Rendering: how to know final file size beforehand?

[John Cline]

3 GB is 3,221,225,472 bytes. For 100 minutes using 192kbps audio encoding with a 5% file size safety margin, then you would use 2-pass VBR with the following parameters:

Minimum = 2,328,000
Average = 3,888,000
Maximum = 6,800,000

If you mean you want exactly 3,000,000,000 bytes instead of 3 GB (again with a 5% safety margin), then use the following:

Minimum = 2,160,000
Average = 3,608,000
Maximum = 6,312,000

Vegas uses exact bits when entering the encoding bitrate, other encoders used KB which is 1024 bits per KB instead. The numbers would be slightly lower in this case.

Since it’s mostly talking heads, it should end up looking pretty good. If it had a lot of motion in it, trying to squeeze 100 minutes of HD into 3GB might end up look a little ragged. Regardless, you definitely want to use 2-pass VBR, the render will take longer but will absolutely be worth it.

[Michal Bronec]

Thanks John!

[Michal Bronec]

BTW, its possible to set 2-pass VBR in Sony AVC rendering options? I dont see it there. I also see only field bit rate (no minimum, average or maximum bit rate).

I see this options in MainConcept AVC, but I cant render with MainConcept in Sony Vegas 11 (it gives me an error). I dont know why. In previous versions it worked.

[David Shirey]

Are you using the latest Vegas 11 build? They did recently add some new templates to the MainConcept h264 codec, worth checking out. I don’t recall Sony’s AVC having a variable 2-pass option at all.

[John Cline]

Michal,

Sony’s AVC encoder doesn’t have a 2-pass option and I in my experience, it doesn’t look as good as the Main Concept AVC encoder.

Regarding the Main Concept rendering error in Vegas v11, in the custom settings, try setting the encode mode to “Render using CPU only.”

[Michal Bronec]

Thanks. It works ok with “Render using CPU only” mode.

[Rodney Guthman]

Although the MainConcept h264 codec is fine on its own, I always prefer to do my encoding and muxing (adding the audio to the video) out of my editing program (Premiere in my case). At least in the cases when I need h264 (Youtube, PS3, BluRay, iPhone, DXVA-compatible etc etc) or XviD.

I export raw video (YUV or YV12) and audio (wave) out of my editor. I then encode my video (depending on the needed format ofcourse) with MeGUI, a x264 GUI.

You can use “easy” presets or you can dig into the valleys of encoding complexity and adjust all settings you want. Talking heads require different settings (for example macroblock size) than high action footage or cartoon videos.

I then set a format for my audio (usually AAC) and queue my video and audio in the rendering queue. After rendering I have 1 audio file and 1 video file (although things like multitrack audio are possible too). After both have finished I mux them together and I end with a video file in an mkv or mp4 container or raw avc format.