Rendering 1080/60p in V.11.0 (64 bit)
 

Rendering 1080/60p in V.11.0 (64 bit)

Build 425 broke MPEG-2 1080/60p rendering with the Main Concept Plug-in. The following observations are directed at the Build 371 which I rolled back to.

The obvious alternative to MPEG-2 rendering is to use h.264. In Vegas Pro 11.0, this comes in two plug-ins, the Main Concept AVC and the Sony AVC. The former does not support 1080/60p encoding, so we turn our attention to the Sony AVC encoder. The first thing to note, is Vegas does not support AVCHD 2.0. You have a choice of outputs that include mp4 and AVC. Mp4 should have audio but I could not get it to work in 1080/60p mode either in stereo or 5.1 multichannel. AVC has a choice to render separate audio and video elementary streams. I chose to render an AVC video stream and an AC3 Pro 5.1 DD multichannel stream. I merged the two streams with TsMuxer 1.10.6. The resultant ts file can play well in Windows Media Player and on the PS3 except as noted below.

The Sony AVC video encoder uses OpenCL/CUDA GPU processing as long as the bit rate is less than 26 mbps. A problem appeared at all encoded bit rates greater than 16 mbps however. At the 20 mbps setting, the playback rate jumped up to 46.1 mbps early in the file, then suddenly dropped to under 15 mbps, sometimes going as low as 8 mbps. While no cause for alarm in itself, it was also accompanied by an unfortunate behavior of dropping frames and adding stuttery, non-smooth playback. It appeared like the playback frame rate had dropped to 30p, and this could happen at either high or low bit rates. Audio was not affected, and remained in sync, but the video would get jerky. This behavior did not appear connected in itself as a consequence of the high encoding rate, or the slow playback rate. It just appears like an encoding problem of some kind that causes dropped frames even at low playback rates, on either the WMP or the PS3, same behavior.

Reducing the encoder bit rate to 16 mbps causes the problem to go away in its entirety. Smooth buttery1080/60p progressive playback seems robust and stable, but unfortunately is of a lower quality than MPEG-2 encoded at a 35 mbps CBR using build 371, and which was easily injested by the WMP and PS3.

My conclusion is that build 371 does an excellent job using the legacy MPEG-2 plug-in, and that Build 425 while unfortunately breaking the MPEG-2 encoder still does a borderline reasonable job at 16 mbps using the Sony AVC encoded video file, but not as good as the MPEG-2 in build 371.

My opinion is that while V11.0 (64 bit) and a supported OpenCL/CUDA GPU appears very stable and robust with video editing and previewing operations, the rendering output plug-ins are rife with bugs and flaws if your output deviates from the run of mill 1080/60i/24p, 720/60p/30p (for NTSC areas). These flaws will mostly become apparent through your journey of discovery.

Re: Rendering 1080/60p in V.11.0 (64 bit)
 

Hi Tom

I am in a somewhat similar situation to you, except that in PAL land I am producing 1920x1080 50P video. This runs on my PS3.

I do use the Sony AVC option - I found a way to get a template that works. Just pick one of the Blu-ray templates; in the Video tab you can select frame rate, size, bitrate etc; Go to System tab - there you can change the file output from avc to mp4. Now back to the Audio tab - you should be able to Include Audio.

I use 26 Mbps; a minor quirk since build 425 is that it seemed to fall over instantly. On dropping the bitrate to 25600000 (OK, a bit less than 26) it performs flawlessly. Because I don't know any better, I wonder if 26 is the ceiling and it needs some room for the audio.

Anyhow, the mp4 files I get are stunning. Might be worth giving it a go. Just for the hell of in, I am transcoding a short clip (1080@50P) to 1080@60P. Taking a while, as expected, but seems to be working, and hasn't fallen over.

Note - the finished product works just as well. Bitrate for a fairly uniform & static shot fluctuates between 18 & 21 MBps.

Good luck

Ron

Re: Rendering 1080/60p in V.11.0 (64 bit)
 

Rendering 1080p50/60 works well using MainConcept AVC. I'd even prefere this over Sony AVC because of the higher bitrates available.

Re: Rendering 1080/60p in V.11.0 (64 bit)
 

Hi

I agree. What is often overlooked is the GPU enabled codecs are different encoders to the CPU versions as the code is different and even the quality can vary between the two.

Using x264 is slow but the quality is excellent (better than Sony or MainConcept offerings) and no issues with bit-rates and crashing and 1080/60p is supported just fine.

My workflow is to export the finished video as Lagarith uncompressed video and audio as AC3, then using x264 encode to H264 and mux the the audio in.

Regards

Phil

Re: Rendering 1080/60p in V.11.0 (64 bit)
 

Hmm, something I'm not seeing here..

I can't find or manipulate any MainConcept template to give a frame rate of 50. Mind telling me how and where? Thanks.

Re: Rendering 1080/60p in V.11.0 (64 bit)
 

You tried in the AVC encoder, not in the MPEG-2 encoder?

Then for example start with the preset "Internet HD 1080p" and in the "Video" tab at "frame rate" type in "50" (don't use the dropdown menu). That's it.

With MainConcept AVC you c o u l d use frame rates up to 172 fps (which is amazing but pretty useless).

Re: Rendering 1080/60p in V.11.0 (64 bit)
 

Ha - how simple! Thanks - I didn't realize you could type values in as well!!

A whole new world.... :)

Re: Rendering 1080/60p in V.11.0 (64 bit)
 

I did try this exactly, several times. It renders to the end, but no audio. The box for include audio is checked, mp4 selected. Also tried pal 50p, same result. I'm not sure why, something unique to my setup I guess.

Re: Rendering 1080/60p in V.11.0 (64 bit)
 

Good points. Superior work flow if you have the time, top quality result I'm sure.

Re: Rendering 1080/60p in V.11.0 (64 bit)
 

I'll give this a whirl next.

Re: Rendering 1080/60p in V.11.0 (64 bit)
 

Just an update on the Build 511...

No change to report, 1080/60p render to Main Concept mpeg2 was broken in the last build, and remains broken in build 511.

This is not truly surprising, h.264 is the codec better targeted for 1080/60p full progressive renders...except that the Sony AVC codec remains manifestly sub-par. I'll elaborate.

There are so few settable parameters, basically now just frame size, frame rate and average bit rate. For 1080/60p this is not enough. For build 511, it's improved in that they have added support for the AVCHD 2.0 specification. So what does that mean exactly? It just means that now you can render 1080/60p with 5.1 audio. You could do that before, but it required rendering your video and audio streams separately, and muxing (combining) them together using TSmuxeR. For anyone who has done that, it's a trivial step, but no doubt a hinderance for a newbie. So that's an improvement. Unfortunately, that's it. And Sony took the additional step of withdrawing one of the two entropy coding modes, CAVLC. Why is that important?

To understand, there were two, CAVLC and CABAC. CAVLC is variable length coding, and CABAC is binary arithmetic coding. The latter is usually preferred as it gives the same or better quality in a smaller file size, but has one drawback, it is very demanding on the playback decoder, (your blu-ray player, PS3 etc.) When are you likely to notice this problem?

You would most likely notice dropped frames or stuttering playback at lower bit rates using CABAC than CAVLC, but since it usually gives better quality at lower bit rates, why would this be a problem?

To understand with h.264, there is no CBR (constant bitrate recording) as there is in mpeg2. Everything done with h.264 is inherently variable bit rate, and the Sony AVC doesn't give you enough controls to prevent some 1080/60p recordings from blowing out the bit rate in high motion scenes, or bit starving them in low motion scenes. If you were experiencing that problem in Sony AVC, you had 2 options before, use CAVLC or go to the Main Concept mpeg2 encoder which although was much less efficient, still gave good (better actually) quality by throwing enough bits at the problem, such as using 35 mbps CBR mode. Mpeg2 was also decoder friendly, it took a lot to choke the player. Well, both of those options are now gone, and all we're left with for higher quality 1080/60p encodes is Sony AVC with CABAC.

Now let's say you are using 1 second crossfades as scene transitions. The Sony AVC encoder sees that as motion, and spends a lot of bits trying to predict which direction the motion is vectoring to, not understanding that the fade is random in all directions. So the bit rate shoots way up, choking the player. Your only compensation at this point, is to drop the average bit rate. At the lower bit rate you've now been forced into, the encoder still wants to play the part of Robin Hood, and solve the motion riddle caused by the crossfade transition, by robbing bits from static parts of other scenes and giving them to the motion intensive scenes. What you can end up with, is bit starved images a good example of which is banding in the blue skies.

Again, these are problems presented by the rigorous demands of 1080/60p processing, still in infancy for most. You probably would never be aware of bit starvation or overloads with 1080/24p or 1080/60i. In this sense, 1080/60p is a game changer with new rules, yet the cameras are starting to proliferate.

The best h.264 encoder is the open source x264 project. While there are a good deal of GUIs and APIs to simplify the user's task of a command line program, the important thing is that fundamentally there exists a plethora of encoding options to manage the bit rate and put the bits to work where you need them, that are not available in the Sony AVC encoder, and they are needed!

As Sony continues to simplify settings, eliminate options and reduce the complexity to one size fits all templates, no doubt pleasing a body of users with convenience like AVCHD 2.0 compliance, they would be losing a pro based core of users , and the product is afterall called, Sony Vegas "Pro."

Re: Rendering 1080/60p in V.11.0 (64 bit)
 

Tom, in the end, where does your 1080 60p video end up, on Bluray? Won't a TV end up converting 1080 60p to 1080 30p, or 1080 60i anyway? I'm asking, because I don't know, and from what I could find after a cursory search that in the U.S., 1080 60p isn't playable as-is anyway, is it? Or am I mistaken?

Re: Rendering 1080/60p in V.11.0 (64 bit)
 

Hi Jeff,

With 1080/60p, you just have to look at your own pictures and decide if it's worth it. It's way more work to grade and render. Done right it's alluring. For pro work, it takes too much time, by comparison xdcam is as easy as it gets. On the other hand, it down converts into anything...blu-ray to youtube to dvd to slow motion, anything to perfection but the cost is just time, how much can you spare?

The lack of a native broadcast format is what it is, same for blu-ray, but nothing about it gets in the way of a superb quality conversion.

I could add a footnote that with Vegas, it is very fast and easy, what with 64 bit and cuda and gpu processing, but compared to x264 and its multitudes of control, it's limiting and lower quality than the Main Concept mpeg2 1080/60p encoder they seem to have abandoned.

Re: Rendering 1080/60p in V.11.0 (64 bit)
 

Hi

See my post here for an alternative:

http://www.dvinfo.net/forum/what-hap...4-encoder.html

Regards

Phil