Vegas Preview Not Matching Render

[George Dean]

Hi Bob, until we can put our finger on the exact cause, could you do a bit of process of elimination? I would turn OFF GPU acceleration of video process ( Preferences > Video tab). Also set the maximum number of rendering threads to ‘1’. Then render using the Magix AVC Mainconcept format. If that cures the issue, we then know (I think we know!) it is probably something with your GPU.

More information may also help user here help…..OS system, Vegas version and build, Mediainfo (text mode) display of your source media specs. And of course (even though they are set the same) a screenshot of your Project settings and Render format template.

Best Regards……George

[Bob Wills]

Thanks for replying. I’m running Windows 7 with a GTX 1080 and an i7 4790k. Vegas 16 Build 361. After I turned off GPU Acceleration I am noticing that it seems to have fixed some of the issue. The fade out isn’t nearly as dark as it was and instead seems brighter. Not entirely sure why that is.

What’s the difference between using GPU Acceleration and choosing the Nvidia Codec? Also what would be the significance of using only 1 thread? I’d like to get a solid understanding of what each of these do so I can figure out the best set up for me.

[George Dean]

The setting I suggest you try are for testing to see if your GPU has any thing to do with you issue, not necessarily what you would choose as the best setup. These are things the community has used in the paste to run down an issue.

Did those setting make any difference in the end result, the render?

Best Regards……George

[George Dean]

Bob, does your Vegas show an option for the Intel HD Graphics in Preferences > Video

Best Regards……George

[Bob Wills]

No I don’t see that in there. There is an improvement with GPU Acceleration off. I wouldn’t say it entirely fixed the problem but it is an improvement. Like I said I think GPU Accel is making the video darker which in turn means the fade is darker so it makes it appear as though its a slower transition.

[Bob Wills]

It’s actually really weird. I have a 3 second fade out and then a 3 second fade in. With GPU Accel on the fade in starts dark and fades in smooth and quickly. In the rendered video the fade in is slower and feels delayed. With GPU Accel off the fade in seems like it starts off as bright white instead of black but it also fades in smoothly. The rendered video from that also fades in brighter but is still some what delayed in comparison.

[Bob Wills]

General
Complete name : D:\videos\1.mp4
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (mp42/mp41)
File size : 1.56 GiB
Duration : 3 min 40 s
Overall bit rate mode : Variable
Overall bit rate : 60.5 Mb/s
Encoded date : UTC 2017-09-27 21:19:18
Tagged date : UTC 2017-09-27 21:19:18
TIM : 00;00;00;00

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L5.1
Format settings : CABAC / 3 Ref Frames
Format settings, CABAC : Yes
Format settings, RefFrames : 3 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 3 min 40 s
Bit rate : 60.4 Mb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 (29970/1000) FPS
Original frame rate : 29.970 (30000/1001) FPS
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.972
Stream size : 1.55 GiB (100%)
Language : English
Encoded date : UTC 2017-09-27 21:19:18
Tagged date : UTC 2017-09-27 21:19:18
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Codec configuration box : avcC

Audio
ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 3 min 40 s
Source duration : 3 min 40 s
Bit rate mode : Variable
Bit rate : 125 kb/s
Maximum bit rate : 201 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 3.30 MiB (0%)
Source stream size : 3.30 MiB (0%)
Language : English
Encoded date : UTC 2017-09-27 21:19:18
Tagged date : UTC 2017-09-27 21:19:18

[Bob Wills]

[George Dean]

Bob, have you tried the Intel QSV render format option, and what are the results? I don’t see anything in your source media that would have caused it, it is constant frame rate, which is good. And, I happy to see you have the pixel format set to 8 bit (not 32 bit).

Also, have you done a full reset of Vegas? Hold down the ‘Ctrl+Shift’ keys, then double left click on the Vegas desktop shortcut. check the box ‘Delete all cached application data’, and then left click on ‘Yes’. This will reset Vegas Pro to it’s installation default settings and delete the pesky build up cached application data, which sometimes causes Vegas to do strange things.

When I have had problems, or read problems that the render is different than the preview (and the preview is running a project properties speeds), most often it is linked to the GPU processing in either an FX during preview or the render acceleration process. Not always, but usually.

If you start Vegas and load your project, then load another instance of Vegas, go back to your project instance and select ALL in the timeline, then do ‘Ctrl+C’ to copy all the tracks and events in your project timeline, then switch over to the second instance of Vegas, and do ‘Ctrl+V’, which should paste everything in your project to this 2nd instance of Vegas, then render it out…..what are the results?

I know this is jumping through hoops, just trying to suggest things that may lead to a solution.

Best Regards……George

[Francois Pénzes]

Hi Bob

Just curious as to what type of fade you are using. Here’s something else you may want to try on top of what George is suggesting. Look at the pic below and see which one you are using (type 1 or type 2 fade out) and try the other way. Don’t ask me why it makes a difference but I did find that in some cases it did.

Let us know how it goes.

Cheers !

PC Win 10 Pro 64-bit 16gb Intel® Core™i7-2600k Quad Core 3.40GHz
Cameras: Canon XF305 + Canon XH-A1
Blackmagic HyperDeck Studio Mini
Vegas Pro 16, User since Vegas 3.0

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