I have no doubt we will. We just have to get everyone on the same page first.
Anyone having card speed issues, please try again without native 24p
- Thread starter Svart
- Start date
I have no doubt we will. We just have to get everyone on the same page first.
PappasArts
Veteran
I just shot C and my new settings with the star chart at 1/40th- 1600ISO 35mm Nikkor at f16 - Class 10 Extreme- Got the card error. Have been shooting well over an hour of test footage between yesterday and today, and not a single ( other than the one in the MJPEG vs AVCHD) tell now- shooting the star chart.
So this should be passed on to Vitaliy- as I'm confident it's something in the camera.....
Pappas
Why are you shooting 1/40th? I thought we're supposed to shoot 1/50th to get proper 24p?
I've been shooting foliage like what Pappas shot in this post:
http://www.dvxuser.com/V6/showpost.php?p=2023859&postcount=81
But I just found that the chart that Svecher linked to will also cause the same error.:
http://www.bealecorner.org/red/test-patterns/star-chart-bars144-600dpi.png
Just set up your camera in front of you monitor so that the chart fills the whole field, focus well and record with Native 24p enabled and you should see the error.
EDIT: I always shoot 1/50 or 1/125 usually but I've found that it'll happen no matter what shutter you use.
Barry_Green
Moderator
On Nero Showtime it tells you the bitrate also. On the Pappas settings I just re-set to, it shows about 48mbps on a highly detailed forest scene, panning around like a madman.
Indoors, low light, on a low-detail scene, it shows about 10mbps, equally panning like a ninny.
Pappas, you're on Windows, yes? You can get a basic mbps just by right-clicking on the filename, going to "properties", then "details".
The clips that were choking on me before show about 49mbps. One of them, that didn't choke, I successfully recorded for 10 seconds, showed about 28mbps. With major "codec pulsing".
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PappasArts
Veteran
Hey Barry,
I have both PC and Mac. When I go to properties- I don't have the details tab. Is that a win7 feature?
PappasArts
Veteran
Hey Mike,
It's didn't matter since I was trying to crank up the bit rate as high as it will go. However I re-shot the chart so we have our t's crossed and i's dotted. It got the card write error...
Papaps
PappasArts
Veteran
Hey Svart, are you getting that error with the chart on 60i wrapper? Or is this error just on the 24PN?
Pappas
Barry_Green
Moderator
Might be; this computer I'm on is running Windows 7...
PappasArts
Veteran
I bet that's it. VLC's gives bit rates. However I don't know if there accurate.
Not sure I'm following all of this, but I just shot that chart twice, once locked down, once just holding it...with an FD 50mm at 5.6 aperture at 100 ISO 50 shutter and didn't have any recording errors, playback errors, etc. C settings, native 24p. Panny Class 10 16gb card.
I'll answer for him. It's just 24pN.
PappasArts
Veteran
Ok, time to try the higher bit rate settings with the 60i wrapper. Damn! I like 24PN......
Pappas
Ha!
Thanks, yes I just ran this test again and I do not get the card speed error when Native 24p is not enabled.
Park Edwards
Veteran
Svart, are you saying you get this error without applying any bitrate settings? Just the native 24p only? As I have at least a dozen of files on a tripod with the 24p patch and never had this problem. I can even post the .mts files.
I too discovered this after reading the thread I'd thought I give it a try.
I put my gh on a tripod and shot the backgarden static ...it ran for about 30 seconds...write error...second time...36 seconds...write error.
I use generic "c" settings on ptool.
If I move the camera around I never get a write error and would continue to record.
I installed new firmware without 24/25p native ticked...camera same position...and it recorded continuous with no issues.
I beleive there is a problem with 24/25p patch rather than just blaming card speed issues (im using a extreme III class 10 that handles 80mbs mjpeg with no problem).
Were all been testing and giving reports so this odd little issue should be reported to vitaliy
I put my gh on a tripod and shot the backgarden static ...it ran for about 30 seconds...write error...second time...36 seconds...write error.
I use generic "c" settings on ptool.
If I move the camera around I never get a write error and would continue to record.
I installed new firmware without 24/25p native ticked...camera same position...and it recorded continuous with no issues.
I beleive there is a problem with 24/25p patch rather than just blaming card speed issues (im using a extreme III class 10 that handles 80mbs mjpeg with no problem).
Were all been testing and giving reports so this odd little issue should be reported to vitaliy
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Phil Seastrand
Active member
This is also happening to me. I had to go to manual focus to get it to happen as it was hunting slightly with auto focus. Fortunately I rarely have this kind of static shot, so I'm willing to live with it, but I can see how it could be a problem for others.
Ben_B
Veteran
Did you mean that you turned off native 24p and you got it to record continuously? Because it sounds like you said the opposite but then said you think there is a problem with the 24p patch. Please clarify.
I tried to reproduce this type of failure in a 1080p video with the following settings:
Video bitrate Simplified 50000000
Overall bitrate adjustment 52000000
Limiting bitrate adjustment 6000000
Native 24p
1080p GOP length 12
I saw no failures using either a Class 6 Transend 16GB SD card or a Class 10 Sandisk 16GB.
However, I did see a potential problem when I examined one of the videos in StreamEye. While the average bitrate was only 28Mbps, the maximum P-frame was over 10 times the size of the average P-frame, and 6 times the size of an average I-frame. It wasn't hard to spot these massive P-frames in the stream - they occurred sporatically, but were always the last P-frame in a GOP.
What is apparently happening is that a stationary video requires so little bandwidth for most P-frames that excess bandwidth builds up in the encoder and eventually forces it to discharge a huge amount of useless bits in a single P-frame at the end of a GOP. This causes a brief, but radical boost in bitrate which triggers a write speed error on many SD cards.
Perhaps the reason the failure doesn't occur in 60i mode is that the extraneous interlaced frames bleed off enough bits to keep the maximum bitrate below the maximum speed of the SD card. What would genuinely fix this problem is a patch that enables the camera to record at as low a bitrate as a video actually needs.