Thank you very much @johnebaker
I run different flavors of MEP and VXPro on eight different machines. This week I found I have this issue on two different machines. I will paste details of one of them below. I have been using the MPeg-4 export set to

MPEG-4-Export (MP4)
Video: H.264; 1920x1080p; 59.94 frames/s; VBR 4000 kbit/s; HW GPU encoding
Audio: AAC; Stereo; 48000 Hz; 160 kbit/s
I have also tried hardware encoding. I have tried both the default and MainConcept codecs with restarts in between. I have re-installed the software. I have gone up a version and tried that. I have tried the HEVC Full HD settings as well. Each time the render played back at about half speed.

Here are some of my settings:
MPEG-4-Export (MP4)
Video: H.264; 1920x1080p; 59.94 frames/s; VBR 28000 kbit/s; HW GPU encoding
Audio: AAC; Stereo; 48000 Hz; 160 kbit/s

Thank you so much for your help. I have read many of your posts and responses over the last few years and often been helped by them.
Blessings,

Rob

Sorry. I forgot mention the source. This footage was shot on five cameras all set to 1080p 59.94 and switched at a Black Magic Atem 4k switcher going into a Magewell SDI capture card and recorded on OBS. I guess it could not be more of a mess, but this has been my regular process for the past several years. The only change since our summer break has been updating the Black Magic from the TV Studio to the 4K model.

@daydreamer11

Your problem is probably with the files captured by OBS Studio which by default will be recording variable frame rate video which video editors can't cut and maintain audio sync to. There is little movement within the frames in that clip so the frame rate will slow. Then if an arm or something else moves more swiftly the frame rate will jump faster to capture the movement. That is fine until you edit such footage where upon the editor does not know how many frames are missing or need to be cut to keep the audio in sync with the image data. The settings within OBS can be changed to constant frame rate and if needed the GOP structure can also be altered to help. This will need much more storage space for a given amount of footage.

The recordings I hope are much better quality than those shown and you produced a low res file for showing here as I use OBS Studio as well and my HD recordings have more resolution than that.

Ray.

Greetings @CubeAce,
If you have figured it out, that would be wonderful. The MediaInfo report for the source media says it was CBR, but I will go back into OBS and check the settings to be sure. I was able to edit on a free editor that was made by a company whose intials are "B" "M" and did not have any sync issues. But I would always rather be editing in Magix. The end result is posted here
I will definately let you know if changing the settings in OBS fixes this! Thank you very much!

@daydreamer11

Hi.

Do not confuse constant bit rate recordings (CBR) with constant frame rate recordings (CFR). They are two separate parts of the recording chain. Look at the Mediainfo data again and see what the minimum and maximum frames rates recorded are. Text view gives the easiest to read viewing.

That recording is taken at quite a high ISO possibly due to lack of light. What is the frame rate of the footage?

Ray.

@daydreamer11

Hi

Please post all the data from the Mediainfo analysis as requested -what you have provided omits some of the most important data we require for a thorough analysis of the issue you are having.

As @CubeAce has commented OBS is the likely culprit.

From the data you have provided the

. . . . H.264; 1920x1080p; 59.94 frames/s; VBR 4000 kbit/s . . .

Is this an exported video from VPX or the output from OBS?

In either case this is too low for Full HD video at this resolution and framerate, for comparison the other export value you have used in VPX is

. . . . H.264; 1920x1080p; 59.94 frames/s; VBR 28000 kbit/s . . . .

From the camera setup you have described, do the cameras actually record to media as well as feeding the video to the Atem switcher or are they none media cameras with no recording capability?

John EB

@daydreamer11

Are the five cameras matching models and if so which ones please?

I understand their outputs are fed into the Black Magic Atem 4k switcher who's selected output is then fed into the Magewell SDI capture card that is then captured by OBS studio.

I would think depending on the camera and lens combos and judging by the depth of field of the images that a slower frame rate might yield better noise results especially if the cameras are recording in any form of auto mode. It is also quite important that the frame rate throughout the record chain is kept constant for best signal to noise ratio within the video.

As you seem to be in an NSTC area I would suggest keeping the recordings to 24 frames per second if your cameras allow it. This may help to also keep the file sizes down once you have a constant frame rate set up in OBS Studio. If on the other hand the action ever gets faster then perhaps 29.97 may be a better option. That should be fast enough for normal human interaction.

As john has mentioned you need to up your Bit rate to much nearer John's suggestion for both export within VPX and OBS Studio. I also tend to record the audio in OBS at 320Kbps for stereo sound tracks using its aac encoder.

Also try setting the Keyframe interval frames to either half the frame rate or the same (or nearest round number) as the frame rate.

Ray.

Thank you both! The cameras are not recording but are 2 Canon Vixia HFG50's and 3 Sony BRC H800's
All cameras are set to match resolution and framerate, the BM ATEM does not adjust these settings for seperate channels, so they must be the same for it to work.

I will up the bitrate and lower the framerate (if all sources allow).

I will keep looking but I have not been able to find variable framerate in OBS.

I will also reset the Keyframe Intervals- I have never known what they should be set to!

Sorry I thought I pasted in the info about the source video.

Here it is:

General
Complete name                            : P:\Videos for Editing\2021-08-31 10-51-28.mp4
Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom (isom/iso2/avc1/mp41)
File size                                : 2.19 GiB
Duration                                 : 1 h 0 min
Overall bit rate                         : 5 179 kb/s
Writing application                      : Lavf58.29.100

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L4.2
Format settings                          : CABAC / 4 Ref Frames
Format settings, CABAC                   : Yes
Format settings, Reference frames        : 4 frames
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 1 h 0 min
Bit rate                                 : 5 000 kb/s
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 60.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.040
Stream size                              : 2.12 GiB (97%)
Writing library                          : x264 core 161 r3020 d198931
Encoding settings                        : cabac=1 / ref=1 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=2 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=12 / lookahead_threads=4 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=1 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=10 / rc=abr / mbtree=1 / bitrate=5000 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
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                                 : 1 h 0 min
Bit rate mode                            : Constant
Bit rate                                 : 160 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                              : 69.6 MiB (3%)
Default                                  : Yes
Alternate group                          : 1

@daydreamer11

Hi. It seems you are correct and the file is constant frame rate. There may be two problem areas though. Even for OBS the overall bit rate is way too low for a quality video output. 2.4GB for an hours recording for me using OBS would be nearer 4.2GB or 10Mb/s. Also the 160kb/s for a dual channel sound recording should be nearer to 320kb/s in my opinion.

Other than that I must say I am at a loss as to why the sound is going slow. I could understand a long video going out of sync sound wise but not a frame number increase effectively putting the video portion of the clip into slow motion.

The current GOP structure also looks fine to me.

If it is the Video file (I haven't completely ruled that out yet due to the small file size) then we will see if increasing the bit rate will improve the situation.

Make sure the movie project is set to the same sample rate as the files. (48Khz) and that the output settings match frame rates when exporting.

It seems both of your camera bodies will record at 50fps at 1080 x 1920 but have no other settings that they have in common so you are stuck at being able to get less grain noise although I must say both makes of cameras should be coping according to the specifications although the Sony's may be giving a cleaner feed than the Cannons.

I take it the clips themselves are playing fine in Windows Film and TV?

Ray.

Original footage plays fine in Windows TV and in VLC.

Do you think lowering frame rate by 10fps might at least make a small difference? I am willing to give it a try. I will definately up my kps for audio and video. I am shooting right now on a different system using OBS with higher KPS so it will be fun to compare with my last shoot on that system.

Yes, the Sony's are SDI all the way through, whereas the Canons are converted from HDMI to sdi near the source.
I think my original issue was a project setting- the project was at 59.94 and video at 60. But the difference seems extreme for .6 frames off, even near the beginning. I rendered a segment and it seems to be doing better.

I am grateful to both of you for not only helping me with this issue but also helping me work on getting better video quality overall. Thank you!