Welcome, Guest
Username Password: Remember me
  • Page:
  • 1

TOPIC: Video and Audio is Out of Sync

Video and Audio is Out of Sync 1 month ago #201711

Hello. I'm trying to edit a video of a family trip that I took on my iPhone 6s. When I'm in Lightworks, the audio from the iPhone is always behind, but when I export it, the video and audio sync fine. I've also put some downloaded music on my video and try to sync the beats with changing sequences, but when I export the video, the music is slightly ahead. I've heard that taking video on a certain frame rate and editing at another frame rate messes with the audio/video lineup (my phone is 30 fps and I'm trying to do the video at 24 fps), but I'm not exactly sure how to fix that problem. Keep in mind I'm a beginner at editing and I'm not very techy. Thanks!

Here's the computer info

OS: Microsoft Windows 10 Home
Processor: AMD FX(tm)-6300 Six-Core Processor, 6 CPUs, 3.5 GHz
Card: AMD Radeon Graphics Processor (0x67EF)
RAM: 8 GB

These are the MediaInfo specs

General
Complete name: C:\Users\Documents\Test_Palmyra4 (dialouge).mp4
Format: MPEG-4
Format profile: Base Media / Version 2
Codec ID: mp42 (isom/mp42)
File size: 65.7 MiB
Duration: 1 min 26 s
Overall bit rate mode: Variable
Overall bit rate: 6 387 kb/s
Encoded date: UTC 2019-07-17 01:59:54
Tagged date: UTC 2019-07-17 01:59:54

Video
ID: 1
Format: AVC
Format/Info: Advanced Video Codec
Format profile: High@L3.1
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 min 26 s
Bit rate mode: Variable
Bit rate: 6 000 kb/s
Width: 1 280 pixels
Height: 720 pixels
Display aspect ratio: 16:9
Frame rate mode: Constant
Frame rate: 24.000 FPS
Standard: NTSC
Color space: YUV
Chroma subsampling: 4:2:0
Bit depth: 8 bits
Scan type: Progressive
Bits/(Pixel*Frame): 0.271
Stream size: 61.8 MiB (94%)
Language: English
Encoded date: UTC 2019-07-17 01:59:55
Tagged date: UTC 2019-07-17 01:59:55
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 min 26 s
Bit rate mode: Variable
Bit rate: 384 kb/s
Maximum bit rate: 467 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: 3.92 MiB (6%)
Language: English
Encoded date: UTC 2019-07-17 01:59:55
Tagged date: UTC 2019-07-17 01:59:55

Re: Video and Audio is Out of Sync 1 month ago #201713

  • hugly
  • OFFLINE
  • Platinum Boarder
  • Posts: 20151
  • 1 month ago
BostonBillings wrote:
When I'm in Lightworks, the audio from the iPhone is always behind, but when I export it, the video and audio sync fine. I've also put some downloaded music on my video and try to sync the beats with changing sequences, but when I export the video, the music is slightly ahead.

Hello,

Your description explains exactly what audio delay in preview causes. It's a known phenomenon with Lightworks. It appears with demanding footage on low powered systems. However, I wonder that it appears on a fairly beefed machine as well:

OS: Microsoft Windows 10 Home
Processor: AMD FX(tm)-6300 Six-Core Processor, 6 CPUs, 3.5 GHz
Card: AMD Radeon Graphics Processor (0x67EF)
RAM: 8 GB

I suspect that the separately imported sound is advanced by less than 1/5th of as second in the exported file on your machine? How much is it, what do you hear?

Please try the internal proxy workflow in order to increase editing performance which might reduce audio delay in preview as well:

www.lwks.com/index.php?option=com_kunena&func=view&catid=217&id=194770&Itemid=81#194787

After proxy creation for all clips in the sequence is finished, align the separately imported sound again, export and see if this fixes the issue.
It's better to travel well than to arrive...
Last Edit: 1 month ago by hugly.

Re: Video and Audio is Out of Sync 1 month ago #201719

  • briandrys
  • Moderator
    Pro User
  • OFFLINE
  • Moderator
  • Posts: 8392
  • 1 month ago
Your phone will gave a variable frame rate, which doesn't show in the mediainfo, which I assume is your export rather than source video.

You computer will be working hard, so the proxy editing should reduce the load,

Is there a reason why you're using 24 fps, rather than 30 fps?

Re: Video and Audio is Out of Sync 1 month ago #201733

Hugly

I created proxies for all of my clips and now it works fine for the most part. My phone clips have reverted back to the delayed audio once or twice since I created the proxies, but once I restarted the editor they were fine. Thank you for the advice and quick response!
Last Edit: 1 month ago by BostonBillings.

Re: Video and Audio is Out of Sync 1 month ago #201735

Briandrys

Ok yeah the proxy editing does help. There's no specific reason why I chose 24 fps. When I started the project I wasn't super familiar with the different frame rate options nor did I know what fps my phone shot videos.

Re: Video and Audio is Out of Sync 1 month ago #201737

  • hugly
  • OFFLINE
  • Platinum Boarder
  • Posts: 20151
  • 1 month ago
Thank you for the feedback!

BostonBillings wrote:
My phone clips have reverted back to the delayed audio once or twice since I created the proxies, but once I restarted the editor they were fine.

Yes, losing sync in preview while editing, which is fixable by restarting the app, appears rarely, for whatever reason. It's another beast to be tamed with some future release.
It's better to travel well than to arrive...
Last Edit: 1 month ago by hugly.
  • Page:
  • 1
Time to create page: 0.36 seconds
Scroll To Top