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Video file from Media Express has no audio in Resolve

PostPosted: Sun Dec 11, 2016 6:41 am
by Patrick Kenny
I bought an Intensity Pro 4K to record 10-bit with my Panasonic GH4. I'm on Windows 10, and in Media Express, I set the project video format to 2160p29.97 and the capture file format to AVI 10-bit RGB.

I then captured a video. When I play this file back in Windows Media Player, I can hear the sound.

However, when I create a new project in Davinci Resolve and add the video file, there is no audio when I drag it onto the timeline. (The file shows a video track, but no audio track.)

So I know the audio has been captured properly because I can hear it in Windows media player-- what do I need to do to get the audio into Resolve?

Re: Video file from Media Express has no audio in Resolve

PostPosted: Tue Dec 20, 2016 9:26 pm
by ted ramasola
I also have the same issue.
I also use the GH4 and I'm capturing at 23.976 4k. The captured video files has audio since I can import the file into premiere and it has both video and audio. It is only in davinci resolve that the audio is not recognized.
I hope someone from BM can advice a solution.

Re: Video file from Media Express has no audio in Resolve

PostPosted: Tue Dec 20, 2016 11:12 pm
by Andrew Kolakowski
Post mediainfo grab. Does your file have 1x8 channel audio track?

Re: Video file from Media Express has no audio in Resolve

PostPosted: Tue Dec 20, 2016 11:31 pm
by ted ramasola
Andrew Kolakowski wrote:Post mediainfo grab. Does your file have 1x8 channel audio track?


Within davinci resolve the media file metadata is indicated as 0 =audio channels.

In windows properties it is 2 channels 48 khz.

Re: Video file from Media Express has no audio in Resolve

PostPosted: Wed Dec 21, 2016 6:29 am
by ted ramasola
I'm beginning to think that this is a quicktime issue with windows 10. But I'm not 100% sure.

Re: Video file from Media Express has no audio in Resolve

PostPosted: Wed Dec 21, 2016 7:33 am
by Adam Simmons
If you drop the file in to MediaInfo and look at it in tree view what does it think the audio is?

Re: Video file from Media Express has no audio in Resolve

PostPosted: Wed Dec 21, 2016 7:58 am
by ted ramasola
Adam Simmons wrote:If you drop the file in to MediaInfo and look at it in tree view what does it think the audio is?


It says
format: PCM
Channels: 2
Sampling rate: 48 khz
Bit depth: 24 bits


The video file was captured as UHD 2160p23.98 AVI 10-bit YUV.

Re: Video file from Media Express has no audio in Resolve

PostPosted: Wed Dec 21, 2016 8:12 am
by ted ramasola
Here's something I found out.

If I play the avi file captured by media express using Quicktime player, NO AUDIO.
If I play it in windows Media Player, AUDIO IS OK.
VLC player, AUDIO IS OK.

Re: Video file from Media Express has no audio in Resolve

PostPosted: Wed Dec 21, 2016 10:18 am
by Andrew Kolakowski
Download ffmpeg and run this command:

ffmpeg -i "path to your source avi" -c:v copy -c:a pcm_s24le "path to output.mov"

output needs .mov extension.

If only BM could make their own products compatible between each other :)

Re: Video file from Media Express has no audio in Resolve

PostPosted: Wed Dec 21, 2016 11:26 pm
by ted ramasola
Andrew Kolakowski wrote:Download ffmpeg and run this command:

ffmpeg -i "path to your source avi" -c:v copy -c:a pcm_s24le "path to output.mov"

If only BM could make their own products compatible between each other :)


Thanks, Andrew, this works and allows resolve to see the audio.

I hope this will also help the OP solve this issue.

You are right, BM should provide a fix for this as their products should be compatible with each other.

Is there a more efficient way to batch convert files in ffmpeg ? I'm not so well versed in command line usage. Like for instance using a string argument to let it do a batch conversion for files with similar numbered file names in one folder ?

Re: Video file from Media Express has no audio in Resolve

PostPosted: Thu Dec 22, 2016 8:57 am
by Jean Claude
This is not exactly what you are asking for but the example below allows you to process all AVI files of a directory and transcode them to MOV with same name and the correct audio parameters. You just have to customize <path to output>: either a point "." For the same directory as the sources or an explicit directory name (X:\zzzz\yyyy).

Code: Select all
@echo off
echo audio convert for all AVI in a directory to MOV
echo *************************
echo video codec : copy
echo audio codec : pcm_s24le
echo *************************
echo.
for /r %%X in (*.avi) do (
ffmpeg -i "%%X" -c:v copy -c:a pcm_s24le "<path to output>\%%~nX.mov"
)
pause


Be careful that in the names of the sources there is no space. Otherwise, they will not be processed.
Edit : add quote before output mov if space are present in file name.

Re: Video file from Media Express has no audio in Resolve

PostPosted: Sun Jan 01, 2017 1:57 pm
by Patrick Kenny
Thanks, the ffmpeg command worked-- but I'm surprised at having to jump through these hoops, since Resolve is included in an SD card in the Intensity Pro box.

I'm sorry for the late reply; I thought I had notifications turned on but I did not.

Re: Video file from Media Express has no audio in Resolve

PostPosted: Mon Jan 09, 2017 5:27 am
by Patrick Kenny
Some more information: I spoke with Blackmagic support about this and was told that the audio does not work with uncompressed AVI in Resolve because Resolve does not (yet) support 24-bit audio, so the ffmpeg workaround will be necessary until it does.

Audio does work when using AVI Motion JPEG as the capture file format.

Re: Video file from Media Express has no audio in Resolve

PostPosted: Mon Apr 10, 2017 7:48 am
by Knud Christiansen
After strugling to get Handbrake to read avi (not jpeg) file with audio produced by Media Express I found out that:

The avi file does not have a complete audio header
VLC was the only one I found which recognize the audio stream

FFmpeg was also not able to do the conversion mentioned earlier in this thread unless you specific specified pcm_s24le as audio input stream.

Let FFmpeg do pcm_s24le in and out stream conversion, copy video, output container format AVI...then I got a AVI file were Handbrake could recognize the audio stream.

Several programs showing file format now also stated a more complete audio header.

Bug in Media Express ???

Knud

Re: Video file from Media Express has no audio in Resolve

PostPosted: Mon Jan 21, 2019 2:26 pm
by jaredroc
Hello Knud - I know this is an aged discussion thread but I am running into the same issue you had where I have a 5.1 channel avi file created with Media Express that loses at least one audio channel when I convert the avi file to mp4.

Can you share the ffmpeg commands you used to fix the audio stream conversion issue by chance?

Thanks!