H.264 VBR encoding in Vegas?

[David L. Jones]

Hi
I'm looking for a way to render my projects in H.264 using a VBR (Variable Bit Rate, e.g.Constant Quality) codec, using Vegas Studio HD Platinum 11.0

Current my workflow is:
1) Shoot and edit in AVCHD 1440x1080 25P @ 12Mbps CBR from my Canon HF G10
2) Render in the same 1440x1080 25P @ 12Mbps CBR (constant bit rate) to a H.264 MP4 file.
3) Use Handbrake to convert the step #2 CBR file into the same 1440x1080 25P H.264 file, but using VBR to reduce the file size. (upload destination is Youtube)
4) Same as step #3 but produce a 480x270 H.264 iTunes compatible MP4 file, also using VBR.

Is there a way to get Vegas to use VBR instead of CBR, eliminating step 3 in my workflow?

Maybe some plugin H.264 encoder?
Or is there a VBR option in Vegas I have missed?

Thanks
Dave.

[Tom Roper]

If platinum includes the Sony AVC encoder, it is already a vbr, just doesn't give you any settable options except for the average bit rate.

[David L. Jones]

Originally Posted by Tom Roper

If platinum includes the Sony AVC encoder, it is already a vbr, just doesn't give you any settable options except for the average bit rate.

Yes, I'm using the inbuilt Sony AVC encoder and it only allows me to chose the bitrate, it doesn't mention VBR or CBR, I assumed CBR.
A quick check with my lastest video shows 3.1GB file size for a calculated 3.6GB video if it was CBR (40:29 @ 12Mbit/sec).
So if it is VBR then it seems to be very poor quality (in term of compression) compared to Handbrake which gives me a 770MB file using default constant quality (i.e. VBR). And there is no perceptible differences in quality between the two.
My videos are mostly talking head blogs, so very little in terms of motion content in the video. hence my desire for good quality VBR to reduce the file size for uploading to Youtube.

Thanks
Dave.

[Tom Roper]

David,

I agree with everything you said. Handbrake renderings are markedly superior especially at low bit rates, it's x.264 open source encoder is better than the Sony AVC, no question about that.

Instead of using the Sony AVC as intermediate step, you should download and install the free Avid DNxHD codec along with Apple Quicktime 7. Render your intermediate file to DNxHD 8-bit from within Vegas, (choose the quicktime 7 and select avid DNxHd).

Handbrake will accept this for input, you render the output with it as usual. It's not faster, but as long as you are going to use Handbrake you might as well get all the quality it's capable of, which you don't if your intermediate file is Sony AVC.

To get good quality h.264 output from Vegas, the bit rate has to be higher by a good margin than Handbrake.

I encode for the web with Handbrake using Avid DNxHD as the intermediate, but I also encode 1080/60p for the Sony Playstation 3 and other Blu-ray players, which have trouble with Handbrake sourced mp4's. The best for me has been to encode with Sony AVC at 18 mbps, with binary arithmetic (CABAC) off, instead use variable run length encoding (CAVLC) on.

The Sony AVC at 18 mbps 1080/60p will playback at variable bit rates from about 6 - 30 mbps.

[David L. Jones]

Awesome, will give that a go, thanks Tom

Would be great if there was some really high quality Handbrake-like encoder you could use within Vegas though.

Regards
Dave.