Suddenly .mp4 video files has no audio

I don't know what's happened but since today the mp4 video files has no audio there are no wave forms and no playback. This is only happening with mp4 video files if I import a mp3 or wav files everything is ok.

I have been working perfectly with this files for days but today i don't know why there is no audio.

I can play those mp4 video files with VLC with no problem.

Windows. 17.3.1 Free version.

I have test the same files on Mac with 17.3.1 (Free version) and they are working.

Thanks you.

Start a new project and import one clip. Does it work?

Hi, does not work. The same problem.

I have uninstalled and installed again and nothing.

The same files are working ok on davinci resolve on mac.

thanks

[Peter Chamberlain]

post a link to a sample clip so someone can test.

The free version on MacOS is supporting more formats in hardware. Under Windows you may need Studio.

Here is a video sample:

https://nofile.org/v/5843da

As I said in a previous message I was using these files without problem in Davinci Resolve for Windows but now suddenly the mp4 files in the projects have stopped sounding. Not so for example a Wav or MP3 file.

In the Mac version everything works fine.

Thanks !

I've seen a bunch of reports today from Windows users saying they can't load audio from files that worked just fine yesterday. In addition to this thread, there's this guy on Reddit: https://www.reddit.com/r/davinciresolve ... any_audio/ and at least one person reporting the same on Discord.

I'm wondering if a Windows update has changed the AAC decoder in some way that isn't working in Resolve?

The person on Discord says they're on Windows 11. EDIT: Guy on Reddit is the same.

I have uninstalled and installed again and nothing.

The same files are working ok on davinci resolve on mac.

I expect you're running Windows 11 as well? I don't think Windows 11 is officially supported by Resolve so you're running a bit of a risk using it.

Check if you have a Windows restore point from a couple of days ago. If you can roll back to an older version, before an update that likely happened early today or late yesterday, it will likely work again.

As you mentioned that you have a working Mac install, you could import the video into Resolve on Mac, then Deliver it to a format that includes Linear PCM audio. Probably best to use a high quality intermediate format like DNxHR or ProRes, to avoid adding more compression to the source. Then import that file into Resolve on Windows. If you don't want to export the whole video, you could Deliver the audio only.

As a general workaround for people who don't have a Mac available: you could use third-party software to convert your video's audio to WAV then import that separately into Resolve. You can use Shutter Encoder to do that: https://www.shutterencoder.com/en/

[Peter Chamberlain]

the mp4 is a single Audio stream: AAC LC, plays on macOS studio ok.. can others check windows 10 please?

Playing fine with audio on Win 10 Resolve Studio 17.3.1.

I've seen a bunch of reports today from Windows users saying they can't load audio from files that worked just fine yesterday. In addition to this thread, there's this guy on Reddit and at least one person reporting the same on Discord.

I'm wondering if a Windows update has changed the AAC decoder in some way that isn't working in Resolve?

The person on Discord says they're on Windows 11. EDIT: Guy on Reddit is the same.

Thats probably me let me know if theres a fix

Same problem here! No audio on MP4 files just after upgrading to Windows 11

There's no fix at this time. Presumably at some point BMD will put out a new version of Resolve that fixes it.

In the meantime, use third party software like Shutter Encoder to convert the audio in the video to WAV, which you can then import separately. WAV will work fine.

You can try to convert the file with https://loader.to. It works fine with macOS, Windows and you can download videos for free from Youtube, Facebook, Instagram, Reddit, in whatever format you want. I do that cause I'm not too fond of Youtube ads and their policies. Marketing tools are so used these days that I have nightmares. It is everywhere, even music I cannot listen to in peace. The converter helps me avoid them and listen to podcasts, gym training, music when I do not have Wifi or signal. Till you wait for the new version, try the converter. It's the easiest way to get what you want.

I ran into this issue today too using Linux Mint 20. I figured out it works fine if I render the file in Quicktime so until there's a fix I'll do that and use Shutter Encoder to change it to an MP4 if I need to. When I set it to MP4 it turns the audio off in the render section.

Hopefully a patch for Win10 and Linux will be forthcoming.

The Windows 11 issue was fixed.

Linux doesn't work with AAC audio.

Running DVR Studio 18.1.4 Build 9 and on [DELIVER] tab as soon as I select Format=MP4 the button "AUDIO" is greyed and I cannot select it. This results in no audio in the rendered final video. However the video sounds fine when I playback in the preview in DVR.

When I use Format=QUICKTIME the button "AUDIO" is displayed, I can click onto it and make the changes needed. I export the video and the rendered file is played back correctly.

So why the heck there is no AUDIO button available (greyed out, shadowed) whenever I choose format=MP4 ? My audio is no AAC, it's linear PCM.

Any help appreciated, this is really annoying because I want my exported videos to be in MP4 container format and not Quicktime. Thanks in advance

Running DVR Studio 18.1.4 Build 9 and on [DELIVER] tab as soon as I select Format=MP4 the button "AUDIO" is greyed and I cannot select it. This results in no audio in the rendered final video. However the video sounds fine when I playback in the preview in DVR.

When I use Format=QUICKTIME the button "AUDIO" is displayed, I can click onto it and make the changes needed. I export the video and the rendered file is played back correctly.

So why the heck there is no AUDIO button available (greyed out, shadowed) whenever I choose format=MP4 ? My audio is no AAC, it's linear PCM.

Any help appreciated, this is really annoying because I want my exported videos to be in MP4 container format and not Quicktime. Thanks in advance

Was this resolved in the final version of 18.5 in Linux? It works fine in 17 but not 18 or 18.5. Very frustrating because I'd like to upgrade but this one issue prevents it.

Running DVR Studio 18.1.4 Build 9 and on [DELIVER] tab as soon as I select Format=MP4 the button "AUDIO" is greyed and I cannot select it. This results in no audio in the rendered final video. However the video sounds fine when I playback in the preview in DVR.

When I use Format=QUICKTIME the button "AUDIO" is displayed, I can click onto it and make the changes needed. I export the video and the rendered file is played back correctly.

So why the heck there is no AUDIO button available (greyed out, shadowed) whenever I choose format=MP4 ? My audio is no AAC, it's linear PCM.

Any help appreciated, this is really annoying because I want my exported videos to be in MP4 container format and not Quicktime. Thanks in advance

It looks like the culprit is 18.5 uses the AAC audio codec whereas 17 uses the Linear PCM. If that option is put back in 18.5 I think it would be a winner.

Was this resolved in the final version of 18.5 in Linux? It works fine in 17 but not 18 or 18.5. Very frustrating because I'd like to upgrade but this one issue prevents it.