@Marc-Gold Please identify the camera that created your MXF file(s).

I added multiple copies of your file to a Vegas Pro 21-315 timeline and rendered to the template you specified.

I observed a four-frame lag in the rendered audio from the original project audio when added back to the original project timeline but no other variation or drift in this sample.

I was surprised to observe more audio and video in the rendered file than the total time of the original Vegas Pro project.

You can make this whole sordid mess go away until the developers fix Vegas by using Shutter Encoder to convert your files to Apple Pro Res.

It's quick and easy.

General
Complete name                            : Downloads\511_0424 MARC S GOLDProRes from MXF.mov
Format                                   : MPEG-4
Format profile                           : QuickTime
Codec ID                                 : qt   0000.02 (qt  )
File size                                : 79.5 MiB
Duration                                 : 2 s 603 ms
Overall bit rate mode                    : Variable
Overall bit rate                         : 256 Mb/s
Frame rate                               : 59.940 FPS
Encoded date                             : 2024-07-24 00:21:19 UTC
Tagged date                              : 2024-07-24 00:21:19 UTC
Writing application                      : Lavf61.3.104

Video
ID                                       : 1
Format                                   : ProRes
Format version                           : Version 0
Format profile                           : 422
Codec ID                                 : apcn
Duration                                 : 2 s 603 ms
Bit rate mode                            : Variable
Bit rate                                 : 253 Mb/s
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 59.940 (60000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:2
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 2.036
Stream size                              : 78.5 MiB (99%)
Writing library                          : Apple
Encoded date                             : 2024-07-24 00:21:19 UTC
Tagged date                              : 2024-07-24 00:21:19 UTC
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

Audio #1
ID                                       : 2
Format                                   : PCM
Format settings                          : Little / Signed
Codec ID                                 : sowt
Duration                                 : 2 s 603 ms
Bit rate mode                            : Constant
Bit rate                                 : 768 kb/s
Channel(s)                               : 1 channel
Sampling rate                            : 48.0 kHz
Bit depth                                : 16 bits
Stream size                              : 244 KiB (0%)
Default                                  : Yes
Alternate group                          : 1
Encoded date                             : 2024-07-24 00:21:19 UTC
Tagged date                              : 2024-07-24 00:21:19 UTC

Audio #2
ID                                       : 3
Format                                   : PCM
Format settings                          : Little / Signed
Codec ID                                 : sowt
Duration                                 : 2 s 603 ms
Bit rate mode                            : Constant
Bit rate                                 : 768 kb/s
Channel(s)                               : 1 channel
Sampling rate                            : 48.0 kHz
Bit depth                                : 16 bits
Stream size                              : 244 KiB (0%)
Default                                  : No
Alternate group                          : 1
Encoded date                             : 2024-07-24 00:21:19 UTC
Tagged date                              : 2024-07-24 00:21:19 UTC

Audio #3
ID                                       : 4
Format                                   : PCM
Format settings                          : Little / Signed
Codec ID                                 : sowt
Duration                                 : 2 s 603 ms
Bit rate mode                            : Constant
Bit rate                                 : 768 kb/s
Channel(s)                               : 1 channel
Sampling rate                            : 48.0 kHz
Bit depth                                : 16 bits
Stream size                              : 244 KiB (0%)
Default                                  : No
Alternate group                          : 1
Encoded date                             : 2024-07-24 00:21:19 UTC
Tagged date                              : 2024-07-24 00:21:19 UTC

Audio #4
ID                                       : 5
Format                                   : PCM
Format settings                          : Little / Signed
Codec ID                                 : sowt
Duration                                 : 2 s 603 ms
Bit rate mode                            : Constant
Bit rate                                 : 768 kb/s
Channel(s)                               : 1 channel
Sampling rate                            : 48.0 kHz
Bit depth                                : 16 bits
Stream size                              : 244 KiB (0%)
Default                                  : No
Alternate group                          : 1
Encoded date                             : 2024-07-24 00:21:19 UTC
Tagged date                              : 2024-07-24 00:21:19 UTC

Other
ID                                       : 6
Type                                     : Time code
Format                                   : QuickTime TC
Duration                                 : 2 s 603 ms
Frame rate                               : 59.940 (60000/1001) FPS
Time code of first frame                 : 20:13:50;14
Time code of last frame                  : 20:13:52;50
Time code, stripped                      : Yes
Language                                 : English
Default                                  : No
Encoded date                             : 2024-07-24 00:21:19 UTC
Tagged date                              : 2024-07-24 00:21:19 UTC

My camera is the Sony PXW Z280V

I should probably mention that both channesl of the audio associated with the original footage/clips is coming to me from a sound board. One channel is the actors' mics and the other are the music tracks. It's not ambient sound. It should be in very good sync with the actors' mouth movements and appears to be the case when the original clips are played on the VP timeline. When it's out of sync, though, in the rendered version of the clip, it's really out of sync, noticeably so, like a poorly synced foreign film. Again, whether a rendered clip is or is not in sync seems to depend on the length of the clip, being present in the longer clips, not the short ones.

This sync issue is only present with VP21 build 315. I've been using my Sony camera and its predecessors for a couple of decades in many of the previous versions of VP going back to when Sony owned it, with no such problems. Now that I've switched back to VP build 208, there are no sync problems.

At this point it doesn't look like an issue specific to this footage.

A regular PCM wav file with a solid black color as the "video" is also 4 frames off with a Mainconcept render to 59.94 whereas NVENC is aligned.

@Marc-Gold @VEGASDerek

Pick a build number <300 and stay there until the next Vegas Pro 21 build or trial 22 when it’s announced.

Sounds like the best idea, John. I'll do that.

That's what I recommend as well. Build 208 is well tested and what I'm mainly using to get anything done (vs testing VEGAS).

For anyone coming late to this thread what it looks like is in builds of VP 21.300+ there is an audio delay issue that affects renders using the Mainconcept encoder.

This audio delay occurs with both MagixAVC and MagixHEVC with Mainconcept.

It does not occur with NVENC renders, nor AV1 nor ProRes. I can't test QSV or VCE here but assume they are unaffected as well.

The source media doesn't matter as MXF, AVC in MP4 and even PCM WAV exhibit the same issue. The video itself doesn't appear to be delayed, only the audio which is about 2 frames behind at 23.976fps and 4 frames at 59.940.

I see no such issue with 21.208.

Thanks, Roger. I saw your recommendation to stay with 208 for now.

Hi Roger. Wondering if you think these render settings (below) might eliminate the sync issues in build 315:

Internet HD 1080P 59.94 NVENC

To quote the post above yours...

It does not occur with NVENC renders

What Frosty said. I am wary about editing MXF with 315 as at times I also see decoding glitches with my NVIDIA systems but if you don't, NVENC could be a workaround. It's also much faster than Mainconcept!

@RogerS said: "I can't test QSV or VCE here but assume they are unaffected as well."

I tested QSV with the UHD770 on-die video adapter and the sync was right on for the test project that I described earlier.

Thanks for confirming John.

For anyone coming late to this thread what it looks like is in builds of VP 21.300+ there is an audio delay issue that affects renders using the Mainconcept encoder.

This audio delay occurs with both MagixAVC and MagixHEVC with Mainconcept.

I think it might just be the MainConcept waveform graphic that's being displayed incorrectly. The graphic looks perfectly aligned on my system if the MainConcept renders are imported into vp21 build 208 or earlier. Whereas they're displayed as misaligned if imported into vp21 build 300 and later. No matter which version of Vegas did the renders or the import.

They look wrong in Fairlight, too.

This sync issue is only present with VP21 build 315. I've been using my Sony camera and its predecessors for a couple of decades in many of the previous versions of VP going back to when Sony owned it, with no such problems. Now that I've switched back to VP build 208, there are no sync problems.

Fixing VP21 with a final build is like a strong positive promotion for VP22, to me it makes moral and economic sense to release a VP21 Final with fixes. With VP21 there are all these decoding bugs left unfixed but for VP22 it's assumed they'll be fixed soon, but by VP23 release they could be working on new encoder and VP22 users could be left with faulty encoding.

Fixing VP21 will be positive reinforcement that VP22 won't be left full of bugs too, it's the best possible advertisement for VP22. I really hope there's not someone in Magix/Vegas that thinks leaving VP21b315 without a fix is the smart thing to do, forcing people to upgrade to VP22, cause my immediate thought would be they'll do the same with VP22 reducing confidence in the product.

Right now Magix is doing an Intel and not publicly committing to a fix, Intel destroyed their reputation doing the same.

I wish they would just do away with the annual releases and version numbers as development is rolling and the idea that any given version is final or mature is wrong. We should be paying for a period of update patches.

Yeah like a subscription except the product keeps working at the end of 12months, it removes the conspiracy theories about forced obsolescence because people will be on different 12 month periods. If the most amazing update comes out 1 week after your 12months expires that's just bad luck, these things happen and nobody could say otherwise.

Marketing people probably won't like it.

They look wrong in Fairlight, too.

@RogerS Also looks wrong on Resolve Studio timeline.

@Marc-Gold

Container formats that wrap AVC video with PCM audio, like your MXF, are notorious for A/V synch issues on playback, whether they are encoded to MP4 in Vegas or other software like Handbrake and maybe others. I first reported the issue with samples to developers of both companies fully 12 years ago, and never got a response, indicating the issue might be fairly entrenched.

I have not tested rewrapping AVC/PCM to mp4 with Shutter Encoder, and I will be very interested in your outcome should you choose to give that a try. Keep us in the loop.