Sound sync and video glitches.

SchrodingerDeeps wrote on 9/25/2020, 8:26 AM

Hello,

I am currently having serious issues editing my videos.

I sorry but this one is hard to describe.

I notice occasionally that sound is out of sync, by seconds. The thing is, I know at first it wasn't out of sync. I edit the video, using the wave form and re-align to a perfect moment (like an explosion or something).

Then after a great deal of messing about, on play back I will suddenly see a few new frames, within the video repeated. These will typically be where the sound SHOULD have been. This aberration was not present before. It's as if, while cutting, video pro X is failing to perform correctly and mixing things up. The headache cant be understated lol.

Then as if to make matters more confusing, it will suddenly appear in sync. Only next play, be out of sync again.

I do not know yet if it is going to encode correct, or if the changes that I have made that appear correct will encode wrong.

I do not believe that made much sense at all. However, if you have seen this it will make perfect sense!

Thank you for anyone capable of taking the time to help with this...

Comments

johnebaker wrote on 9/25/2020, 10:31 AM

@SchrodingerDeeps

What is the format and source of the videos you are importing - a MediaInfo analysis of a clip that is exhibiting this behaviour would help - post the analysis from the Text view in MediaInfo.

John EB

SchrodingerDeeps wrote on 9/25/2020, 11:32 AM

Here is the info, I am using multiple audio channels which I naturally extract before editing.

This seems to be a major factor. I have just spent a age re-editing an encoded video trying to fix it which has cost me part of my soul. Especially since the quality turned potato double encoded.

Your help is massively appreciated.

General
Complete name                            : F:\Profile_Info\xxxx\Videos\BigBattle.mp4
Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom (isom/iso2/avc1/mp41)
File size                                : 1.50 GiB
Duration                                 : 1 h 15 min
Overall bit rate mode                    : Variable
Overall bit rate                         : 2 839 kb/s
Writing application                      : Lavf58.29.100

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L4
Format settings                          : CABAC / 2 Ref Frames
Format settings, CABAC                   : Yes
Format settings, Reference frames        : 2 frames
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 1 h 15 min
Bit rate mode                            : Constant
Bit rate                                 : 2 500 kb/s
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 30.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.040
Stream size                              : 1.32 GiB (88%)
Color range                              : Limited
Matrix coefficients                      : BT.470 System B/G
Codec configuration box                  : avcC

Audio #1
ID                                       : 2
Format                                   : AAC LC
Format/Info                              : Advanced Audio Codec Low Complexity
Codec ID                                 : mp4a-40-2
Duration                                 : 1 h 15 min
Bit rate mode                            : Constant
Bit rate                                 : 160 kb/s
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 44.1 kHz
Frame rate                               : 43.066 FPS (1024 SPF)
Compression mode                         : Lossy
Stream size                              : 86.6 MiB (6%)
Title                                    : Desktop Audio
Default                                  : Yes
Alternate group                          : 1

Audio #2
ID                                       : 3
Format                                   : AAC LC
Format/Info                              : Advanced Audio Codec Low Complexity
Codec ID                                 : mp4a-40-2
Duration                                 : 1 h 15 min
Bit rate mode                            : Constant
Bit rate                                 : 160 kb/s
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 44.1 kHz
Frame rate                               : 43.066 FPS (1024 SPF)
Compression mode                         : Lossy
Stream size                              : 86.9 MiB (6%)
Title                                    : Mic
Default                                  : No
Alternate group                          : 1

Audio #3
ID                                       : 4
Format                                   : AAC LC
Format/Info                              : Advanced Audio Codec Low Complexity
Codec ID                                 : mp4a-40-2
Duration                                 : 1 h 15 min
Bit rate mode                            : Variable
Bit rate                                 : 2 090 b/s
Maximum bit rate                         : 160 kb/s
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 44.1 kHz
Frame rate                               : 43.066 FPS (1024 SPF)
Compression mode                         : Lossy
Stream size                              : 1.13 MiB (0%)
Title                                    : adv_aac2
Default                                  : No
Alternate group                          : 1

Audio #4
ID                                       : 5
Format                                   : AAC LC
Format/Info                              : Advanced Audio Codec Low Complexity
Codec ID                                 : mp4a-40-2
Duration                                 : 1 h 15 min
Bit rate mode                            : Variable
Bit rate                                 : 2 090 b/s
Maximum bit rate                         : 160 kb/s
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 44.1 kHz
Frame rate                               : 43.066 FPS (1024 SPF)
Compression mode                         : Lossy
Stream size                              : 1.13 MiB (0%)
Title                                    : adv_aac3
Default                                  : No
Alternate group                          : 1

Hope this sheds maybe a little light!

johnebaker wrote on 9/25/2020, 1:02 PM

@SchrodingerDeeps

Thanks for the MediaInfo data, it indicates that this is an OBS screen recording - is this correct?

If so then, in a nutshell, this is a known issue with OBS screen recordings - see this rather long topic on the same issue and also applies to VPX.

John EB

SchrodingerDeeps wrote on 9/25/2020, 1:45 PM

Very many thanks! The horror. I will need to find an alternative platform then.

I will mark your answer as the solution.