What are currently the highest quality stable AVC 25p Ptool settings?

D

Drcoffee

Well-known member
Hi Guys,

I've been using the original 'C' settings for a while now. What are currently the highest quality stable AVC 25p Ptool settings?

I use '8GB Sandisk Extremes 30MB/s class 10' If I use one of the new 'SanDisk Extreme Pro - SDHC - UHS 45MB/s' can I up the data rates?

Many thanks for any advice in advance.
Jon
 
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lpowells 75Mbps Patch is a winner for PAL GH13 users, its not native 25p but i think native has been attempted by everyone and it cant be stable.
i've tried various known high bitrate settings and they always either speed write error or jump a frames or glitch.

been using the 75Mbps Patch for a while and its not failed on me once, been shooting the same max detail scenes i was getting fails on before but with this patch it just wont error, the average bitrates arnt as high as some settings but i've come around to knowing that an average of 40ish is still really really high :smile: and so far its been flawless with me.

i think lpowell tested the new UHS cards and found them to be the same speed as normal class 10's (i can only speak from what i remember reading briefly)

found it...
I recently got a 32GB Sandisk Extreme Pro 45MB/s UHS-1 SDHC card. I benchmarked it on the built-in SD card reader of my HP Pavilion Elite HPE Intel i7 workstation and tried it out on my GH1 with my 75Mbps Peak Performance Patch. I then compared its performance to a 16GB Sandisk Extreme 30MB/s Class 10 SDHC card.

Verdict: On my equipment, the 32GB Sandisk Extreme Pro UHS-1 was no faster than the 16GB Sandisk Extreme Class 10 SD card.
hope lpowell doesn't mind me passing on his findings :smile:
 
I've been using the settings below for ages now, with Sandisk 30mb/s 8gig SD's:

-Video bitrate adjustment - c)50000000
-Overall bitrate adjustment - c)52000000
-Limiting bitrate adjustment – c)60000000

With Native 25p Ticked, and I've not had a single problem.

I wanted to have a look at the latest improved settings.

1) Will using the newer "75mbps GH1 Peak Performance Patch" be noticeably better than my original "c settings"?

2) I just had a look at the latest Ptool, and there seems to be 4 sections to the AVC date rate. How do the old:

-Video bitrate adjustment
-Overall bitrate adjustment
-Limiting bitrate adjustment

settings now relate to the new 4 options?

Thanks for any advice in advance.
Jon
 
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Drcoffee said:
1) Will using the newer "75mbps GH1 Peak Performance Patch" be noticeably better than my original "c settings"?

2) I just had a look at the latest Ptool, and there seems to be 4 sections to the AVC date rate. How do the old:

-Video bitrate adjustment
-Overall bitrate adjustment
-Limiting bitrate adjustment

settings now relate to the new 4 options?
Click to expand...
The latest version 3.51d of PTool incorporates a variety of both built-in and user-adjustable stability patches that previous versions lack. Since it no longer uses the original "Limiting bitrate adjustment" patch, settings for older versions of PTool cannot be precisely replicated in PTool 3.51d. The "C settings" suggested by PTool were originally chosen for use with early versions of PTool. It performs well in most circumstances but has been known to fail at high bitrates.

My Peak Performance Patch is tuned to produce AVCHD bitrates approaching 75Mbps when needed, while limiting average bitrates to a maximum of around 50Mbps. This can be useful in filming well-lit, sharply focused, highly detailed subjects. In dimly lit conditions, the patch's MJPEG encoder can maintain high bitrates using 4:2:2 color depth. In typical shooting situations, however, you may not see a marked improvement in image quality when the camera is able to use lower bitrates to encode a video.

For reliability reasons, the Peak Performance Patch does not use the Native 24/25p patch. Combining this patch with these settings will likely produce unstable results.
 
Thanks for the advice Ipowell, appreciated. I've installed your new settings.

Might be a stupid question, but is it possible to just max out the bit rate in AVCHD to have a constant 50Mbps or 75Mbps..?
 
Drcoffee said:
...is it possible to just max out the bit rate in AVCHD to have a constant 50Mbps or 75Mbps..?
Click to expand...
No, the AVCHD encoder does not have a CBR (constant bitrate) option, it always works in VBR mode. With dimly lit, soft-focus, and/or low-complexity scenes, it will only use as much bitrate as it needs.
 
Thanks Ipowell. So do you reckon the new Sandisk 45MB/s has no benefit in terms of speed over the 30MB/s cards...? Has anyone tried settings which previously failed on the 30MB/s with the 45MB/s?

Cheers
Jon
 
As others have already pointed out: your card is not the limiting factor. It can already do more than the 75Mb feed (9MB) needs
 
Has anybody checked that the 25p footage is actual progressive footage? I use 50FHD-36H-27L-54OB-45OB2-540PB2 settings with 24/25p ticked and FCP (through log and transfer, Apple ProRes, either remove pull down checked/unchecked) interprets footage as interlaced. Also VLC reads 50 fps playing back the mts file... So I'm suspecting I'm really shooting interlaced.

Can anyone help with this?

Thanks!
 
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No matter if you checked 24/25p or not, you are having progressive footage. The only difference is the way how the information is coded into AVCHD. It is believed that ticking 24/25p option results in more efficient coding (at least with colour information).
 
In the current, version 3.51d of PTool, when the Native 24p patch is enabled, Stream Parser reports that NTSC 1080p videos are recorded in non-interlaced 24p format. However, Stream Parser reports that PAL 1080p videos are recorded at 25fps wrapped in an interlaced 50i container. Since PAL requires no 3:2 pulldown, it is a straightforward, error-free procedure to extract a progressive 25p video stream from an interlaced 50i container. I suspect the GH1 has always worked this way in PAL mode.
 
crunchy said:
No matter if you checked 24/25p or not, you are having progressive footage. The only difference is the way how the information is coded into AVCHD. It is believed that ticking 24/25p option results in more efficient coding (at least with colour information).
Click to expand...

Thanks, crunchy:

Well, as far as I know tcking 24/25p, eliminates the 50i/60i wrapper, which I think is one of the greatest thing about this hack... And I don´t think it has nothing to do with color (that would be only the 4:2:2 in MJPEG) but still I don't understand why Final Cut Pro and VLC read those files as interlaced...
 
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lpowell said:
In the current, version 3.51d of PTool, when the Native 24p patch is enabled, Stream Parser reports that NTSC 1080p videos are recorded in non-interlaced 24p format. However, Stream Parser reports that PAL 1080p videos are recorded at 25fps wrapped in an interlaced 50i container. Since PAL requires no 3:2 pulldown, it is a straightforward, error-free procedure to extract a progressive 25p video stream from an interlaced 50i container. I suspect the GH1 has always worked this way in PAL mode.
Click to expand...

Thank you, Ipowell, I hadn't seen your post but this really makes sense... So, you think that even if Final Cut Pro is interpreting interlaced (upper) 50i PAL footage, what we have is actual 25p and we just have to set field dominance to "None" in the sequence settings, right?
 
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