AVCHD Smart-render

Sebaz wrote on 5/15/2009, 6:54 PM
There's another thread talking about this but it became too long and it takes a while to read, so I thought I might put a couple of tips and opinions from my short experience with this.

It's a great addition to v9 that we now have a smart-render for AVCHD almost as good as for HDV, but it's not quite there yet. A good smart-render is when the program only recompresses a few frames around cuts and where filters have been applied. However, while on some test projects I've seen the render run like hell and give me a final file in about 1/3 of the real time of the timeline, then I've seen one that for no good reason it started rendering in the middle of a long take. But other tests I did came out pretty good. Either way it's a great step in the right direction, hopefully in future updates they will make it better.

I do find it absurd though, given that DVDA Pro comes from the same company, that they will setup the smart-render module with an audio encoder that when imported into DVDA it will force a re-render. Also the default is not the same bitrate as the source file (AVCHD is 256 kbps, at least for stereo, I don't know about the Sony 5.1 camcorders) but instead at 192 kbps. It's just a matter of modifying the template and set it to 256, but I don't know if it smart-renders the audio track as well. But even if it smart-renders the audio, then what's the point when DVDA will force it to recompress? So to me the best solution is to do a smart-render using the module with the = sign, and then also do a separate render to a PCM audio file, so in DVDA you can use the video track from the smart-rendered file, and then the PCM track, both of which will not cause to force recompress. That will allow less footage time in a BD5 or 9, but at least you will keep the original audio, since it's converted from AC3 to PCM, but not recompressed to AC3.

Of course, if you do a lot of color correction or apply any other filters, then using the smart-render template is not a great idea, because 1920x1080 at 16 mbps will compress too much. The best in that case , if you need to make a BD5 or BD9, is to render to a lossless format, then import it into DVDA and set to it recompress to AVC at 20 mbps. It will take forever, but it will look the best possible for a BD5 or BD9. Of course if you can burn to real BD-R then you can just render the Vegas timeline to MPEG2 at 40 Mbps and the quality will be great, but you could never use that for a BD5 or BD9 because the bitrate would be too high, and you would get a very short time even you could play it.

Comments

srode wrote on 5/15/2009, 8:07 PM
I was thinking the same thing on the lossless format - was thinking of using another bluray creation software as I am not impressed with the quality of the AVC or MPEG results from Vegas or DVDA . As a test, tried a render to AVI with 1920x1080 of a 13 minute video progressive scan - it looked like it was going to be a bit big while it was working - final product was 370GB! Of course interlaced would be smaller - but to fill a bluray with say 23GB of finished menu'd videos it will take lots of storage space - probably 2 TB?

See my last post in the 'other thread' for results of some of my testing with the 'smart render' - I agree it's a great step forward - just could be better if it kicked in quicker after getting to the end of an effect or transition.
PLS wrote on 5/16/2009, 12:12 AM
Doesn't work for PAL AVCHD from my SONY HDR-CX6. If I render to a .m2ts and bring this back into Pro 9 it will smart render... if I render an .m2ts from the camcorder it will not... it flashes No Recompression for a second and then renders.

I was hoping to use this as the free Cineform codec is not installed with Pro 9 and copying the CFHD.dll from Pro 8 does not work.

So Pro 9 stuffs my current AVCHD workflow...