Video track shifts 5 frames when project is moved to different PC

AlanMintaka wrote on 3/20/2020, 5:27 PM

Hello,

I have two identical PCs (Dell XPS 8700) both running windows 10 1909. Vegas Pro 17 build 421.

MediaInfo details for the video files in the project are shown below.

If I copy a project from one PC to another, the video track gets shifted 5 frames to the left. However A/V are still in sync so the audio must be getting shifted too.

The overall length of the A/V tracks is the same on both machines. It's as though my edit points on one PC were moved 5 frames on the second PC.

The only clue I think I have is that the audio track peaks are rebuilt when I first open the project on the second PC. Since the copy included the SFK files in the original project, shouldn't the peaks already be built on the second PC? Why does it have to regenerate those files?

Anyone have any idea why this might be happening? I know this is a pretty vague post but I don't know where to start analyzing the problem and/or asking questions about it. I examined the project properties and preference settings on both machines and couldn't see any obvious differences.

If there's additional info I need to provide here, please let me know, and thanks for your patience,

Alan Mintaka

MediaInfo report on input files:

Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom (isom/iso2/avc1/mp41)
File size                                : 12.4 GiB
Duration                                 : 2 h 4 min
Overall bit rate                         : 14.2 Mb/s
Writing application                      : VideoReDo (Lavf57.71.100)

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L4
Format settings                          : CABAC / 3 Ref Frames
Format settings, CABAC                   : Yes
Format settings, Reference frames        : 3 frames
Format settings, GOP                     : M=4, N=54
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 2 h 4 min
Bit rate                                 : 14.0 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)                       : 0.225
Stream size                              : 12.2 GiB (99%)
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                                 : 2 h 4 min
Duration_LastFrame                       : -21 ms
Bit rate mode                            : Constant
Bit rate                                 : 192 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                              : 168 MiB (1%)
Language                                 : English
Default                                  : Yes
Alternate group                          : 1

 

 

Comments

Former user wrote on 3/20/2020, 11:16 PM

Can you post some framegrabs showing the two timelines with project properties visible and the error you are seeing.

matthias-krutz wrote on 3/21/2020, 2:19 AM

I suspect that different decoders are involved. I can see shifts by a few frames with trimmed clips if they are decoded with compoundplug.dll instead of so4compoundplug.dll. I have not yet checked whether there are any differences between software and hardware decoders.

AlanMintaka wrote on 3/21/2020, 4:55 AM

Did you happen to grab the timeline and drag it to the left?
(snip)
Download this project a report whether the markers match the timecode in the preview and the position counter in the lower right of the screen.

RE grab the timeline: good question. No, the only thing I did with the timeline was zoom it and examine the first few frames to see why the ones I had cut in the original project were now appearing at the start of each event in the copied project.

Since my first post I've copied a different project and observed the same symptoms, also without grabbing or moving the timeline myself.  It's not something I could have done, even by accident, to both projects exactly the same way - a 5 frame shift.

RE your project: thanks for this, I can see where it will come in very handy in the future. I exercised it on both machines and found:

  1. In each of the 4 projects (2 originals, 2 copies) the marker and the preview timecodes were all mutually consistent with the position counters.
  2. Comparing original to copied projects, the marker and the preview timecodes were also consistent with the position counters. In addition, I stepped through the frames to verify that the preview changed consistently, frame-by-frame, in original vs. copied projects. No shift! Don't know how to interpret this. Why do my projects show that 5 frame shift on different machines, whereas your project doesn't?

Another commentator suggested that different decoders (and encoders maybe?) might be the cause. I'm investigating that now.

And thanks again for that great project!

AlanMintaka wrote on 3/21/2020, 5:08 AM

I suspect that different decoders are involved. I can see shifts by a few frames with trimmed clips if they are decoded with compoundplug.dll instead of so4compoundplug.dll. I have not yet checked whether there are any differences between software and hardware decoders.

Ouch, I was hoping that decoders (and/or encoders) were not the cause, since I don't know where to look. But you've put a name to at least one of the decoders. I'm checking on that now.

OK, both decoders are present in the VP 17 installation on the two machines. But how do I know which one(s) were actually used on which machines? Is this something to do with the codec ID's in the MediaInfo report?

In my case the projects were just copied from one machine to the another. No rendering or any other operation was performed - just a straight copy. Are the decoders used when Vegas displays events in the timeline, such that different decoders would shift the timeline display even though no other operation is performed?

EricLNZ wrote on 3/21/2020, 5:37 AM

No it's not in the media info report. Go to a clip on your timeline and right click for its properties and near the bottom of the General Tab it will show the plug-in (codec) used to read the file.

This is from VMS but I assume VP is the same:

AlanMintaka wrote on 3/21/2020, 10:36 AM

I suspect that different decoders are involved. I can see shifts by a few frames with trimmed clips if they are decoded with compoundplug.dll instead of so4compoundplug.dll. I have not yet checked whether there are any differences between software and hardware decoders.

That looks like it!

In the original project, the decoder was so4compoundplug.dll. In the copied project, the decoder was compoundplug.dll.

I did a little research in the forum and found a reference to the Options | Preferences | Internals tab. The article linked below suggested verifying the settings of fields containing the string "So4".

In my case, the setting in the original project for "Enable So4 compound reader for AVC/M2TS" was set to TRUE. In the copied project it was set to FALSE.

I changed the copied project setting to TRUE and the problem went away! Event edits performed in the original project now appear in the correct timeline locations in the copied project.

This solution was a little on the obscure side for an amateur like me, so I'm very grateful to you for the suggestion.

What still bothers me though is: how did that compound reader setting get changed to FALSE in the copied project? The Internals tab shows that the default setting is TRUE. What could have changed it?

Anyway, here is the article that helped me locate the "So4" setting in the Internals tab:

https://www.vegascreativesoftware.info/us/forum/avc-xavc-s-issues-in-vp15-try-disabling-so4compoundplug-dll--108345/

Thanks again,
Alan Mintaka

 

 

AlanMintaka wrote on 3/21/2020, 11:07 AM

No it's not in the media info report. Go to a clip on your timeline and right click for its properties and near the bottom of the General Tab it will show the plug-in (codec) used to read the file.

This is from VMS but I assume VP is the same:

Thanks, this helped me ID the difference in decoders between the two projects. See my response to matthias-krutz above for the details of the fix....