I'm just back from a teather show where I recorded two 45 minutes parts with pal gh-1, avchd 720 50p , video bitrate 44.000.000, manual fd lens, time limit removed ... I got background detail pulsing but otherwise it was ok... it was the minidv camera I used to record audio that was really hot ! One question. In last week I did record 2 theater shows. to record the whole stage I used a 50mm f1.8 (stepped down to about f2.4) in a big teather. This evening, in a smaller one, I used a 35mm f2.5 stepped down to f5.6... With a FD135 do you get the faces ?
AVCHD high bitrate tests- MUD FREE footage
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What settings did you use? avchd or mjpeg?
This is a huge overkill for audio bitrate. In commercial DVD use of the Dolby AC-3 encoder, 448Kbps is only used for six-channel surround sound encoding. For stereo, the standard DVD rate is 192Kbps. Since the GH1 only encodes two-channel stereo, the standard 192Kbps provides plenty of bandwidth already. For a comparison, AAC stereo audio tracks downloaded from iTunes range from 128Kbps up to a maximum of 256Kbps. I've listened to samples of both bitrates, and I didn't hear any difference. If it's of interest to you, download a track in both bitrates from iTunes and see if you can consistently identify which is which.
Could this be why the camera overheated?
I'd say that messing with the audio bitrate for almost no useful return, but some known disadvantage(s) (can't play in camera, maybe just maybe causing overheating), at this stage is a bad idea. Let's be quite sure where we are with the video, then start on the audio (but it's up to you of course!)
I ran some tests with the "C" settings (50, 52, 60) with Native 24p not checked on a Transcend 16 GB class 10 card and here are some results:
This is very well behaved setup. I got no pulses and never a failure. With Native 24p I can always get pulses. The 60, 62, 70 settings, for example, are not totally reliable.
The average bitrate under various conditions (1/50, 1/125, and 1/500 shutter speed and NR=0, and NR=-2) was always nearly identical.
There were some differences, though. The peak frame size changed (the maximum frame data). With lower shutter speed the peak was lower, with higher speed, it was higher. With Noise reduction at 0 the peak was lower, with NR= -2 it was higher.
As I suspected higher shutter speed and lower Noise reduction both have an effect because they create more fine detail. Here are some numbers:
All clips were the same subject (bushes and flowers in a breeze - lots of detail)and ran 30 seconds producing a file size of 168-171 Megabytes.
At 1/500 and NR -2 the peak frame size was 649536
At 1/125 and NR 0 the peak frame size was 566400
At 1/50 and NR -2 the peak frame size was 515328
At 1/50 and NR 0 the peak frame size was 488832
I would expect sharpness settings to have a similar effect, the higher the setting the higher the peak frame size.
Because the average data rate was constant, I assume the increased peak frame size is at the expense of detail in other frames.
A fast shutter has more of an effect than noise reduction settings (actually, that makes sense).
My conclusion is that one should use 1/50 shutter speed (which everybody does most of the time anyway). One should avoid sharpening in camera (set sharpen to -2). One should consider allowing some in camera noise reduction - a setting of 0, perhaps - this is the setting that goes against what many people do today. One should avoid the native 24p setting for now.
Chris
This is very well behaved setup. I got no pulses and never a failure. With Native 24p I can always get pulses. The 60, 62, 70 settings, for example, are not totally reliable.
The average bitrate under various conditions (1/50, 1/125, and 1/500 shutter speed and NR=0, and NR=-2) was always nearly identical.
There were some differences, though. The peak frame size changed (the maximum frame data). With lower shutter speed the peak was lower, with higher speed, it was higher. With Noise reduction at 0 the peak was lower, with NR= -2 it was higher.
As I suspected higher shutter speed and lower Noise reduction both have an effect because they create more fine detail. Here are some numbers:
All clips were the same subject (bushes and flowers in a breeze - lots of detail)and ran 30 seconds producing a file size of 168-171 Megabytes.
At 1/500 and NR -2 the peak frame size was 649536
At 1/125 and NR 0 the peak frame size was 566400
At 1/50 and NR -2 the peak frame size was 515328
At 1/50 and NR 0 the peak frame size was 488832
I would expect sharpness settings to have a similar effect, the higher the setting the higher the peak frame size.
Because the average data rate was constant, I assume the increased peak frame size is at the expense of detail in other frames.
A fast shutter has more of an effect than noise reduction settings (actually, that makes sense).
My conclusion is that one should use 1/50 shutter speed (which everybody does most of the time anyway). One should avoid sharpening in camera (set sharpen to -2). One should consider allowing some in camera noise reduction - a setting of 0, perhaps - this is the setting that goes against what many people do today. One should avoid the native 24p setting for now.
Chris
I think people need to go through the threads and read as much as possible.
I've been running the hack and did a 2hr record test WITH the camera sitting in the sun while driving around. That was a few days ago, it works fine. No overheating, no anything. Don't mess with the audio bitrate. It's been said quite a few times.
Also, we've already established that the first few moments of recording = mud. FOr whatever technical reason, it takes a second to kick in, beyond that no mud. I've experimented in situations that I know the camera couldn't handle, i.e. hanging out of a car window and shooting incredible amounts of moving, fast detail blowing by the lens.
Couldn't locate a single frame of yuck.
I've been running the hack and did a 2hr record test WITH the camera sitting in the sun while driving around. That was a few days ago, it works fine. No overheating, no anything. Don't mess with the audio bitrate. It's been said quite a few times.
Also, we've already established that the first few moments of recording = mud. FOr whatever technical reason, it takes a second to kick in, beyond that no mud. I've experimented in situations that I know the camera couldn't handle, i.e. hanging out of a car window and shooting incredible amounts of moving, fast detail blowing by the lens.
Couldn't locate a single frame of yuck.
I'm intrigued by the reports of 24p-inside-60i being more stable with respect to write speed errors. I continue to run up against write speed issues on my 8GB Sandisk Extreme when doing deep focus type shots of detailed natural environments, so I'd gladly spend a little longer on the transcode side if it meant not having those crop up 15 seconds into an awesome shot. I'll try leaving the native 24p patch off next time I update my camera firmware.
PappasArts
Veteran
Excellent report Chris,
What did you find about the 60 62, 70 settings not totally reliable? Shot since yesterday with it as well my star chart testing process in 60i/24 wrapper with class 10. No issues. Good image though. I shot a high detail with class 6, and it stopped, switched out the card for my 10 and it went without a hitch. Or did you find some thing else?
Pappas
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If you do, report your findings in this thread:
http://www.dvxuser.com/V6/showthread.php?t=213908
Thanks!
PappasArts
Veteran
Isn't that a wonderful thing.....
Hi Pappas.
With the 60,62,70 I got the write error occasionally. I'm using transcend class 10 cards, which are slower than the Sandisk ones, so that may be the difference. Also, the scene I'm testing with contains a lot of fine detail - more than you would typically encounter.
I'm trying to figure out how to get 90% of the benefit of these patches with stability, not necessarily the ultimate performance possible. I considered getting some Sandisk class 10 cards but it occurred to me that there are a lot of people using somewhat lesser cards like Transcend and I could best contribute to these testing efforts by sticking with them. Other people have the Sandisk card testing pretty much covered.
I'm using the 14-140 lens with the OIS, autofocus, and auto exposure on, various shutter speeds, as well as zooming in and out, to stress the camera. I don't normally use those features, but I want them available to me without memory write problems.
So for me the 50,52,60 settings with Native 24p not checked is the sweet spot producing excellent results with no pulses and utterly reliable performance under stressed conditions with relatively inexpensive memory cards.
Maybe later I'll test with my Zeiss primes at just 1/50 shutter and see what happens when the camera doesn't have to process any lens related stuff or high shutter speeds
Chris
With the 60,62,70 I got the write error occasionally. I'm using transcend class 10 cards, which are slower than the Sandisk ones, so that may be the difference. Also, the scene I'm testing with contains a lot of fine detail - more than you would typically encounter.
I'm trying to figure out how to get 90% of the benefit of these patches with stability, not necessarily the ultimate performance possible. I considered getting some Sandisk class 10 cards but it occurred to me that there are a lot of people using somewhat lesser cards like Transcend and I could best contribute to these testing efforts by sticking with them. Other people have the Sandisk card testing pretty much covered.
I'm using the 14-140 lens with the OIS, autofocus, and auto exposure on, various shutter speeds, as well as zooming in and out, to stress the camera. I don't normally use those features, but I want them available to me without memory write problems.
So for me the 50,52,60 settings with Native 24p not checked is the sweet spot producing excellent results with no pulses and utterly reliable performance under stressed conditions with relatively inexpensive memory cards.
Maybe later I'll test with my Zeiss primes at just 1/50 shutter and see what happens when the camera doesn't have to process any lens related stuff or high shutter speeds
Chris
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crashandannie
New member
Hi, Pappas,
I just tested the 60 62 70 AVCHD settings. Same as with every other variation of settings I've tried, I get mud in the darkest shadowed high detail areas areas in otherwise brightly sunlit scene (ie grass in shadow under trees in a park, Spanish moss in shadow areas of trees). This happens with both the stock lens and manual prime lenses (Cooke SPs). No problems at all with areas of less extreme lighting.
Also, and a new issue with these settings, I cannot use log and transfer with FCP, which gives me an "unsupported media" message. Cineform NeoHD still works, however.
PappasArts
Veteran
50,52,60 is very good and stable. I find the 60-62-70 is 90% stable, however zero error is what were all trying to get to.
Try these numbers 54 - 58 - 68 - GOP15 or unchecked- 60i/24 wrapper . I've had good performance with them.
Pappas
PappasArts
Veteran
Hi, Pappas,
I just tested the 60 62 70 AVCHD settings. Same as with every other variation of settings I've tried, I get mud in the darkest shadowed high detail areas areas in otherwise brightly sunlit scene (ie grass in shadow under trees in a park, Spanish moss in shadow areas of trees). This happens with both the stock lens and manual prime lenses (Cooke SPs). No problems at all with areas of less extreme lighting.
Also, and a new issue with these settings, I cannot use log and transfer with FCP, which gives me an "unsupported media" message. Cineform NeoHD still works, however.
I know, the settings is still a mystery- we'll get there. I was bummed that 24PN isn't really working out well. I'm at 60 - 62 - 70 60i/24 wrapper.
Your image is very sharp and detailed though.
Pappas
wanderer63
Active member
I have just uploaded a "C" "Stress Test"......out come good on Panasonic Class 10 http://www.vimeo.com/12792325
Hope this helps
Paul
Hope this helps
Paul
Park Edwards
Veteran
are you guys testing 720p?