Video Scopes slows down preview a lot

fifonik wrote on 1/1/2024, 8:57 PM

Playing with footage from my new camcorder (4K-60p 8-bit AVC).

- Reset VP21 options (Ctrl+Shift when starting then 'Yes')

- Options | Preferences | Video | Automatically create proxies -- Off

- Preview - Best | Full

- Dropped one file to timeline, adjusted project video settings to match the media

Play -- video is playing at full speed (60pfs)

- View | Window | Video Scope -- tick

Play -- video is playing with ~30fps

- View | Window | Video Scope -- untick

Play -- video is playing at full speed (60fps)

By default the video scopes not updating while previewing video so I do not really understand why just enabling the scope window slows playback down so much.

Is it known issue?

Demo (~250MB)

Media file I used in the demo (~100MB)

The file's media Info:

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L5.2
Format settings                          : CABAC / 2 Ref Frames
Format settings, CABAC                   : Yes
Format settings, Reference frames        : 2 frames
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 6 s 507 ms
Bit rate mode                            : Variable
Bit rate                                 : 143 Mb/s
Maximum bit rate                         : 158 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 59.940 (60000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.288
Stream size                              : 111 MiB (98%)
Language                                 : English
Encoded date                             : 2024-01-02 00:06:58 UTC
Tagged date                              : 2024-01-02 00:06:58 UTC
Color range                              : Limited
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709
Codec configuration box                  : avcC

Comments

Former user wrote on 1/2/2024, 3:36 AM

The frame rate doesn't change for me, although instead of rock solid 60fps it stays at 60fps with some drifting down to 48-59 fps .

What I noticed is having the scopes on screen increases GPU useage by 20watts. If you don't have an extra 20watts of GPU then your frame rate will fall. Animated or static scopes during playback consume the same power.

Playback 8bit, no scopes, 70w GPU

Playback 8bit, scopes, 90w GPU

Playback 8bit, Color Grading module with or without scopes, 100w GPU

When Vegas still used CPU for the scopes, a static scope worked how you'd think, it used no CPU, with the conversion to GPU powered scopes the scopes are processing even when static.

fifonik wrote on 1/2/2024, 8:06 PM

Sure that consequencies will depend on performance of exact system.

My post was not about exact numbers I provided but that enabling the Video Scope window slows preview down quite a lot.

As per my demo this happening even when the scopes window is not visible.

I will try to create bug report, but based on my personal experience with Magix they will ignore it :(

mark-y wrote on 1/2/2024, 8:19 PM

Will try to duplicate.

Former user wrote on 1/2/2024, 10:18 PM

Sure that consequencies will depend on performance of exact system.

My post was not about exact numbers I provided but that enabling the Video Scope window slows preview down quite a lot.

If Vegas did not use so much GPU for scopes you would not have noticed the problem, so it is a dual bug. The idea for using GPU over CPU for scopes should be about efficiency, but actually it's less efficient, 20watts for scopes is huge and most likely using more wattage then back when they used CPU powered scopes. There is the advantage in removing the load from the CPU, but I wonder if you go back to a CPU powered Scopes version of Vegas, maybe the same project with animated scopes on screen plays back without reduced frame rate with your 5700x cpu.

As per my demo this happening even when the scopes window is not visible.

I will try to create bug report, but based on my personal experience with Magix they will ignore it :(

Yeah it's a bug that's been around for years.

john_dennis wrote on 1/3/2024, 2:03 AM

@fifonik

No Video Scopes Window

Video Scopes Window Visible, No Update

Video Scopes Window Visible, with Update

VEGASPascal wrote on 1/3/2024, 2:25 AM

@fifonik Thanks for the reports. I will add this to the backlog.

bitman wrote on 1/3/2024, 4:15 AM

@fifonik good find, I personally have the scopes window on, but never had enabled "update scopes while playing", I noticed no drop in framerate, but my CPU fan audibly kicked in, so I took a look at performance, temperature and power readings. On my setup there is little difference on the NVIDEA GeForce RTX 3090, about a 2 to 3 watt consumption more, and usage pretty much the same. On the CPU side however, a steep increase in usage (from 12% to 80%) and CPU power consumption jumped from 49 W to 144 W (that is why the CPU fan starts making noise).

Conclusion: on my system it does not seem that scopes treatment involves GPU, but is still a CPU thing.

fifonik wrote on 1/3/2024, 5:46 AM

In my case it also play with full fps in Best | Half (and this is perfectly fine for me with 4K footage).

However, the post is not about "How to deal with the situation?". I believe I'm experienced VP user and I know how how I can work around the issue (Best | Auto, proxy)

It is about "I've found something that looks very sub-optimal and I believe it should be fixed". I believe VP users do not mind if devs fix this issue so the program become a bit faster.

fifonik wrote on 1/3/2024, 6:43 AM

> Monitoring signal on-live surely costs some resource

What kind of monitoring are you talking about?

By default (as in the demo) scopes not updating while playing. They updated only when you click at different position on timeline. So while playing it should cost zero resources, imho.

Also, when scopes window enabled but hidden (as at the end of the demo), it must use zero resources as well as no reason to do any analysys.

I'd agree with you in case option "Keep batpassed FX running" would be ticked. But it is not ticked by default.

fifonik wrote on 4/9/2024, 4:05 AM

Can anyine check if the issue is fixed in VEGAS Pro 21 Build 300 please? (I checked change log and have not found anything related to 'scopes' there).

Thanks.

RogerS wrote on 4/9/2024, 4:23 AM

The underlying engine is different so at least on my desktop system I am normally at the full framerate (up to 60fps) using NVIDIA decoding. I almost always have live scopes on.

On my laptop I'm at full fps with scopes on or off but at preview/full. At good/full or best/full I'm at closer to 30 fps and can't see any meaningful difference whether it is checked or not.

Reyfox wrote on 4/9/2024, 8:10 AM

Timeline playback on UHD 4K 10bit 422 25P plays back fully with Best>Full. Mind you, no effects though.

It's working great for me so far!

ALO wrote on 4/9/2024, 9:50 AM

I'm on a laptop GPU and I notice the new build is much laggier/stutters when I'm scrubbing through footage in a 4k project (even proxies) and/or trimming clips on the timeline. I wonder if this is related?

RogerS wrote on 4/9/2024, 10:08 AM

I'm on a laptop GPU and I notice the new build is much laggier/stutters when I'm scrubbing through footage in a 4k project (even proxies) and/or trimming clips on the timeline. I wonder if this is related?

Related to what? Having scopes open?

I assume it's specific to whatever media you are using as NVDEC has been overhauled in build 300 and there is a new decoder mxcompound in use. For me it's much faster/smoother than NVDEC in 208 and older (I mainly used QSV for better performance with so4compound)