@David-Jodon Hi David, I found the black screen issue goes away by enabling Legacy AVC decoding in file I/O.

Enabling the Quicktime plug-in didn't work for me. The problem then is, as you know from a previous thread, that you lose the Nvenc render options.

You could convert the .mov files to .mp4 and then use ok in VP18. The VFR2CFR util in my signature will do this, also Handbrake HOS Tools etc.

I converted one of the 3.92 GB clips, set to pretty good quality, 18, it weighed in at 0.98 GB, because the original is ALL-I, whereas the converted file is Long GOP. So you save in file size, but you have to select AAC audio, say 512, as the PCM audio in the .mov file won't go into the .mp4 file.

I can work with the files just fine with Vegas Pro 18-482. I don't have Quicktime loaded and I don't have Legacy AVC decoding turned on in File I/O.

I do, however have an AMD video adapter. See my signature.

Thanks to everyone for all your help. I turned on Legacy quicktime, had to download version 7 codec and now everything is humming along nicely - and I am liking the way the new build is working with my GPU! I am suprised I had to jump thru those hoops, but quite pleased with the results.

I downloaded one of the files (2719).

Vegas (media/properties) says it decodes with so4compoundplug.dll, so QuickTime shouldn't have any relation to it. It uses my Intel GPU to decode.

I then enabled legacy AVC decoding. It then decoded with compoundplug.dll (not QuickTime) and as expected there is no evidence of GPU decoding as it's disabled in file I/O. I don't have Quicktime enabled in deprecated features or installed.

Here's MediaInfo for the file- it's just AVC:

General
Complete name                  : C:\Users\Roger\Desktop\Vegas Footage\Canon 80D MVI_2719.MOV
Format                         : MPEG-4
Format profile                 : QuickTime
Codec ID                       : qt   2012.08 (qt  /CAEP)
File size                      : 3.93 GiB
Duration                       : 6 min 9 s
Overall bit rate mode          : Variable
Overall bit rate               : 91.2 Mb/s
Encoded date                   : UTC 2021-03-13 22:14:12
Tagged date                    : UTC 2021-03-13 22:14:12
com.apple.quicktime.make       : Canon
com.apple.quicktime.model      : Canon EOS 80D

Video
ID                             : 1
Format                         : AVC
Format/Info                    : Advanced Video Codec
Format profile                 : High@L5.1
Format settings                : 1 Ref Frames
Format settings, CABAC         : No
Format settings, Reference fra : 1 frame
Format settings, GOP           : N=1
Codec ID                       : avc1
Codec ID/Info                  : Advanced Video Coding
Duration                       : 6 min 9 s
Bit rate mode                  : Variable
Bit rate                       : 89.6 Mb/s
Width                          : 1 920 pixels
Height                         : 1 080 pixels
Display aspect ratio           : 16:9
Frame rate mode                : Constant
Frame rate                     : 29.970 (30000/1001) FPS
Standard                       : Component
Color space                    : YUV
Chroma subsampling             : 4:2:0
Bit depth                      : 8 bits
Scan type                      : Progressive
Bits/(Pixel*Frame)             : 1.442
Stream size                    : 3.86 GiB (98%)
Language                       : English
Encoded date                   : UTC 2021-03-13 22:14:12
Tagged date                    : UTC 2021-03-13 22:14:12
Color range                    : Full
Color primaries                : BT.709
Transfer characteristics       : BT.709
Matrix coefficients            : BT.709
Codec configuration box        : avcC

Audio
ID                             : 2
Format                         : PCM
Format settings                : Little / Signed
Codec ID                       : sowt
Duration                       : 6 min 9 s
Bit rate mode                  : Constant
Bit rate                       : 1 536 kb/s
Channel(s)                     : 2 channels
Channel layout                 : L R
Sampling rate                  : 48.0 kHz
Bit depth                      : 16 bits
Stream size                    : 67.7 MiB (2%)
Language                       : English
Encoded date                   : UTC 2021-03-13 22:14:12
Tagged date                    : UTC 2021-03-13 22:14:12

I did nothing special with Vegas 18, I just dragged both clips to the timeline and it played back with no issues.

I do have enabled Quicktime plugin in Deprecated Features. I disabled it and the .mov files I had in my project would not load.

My computer specs are listed in my sig....

What I have been able to establish, not much, but the problem files have one thing in common, ALL-I. The OP's .mov clips are also ALL-I.

Below is a Mediainfo screenshot of two clips, the only difference is that the left one plays aok, it's IPB, and the 2nd. one is ALL-I. The "Format profile" is higher for the ALL-I.

IPB Plays OK ......... ALL-I Plays not OK

The OP's file ... ALL-I.

Plays not OK

This is strange, so All-I clips are playing on some computers but not on others.

What's the difference? I was thinking it was a AMD CPU but JN is having issues with Intel CPUs.

@RogerS It is strange. I tested most of this on my laptop, which has no iGpu enabled, (locked out by Acer, by design) only Discrete Nvidia Gpu.

My PC has Intel iGpu and Nvidia Gpu, so tomorrow I will confirm the ALL-I theory on my PC, using the OP's clip and mine.

Of course, its only these All-I, “modern” clips that have issues. Cineform, Magix Intermediate, Prores, All-I play fine.

I also thought it might be a high data rate thing, but the OP's files are not so high.

Here on my Intel laptop with iGPU and NVIDIA card I had no issue with the OPs clips in regular or legacy AVC decoding mode. (no Quicktime installed) Very odd.

@RogerS Forget it, I found, tested on my laptop, a GH5 ALL-I clip, that has Quicktime TC and plays ok.

For a while there I thought that it was a clip with a combination of ALL-I and either a Quicktime "Format Profile" or a Quicktime Timecode.

Staying with a single clip. Tested on my PC

When I played the Canon 80D clip on my PC, the issue of black frame is nearly gone. When playback is stopped, if I seek to a forward position it's ok. If I seek to an earlier position (when playback is stopped) I sometimes get the black preview screen.

If I seek to an earlier position (when playback is not stopped) playback preview is mostly ok, but you can just see sometimes at start of playback the black preview screen, see below.

Pressing play gives 99% ok preview, but as you watch playback there is occasionally a momentary flash. It's probably a single frame (black) that's just not getting played. This also happens when during playback, you seek to an earlier position, the starting frames, very few are black for a moment.

@JN- I haven't experienced any black frames during playback. If I stop playback and go to an earlier position to start play, no black frames are stutter. I've "bounced" around the clip after pausing it to different locations to see if it would happen (black frame or stutter) and the clip continued to play back as it should.

@Reyfox OK. I don't have a solution, thanks anyway.

I assume u have Legacy Avc unchecked.

@JN- correct. I do have "Enable Legacy avc decoding" unchecked.

@Reyfox Well, thank u for checking. Did u see what I did there😅.

It's a mystery.

We both have capable hardware to be able to play those clips. The difference is that I am using AMD graphics (with latest drivers). Your GPU's are more powerful than what I am running so am I too am stumped.

When I enabled the Quicktime plug in the 80d files work. At the end it renders an mp4 file with High Efficency Video Codec (HVEC/NVENC) fine & fast. If I want a DVD & a Blu-Ray disc Vegas will crash when trying to render mp2 files UNTIL I go to Options/Preferences/File I/O and enable AVC decoding. Then I can render the mp2 files, but the GPU gets far less of the action (acts like Vegas version 17). Not sure, but I think this may work fine as long as I enable legacy AVC decoding when making mp2 files and uncheck that box as soon as I am finished. I love the way it (Vegas) works my GPU when legacy AVC is unchecked. It uses from 6 to 9.2 gb memory from the GPU depending on what exactly I am doing. The 3080 can handle that. GPU is used when playing from the timeline, as well as when rendering. This (Build 482) is the 1st time I have seen a GPU worked like that in Vegas (I have used Vegas 10, 12, 15, 17 & 18).

Sorry it takes me so long between posts, but I have to get several weddings edited & out the door so I do one or 2 and tell everyone what I learned. I will continue to do so.

Does anyone out there use a 3090 card, by chance?

@David-Jodon Aok, the 80D takes lovely image. @Reyfox One more thing. Assuming that you have Quicktime enabled in Depreciated features, when you right click the timeline media and check its properties, General tab, what plugin is it using?

Whether I check or uncheck (sounds like a game of chess) Quicktime in Deprecated, I still only ever get the So4 ... .dll plugin as used. Is that the same in your case.

I take part of what I said back. I just loaded a new project and I can only see my 80d video until I scrub back a few frames. Then it turns to a black screen.

I guess when I shoot this weekend (if I use the 80d) I should switch the output from mov All-I (the way I have shot since purchasing DSLRs for video) to mp4 - at least until somebody at Magix looks into this.

Checking the box next to "Enable legacy AVC decoding" allows me to scrub & still see the video from this camera. At least now I don't have to copy the project in to version 17. We will see if the edited video will render properly without enabling the legacy AVC decoder (to an HEVC/NVENC file) after I finish editing and turn legacy AVC off again.

@JN- here is the screen shot with the info on plugin used.

@Reyfox Thanks. It’s still a mystery. I mean, what does enabling Quicktime do if it’s not used. Your screenshot shows the So4 ... .dll plugin in use, similarly to mine.

Anyway, i’m sick of it.