This content has been marked as final. Show 3 replies
Well, the question is, what you consider an acceptable quality. The problem with your suggested approach is, that you are applying a sampling/ convolution operation twice and as a known fact of life, this has the downside of accentuating edges. Those may look more pristine and pleasing to your eye, but in technical terms they are degenerating the footage even further. They would also lead to further artifacts on transcoding them as they worsen the efficiency of block-based algorithms such as used for MPEG derivatives. Ultimately it still comes down not so much to how you process the source footage, but how your encoding tools handle them. I believe Liquid also uses the Mainconcept CoDecs, which would bring it in line with Adobe's tools. You should however at least use 1-pass VBR, 2-pass would be ideal. Contrary to common believe, VBR does a much better job of retaining quality, as it allocates more bytes where really needed instead of enforcing a constant data rate even in uncritical areas. And of course consider other tools like ProCoder and TMPEGEnc...
Thank you for your reply.
From my enquiries today I have realised, I think, that it is impossible to improve the sharpness of my SD footage playing on an HD TV when it is burned to DVD - because any upscaling success with either Avid Liquid or MB Instant HD cannot make it onto a SD disc. SD can only be made to 'look sharper' when applying such affects to a final output of BluRay.
At least I can put that one to bed, and start experimenting with other visual filters such as slight blurring etc to try and soften those jaggs I am seeing on big new TVs.
The answer of course is to film in HD/V, which I will once I can afford new cameras :)
So VBR is the way to go for my projects, which are between 45 and 75 minutes? I had been advised CBR for projects under a certain running length. I do not think I can run '2-pass' within Avid Liquid, so do you think I should fuse my timeline as an AVI, and run it through an external encoder - which one is most recommended? What are recommended minimum/maximum BitRates for a 45 - 75 minute film, and could there be problems with some DVD players with too high a BitRate?
Thank you for any further advice :)
TMPEG is still top notch and has a sensible price (though it seems their support for BluRay/H.264 has made it less stable and a bit buggy). The pro-version even allows you post-encode profiling and matrix adjustments.... Short of that, ProCoder LE or Sorenson Squeeze of course. Regarding the bitrate discussion: As said before, this depends more than anything else on the type of content. Evenly lit and colored footage, that is not moving too fast will not show much difference between VBR and CBR, that is true. High contrast items with lots of edits and fast moves however will due to the allocation scheme. In general it is better to keep a somewhat tight leash as it enforces the analysis algorithm to act smarter, so e.g. a full 7.5 MBit/sec may result in a uniform visible grid, but 4 Mbit/sec may produce a larger number of smaller P and B frame blocks which are less visible. Our trusted specs are all in the 5Mbit/sec average data rate, with 3.5 for the minimum and 6 as the ceiling (as some of our DVDs have up to 12 foreign language audio tracks that need room). As usual - a short test run with e.g. 2 or 3 minute samples is the only reliable way to find the perfect setting for a given project. No need to feel bad or amateurish about it - even we occasionally still encode many hours worth of footage several times to find the right settings, and we've been producing DVDs ever since 1998... It's perfectly normal.