Broken codec concern, maybe me

[Justyn]

As Barry stated.. it's all relative but to a lot of people this might be the most expensive piece of gear they own and thus there's lot of pressure to perform as perfectly as possible.. but nothing will. I love the GH2, but it's not as rock solid as the 150 and yet I'm drawn to using it cause of the flexibility options it offers me. However, there's more of an elegance about the 150 as well.

I will be posting some low light stuff I shot with the Gh2 that seems pretty decent in my initial views.. I did see the pretty dishartening Rolling shutter lines and weird squiggles over flashs and strobes and some firework pops.. None of that would have ever been a factor in the 150.. at all. However the voigtlander affords low-light options that the 150 would never be able to meet...

It's just another tool in the bag.. just like the AF100, and the Gopro, and 4 5 other HD cameras that all serve some fucntion... They all get used and none get jealous... Except if the wife can't get to use her extremely color saturated SD9. She friggin loves that camera more than any other... so it's all a preference.

I too was a bit guilty of not fully understanding the love of the DSLR.. but now I get it... Stealthy, cinematic, manipulative.

 

[Park Edwards]

laugh, i love how this thread started with a question about whether or not I had a faulty setting and it was completely derailed. either way, i've noticed 2 things. if you add +2 to noise reduction it helps it out just a tiny bit. smooths things out. the codec noise isn't as bad as I thought at first, but nonetheless, it would be nice to see the avchd codec improve for the dslr line. I'm okay with how it performs and can't wait to get a new project going. And +1 for a Gh2 hack to up the bitrate. I can't imagine how cool that would be.

ha, second thing is that i've changed my monitor cable to hdmi to dvi and it seems to have cleaned up some of the picture. dunno if this is something psychological or it really helped.

 

[stonebat]

I'm afraid that GH series will make me spend a lot more money unless I'm willing to wait. I really can't be a true early adapter. For people like me, it's good thing that most m43 gadgets lose value quickly. I recall GF1 with 20mm was more than $1K when it first came out. I paid $699.99 + shipping on 9-18mm when it first came out. Only if I had waited a few more months. Haha. So I learned my lesson. No matter how it sounds great, wait a bit. Some early adapters will try out new products and find flaws. When we see some flaws, we should suggest Panasonic to address the issues. Let's wait and see how they address the issues in the coming months. If GH2's target market segment is truly thin, it will be silly if they don't listen to this forum's suggestion.

 

[TheDingo]

How? It's straight in the .mts file?

You have to keep in mind how the AVCHD CODEC works. It is very highly compressed and needs to be properly decompressed in order to see the image correctly.

It seems that some of today's editors take short-cuts when decompressing AVCHD video and thus introduce artifacts, which is what I think you are seeing. I know from experience that Sony Vegas Pro 9 / 10 handles AVCHD video really well, as I've seen the type of artifacting that you describe when friends have edited video that I've shot for them. ( i.e. They have problems with my footage, but when I do the edit the problems aren't there )

I've looked into neat video and may use that if it ever comes down to.

NeatVideo is great. It's fairly cheap ( about $100 for the PRO version ) and does a great job.

Also .png files clean up the artifacts a little more than a .tif file.

I'm sorry to say that you are 100 percent WRONG here. PNG uncompressed cleans up NOTHING. The PNG files that I posted are generated directly by Sony Vegas Pro, and look IDENTICAL to what I am seeing within the editor itself.

I'm not sure how you say it's a workflow issue.

The problem you originally described completely goes away when I use Sony Vegas Pro and the NeatVideo plug-in. I think your NLE can't properly decompress AVCHD and so you are seeing artifacting in your image. When I examine your MTS file with Sony Vegas Pro I see pretty much normal AVCHD video with a tiny bit of image noise in the poorly lit areas, and this little bit of noise can be completely cleaned up with NeatVideo.

 

[roei z]

The problem you originally described completely goes away when I use Sony Vegas Pro and the NeatVideo plug-in. I think your NLE can't properly decompress AVCHD and so you are seeing artifacting in your image. When I examine your MTS file with Sony Vegas Pro I see pretty much normal AVCHD video with a tiny bit of image noise in the poorly lit areas, and this little bit of noise can be completely cleaned up with NeatVideo.

i think he means when watching the MTS file on a player outside the NLE

 

[TheDingo]

i think he means when watching the MTS file on a player outside the NLE

Then the problem lies with the AVCHD decompression of the video player. Barry has a whole AF-100 thread going about "phantom" noise that some people are seeing when viewing AF-100 MTS footage with players that can't properly decompress AVCHD footage and un-calibrated video monitors that are not displaying the full tonal range correctly.

The bottom line is that we need to be a lot more careful when selecting the software and hardware that we use to view AVCHD / .H264 footage with.

 

[roei z]

hmmm... that's a pixel peepers thread of it's own - i give you the honor to open one

 

[TheDingo]

hmmm... that's a pixel peepers thread of it's own - i give you the honor to open one

...Sorry, I have a life.

Perhaps a quick solution to the AVCHD decompression problems is to always render to a more common lower compressed format like MPEG-2 unless you can confirm that the display system can properly handle AVCHD footage directly. I imagine that brand name TVs and Blu-ray players should be able to properly decompress AVCHD footage. ( I've heard that you can just pop the SDHC card in to some Panasonic TVs / Blu-ray players and play without any problems )

 

[stonebat]

NLE really didn't work on After Effects CS5. Good transcoding can make the life easier.

BTW as memory gets cheaper and bigger, I don't really see the point of such high compression ratio. Obviously GH13 showed it can be less compressed.

 

[TheDingo]

BTW as memory gets cheaper and bigger, I don't really see the point of such high compression ratio. Obviously GH13 showed it can be less compressed.

The AVCHD spec was designed around a low write speed. It's not an issue of file size but rather of guaranteed minimum write speed for SDHC memory cards. Good SDHC cards can handle a 10+ MB/sec minimum write speed, but many cards can't.

I am hoping that the SDXC card spec will fix this once fast SDXC cards are fast, cheap and reliable.

 

[stonebat]

It might have been when AVCHD spec was designed. My class 6 SDHC had no issue to handle high bit MJPEG writing for GH13. Make GH2's AVCHD implementation less compressed and less efficient?

 

[TheDingo]

It might have been when AVCHD spec was designed. My class 6 SDHC had no issue to handle high bit MJPEG writing for GH13. Make GH2's AVCHD implementation less compressed and less efficient?

The problem is that companies want to produce standardized products, so formats like 28 Mbps AVCHD which Panasonic added to the TM700 camera to support 1080 60P video, is not supported by anyone else because the current AVCHD spec does not allow for it.

So yes these standardized specs need to be extended to allow for higher bit-rates, but I'm not holding my breath about it happening anytime soon...

 

[Lpowell]

Then the problem lies with the AVCHD decompression of the video player. Barry has a whole AF-100 thread going about "phantom" noise that some people are seeing when viewing AF-100 MTS footage with players that can't properly decompress AVCHD footage and un-calibrated video monitors that are not displaying the full tonal range correctly.

While I'm not sure whether a consensus has been reached in Barry's AF100 thread, I strongly suspect the problem is related to the infamous QuickTime H.264/AVC Gamma Bug which has been plaguing cross-platform video production for years. Here are links to articles that examine the problem in depth:

http://provideocoalition.com/index.php/cmg_blogs/story/brightness_issues_with_h264_quicktime_movies/

http://provideocoalition.com/index.php/aadams/story/quicktime/

 

[Park Edwards]

I still see it in the .png as much as I see it in the .tif. I've run it through a few different players. And not to sound condescending, but I think Adob'es mercury engine decodes AVCHD just a little bit better than Vegas. Nevertheless your insight is helpful. I've noticed less artifacts the now that I've hooked up my monitor to HDMI. It has issues, but it's not critical enough to warrant any returns.

 

[TheDingo]

I still see it in the .png as much as I see it in the .tif.

Then you are seeing what I am seeing which is not any problem with the AVCHD CODEC, but rather a tiny bit of noise being recorded in dimly lit areas with long tonal ranges. This is totally normal for video, and something I see when I shoot with my HMC-150 AVCHD camera.

The fix for this tiny bit of noise is noise-reduction software like NeatVideo. ( I always prefer to do noise-reduction in post as I think software does a better/more controllable job than using in-camera noise-reduction )

And not to sound condescending, but I think Adob'es mercury engine decodes AVCHD just a little bit better than Vegas.

I can't accept your claim without seeing some actual proof to back this up. I know that CS5 is a very good editor, but I don't know if it is better than Sony Vegas Pro in terms of image quality. ( I know that it's one of the few to use hardware-assisted AVCHD acceleration via the right nVidia GPU making it a very very fast editor )

...And if CS5 decodes AVCHD better than Sony Vegas Pro, then why are you complaining about a broken CODEC, because I'm not seeing anything other than normal HD video noise when I examine your MTS file with Vegas. No blocking. No image break-up.

 

[Lpowell]

I know that CS5 is a very good editor, but I don't know if it is better than Sony Vegas Pro in terms of image quality.

On Win7, Adobe Premiere Pro CS5 allows you to install external codec plug-ins and select which codec is used by default for file imports. The Mercury Playback Engine is one of the choices, and on my workstation I also have the MainConcept Codec Suite 5.1 installed. In my experience, they both do a visually flawless job of decoding AVCHD video at Premiere's internal 32-bit precision.

 

[TheDingo]

In my experience, they both do a visually flawless job of decoding AVCHD video at Premiere's internal 32-bit precision.

...And I have found the same with Sony Vegas Pro's internal 32-bit precision, which is one of the reason's why I've been using Sony Vegas / Sonic-Foundry Vegas for more than 10 years now. Vegas can be slow sometimes ( it's almost all software based, with very little support for hardware acceleration ) but I've never had any issues with the visual quality it delivers.

 

[Blackout]

I find the standard windows media player avchd playback to be STELLAR. I see amazing noise / streak free images from my gh13 all the time.... and I also agree Sony Vegas 9/10 rocks with avchd editing as far as the final output master is concerned. I don't know how much my graphic card is affecting it. I have a ati hd 4870 x2.. but it can't be the card because I see plenty of ugly blocky mud infected footage in native .mts files I download and none in mine.

 

[Park Edwards]

Then you are seeing what I am seeing which is not any problem with the AVCHD CODEC, but rather a tiny bit of noise being recorded in dimly lit areas with long tonal ranges. This is totally normal for video, and something I see when I shoot with my HMC-150 AVCHD camera.

The fix for this tiny bit of noise is noise-reduction software like NeatVideo. ( I always prefer to do noise-reduction in post as I think software does a better/more controllable job than using in-camera noise-reduction )



I can't accept your claim without seeing some actual proof to back this up. I know that CS5 is a very good editor, but I don't know if it is better than Sony Vegas Pro in terms of image quality. ( I know that it's one of the few to use hardware-assisted AVCHD acceleration via the right nVidia GPU making it a very very fast editor )

...And if CS5 decodes AVCHD better than Sony Vegas Pro, then why are you complaining about a broken CODEC, because I'm not seeing anything other than normal HD video noise when I examine your MTS file with Vegas. No blocking. No image break-up.

I have never used the HMC-150. I have used the Gh1 and never ran across this problem. I haven't complained any about the codec. I simply asked a question whether or not this was faulty setting in my camera and if anyone was experiencing the same thing. Mayhaps you expect to see the AVCHD codec break up under dimly list area's. I do not, did not, expect it to so easily when comparing it with its predecessor. I feel that the Gh1's codec under exposed area's is better. It was confounding to see the Gh2's 160 ISO rendering such a noisy image in 1-2 stops underexposed. You see it as a "tiny bit of noise;" I see it as distracting, and I'm not even a pixel peeper. First time ever pointing out something I found wrong. But this is a camera with a excellent video feature, and I'll take it for what it's worth.

Regarding NLE's and decoding, well I have no say. I don't use Vegas, and if works for you I'm glad. Adobe/Media Player/VLC player on Win7 have done me well.

 

[Isaac_Brody]

I finally looked at this, I've seen this on my GH13 footage too. I think it's partly software decoding and also the limits of 8 bit. It is pretty easy to fix in after effects with a little noise reduction and working in a higher colorspace.