Magic Lantern Forum

Using Magic Lantern => Raw Video => Topic started by: vinyss on September 26, 2014, 05:41:17 PM

Title: MLV Audio Breaking
Post by: vinyss on September 26, 2014, 05:41:17 PM
Hey guys,

I'm new here so please take easy if this topic is dumb and the issue is already solved somewhere. I just couldn't find an answer!
I am a 6D owner, and I am trying to record RAW with Audio to later on sync with High-Res audio from my lavalier mic.

Right now I'm able to shot with Audio but when I export the files, the audio somehow gets a bit funky and the beginning of the audio file turns to be cut of, then placed back at the end of the file, therefore causing me issues while synchronizing both Audio and Video.

Is there a solve for that?

A bit of an extra topic, does anyone here owns a 6D and shoot RAW? I'm looking to buy a Sandisk Extreme Pro 64gb, 90mbs. Does anyone here knows if I can shoot continuously (without being stopped at all) with this card? I've been reading some stuff on internet, but nothing seems like a solid information still.

Thanks.
Title: Re: MLV Audio Breaking
Post by: spnsir on September 29, 2014, 02:46:44 AM
Wow, I just came to post this very thing. It is happening with myself and two other shooters. All on 5D3, 1.2.3 and 1.1.3, mostly happens, if not only (haven't confirmed yet) while shooting 50 or 60fps, not 23.976.

To illustrate what's happening, see this image:
https://www.dropbox.com/s/gbqyls5dr4jjmj0/MLVaudio.jpg?dl=0 (https://www.dropbox.com/s/gbqyls5dr4jjmj0/MLVaudio.jpg?dl=0)

We've only experienced it shooting RAW video with the MLV format (only way for sound of course). I don't believe it is a conversion problem. The MLV files themselves have this error and it can be heard during playback using MlRawViewer (for example). It doesn't happen to all files, but does seem to happen to a good chunk of them on every shoot (pretty much all of our shooting is at 50 or 60fps).

To add on, it seems like the final 30-40% of the audio gets inserted before the first 60-70% of the audio file. I am wondering if because recording usually stops early while shooting slowmo at 1920 x 508 (1920x818) if the sound metadata is not being closed/ended properly, or something along those lines.
Title: Re: MLV Audio Breaking
Post by: g3gg0 on September 29, 2014, 09:01:35 PM
do you have an example file for me?

if you use btsync, use this key: AZBFSOPD2AB4P6P4F2CJNGNMNBTNVMPAQ
Title: Re: MLV Audio Breaking
Post by: spnsir on September 29, 2014, 11:07:24 PM
I delete my mlv files often before I have a chance to go through my converted footage. I'll upload to dropbox as soon as I come across a file with this issue
Title: Re: MLV Audio Breaking
Post by: vinyss on October 02, 2014, 10:58:26 PM
Hey G3gg0,

I get this in every single attempt of video. I kinda figure a work around it, that sometimes work, but sometimes doesn't.
My first shoot goes on 8Hz, which bugs my camera an freezes everything for almost a minute... Then I start to shoot with 11Hz and somehow the video and the audio sync perfectly (not always though).

I can certainly update a file as example so you can take a look into it.
Title: Re: MLV Audio Breaking
Post by: g3gg0 on October 02, 2014, 11:30:28 PM
i changed the btsync key
Title: Re: MLV Audio Breaking
Post by: vinyss on October 03, 2014, 02:32:19 AM
No problem, g3gg0!
Here's a link for my dropbox. As you can hear what happens is that the beginning of the audio get cut then placed at the end... NO! I don't count backwards. lol

https://www.dropbox.com/sh/zbt1zp3nalv1hzv/AADF2gSClF-PJkXS31xDkjJta?dl=0

Cheers