XAVC-S playback is better than XAVC-I? Shouldn't it be the opposite?

prairiedogpics wrote on 5/10/2017, 2:18 PM

Hello,

Just got a new toy, a Sony HDR-CX405, which is a stripped down, basic camcorder. I got it mainly because it can record XAVC S 60 fps.

I had read this thread before: https://www.vegascreativesoftware.info/us/forum/xavc-s-editing--102038/#ca627149

which is interesting because it describes how to convert from XAVC S to XAVC I, and the resulting XAVC I files, if only cut and not layered with fx, will render with no recompression. I used Sony Catalyst Browse to convert some test footage from my new CX405 and that worked.

However, here is my question:

In the thread I linked to above, OldSmoke says that XAVC I files should playback better (faster) in VP. I am not finding this at all; quite the opposite! I am finding VP 14 plays the XAVC S files at 59.94 fps (Best, Full) without a hiccup or frame rate drop (Integrated graphics: Intel HD3000). But when I play the XAVC I files (the ones I converted, or even other samples from the web), I can't get past a 45 fps playback.

Silvertone's comment in the thread: The reason for this is that XAVC-I is easier for Vegas to handle and will likely perform better on the timeline.

Did I misinterpret the comments, or what is going on here....?

Comments

john_dennis wrote on 5/10/2017, 7:09 PM

1) XAVC-I has a higher I/O rate. That could be a factor if you're running on a laptop or system with slower disk.You can see that effect in the Windows Performance Monitor.

2) This thread has a mind-numbing amount of information mostly focused on 4K XAVC-I.

prairiedogpics wrote on 5/10/2017, 9:30 PM

@john_dennis Looks I have some homework to do! Thanks!

john_dennis wrote on 5/11/2017, 9:54 AM

Ever curious, I used a clip from a Sony RX10III and converted it to XAVC-I using Catalyst Browse. I created two different XAVC-I files using the Sony and Mainconcept encoder options.

With Vegas Pro 13-453 on my i7-3770(k) system with only the on-die video adapter I got the following preview results:

Sony RX10 III Original

Catalyst Browse Converion to XAVC-I using Sony Encoder

Catalyst Browse Conversion to XAVC-I Using Mainconcept Encoder

Uncompressed AVI rendered from Vegas Pro 13-453

Moving the AVI to a separate 7200 RPM disk did NOT help:

My results appear to match your observation. I'm not prepared to explain the differences. The uncompressed AVI did not play at full 59.94 FPS, either. The source files were on SSD along with the system and Vegas Pro.

The original media was decoded by:
Plug-In
Name: compoundplug.dll
Folder: C:\Program Files\Sony\Vegas Pro 13.0\FileIO Plug-Ins\compoundplug
Format: Sony AVC
Version: Version 13.0 (Build 453) 64-bit
Company: Sony Creative Software Inc.

The Catalyst Browse Sony and Mainconcept encodes were decoded by:

Plug-In
Name: mxfxavc.dll
Folder: C:\Program Files\Sony\Vegas Pro 13.0\FileIO Plug-Ins\mxfxavc
Format: Sony XAVC / XAVC S
Version: Version 13.0 (Build 453) 64-bit
Company: Sony Creative Software Inc.

The Uncompressed AVI was decoded by:

Plug-In
Name: aviplug.dll
Folder: C:\Program Files\Sony\Vegas Pro 13.0\FileIO Plug-Ins\aviplug
Format: Video for Windows
Version: Version 13.0 (Build 453) 64-bit
Company: Sony Creative Software Inc.

prairiedogpics wrote on 5/11/2017, 11:00 AM

Thanks for the extra work. I also tried comparing Sony vs Mainconcept in Catalyst, and also have the XAVC-I files on a secondary drive (OS is on SSD).

Helps me feel not-so-crazy!

Edit: I have a GTX-580 arriving from eBay tomorrow...I understand that may not make a difference, but I bought it to play around with that new R*****e everyone keeps mentioning. I will retest with it and these XAVC-I nevertheless.

OldSmoke wrote on 5/11/2017, 11:05 AM

John, do you see a difference in playback performance with the wave monitor showing and not showing (closed)?

john_dennis wrote on 5/11/2017, 2:43 PM

On the I7-3770(k) showing the Waveform makes ~10 FPS hit on the compressed formats. Waveform doesn't appear to affect the uncompressed AVI.

The i7-6850K could sustain 59.94 FPS when reading from an NVMe disk with the Waveform monitor on for all of the formats even while recording the screen.

Note the changes in CPU usage and disk throughput for the different formats. The file names being read indicates which format is active.

marc-s wrote on 5/11/2017, 2:53 PM

I have a Sony A7rii (XAVC-S) and a Sony X70 (XAVC-L). Both record 4K at 100mbps and the X70 footage (XAVC-L) is always harder to play back.

prairiedogpics wrote on 5/15/2017, 9:43 AM

Just an update: Over the weekend I installed the GTX580 card I purchased on eBay. When I play the XAVC-I files on the timeline in VP14, the playback rate is now pegged at 59.94 fps on Best/Full. Go figure. (And now my NewBlue FX Title Express that came with the Vegas 14 Pro bundle works without a hitch).

john_dennis wrote on 5/15/2017, 10:50 AM

Glad you're having sucess.