DJ,

As someone who is constantly archiving video, I can honestly say out of the H.264 AVC implmentations I have used, Sony's PSP preset and MC's in Vegas leave alot to be desired. Now I understand that many on this forum didnt even have a clue that there are other settings that can be enabled in H.264 AVC that are unfortunately hidden from the user in Vegas. What I am asking for is for Sony to open them up so those of us who are quality minded can further tune our renders. Sony's encoder limits you to 720x480 resolution and MC limits you to the main and Baseline profiles.

Below this was taken from Doom9's website explaining the differences.



The AVC/H.264 standard defines four different Profiles: Baseline, Main, Extended and High Profile (which themselves are subdivided into Levels):

- Baseline Profile offers I/P-Frames, supports progressive and CAVLC only
- Extended Profile offers I/P/B/SP/SI-Frames, supports progressive and CAVLC only
- Main Profile offers I/P/B-Frames, supports progressive and interlaced, and offers CAVLC or CABAC
- High Profile (aka FRExt) adds to Main Profile: 8x8 intra prediction, custom quants, lossless video coding, more yuv formats (4:4:4...)

It seems the most usable profile for DVD Backups is the High Profile with maybe the following tools (also check out the tool description of MPEG-4 ASP as all, except GMC, are available in AVC too):

CAVLC/CABAC:
AVC/H.264 defines two, more advanced tools for entropy coding of the bitstream syntax (macroblock-type, motionvectors + reference-index...) than MPEG-4 ASP: Context-Adaptive Variable Length Coding (CAVLC) and Context-Adaptive Binary Arithmetic Coding (CABAC)
CABAC, compared to CAVLC (aka UVLC) which is the default method in AVC/H.264, is a more powerful compression method, being said to bring down the bitrate additonally by about 10-15% (especially on high bitrates). CABAC (as CAVLC) is a lossless method and therefore will never hurt the quality, but will slow down encoding and decoding.

Loop/Deblocking Filter:
in contrary to prefiltering (for example via avisynth, done on the input), or postprocessing/filtering (via the decoder, done on the final output), LoopFiltering is applied during the encoding process on every single frame, after it got encoded, but before it gets used as reference for the following frames. This helps avoiding blocking artifacts, especially on low bitrates, but will slow down en/decoding

Variable Block Sizes/Macroblock Partitions:
in contrary to MPEG-4 ASP (where, only with Inter4V/4MV, the Block Sizes can varry between 16x16 and 8x8 pixels), AVC/H.264 offers for Motion Search Precision the division of a macroblock down to 4x4 pixels (including steps like 8x4...). The Block Size is adaptive/variable, a good encoder will be smart enough to decide which one is best to use in every specific macroblock

Multiple Reference Frames:
in contrary to MPEG-4 ASP (which only allows using the frame before the actual frame as reference), AVC/H.264 offers choosing from multiple ones for inter motion search, which means the codec can decide whether he wants to simply refer to the previous frame (like in ASP) or even to a frame before that. Because of that (eg a P-Frame can refer to a frame before the latest I-Frame) a new frametype had to be introduced: IDR-Frames, which are I-Frames before which no following frame is allowed to refer to. Allowing multiple reference frames will slow down encoding and decoding and cutting will be only possible at IDR-Frames

Weighted Prediction:
With Weigthed Prediction there can be weights applied to a reference frame (eg you can scale (brightness-wise) a previous picture). This helps especially whenever there are fades, where the subsequent picture is very similar to the previous one except that it is darker. WP will not help with cross-fades (eg a fade from one scene to another)

Rate Distortion Optimisation (RDO):
RDO allows the encoder to make the most efficient coding decisions whenever it has to choose between different choices (for example when it comes to inter/intra decisions, motion search...)
RDO is not a tool defined by the AVC/H.264 specs, but it's a new decision making approach which was first introduced by the H.264 reference software. Other codecs can also make use of RDO, like XviD's VHQ Mode enables RDO already for example


I can understand Sony wanting to make rendering easy for the average user but a pro app should be able to do the things that pros need to produce quality renders. Are the current renders bad quality? Not at all but they could be a heck of lot better.

"I can understand Sony wanting to make rendering easy for the average user but a pro app should be able to do the things that pros need to produce quality renders. Are the current renders bad quality? Not at all but they could be a heck of lot better."

i totally see wher eyour coming from, but what your refering to is for the top notch, High quality arching, not for BD or HD DVD output. At this time if Sony were to start offering the higher definition resolution encodes, as well as custome tweks for said material, there would be no need for users to upgrade to V7. Now when u consider that PS3, Vegas7 and DVDA4 are all launched within a 12 weeks period, it makes marketing sense to hold back on ALL the tweaks until theyve established the medium.

Dont get me wrong, we'd all love to be able to tweak to our hearts content, but in reality, as far as SOny and Sony licensing of MC''s encoder is concerned, we only "need" these lower end templates to get us through for now (ipod, PSP, web...).
When we can actually start buring these higher def h.264 videos to BD, then we will most likely see an improvement of the codec as well as the encoder itself. This again, will be a marketing thing, as for them to offer THAT kind of encoding free of charge, would pretty much make V7 obsolete.

IMO V7 and DVDA4 will be using these HD optical delivery formats as a marketing tool to sell V7....
It makes sense to do it this way... gives people a reason to upgrade...