepaper for FCP. It states that if the sequence is a native XDCAM HD format, no re-compression is required. However, a couple pages later, it states that 'minor' re-compression may occur around edit points to ensure group of pictures and data rate meet MPEG2 compliancy.

Thanks for that... I don't know how they do it, but I guess that is better than what I would have expected. I don't imagine that Vegas is any different...

Simon Wyndham October 21st, 2007 05:34 AM

Quote:

You may be right, but using that logic, no software, not even Vegas 8 as Simon mentioned, could work without re-compression after editing.
The recompression of a small group of frames is possibly the only way it could be done, thinking about it. I'm just going on what I am told by the Vegas people. When outputting a sequence Vegas displays the actual footage in its preview window. If no recompression is required then it shows a message stating that. I haven't seen any recompression being applied with HDV or XDCAM HD so far on cuts only edits.

I'm not sure how FCP works. I have only just started using that software so I don't know much about it.

Bob Grant October 21st, 2007 06:04 AM

The demo of Vegas Pro 8 with EX1 footage in Sydney was pretty impressive. Yes if it's cuts only no recompression is required, obviously if there's dissolves or anything else that affects the image recompression is required but only of the affected portion.
FCP seemed to import the footage as easily as Vegas Pro 8 although the process didn't seem quite as fast. It seemed to loose the metadata in the process. Vegas by comparison gives it to you as markers on the T/L. You also get a basic burn to BD disk for quick previews.
At the same event Edius seemed to cope quite capably, Avid Liquid seemed unable to ingest but will in the next release. They were able to playback the footage once ingested outside of Liquid.
Adobe were invited but didn't show.

Piotr Wozniacki October 21st, 2007 06:15 AM

Thanks for the nice NLE's vs EX1 round-up, Bob. My question is: based on HDV renders, I'm getting exactly what you describe from Vegas Pro 8.0a: recompression of only substantially modified parts. However, what beats me is that when I play back the no-recompressed renders using Nero Showtime, I'm getting clean video only if the hardware accelleration is off, otherwise it seems the whole bottom 1/3 of the picture sort of gets frozen, then pixelated, from time to time - even outside the cut points of the project. Of course it goes without saying no such problem playing back the original, native m2t's.

Did you actually see any EX1 1920x1080 clips smart-rendered by Vegas, and how it was played back?

Bob Grant October 21st, 2007 06:39 AM

Quote:

Originally Posted by Piotr Wozniacki (Post 762160)
Did you actually see any EX1 1920x1080 clips smart-rendered by Vegas, and how it was played back?

No, this was a very quick demo by 4 people, one each from Apple, Grass Valley, Avid and Vegas camps. They were only demoing (or not in Avids case) ingesting and getting the footage onto the T/L and very briefly playing it back.

I don't know why the hardware acceleration is having problems, this would be totally dependant on the graphics card itself, most likely not even a Nero issue. I can only speculate that as any mpeg-2 smartrender has to produce non fixed length GOPs this could be causing the hardware decoder to have issues. If this feature is vital to you my only suggestion is to try it on a better graphics card.

Piotr Wozniacki October 21st, 2007 06:49 AM

Quote:

Originally Posted by Bob Grant (Post 762169)
I can only speculate that as any mpeg-2 smartrender has to produce non fixed length GOPs this could be causing the hardware decoder to have issues. If this feature is vital to you my only suggestion is to try it on a better graphics card.

Well, I guess it's vital to all of us, as it suggests the smartrendered mpg2's are not fully compliant. BTW I have a higher class ATI card with newest drivers, but this is of secondary importance as we cannot control how customers will be playing back stuff...


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