XAVC-L GOP Editing

Jay_Mitchell wrote on 2/5/2016, 1:14 PM

I purchased the Sony X-70 and it will be here next week. I would like to know the best editing practice for the XAVC-L GOP 4:2:2 10bit HD (1920x1080) in SVP13. I also picked up a license for Catalyst Prepare in case it is needed to transcode. What I would like to know is:

1. Does SVP13 import the XAVC-L GOP natively. Or do the files need to be transcoded in something else first?

2. If transcoding is required, What is best for straight cuts, a few overlays and outputting to a lower resolution mp4 file?

I have a very fast i7 laptop and speed is my concern. These files are for ENG and the fastest turnaround is required. Not sure how long transcoding 5 minutes of clips would take if necessary.

I would appreciate some accurate advice and help on editing these XAVC-L GOP files.

-Jay

Comments

astar wrote on 2/5/2016, 2:15 PM

Without knowing more about the system hardware on your laptop, you rendering speed is just going to have to be tested by you. XAVC-L and intra are heavily GPU assisted in 32-bit Video level mode, to maintain the 10-bit color info. Vegas should be able to do all your format conversion without prepare, but either way should work.

I would try conversions to:

HDCAM-SR-Lite in 32-bit-VL project mode for editing (format will smart render if no render effects are required.)

Cineform-Medium or High.AVI in 32-bit-VL project mode for editing

XAVC-intra in 32-bit-VL project mode for editing (format will smart render if no render effects are required.)

You can always switch your project mode to 8-bit for editing, and back to 32-bit VL for rendering final.

You may want to know what the format you need to render to for submission to the ENG source, as they may only accept certain types. This may change how you edit and render the footage for submission.

mountainman wrote on 2/5/2016, 2:44 PM

I have an older i7 laptop. Just edited some x70 footage that was -L at 35 megabit. One hour took 3.5 hours to render to mpg2.
Editing 35 m (1920/60p) is doable but wont play at full 30fps. More like about 20fps. It was an easy edit so I was not too concerned about it. 50 meg is very difficult to work with on this older machine. You can always edit with proxies.

j

Jay_Mitchell wrote on 2/5/2016, 3:32 PM

The laptop specs are:

i7-4810MQ
DDR3L 16GB RAM
SSD 256
Nvidia Geoforce GTX 870M Graphics Card

I have been using this laptop to edit files from the JVC GYHM100 35Mbit MP4 files at blazing render speeds. So, am hopeful to be reasonably fast with the 50Mbit XAVC-L GOP files. I won't know until I try it.

But, I have never had to transcode anything first, before editing. And I wanted to know how much time does the transcode take before starting to edit.

The best case scenario would be for SVP13 to see the XACV-L 50Mbit files and allow me make my straight cuts, add a watermark and render out to a 854x480 MP4 file for delivery.

musicvid10 wrote on 2/5/2016, 3:38 PM

My bet is it will open and edit pretty well on your laptop; I don't see any glaring limitations except perhaps reduced preview fps. For that, you can do a RAM preview.

OldSmoke wrote on 2/5/2016, 3:52 PM

The best case scenario would be for SVP13 to see the XACV-L 50Mbit files and allow me make my straight cuts, add a watermark and render out to a 854x480 MP4 file for delivery.

You delivery format is rather low quality; why not use the dual record function and edit the lower res MP4 files first? You can always "replace" the low res MP4 file with the higher res XAVC-L files. I do that when I am on the road with my AX100 and want to do quick cuts on my Surface Pro 3. The only issue I face with the AX100 is that the file numbers drift apart as soon as I take a picture inbetween. I then have to use a file reanming tool to align them and I use Vegasaur's "Replace Media" function to swap the low res files with the high res files later.

mountainman wrote on 2/5/2016, 11:51 PM

Even with my old machine it renders at 3.5 to 1. If your doing a two minute news piece that's only 10 minutes or so. Old Smoke has a good idea as well. j

Wolfgang S. wrote on 2/6/2016, 3:33 AM

You could use the Catalyst to convert to XAVC - where a lot of people state that XAVC has a better preview performance in the timeline then XAVC-S. Or you could convert to Cineform, but that will requir another batch encoder (I use TMPGenc 5/6 for that).

But be prepared that this conversion will take significant time. With TMPGenc 6 on my 8 core System, TMPGenc 6 uses 1 (!!) core only to convert UHD ProRes to Cineform, what is in time for 1h footage about 4,5 h (but I run 6 instances of TMPGenc to bring the total time down what works fine).

So the best would be to try to edit the footage native, use tricks like to set the project to 8bit for editing and to 32bit for rendering only. And reduce preview settings to preview/half if necessary.

You could also think about a proxy workflow what is available in Vegas Pro 13.

astar wrote on 2/6/2016, 3:55 AM

My recommendation to convert the footage was to improve edit/timeline/scrubbing playback performance. You do not need to convert the camera original if you only need to trim the footage and add an overlay. I was getting about 3:1 on rendering to an alternate format, and even longer to Cineform.

Since your delivery format is so low res, you could shoot in 720P and process a lot less information in Vegas for more speed.

You may want to consider delivering in an actual 16x9 resolution for better scaling.

https://pacoup.com/2011/06/12/list-of-true-169-resolutions

The laptop specs seem good, I would use something like GPU-z to verify that the GPU is being used during playback and rendering. Rendering to Sony XAVC or Sony AVC for delivery, depending if they support XAVC, but either should use the GPU assist better than the older MC encoder.

Jay_Mitchell wrote on 2/6/2016, 3:19 PM

@astar

That was a very interesting article about 16x9 resolutions. And there was a lot of valuable info in reading all of the comments. Up until now, I have been shooting 720p on my JVC-HM100 and delivering 854x480 files to the news stations. How this number was derived came from what software and editing systems were in the actual news vans vs. the news stations. For example: the newsvans would choke if I gave them 864x486 which was a true 16x9 aspect ration. 854x480 caused no delays. It had to do with a grass valley system in the news vans. When feeding directly to the news stations they could take 720p and/or the 854x480. I was told that because they simulcast in both HD and Non-HD that the 854x480 would accommodate both. I'm sure that there software must be updated by now to accept more ratios. The stations themselves don't care if you deliver one or the other. So with that, I opted for speed of editing and file sizes for uploading. But, I will ask the tech guys at the stations if their preferences have changed.

I have been shooting and archiving the 720p for years. It is definitely time to start shooting 1080p for future stock footage concerns.

I am looking forward to testing this all out when the X-70 arrives on Tuesday.

Thanks to everyone for your inputs.

Jay

Jay_Mitchell wrote on 2/11/2016, 5:14 PM

Here is my update:

Shooting in XAVC-L GOP 1920x1080p 29.97fps

1. The files play natively without any glitches on the laptop
2. Files very easy to import in SVP13
3. No transcoding required at all
4. Rendering out 720p mp4 5m bps constant takes 1.5x time

I am very happy and relieved to know that I can use this codec in SVP13 and work very quickly.

-Jay