Comments

PeterDuke wrote on 10/10/2012, 9:10 AM
Not for me. I rendered a 28 second AVCHD clip using Vegas Pro 12 build 367 and it took 48 seconds with the default GPU enabled and 44 seconds without! (So much for GPU rendering). Using Vegas Pro 9c it took all of 5 seconds, with the happy message "No recompression required".

Since SCS removed smart rendering of AVCHD within a release (9c to 9d), who knows, they might restore it at the next update of version 12.

And pigs might fly!

Smart rendering AVCHD is the Holy Grail for me. In view of the unreliable smart rendering in Vegas Pro 9c, I took a serious look at Magix Video Pro X4, but found it to be buggy when smart rendering.

A few clips had the start scrambled with usually a green cast, but I found that passing the clip through tsMuxer seemed to fix that although the last frame was black. This was of no consequence, since I usually had to trim the end in any case. Then I found that adding a text subtitle (caption) to some clips caused a jump forward and back at the start and end of the subtitle. Magix says that the problem is in the MainConcept encoder and have referred this and other issues to them.

I then tried Cyberlink PowerDirector 11, but found that trimming the end of a clip caused a jump forward by a frame towards the end of the clip. I have yet to contact Cyberlink support about this.

I then tried Corel VideoStudio, but found that placing a subtitle on a clip could cause a jump at the start and end of the subtitle. I have yet to sort out more precisely when this happens and contact support about it.

What else is there? Premiere Pro, Premiere Elements and Edius don't smart render.
Chienworks wrote on 10/10/2012, 9:17 AM
"48 seconds with the default GPU enabled and 44 seconds without!"

Just a little comment that GPU acceleration is highly unlikely to be involved in smart rendering, since smart rendering isn't rendering at all but is merely copying bytes from the input file to the output file.

That being said, having a difference in time with it enabled is a very sure indication that smart rendering did not take place.
PeterDuke wrote on 10/10/2012, 9:20 AM
Yes, I am well aware that Vegas 12 was not smart rendering. My point in mentioning the render times was to note that the use of the default GPU processing was unhelpful in my case.
Kimberly wrote on 10/10/2012, 11:33 AM
@PeterDuke:

Using Vegas Pro 9c it took all of 5 seconds, with the happy message "No recompression required". Since SCS removed smart rendering of AVCHD within a release (9c to 9d), who knows, they might restore it at the next update of version 12.

Do you have any idea of what SCS removed to nix on the smart-rendering? Or was it one of those "pay no attention to that man behind the curtain" things?

Why ever would they remove smart rendering if it was there in 9c? I started with 10 so I always assumed it never existed for AVCHD. I love it for my old HDV footage, but now I have an AVCHD camera.

Regards,

Kimberly
videoITguy wrote on 10/10/2012, 11:42 AM
Kimberly has a good question - and I think Peter has done an excellent exploration of the NLE market to explore this issue further.

I think the answer lies somewhere in the battle of SCS to bring a bug-free version of 9.0 to market. They had a long and difficult battle with succeeding versions of that v 9.0 breaking under stress in the real world of users. I think they tried some things which evidently got close to this feature, and then had to back out when other things broke. The compromise was not to explore it any further.

I would love to see the trouble logs on this sequence of the Version 9.0 builds but as you realize it now rests as the intellectual properfy of SCS and is locked away at this time.
dlion wrote on 10/10/2012, 1:07 PM
hopefully, in 50 years, it'll become public domain.
Kimberly wrote on 10/10/2012, 1:15 PM
I was wondering from the standpoint of identifying a user workaround to get an AVCHD smartrender. Not a hack or anything nefarious, just a combination of settings, workflow, etc. that might get the job done.

Maybe SCS had to remove the smart render because it was infringing on somebody's turf? That is what happened in DVD-A Pro 5.2 with the ablity to create "BD9" and "BD5" disks.

In Build 123 or 126 or whatever you could put a BD format disk on a DVD, aka BD9 or BD5. Then in Build 135 that capability vanished. I wrote to SCS about it and heard back they removed it due to infringement issues. Not the answer I wanted to hear, but certainly a valid reason if somebody else owned the rights to that technology and said don't do this any longer.

Oh well. Maybe I will write to SCS and ask about this one : )
Marco. wrote on 10/10/2012, 1:37 PM
Vegas Pro never officially supported H.264 smartrender (I know what could be done in VP9 …). Actually there is no such a thing like H.264 smartrender. This is far from other video compression formats like MPEG-2 where this can be done quite easily. But the structure of H.264 doesn't allow this.
If a system claims to offer H.264 smartrender it either just pretends to do but does something else (like settings pointers) or it accepts the risks of causing decoding errors or it does something more complex what then is no more smartrender.
I wouldn't wait for any pro system to support such a feature.
johnmeyer wrote on 10/10/2012, 4:25 PM
There is no "workaround" for AVCHD smartrender from within Vegas. Even MPEG-2 smart render doesn't work any more (at least for most things).

You can smart render AVCHD using VideoRedo. It's pretty inexpensive and is a good tool to have for lots of situations like the one you're in. You can download a trial and see if you like it.

For MPEG-2, I prefer Womble.
MozartMan wrote on 10/10/2012, 6:39 PM
@Cornico,

VideoReDo re-renders small portions around cuts and smart-renders the rest of untouched video.
PeterDuke wrote on 10/10/2012, 7:12 PM
There are two things that I have found that seem to cause problems: simple cuts and adding text subtitles. Naturally the part where the text overlays the video has to be dumb rendered.

AVCHD has a long GOP, so the repair at a cut or added text could be a second or two of video.

VideoReDo, SmartCutter and a few others can handle simple cuts but do not allow adding subtitles. I haven't tried them extensively, so I don't know if they have any bugs. The output won't smart render in Vegas 9c.

Another thing I found was that those programs that smart rendered some AVCHD may not like AVCHD from other sources. I couldn't find a setting for Premiere Pro CS6, for instance, such that the output would be smart rendered by other software. Nor would Encore accept Vegas output without re-rendering. The Magix rendered AVCHD (smart or not) crashed Vegas (all versions I tried) and was dumb rendered by TMPGEnc Authoring Works.

Very depressing.
Hulk wrote on 10/10/2012, 7:15 PM
Thanks for the replies I guess I'll ask again with version 13 comes out.

Marco,

You say that it's impossible to smartrender AVCHD? Hmm sounds strange.

Let's see. Imagine you have a 1 minute AVCHD clip in the timeline. Half of the clip needs no post-processing, the second half you apply a filter of some sort. To make things more difficult the filter start area starts right in the middle of a GOP.

So tell my why the first half of the clip, up to the point where the GOP that at some point within it has the filter, can't be "passed through" unrendered and joined to the second half of the clip. If the GOP is 10 seconds long and only 1 second are filtered then 9 seconds would obviously have to be rerendered. No big deal. The point is it can be done. MPEG-2 and AVCHD are very similar actually if you look at the math behind both of them. Both are based on a FFT with AVCHD using some additional compression techniques and much long GOP sequences.

- Mark
NickHope wrote on 10/11/2012, 1:28 AM
Before HDV smart rendering was available in Sony Vegas, I used to export an EDL from Vegas and translate it to a trim list format for use in Womble MPEG Video Wizard, where it could be smart rendered.

I wonder if a similar workflow is somehow available with VideoReDo or another program that can smart render AVCHD. Can VideoReDo accept some sort of trim list?
Marco. wrote on 10/11/2012, 4:00 AM
That's one of the main differences to formats like MPEG-2, which doesn't use IDRs. There is only one IDR at the very beginning of a coded video sequence (not per GOP - the Apple information goes wrong there) and you cannot cut off the IDR without finding slices of frames being lost in a certain way. And if you rebuild an IDR you have to rebuild relationships of many slices to the IDR. This is a complex process and if a software does this effective it could not be called "smartrender".
There are more differences on how slices are handled which also makes smartrender doesn't work in matters what "smartrender" means.
Many apps claiming they do "smartrender" H.264 accept errors (which is not acceptable for an app like Vegas Pro). Maybe them do so because they are meant for a much more limited use.
PeterDuke wrote on 10/11/2012, 9:03 AM
I have noticed with Vegas that if you trim off the start of a clip, it takes several (many?) seconds before smart rendering happens. That would suggest that links to the IDR cease after several seconds.
PeterDuke wrote on 10/11/2012, 9:17 AM
In this reference
http://en.wikipedia.org/wiki/Network_Abstraction_Layer

it says:

"Coded Video Sequences

A coded video sequence consists of a series of access units that are sequential in the NAL unit stream and use only one sequence parameter set. Each coded video sequence can be decoded independently of any other coded video sequence, given the necessary parameter set information, which may be conveyed "in-band" or "out-of-band". At the beginning of a coded video sequence is an instantaneous decoding refresh (IDR) access unit. An IDR access unit contains an intra picture -a coded picture that can be decoded without decoding any previous pictures in the NAL unit stream, and the presence of an IDR access unit indicates that no subsequent picture in the stream will require reference to pictures prior to the intra picture it contains in order to be decoded. A NAL unit stream may contain one or more coded video sequence."

This reads to me that there can be more than one IDR. The stream may have several coded video sequences each headed by an IDR. After all, what sense would it make to have coding references back to something many minutes or even hours earlier?


Marco. wrote on 10/11/2012, 9:59 AM
There also are (more) regular I-frames beside the IDR (an IDR actually contains an I-frame but an I-frame is not equal to an IDR). Some other infos here.
PeterDuke wrote on 10/12/2012, 7:41 AM
Nick Hope asked:
"I wonder if a similar workflow is somehow available with VideoReDo or another program that can smart render AVCHD."

Well SmartCutter
http://www.fame-ring.com/
has a couple of buttons relevant to batch processing. I haven't looked into it myself so can't comment how useful it might be.
Hulk wrote on 10/12/2012, 8:52 AM
I understand the complexity of AVCHD smartrender. And I also understand it's probably very low on Sony's to-do list.

Most likely my next camera will have a high enough bitrate so that I'm not scraping every last recorded bit for picture quality and can simply render to a very high bitrate codec and then transcode to the final viewable video using Ripbot or another high quality encoder. While VP's AVCHD render quality is pretty good it's nowhere near what some of the freebies like Ripbot can do bitrate for bitrate.
PeterDuke wrote on 10/13/2012, 2:56 AM
Just as a matter of interest, I downloaded h264_parse.zip from
http://www.w6rz.net/h264_parse.zip
and had a look at one of the AVCHD clips produced by my camera. It seems to have a GOP of 26 slices, where each slice probably corresponds to a field (two slices per frame). The slice types seem to come in pairs (except for the initial I and P slices), which ties in with that theory.

The GOP is
IPBBBBPPBBPPBBPPBBPPBBPPBB
with a null slice in random position in many GOPs. (I don't know what that means.)
NickHope wrote on 10/13/2012, 10:51 AM
Thanks for these Links Peter. Smart Cutter looks like it might be a useful program for rough cutting. Possibly a better bet than VideoRedo. From their website, it doesn't look like it will accept something like an EDL or trim list but perhaps that's a feature they can add. It looks like "Add Batch" just adds the edits to a background list for processing when you're ready. I don't want to blow my free trial of it until I actually have a camera that shoots AVCHD.
Kimberly wrote on 10/13/2012, 11:00 AM
@nickhope:

I can put some AVCHD footage on dropbox.com for you. I did it a few weeks ago with my Sony CX760v (NTSC). It's random stuff walking around the duck pond, seeing how the camera works, the dynamic stablization, etc. It's definitely not ready for prime time, mostly Blair Witch goes to the Duck Pond.

I have 60i and 24p.

PS. Can't remember if I told you but I did order the Gates and am now anxiously awaiting its arrival!

Regards,

Kimberly
NickHope wrote on 10/13/2012, 12:42 PM
@Kimberley

Thanks but I think I'll wait until I have my own camera, so I'm testing the program with exactly the files it shoots. There are lots of different flavours.

Happy shooting with your Gates!
NickHope wrote on 10/24/2012, 1:11 AM
TMPGEnc are launching the snappily-titled TMPGEnc MPEG Smart Renderer 4 on October 30th. Knowing the quality of their software, it will probably work. Interesting to see if it accepts any sort of cutting-list that could be exported/converted from Vegas. Otherwise I can imagine this becoming my preferred program for rough-cutting AVCHD footage.