Blackmagic Forum

Recently I have shoot a documentary for Psychiatry on line Vdeo Channel, consisting in a collection of interviews of course edited and mixed with DA VINCI RECOLVE.
All the tracks were made with a SONY NEX VG 900 (with internal reecording on SD card) except one I was compelled to make with my Iphone 8 PLUS using FILMIC PRO saved in HD with "extreme" setting.
I had no problem to make the editing and to put the video on youtube.
I made also a presentation of this documentary days ago using a MACBOOK PRO with no problem at all.
Today I was involved in a public presentation of the documentary and I went to the hall with the video (.mov H264) in my stick. They had no Mac gear so we stansfered the video on a WINPC and we used VLC to see the documentay in the hall in preparation of the event of tomorrow.
All ok BUT all the cuts MADE WITH Iphone were MUTE (no audio) only THESE PARTICULARY CUTS, the rest of the documentary was OK.
I really dont understand why this appened as on a Mac Gear all is OK including the audio of the cuts from Iphone footage...
Is someone able to help me to understand the mistery?
PS of course we will use a mac during the event but the mistery remains

no suggestions?

Is it possible that the faulty footage is 2 track mono but out of phase, played back in stereo and you would hear the audio, played back in mono and it would be mute.

Richard Knight wrote:Is it possible that the faulty footage is 2 track mono but out of phase, played back in stereo and you would hear the audio, played back in mono and it would be mute.

the footage is good for youtube and good for playback on a mac gear the problem appears ONLY on a WIN enviroment THIS IS THE MISTERY!!! We have tried all the possibleconfiguration but the cuts from Iphone result MUTE AT ALL only these cuts and OLNY UNDER WINDOWS

There's some freeware called MediaInfo that will examine the metadata embedded in the video file. It might shed some light on the mystery.

Michael_Andreas wrote:There's some freeware called MediaInfo that will examine the metadata embedded in the video file. It might shed some light on the mystery.

Yes BUT I dont understand why if a video h264 edited with DaVinci works fine on a Mac and works fine on youtube doesnt work UNDER WINDOWS not AT ALL but only in the cuts made with Iphone (considering that both audio and video footages inserted in the edtinf line were treated by DaVinci during DELIVER and the result is a footage the one only video track and one only audiotrack edited out of the editor THIS IS THE MISTERY

Have you tried playing the video on a different Windows computer? If you bring your video file back into Resolve, does the iPhone section play with sound? Make a new export using this file and see what happens. In your original project try exporting to a different format and see if it works in Windows.

...but you are correct, this is very Mysterious.

Gary Hango wrote:Have you tried playing the video on a different Windows computer? If you bring your video file back into Resolve, does the iPhone section play with sound? Make a new export using this file and see what happens. In your original project try exporting to a different format and see if it works in Windows.

...but you are correct, this is very Mysterious.

I have done that all with no result at all
All works fine both on resolve and on a Mac with the videofile edited with resolve
when you try to play the video under WINDOWS with VLC of course all work fine except the audio (video works) of these pèarticular cuts made with iphone
It's really a mistery!!!!!!

could you dropbox a sample?

Francesco Bollorino wrote:Recently I have shoot a documentary for Psychiatry on line Vdeo Channel, consisting in a collection of interviews of course edited and mixed with DA VINCI RECOLVE.
All the tracks were made with a SONY NEX VG 900 (with internal reecording on SD card) except one I was compelled to make with my Iphone 8 PLUS using FILMIC PRO saved in HD with "extreme" setting.

I think the answer is that you're trying to work with H.264 formats that are not optimal for editing. My advice would be to transcode them all to something easier like DNxHD (or DNxHR), and avoid H.264 entirely. It's better for editing, for backup, for sound, and for color.

Note that Resolve Studio will playback more formats than the free version, so that's another consideration.

Marc, the mystery is why the iPhone portion of the “exported” video has no sound only on Windows.