My God, this stuff gives me a headache.
I hate computers and computer cr@p.
Well, naturally I don't wanna record material in a lossy format as H.264 (heretofore muttered as "Beelzebub" under my breath) but it seems rather inescapable for the fresh and soft meat classes of indie film makers.
http://www.luminous-landscape.com/tutorials/video-primer.shtml
"AVCHD (Advanced Video Codec High Definition) is the latest format standard, and has been adopted by the big three; Sony, Canon and Panasonic. It allows for a very high degree of compression without quality loss, but during its first couple of years on the market has been plagued with issues related to artifacting, overall image quality, and difficulty of editing. Now on its third generation these issues are starting to disappear, though the format still requires the most powerful computer possible if one is interested in transcoding AVCHD. Bit rates are around 17 Mbps, but the latest Canon cameras, like the HR-11 have upped this to the format's theoretical maximum of 25 Mbps.
Because of AVCHD's high degree of data compression batch processing to a more standard (and less compressed) format is the best way to work, though file sizes balloon considerably when this is done. This is called transcoding. AVCHD is based upon the AVC/H.264 MPEG-4 codec.
AVC/H.264 MPEG-4 (AVC) is the format used by Sanyo and Samsung. It uses a lower bit rate than AVCHD (usually 12 - 16 Mbps), but is easier to edit as it requires less processing power since it is less compressed. Now that AVCHD has matured in the latest generation of cameras it's likely that AVC/H.264's days may be numbered, and I wouldn't be surprised to see Samsung and Sanyo eventually adopt AVCHD along with the big three.
MPEG-2 Transport Stream is an alternative format exclusively backed by till now JVC, and used in its Everio line of camcorders. (JVC has recently adopted the AVCHD format as well). MPEG-2 Transport Stream is reported to not offer as high image quality as AVCHD and is not necessarily compatible with a broad range of editing programs, though it needs to be said that none of the new consumer HD formats is particularly easy to work with because of their demand for the most powerful computers when decoding."
Beelzebub... I mean H.264 is everywhere, it just got here so it ain't going away anytime soon, so just deal, Lucile.
CamVader -
I like your 1gb test idea and am thinking of a couple others where H.264 is converted to a whopping AVI file, edited, then saved for viewer delivery as several different formats including right back into H.264/MP4.
My guess is that... well, first let me premise that I could be wasting my time as I have little idea what I'm actually doing, my guess is that much of the delivery outcome won't matter.
It'll largely look fine or arguably the same rather than notably worse.
Input/Output experiments to come, but don't hold your breath. Maybe next week. Maybe.
ItDonnedOnMe -
EXCELLENT explanation of WTH is happening:
As others have said, h.264 is a lossy codec, and to keep file sizes manageable it throws away a lot of image information. It does a very good job of maintaining a good looking image while doing so - but the key is good 'looking'. It's designed to throw away information that is unlikely to be perceived by the human eye, while maintaining the appearance of the stuff that is likely to be noticed.
There's two problems with this when it comes to post. The first is that once you start pushing the image around, in color correction or a similar process, you potentially move image data from a range that is unnoticeable to the human eye up into that range. An example is where you try to pull up detail in the shadows and blocky compression artifacts appear instead of clean image data - that's because the codec knew those areas were below a visible threshold (when you shot them) and applied more aggressive compression to that area.
Understood.
This is why I'm wondering if the compressed file can be uncompressed as a larger AVI format, monkey with... I mean edited, then re-compressed back into H.264/MP4 or other.
I don't know how to designate the 8 vs 10bit output for delivery, but I'll figure out something.
Maybe it's because I'm working with a 2 bit computer (that was a joke, BTW) which already has a short a$$ shelf life.
(The buzzards be gatherin' about this gimpy mule.)
Somehow, the collective "We" need to figure out a standardized path from H.264 to delivery that we can just throw at every nube (myself included) who scratches his/her head and asks "WTH happened?"
Seems there's too much "Let everyone invent the wheel! The industry supports the right of consumers to figure it out on their own!" going on.