I've posted this on 'compression techniques', but thought actually it might be more relevant here:
In my capacity as an editor at a post-production house, I often have to play out other people's edits to digibeta. These are generally delivered to me as quicktimes, and I usually ask for these to be rendered out as 8- or 10-bit Uncompressed video, or DV if that's what has been shot.
However, these requests are often lost in the chain of me - my managers - the client's PA - the client - the kid he's paid
You're not going to get a definitive answer. If all you've got is H.264 then that's what's gotta go into the programme, otherwise you'll have a hole!
The H.264 file can be re-encoded into uncompressed for you to play it out but, as I'm sure you already realise, it won't improve the picture quality.
Is it good enough? Well, this is debatable. It really depends on the type of picture and how much of the H.264 compression they've added. As an on-line editor I guess it's really your call.
Should you push to get uncompressed quicktimes? Of course, as a professional you should be aiming to achieve the best possible product for your client. If they're supplying sub-standard files when top-notch is available then you should be asking for the file again. Don't let the in-experienced dictate your job.
The more times you compress along the post production chain the more noticable it's effect will be. In certain cases the unwanted artifacts that compression adds are amplified everytime the picture is re-compressed, until you have something that looks terrible.
In my opinion you should be creating uncompressed master tapes. i.e. The best quality you can possibly achieve. How much it is compressed by the broadcaster or webmaster is up to them, but atleast you're giving them a choice. Who knows, in the future technology may be good enough so we don't have to compress for the internet or broadcast. When this happens all your masters will need re-making...
I guess I will just continue to ask for uncompressed files, and have the client make the call on whether they want to run the risk. The problem I have is that clients generally want me to just give them yes or no answers on whether files are 'broadcast quality'- and I don't want to look like I don't know what I'm doing with this, as I don't want them to start worrying about my competence generally.
I guess if there is no definitive answer, then I can't give one. Now I just have to try and explain that to my clients...