Auto Sync Audio > Based on Waveform | Hardly ever works

A place for feedback and discussion on DaVinci Resolve 15
  • Author
  • Message
Offline

TornadoTwins

  • Posts: 19
  • Joined: Sat Apr 14, 2018 6:01 pm
  • Real Name: Efraim Meulenberg

Auto Sync Audio > Based on Waveform | Hardly ever works

PostWed Jun 20, 2018 8:52 pm

For our videoshoots we use one (or multiple) cameras and a ZOOM H6 recorder for audio.
I should specify that the audio from camera and ZOOM are both very clear and audible.

After importing the footage and audio, I select all of the clips, right click and choose "Auto Sync Audio >> Based on Waveform and Append Tracks".

The software does its analysis and that's when the trouble starts.

Often times, it says some clips could not be matched. Even though the exact same number of audio and video clips are selected, all of which can easily synced by, for example Premiere Pro.

The appended tracks aren't even remotely related. Sometimes it syncs the "clap" sound from the slate as significant audio event but all the rest is wrong.

Here's a screenshot of one of the appended tracks, as you can see, the waveform doesn't match at all:
https://cp.sync.com/dl/0fa05f450#4tbphd9j-j7wr9y32-gw4wvtbi-x2yj7vfa

My "work-around" has been to sync audio in Premiere Pro, throw it on one timeline and export the timeline back to Davinci. Which is quite inconvenient.

In the previous betas it didn't work well either and I'm not sure if Resolve14 was any better.
In short: auto sync based on waveform is quite unusable.
Davinci Resolve Version: 15.0.0B.057
OS: Windows 10 Pro
Processor: i7-6700k CPU @4.00Ghz 4.01Ghz
RAM: 32 GB
Video Card 1: GeForce GTX 970 – GUI Only
Video Card 2: GeForce GT 740
Hard Drives: Three SSD’s of 1TB, one of SSD of 2 TB
Offline

TornadoTwins

  • Posts: 19
  • Joined: Sat Apr 14, 2018 6:01 pm
  • Real Name: Efraim Meulenberg

Re: Auto Sync Audio > Based on Waveform | Hardly ever works

PostWed Jun 20, 2018 9:25 pm

Further exploration:

The ZOOM audio is imported as 44100 Hz.
The camera audio is imported as 48000 Hz.

When selecting ONLY one audio and video clip that are supposed to by sync-able (rather than letting the algorithm figure out which clips need to sync) there are still major problems:

It tries to sync the timeline in the beginning but quickly the audio shifts out of proportion. The further in the timeline, the more out of sync.

But here's the kicker: the audio tracks are still equal in length. Although one seems to play much faster, the tracks are still ending at the same spot.

HOW IS THIS POSSIBLE?

Is there a difference in tempo between 44.1 and 48 kHz playback?

I'm also noticing that the Fairlight tab has much more detailed Waveforms than the Edit tab. But, when zooming in on the Fairlight tab, certain zoom levels make the waveform "pop" out of place.

It's crazy!

I don't know what to do here.

Unless I'm supposed to do something special to make 44.1 and 48 kHz tracks play back properly, it's definitely a bug.
Davinci Resolve Version: 15.0.0B.057
OS: Windows 10 Pro
Processor: i7-6700k CPU @4.00Ghz 4.01Ghz
RAM: 32 GB
Video Card 1: GeForce GTX 970 – GUI Only
Video Card 2: GeForce GT 740
Hard Drives: Three SSD’s of 1TB, one of SSD of 2 TB
Offline

TornadoTwins

  • Posts: 19
  • Joined: Sat Apr 14, 2018 6:01 pm
  • Real Name: Efraim Meulenberg

Re: Auto Sync Audio > Based on Waveform | Hardly ever works

PostWed Jun 20, 2018 9:29 pm

Further exploring:

The audio files seem to have a "FPS" of 29.970 DF.
The video files have an FPS of 24.000

The auto-synced clips have a fps of 24.000.

Does this have anything to do with it?

Is there a reason that audio has a "Frames Per Second" setting when there are no frames in audio?
Davinci Resolve Version: 15.0.0B.057
OS: Windows 10 Pro
Processor: i7-6700k CPU @4.00Ghz 4.01Ghz
RAM: 32 GB
Video Card 1: GeForce GTX 970 – GUI Only
Video Card 2: GeForce GT 740
Hard Drives: Three SSD’s of 1TB, one of SSD of 2 TB
Offline

TornadoTwins

  • Posts: 19
  • Joined: Sat Apr 14, 2018 6:01 pm
  • Real Name: Efraim Meulenberg

Re: Auto Sync Audio > Based on Waveform | Hardly ever works

PostWed Jun 20, 2018 9:35 pm

Further exploring:

I've converted the audio to 48 kHz instead of 44.1.

Resolve still imports it with a 29.970 FPS.

I don't know what to do until someone replies here.
Meanwhile I'll have to revert to Premiere Pro. CRAP. I hate Premiere.
Davinci Resolve Version: 15.0.0B.057
OS: Windows 10 Pro
Processor: i7-6700k CPU @4.00Ghz 4.01Ghz
RAM: 32 GB
Video Card 1: GeForce GTX 970 – GUI Only
Video Card 2: GeForce GT 740
Hard Drives: Three SSD’s of 1TB, one of SSD of 2 TB
Offline

TornadoTwins

  • Posts: 19
  • Joined: Sat Apr 14, 2018 6:01 pm
  • Real Name: Efraim Meulenberg

Re: Auto Sync Audio > Based on Waveform | Hardly ever works

PostWed Jun 20, 2018 9:57 pm

Further exploring:

I've re-encoded the video to be 29.970, since the Resolve project was set to that. This is probably why the audio is given the same FPS.

However, even syncing the video clip with the same FPS as the audio, still is wildly out of sync.
So perhaps it has nothing to do with the framerate.

(Makes no sense to have FPS for audio still, but whatever).
Davinci Resolve Version: 15.0.0B.057
OS: Windows 10 Pro
Processor: i7-6700k CPU @4.00Ghz 4.01Ghz
RAM: 32 GB
Video Card 1: GeForce GTX 970 – GUI Only
Video Card 2: GeForce GT 740
Hard Drives: Three SSD’s of 1TB, one of SSD of 2 TB
Offline

TornadoTwins

  • Posts: 19
  • Joined: Sat Apr 14, 2018 6:01 pm
  • Real Name: Efraim Meulenberg

Re: Auto Sync Audio > Based on Waveform | Hardly ever works

PostWed Jun 20, 2018 11:03 pm

Further exploring:

I've edited the video in Premiere and exported it as XML, then imported that timeline in Resolve.

Result? The video and audio clips are there, but the audio is completely offset. Unusable.

Sigh. Guess I can't use Resolve until this gets fixed.
Davinci Resolve Version: 15.0.0B.057
OS: Windows 10 Pro
Processor: i7-6700k CPU @4.00Ghz 4.01Ghz
RAM: 32 GB
Video Card 1: GeForce GTX 970 – GUI Only
Video Card 2: GeForce GT 740
Hard Drives: Three SSD’s of 1TB, one of SSD of 2 TB
Offline

Rohit Gupta

Blackmagic Design

  • Posts: 951
  • Joined: Wed Aug 22, 2012 5:00 am

Re: Auto Sync Audio > Based on Waveform | Hardly ever works

PostThu Jun 21, 2018 2:58 am

TornadoTwins wrote:For our videoshoots we use one (or multiple) cameras and a ZOOM H6 recorder for audio.
I should specify that the audio from camera and ZOOM are both very clear and audible.

After importing the footage and audio, I select all of the clips, right click and choose "Auto Sync Audio >> Based on Waveform and Append Tracks".

The software does its analysis and that's when the trouble starts.

Often times, it says some clips could not be matched. Even though the exact same number of audio and video clips are selected, all of which can easily synced by, for example Premiere Pro.

The appended tracks aren't even remotely related. Sometimes it syncs the "clap" sound from the slate as significant audio event but all the rest is wrong.

Here's a screenshot of one of the appended tracks, as you can see, the waveform doesn't match at all:
https://cp.sync.com/dl/0fa05f450#4tbphd9j-j7wr9y32-gw4wvtbi-x2yj7vfa

My "work-around" has been to sync audio in Premiere Pro, throw it on one timeline and export the timeline back to Davinci. Which is quite inconvenient.

In the previous betas it didn't work well either and I'm not sure if Resolve14 was any better.
In short: auto sync based on waveform is quite unusable.


Are you able to send a few clips and the audio files so we can check it out? Please send the originals.

Please upload to Dropbox, or similar, and PM me a link. We'll investigate.
Rohit Gupta

DaVinci Resolve Software Development
Blackmagic Design
Offline

TornadoTwins

  • Posts: 19
  • Joined: Sat Apr 14, 2018 6:01 pm
  • Real Name: Efraim Meulenberg

Re: Auto Sync Audio > Based on Waveform | Hardly ever works

PostThu Jun 21, 2018 4:38 am

Certainly, I’ll send you the files tomorrow morning by replying to your DM.
Thanks for looking into this!
Davinci Resolve Version: 15.0.0B.057
OS: Windows 10 Pro
Processor: i7-6700k CPU @4.00Ghz 4.01Ghz
RAM: 32 GB
Video Card 1: GeForce GTX 970 – GUI Only
Video Card 2: GeForce GT 740
Hard Drives: Three SSD’s of 1TB, one of SSD of 2 TB
Offline

Uli Plank

  • Posts: 2810
  • Joined: Fri Feb 08, 2013 2:48 am

Re: Auto Sync Audio > Based on Waveform | Hardly ever works

PostThu Jun 21, 2018 6:04 am

As much as I like DR, I’ve never found waveform syncing acceptable in any NLE.
Rather give PluralEyes a try, it works very well for us. If I remember correctly, they have a fully functional 10 days demo.
Resolve Studio and Fusion Studio
iMac 2017 Radeon Pro 580 8 GB VRAM and 32 GB RAM
Offline

TornadoTwins

  • Posts: 19
  • Joined: Sat Apr 14, 2018 6:01 pm
  • Real Name: Efraim Meulenberg

Re: Auto Sync Audio > Based on Waveform | Hardly ever works

PostThu Jun 21, 2018 10:44 pm

@Rohit Gupta - Thanks, I've sent you an Enrico a DM with the project and audio/video files.

@Uli Plank - I do like the idea of PluralEyes... however, since it's about the same price as Davinci Resolve Studio, and since it does work fine in Premiere Pro, it would be really great if I didn't have to buy anything extra.
That said, great tip, thanks for sending this along!
Davinci Resolve Version: 15.0.0B.057
OS: Windows 10 Pro
Processor: i7-6700k CPU @4.00Ghz 4.01Ghz
RAM: 32 GB
Video Card 1: GeForce GTX 970 – GUI Only
Video Card 2: GeForce GT 740
Hard Drives: Three SSD’s of 1TB, one of SSD of 2 TB

Return to DaVinci Resolve 15 Beta

Who is online

Users browsing this forum: mattwilliams2321, Niels Vestergaard, Steve Alexander and 5 guests