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GH1 stable 720p AVCHD settings
  • For any folks still using the GH1, I did a lot of testing to develop a set of stable patch settings for 720p AVCHD shooting. The existing patch settings, it seems, had zero testing in 720p or totally missed several key points.

    I will simply outline my findings, so that you can create your own patch settings to suit your needs:

    * Increasing the overall bitrate will decrease reliability while doing nothing to improve video quality or increase the recorded bit rate. Just leave it at the default 18 Mbps.
    * SH and H modes are equivalent. Feel free to program them with different bit rates and switch between them.
    * The GH1 codec accumulates errors over the length of the GOP. Thus you need to keep the GOP somewhat short, under 12 frames or so, to keep the errors from becoming visible. Shortening the GOP increases the recorded bit rate and decreases reliability. I settled on 10 frames.
    * Using a GOP 10 frames long: no failures with the bit rate set below 27 Mbps; failures were produced with great difficulty at 27 Mbps; failures occurred infrequently at 30 Mbps, and easily at 33 Mbps. I settled on SH=27 and H=25.
    * No differences in reliability were observed between a Transcend class-6 card, a SanDisk Extreme HD Video UHS 30 MB/sec card, and a SanDisk Extreme 30 MB/s Edition card. It would seem that the bottleneck is not the card, even though failures are shown with a card write failure message.
    * Changing the overall bitrate 2 or video buffer size produced no change in reliability, recorded bit rate, or video quality.

    On the GH1, 720p remains my favorite shooting mode due to this camera's lack of 30 fps in 1080p, and because there is much less jello effect in 720p.
  • 6 Replies sorted by
  • hi I'm new to this forum and found your post very interesting,so how about the 1080p,24p?do you have any insight on a optimized more reliable setting for this mode as well..I'm a new GH1 owner and have tried multiple patches that have not worked out so well in various situations..I guess I'm saying do you know of any settings that the reliability/quality ratio stays intact?I don't want to get into moving bitrate numbers just for the sake of moving them with no real quality improvement sacrificing camera stability.Don't know if I'm allowed to ask such direct questions here but any help would be greatly appreciated thanks!
  • There are plenty of good patch settings around for 1080/24p on the GH1. Try some out, and adjust the bit rate numbers up or down if the settings aren't giving you the quality or reliability that you want.
  • @EYESOUL
    For highest reliability in all video modes on the GH1, I recommend the Reliable In-Camera Playback Patch:

    http://www.personal-view.com/talks/discussion/173/gh1-gf1-reliable-in-camera-playback-patch-version-2-

    If you need Native 24p or 25p video recording on the GH1, I recommend the Blackout-Powell Patch:

    http://www.personal-view.com/talks/discussion/184/gh1-blackout-powell-native-24p-patch-v2-

    For the highest practical 720p50 or 720p60 bitrate on the GH1, I recommend the Peak Reliability Patch:

    http://www.personal-view.com/talks/discussion/334/75mbps-gh1-peak-reliability-patch-v2-update
  • thanks guys really appreiciate your help!
  • @balazer so would you say these patch settings you speak of produce identical results in image quality as the"peak reliability patch" in 720p with more reliability?bare with me I only had my gh1 a total of four days and I'm really trying to wrap my head around all of this patch talk.when you say"The existing patch settings, it seems, had zero testing in 720p or totally missed several key points,which existing patch settings are you basing these findings on?If indeed you have found patch settings that are just as good as the "peak reliability patch" in 720p with a little more stability I for one want to try them out thanks!
  • The other patch settings that I tried were all less reliable. Some of those other settings had higher quality, and some of them didn't. I don't want to get specific about what other settings I tried. I encourage you to try different settings and see for yourself what works best for your particular shooting scenarios.
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