Audio and Video in VOB file not sync'd

mkennedy Posté à 22/04/2020 19:25

We've recorded a file in which the audio was recorded on a device separate from the camera. After importing the audio is not aligned with the actors on video? How can I align or sync the sound to the video? I'm using Magix Movie Edit Pro Plus v. 16. I've tried taken the high marks after separating the sound to align with a video point, but it seems to not be precise. I am somewhat new to using this tool.

Commentaires

emmrecs Posté à 22/04/2020 20:43

@mkennedy

Is the audio also on the video recording? If so and if the facility is available in MEP Plus (it is in Premium) there is a right-click option called "Align other audio objects with this track". You would need to put the recording from the camera on track 1 (if you have selected to put the audio and video from this recording on separate tracks the audio will appear on track 2).

Put the separate audio recording on a different track, e.g. 4, right-click on the audio track from the camera and choose the option I have named above. MEP will then do its best to align your separate audio to the original audio.

However, the above can only apply if you have audio included on the camera file. Otherwise, there is no alternative to visually syncing the audio to the actors, as you have been doing.

Should the alignment provided by MEP still not be "tight enough", there is a software which can do quite remarkable things to align your independent (separate) audio to the audio from your camera. It is called PluralEyes. But it is not cheap, though if you have to do this sort of job on even a fairly regular basis, it is well worth the money, IMO.

HTH

Jeff

Win 11 Pro 64 bit, Intel i7 14700, 32 GB RAM, NVidia RTX 4060 and Intel UHD770 Graphics, Audient EVO 16 audio interface, VPX, MEP, Music Maker, Vegas Pro, PhotoStory Deluxe, Xara 3D Maker 7, Samplitude Pro X7 Suite, Reaper, Adobe Audition CC, 2 x Canon HG10 cameras, 1 x Canon EOS 600D, Akaso EK7000 Pro Action Cam

mkennedy Posté à 22/04/2020 21:18

Yes, the audio and video are on the same file; however, that audio was not part of the camera recording - separate. I did think of using the option you described but I don't have an additional audio file. I'll look at PluralEyes and see what is possible. Thank you.

johnebaker Posté à 22/04/2020 21:46

@mkennedy

Hi

. . . . the audio and video are on the same file; however, that audio was not part of the camera recording - separate . . . .

How did the audio end up in the video file if it was recorded separately, eg has the separate audio been remuxed into the video file by someone else, or the separate recording device audio fed back to the camera while recording?

What format is the imported video file?

John EB

VPX 16, Movie Studio 2025, and earlier versions 2015 and 2016, Music Maker Premium 2024.

PC - running Windows 11 23H2 Professional on Intel i7-8700K 3.2 GHz, 16GB RAM, RTX 2060 6GB 192-bit GDDR6, 1 x 1Tb Sabrent NVME SSD (OS and programs), 2 x 4TB (Data) internal HDD + 1TB internal SSD (Work disc), + 6 ext backup HDDs.

Laptop - Lenovo Legion 5i Phantom - running Windows 11 24H2 on Intel Core i7-10750H, 16GB DDR4-SDRAM, 512GB SSD, 43.9 cm screen Full HD 1920 x 1080, Intel UHD 630 iGPU and NVIDIA GeForce RTX 2060 (6GB GDDR6)

Sony FDR-AX53e Video camera, DJI Osmo Action 3 and Sony HDR-AS30V Sports cams.

mkennedy Posté à 22/04/2020 22:17

VOB. The DVD was given to me after the filming indicating the rough version. I know they must combined it as it has chapter headings.

johnebaker Posté à 23/04/2020 10:38

@mkennedy

Hi

. . . . VOB . . . .

VOB files are actually MPG files and because of their internal structure are prone to audio drift when imported into a video editor.

Assuming you have copied the VOBs from the DVD to your computer hard drive (if not do this) then:

- Create a new project and import the VOB(s) do not do any editing on them at this stage
- Select each video object on the timeline, right click it, from the popup select Create frametable(new)

This should fix the syncing issue and you can continue editing.

HTH

John EB

VPX 16, Movie Studio 2025, and earlier versions 2015 and 2016, Music Maker Premium 2024.

PC - running Windows 11 23H2 Professional on Intel i7-8700K 3.2 GHz, 16GB RAM, RTX 2060 6GB 192-bit GDDR6, 1 x 1Tb Sabrent NVME SSD (OS and programs), 2 x 4TB (Data) internal HDD + 1TB internal SSD (Work disc), + 6 ext backup HDDs.

Laptop - Lenovo Legion 5i Phantom - running Windows 11 24H2 on Intel Core i7-10750H, 16GB DDR4-SDRAM, 512GB SSD, 43.9 cm screen Full HD 1920 x 1080, Intel UHD 630 iGPU and NVIDIA GeForce RTX 2060 (6GB GDDR6)

Sony FDR-AX53e Video camera, DJI Osmo Action 3 and Sony HDR-AS30V Sports cams.

Craigster Posté à 07/05/2020 23:44

Is this an issue of being mis-aligned or losing sync?

I have been doing tons of this weekly recently (i.e. receiving footage from a videocam or iphone and syncing to audio from a mic'd source which is mixed from a DAW, and replaces the original camera audio).

I am discovering a variety of sync issues.

If an iPhone, or any device recorded in "variable frame rate" (curses be on them), then you can expect to have sync timing issues where the video may float off of the audio alignment. So, this is a sync issue. A solution has been to use Handbrake to convert the iPhone footage to 29.97 CONSTANT frame rate.

Meanwhile, ALIGNMENT is a different issue, and is more common anytime you have 2 audio sources. This is a matter of moving the preferred audio precisely to match the original camera footage audio.

As others have mentioned, the "align audio with this track" is a helpful tool -- but to START with. I rarely am finishing with it. Why? Well, speed of light and sound dynamics. And inconsistent results. And video frames. Each of these 3 may need to be addressed manually.

VPX is generally really good at initial line up if there was a CLAP at the beginning (still helpful), or clear percussive drums that stand out. Let's assume that VPX/MEP does the initial line up fairly accurately.

If you then zoom in on the waveform you may notice that while they are lined up accurately within half a frame (i.e. to the nearest frame, so maximally 1/2 frame off), they are not exact. This is really common! You cannot shift the camera audio. It is locked in by frame (i.e. approx. 1/30 of a second). But if you defeat the SNAP setting (icon), you may freely move the preferred audio - down to the sample level. So, you can manually align the new audio perfectly!

In many cases, now you are done. But not all. Where were the audio sources originally coming from? What was the camera distance? If the preferred audio was picked up from a stage mic and the camera mic was 50' away, you will notice visually a discrepancy between perfectly lined up audio waves! So, I frequently will finally run audio and video tests with my eyes and ears for final alignment.

One good approach: Use the mixer and send the same amount of audio (original camera audio channel and new mixed audio); match volumes for each channel. Then pan one hard left and one hard right. Listen carefully. Does one side seem LOUDER than the other? If so, it is ahead. Go ahead and move the new audio track a bit left and a bit right. You will hear it go in and out of phase, and be early and late. Then there is the magic spot where it just locks in. THAT's the keeper location. (Then remember to re-set your pans). Also, check visually to see if consonants are now all matching up with close-up vocals, or if visible drum hits are landing correctly. All of this is mutually verifiable. Meaning, the different approaches support and validate one another, with increasing precision.

Craig

 

System 1: Gigabyte Z390 Designare, i9-9900k, 64GB RAM, Radeon RX580/Intel 630, Apollo X6, multiple Black HDD & SSDs. System 2: Gigabyte Z390 Aorus Pro WiFi, i7-9700k, 64GB RAM, Radeon RX560/Intel 630, Audient iD44, multiple Black HDD & SSDs.

mkennedy Posté à 08/05/2020 00:02

Great tip, I'll check this out.