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Lastly Part 5
FlaskMpeg note: If you used FlaskMpeg to frameserve you should also compress the audio. Do that by selecting Audio - AVI audio, then Audio - Compression which allows you to configure the audio codec.
The last step before encoding is setting up the internal VirtualDub Scene Change Detection (for VKI): Press Options - Preferences and select the Scene tab:
You can play around with these settings if you like but the default ones work fine in most cases (and after all we've set up Nandub to insert a keyframe if the internal detection fails).
Use stronger Interframe cut for very dark movies.
Or you can use Nandub's alternative setting which works even better imho. This is the alternative I mentioned in the DivX setup settings. This SCD is actually based on luma levels rather than motion. It works as follows: if curr_diff > last_diff the frame becomes a keyframe. curr_diff = absolute difference between the current and the last frame in terms of pixels in the luma space. last_diff is then set to last_diff = curr_dif * multiplier / 10, and if last_diff is below 10'000 after this it's set to 10'000.
Last but not least go to the SBC tab:
Here you can set the crosspoint which is used for the Calc... button mentioned before. If you think the calculated value for the compression is too high just lower the crosspoint.
The crosspoint value is used in the calculation (calc-button) at the curve-compression. Until now there is no final rule how this should be set, but using a crosspoint of 230-280 for 1 CD rips and 350-460 for 2 CD rips is been tested to work well. If you think the
See the Nandub documentation (readme.doc) for how the crosspoint works.
Press Save and Nandub will save your settings for good.
Once you've set it all up it's time to start the 2nd pass by pressing F7. Don't forget to verify that are your filters are still properly configured before you start! Hope you didn't get too confused with all these settings.
Even though preview is nice I'd suggest you disable Show input video and Show output video. The height of the bars you see represent the size of each frame. Blue bars are low-motion frames, green frames high motion frames (using the default - and suggested - setup you don't get any of these). Red bars are keyframes inserted by the internal SCD (which you can disable by setting it to 100%), yellow bars keyframes inserted by the alternative SCD. The white curve is the stats curve (targeted average bitrate) and the cyan curve is the motion curve. As you can see below the graph the current bitrate of the video is also being displayed. When you see the white curve go flat that means that the min bitrate limit has kicked in to limit the bitrate from dropping further.
Also, disable the previews since the preview lags behind the stats curves and you might get confused.
If you prefer to work besides encoding you can lower the processing thread priority. Setting this to idle and Nandub will only use whatever CPU time is left after all the other apps have had their share.
Last but not least Nandub has a safety feature. If you close the application all your current settings are saved in the __last__.vcd profile in the Nandub directory. This might come in handy if you accidentally close down Nandub or if you forgot to save your profile.
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Read all that?
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