HDMI output interaction with raw recording

Started by cthornhill, June 25, 2013, 06:33:50 AM

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cthornhill

Just a note to document what I found today. I have a 60D and was having a lot of issues with corrupt frames (about 10% per shot) in raw recording. Took me a bit but I finally thought to try recording without my EVF. I use it as a matter of course and had not even thought about it at first. Of course that worked and I did test with and without it to check. Clearly there appears to be an issue sending data to the card and the HDMI port at the same time. I am not sure how many people might need to know, but in case it helps I wanted to post this note.

Perhaps in the future it will be possible to use the HDMI port for external monitors and do raw, but for now, that does not appear to work.

Let me know if anyone needs further details or tests.

vickersdc

That's curious, because I quite happily used my external monitor via HDMI out on my 600D, whilst recording in RAW, with no issues!
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cthornhill

vickersdc - glad to hear it! I am about to try testing with a plain monitor. I will post the results. My issues were traced to my Zacuto EVF, and I am anxious to find out if the issue is unique to the EVF or if I also see it on my field monitor too. It also may be unique to the 60D or even unique to my camera or some setting...hard to say just yet. Most of the time I keep my EVF on my rig, and when testing outdoors (especially in bright sun here in Florida) I use it not only for peaking, but for exposure control, etc. so I just did not think of not using it at first...hence it took me a while to trace the issue. I use my field monitor a lot less except for indoor shots or when I am configured so that the EVF would not work (Steadicam or crane, etc.). I will see if I can get the tests done today...

Again - really glad if this is not an issue for others on their systems, but since it was the dickens to find for me, I wanted to let people know what I saw.

Felix

Same thing happened to me when i tried with my Mark iii...
It worked fine with a Komputerbay card, but with my slightly slower transcend card it stopped recording after a few frames.
5D Mark iii

cthornhill

Felix,  that is  pretty interesting.

I just did a super quick test with my small 5" generic field monitor attached to my 60D (not a fancy unit, just a basic small - 5" monitor from CoolLCD). My first two tests had some pink blocks (up to 18 ruined frames), but the next runs (two more) were totally clean. I never had a single clean run with my Zacuto EVF attached (not blaming Zacuto, but just reporting). Now my EVF does lots of fancy stuff and understands a lot about HD modes, but my simple monitor is just that - is shows pixels on a screen...no offense, but it is just an affordable monitor - not something fancy.

Loosing the first two runs is something BioskopINC says happens to him on his system (see post #595 in the 60D thread), so I sort of expected that as a possible outcome...not sure why. For me, with no attached HDMI device all runs are clean now. I can get more details if you want...with the simple monitor the first two runs are bad, but subsequent runs look good...with my EVF no runs are good.

I expect it is a timing issue with the HDMI port but that is just my guess, and I suspect some devices have more complex interaction with HDMI ports than others, but that is a guess at this point.

Cecil

Felix

I just did some more testing using a JVC monitor connected through DVI to HDMI.

Transcend 64 1000x UDMA7:
First test: 414 frames then skipped frame.
Second: 379
Third: 808
Fourth: 826

When its not connected to a monitor it will fill up the card on first try without skipped frames.

Komputerbay 64 1000x UDMA7:
Filled up the card on first attempt.

I did not experience any pink blocks as you did.
5D Mark iii

cthornhill

Thanks for the data! I was wondering what a 5DM3 might see...it is a much more powerful and modern set of hardware than my older 60D!

Sounds like connecting an HDMI device does impact data transfer in at least some cases. Other's appear to have external monitors with different results (and are on other Canon cameras like the 600). I can only assume that the raw record process might be sensitive to the availability of system resources (some buffer or port or register, etc.)  that also are used for output of data to the HDMI port. Anyway the result for now appears to be that you may have issues if you send to both locations (the storage chip and the HDMI port device) at the speed needed. Not sure anyone has time to look into it much more right now, but at least we know a way to avoid the issue - unplug the device causing the issue... :).

I expect that once things settle down developers may have more time to consider this sort of thing, but I expect it is not 'top of the pile' right now. I certainly understand. Personally I am just going to work with the built in screen for now, and wait to see what happens.

Felix

i'm fine with using the monitor when setting everything up, like the focus.
After everything is up and running i unplug the monitor.
5D Mark iii

vickersdc

My monitor is just a very basic 7" generic model bought off of Amazon - the name escapes me for the moment, but it's not expensive and seems to work ok.
Farnham360: my personal video project for 2014... http://www.farnham360.co.uk
Learn the basics of Davinci Resolve 10 Lite by following the tutorials at http://www.davidvickers.co.uk
Twitter: @DVMediaPro

AnotherDave

You are turning global draw off when you are doing these tests?

1%

Haven't seen corrupt frames but there does appear to be a speed drop when recording with HDMI plugged in.

cthornhill

Thanks 1%! - Driftwood says he is not seeing any issue on his 5DM3 either (with an HDMI monitor). I will try a new build and see if I get the same results of different ones in a day or so...like I said, my simple monitor was OK for all but the first two shots (the so called 'warm up' I guess). My EVF not so much...but hey, that could change. Anyway, I expect my 60D won't be able to act like a 5DM3...:-)

cthornhill

To the moderators - I suggest merging this and the "HDMI" thread as they seam to be about the same issue. It looks to me like people's experience is pretty variable, so I guess there are factors here not yet totally revealed. Glad it works better for some!

1%

50D just had a speed drop, same with 6D.. Low end SD digic IV might have issues tho.. they work best in like 640x480 (or dead LV) so using a 1920x1080 image vs the lcd screen is an even bigger resource hog.

Torben Scharling

Where are these options for the 600d ? it's gone from the menu......