Magic Lantern (RAW) Video format v2.0 (mlv_rec.mo)

[tonybeccar]

Is there an *easy* way to extract a thumbnail (aka first frame) of an mlv file? I want to implement thumbnails in my software and I'd like to know how can I do it.. I notice mlvbrowsesharp does it, kinda slow though.. any help please?

[g3gg0]

mlv_dump -f1
will dump two frames, 0 and 1

[tonybeccar]

THANK YOU!

[ted ramasola]

Its dependent on GD, there is a full time color option in advanced. When you record it does lag, etc. Nobody has been really trying it either way.

@1% and g3gg0

This Full time color preview for Crop mode is WAY BETTER. I've tested it and it helps in getting proper focus. A user can develop mental anticipation for predicting movement for framing to compensate for frame refresh lag,  BUT its difficult to anticipate and mentally interpolate to focus manually. So having a better image in color albeit slow refresh is better than grayscale and lo res image. The lag difference between grayscale and color is just about the same.

[Canon eos m]

there is nothing that comes from raw video.
alex and me double checked the raw+jpeg and the only thing we could imagine is that you just
a) underexposed the image by a few stops (fact) and
b) used some post processing settings that crushed the blacks too much

this gives you the impression that there is banding or edges.
i sent you an JPEG from alex that he shifted by 3.5EV which looks better.

-> just a post processing issue that you would have with CR2 too

Thanks g3gg0. Heartning to know that it was something I did to cause the blackening in part of the frame. Will keep a watch on exposure henceforth. ETTR should help.

 However, I did not use any post processing settings at all. The picture is straight out of the Day converter (I think MLV converter 1.4) into ACR.

Any tips on how to stay away from the blacks when shooting people.

[ted ramasola]

@g3gg0 and 1%

is it also possible to implement the audio meters when FPS over ride is on in MLV raw recording since audio is now being recorded regardless of what FPS is in MLV raw?

[tonybeccar]

mlv_dump -f1
will dump two frames, 0 and 1

Yes, into another mlv that needs to be further processed. Is there not a faster way of doing it? Can't it dump the first .dng from it?

[tonybeccar]

Will something like this work to read the first frame of an image? Translate the byte array into an image basically..

http://go4answers.webhost4life.com/Example/convert-array-bytes-image-68125.aspx

Maybe bitmap is too simple.. we're talking about raw here... will it work?

[reddeercity]

Checking the nighty build magiclantern-v2.3.NEXT.2014Feb04.5D2212 with HDMI.
I had a crash/lockup --Error 70, I haven't seen that for a few mouths.
 
Zacuto Evf, 5D2, GD=off, buffer=0, preview=hack view, canon menu small raw=photo,
mlv+audio 1856x928, 23.976p, fps override=on, audio=4800
42GB, 14,785 frames. Skipped frame then stop recording then a few second later error 70.
Preview the clip in  MLVBrowseSharp played fine off card, had errors "5 frames missing mlv id"
But ok.
 
I put the Log crash file in my dropbox for the developers to look at
https://www.dropbox.com/l/rLZWcQKMRtOKZK7LMe2Wjd 

[1%]

ASSERT: 0
at Memory\Memory.c:561, task RscMgr
lv:0 mode:3


Magic Lantern version : v2.3.NEXT.2014Feb04.5D2212
Mercurial changeset   : 80c96bc57ed4 (unified) tip
Built on 2014-02-03 23:09:57 UTC by jenkins@magiclantern.fm.
Free Memory  : 126K + 4001K

Shoot maloc memory error. Maybe some failure making preallocated files?

[refl3x]

been scouring the forums, and just have one question.  Which build should I use for the most stable RAW video on a 5dmiii?  Should I use the nightly builds or go with Alpha?  Or something else I am not aware of?  Thanks for everything you guys do!

[g3gg0]

Yes, into another mlv that needs to be further processed. Is there not a faster way of doing it? Can't it dump the first .dng from it?

well, then add --dng

[g3gg0]

Shoot maloc memory error. Maybe some failure making preallocated files?

any more details?

[tonybeccar]

well, then add --dng

[1%]

That was from his log. I haven't seen it happen yet.

Hmm.. maybe to solve the timecode problem this would help:

http://en.wikipedia.org/wiki/Broadcast_Wave_Format

Shot with sound and the new pre-buffering/allocation. The delay before start is huge. At least 3-4 seconds. Didn't see any pink frames from 30 mins of green screen or have any crashes.

[Sthirasukha]

Hi there,

I'm using the last build (05feb) with 5D MKIII Lexar x1000 64GB. With raw_rec I can have a file higher than 4.29 GB but I can't do the same with the MLV_Rec (1980x1200, 25 fps, GD allow, extra hack on). It stops automatically after about 1200 frame. Can someone tell me what's wrong?

[Sthirasukha]

I just noticed it only happens when I use the HDMI output (to an EVF Zacuto)
To resume: with MLV_Rec (+MLV_Snd) it automatically stops at about 4.29  (a little bit more, just the time to create a new MLV_01) when I use HDMI Output.

[arrinkiiii]

Shot with sound and the new pre-buffering/allocation. The delay before start is huge. At least 3-4 seconds. Didn't see any pink frames from 30 mins of green screen or have any crashes.

With my slow card i need to wait 17 seconds...

In the begging, wend i turn the camera one and try for the first time this new version, i see some kind of pink/flash in the LV, not while recording, (like the corrupted/pink frames in the dng's but this time in the LV), after a while just didn't happen again. I did this test yesterday but if i remember well in crop mode is there the random pink/flash in the LV.

In the firsts MLV i got a pink/corrupted dng in the 13 frame/dng.

I test with GD on, buffer 4 (default)

Tomorrow i can make more test to see if the behavior still there. 

[Sthirasukha]

I got it: in Raw MLV_rec, the option Files>4GiB (exFat) needs to be turned ON if one wants to use the HDMI output with higher than 4.29 GB recording otherwise it doesn't work.

[1%]

600D was doing these flashes too when CPU load was really high. 17 seconds is insane. I've got no pink frames in any of the clips tho. Didn't record while HDMI was plugged in and definitely not with the preview up.

the option Files>4GiB (exFat)

From the code it looked like exfat was default unless you have a 5DII/50D/7D

... ok now I see a setting for "large file support", have to add it.

[Sthirasukha]

One more thing:
It could be great if the GB (CF card) information on the top right of the LV would be update each time the record is off or even better in real time. It only updates when one switch off then turn on the camera.
Thanks for all.

[arrinkiiii]

17 seconds is insane

Indeed, i have measure with windows watch.

It could be great if the GB (CF card) information on the top right of the LV would be update each time the record is off or even better in real time. It only updates when one switch off then turn on the camera.

Would be nice 

[ted ramasola]

5D mkII  note on the mlv snd wav file for Feb 4 build by a.d.

If you stop recording manually your WAV file would "normally" be longer than the video file by 7-10 frames -which is fine.

However, if you keep on recording till Card is full, and the recording abruptly stops on its own, the resulting WAV file would be significantly shorter than the video file from 10 seconds to more than 1 minute.

Can we place safeguards on this behavior? perhaps based on CF capacity, the recording should stop safely?

[1%]

It could be great if the GB (CF card) information on the top right of the LV would be update each time the record is off or even better in real time. It only updates when one switch off then turn on the camera.

This is the problem with canon and why the pre-creation of files, etc is happening. Also why parts of the wav would be lost, etc.

[ted ramasola]

But in the case of wav files, can't we let ML stop recording when there would be just enough space left to finish writing the sound from buffer to cf? My understanding is since the resulting files are almost 64gig there was not enough space left for the last "chunk" of sound data?
Does a set of instructions for checking of capacity size for ML so disruptive that to do so would affect the writing of video and sound to the buffer and card?

The size of the audio NOT recorded should be about 13,173KB or 12.8 MB for the 1'10" length there was no audio, if this can be "preallocated" before a shutoff then perhaps more or all of the audio could be recorded to CF. This is based on my recording to capacity a 64gig CF.