[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.”

[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.

[John Cline]

Determining the best encoding bitrate is a balancing act between image dimensions, image complexity, amount of motion and available storage space. A fairly static shot of a talking head with a solid background will look much better encoded at a lower bitrate than a video of a Formula 1 automobile race. Video encoding is an art and it takes experience to do it well.

In your case, Michal, your limiting factors are length of program and available space. How long is your program? If it’s relatively long then you will likely want to use 2-pass variable bitrate encoding in which the encoder will intelligently allocate fewer bits for less complex scenes and more bits to the complex scenes while hitting a set, average bitrate which will fit it all into a fixed file size.

[John Cline]

Yes, it’s absolutely possible, it is a simple matter of total combined bitrate of the audio and video multiplied by the length of the program.

If it’s a constant bitrate (CBR) codec it’s quite easy. For DV, it is 3,178,117 bytes per second multiplied by the total number of seconds in the project.

In the case of MPEG2 or h.264-based AVC or MP4, where you can set either a constant or average bitrate per second, then it’s the bitrate in bits (divided by 8 to get bytes), then multiply by seconds.

However, if it’s a variable bitrate codec where you set a constant quality, like MJPEG or Cineform, for example, then you can’t determine the final size as the bitrate will change depending on varying image complexity throughout the program.

[John Cline]

Select “Dolby Digital AC-3 Pro” and hit the “Custom” button, under the “Audio Service” tab, set dialog normalization to -31. On the “Preprocessing” tab, set both the “Line Mode Profile” and the “RF Mode Profile” to “None.”