Audio Conversion Question

[SHEIMWOLF]

Okay, I am trying to convert a DIVX file to an MPEG1 file using TMPGEnc and VirtualDub. Everything has been smooth sailing but I was wondering about the audio conversion I used and was wondering if there is a major difference between "Direct Stream Copy" and "Full Processing Mode"? I used Direct Stream Copy on 3 files thus far, should I change them to full processing mode? I would like to keep the end file under 700 MB. Any help will be appreciated.

Don

[Vejita-sama]

Hmm? If you already have the DivX file what are you using VDub for? I would just load the DivX file in TMPGenc and encode from there.

As far as size goes, remember that for a standard vcd 1min=10MB. The size of the source file does not matter. Use a bitrate calculator (look under Tools on the left) to determine the exact bitrate for the number of CDRs you want to use.

[SHEIMWOLF]

Well, I guess my question is now altered. I have encoded 3 files using the VDub for the audio and TMPGEnc to combine the audio and the video, should I change it to just TMPGEnc, will there be a difference? Reason I ask is because I don't want to waste another 2 hours to find out it does the same thing. And can someone tell me diff. between "Direct Stream Copy" and "Full Processing Mode" on VDub? What do both of these encode the audio to?

Thanks
Don

[Graham Meredith]

Yes. Direct stream copy just passes on the video info without processing it, eg adding filters, codecs, etc. You would use this mode if you just wanted to trim your clip eg. remove commercials, trim beginning and end, etc, and then either frameserve to TMPEGEnc or something, or render it to a new uncompressed AVI. This mode is very fast.

Here is Virtual Dub's help comment:

"1. Direct stream copy

In this mode, video data is copied directly from input to output without any processing.

Advantages:

· Fastest mode; as fast as 400fps with many input files.

· No quality loss.

Disadvantages:

· Processing must begin on a keyframe.
· All frames in the range must be copied (no decimation).
· The video cannot be seen."



Full processing mode is used when alteration (other than trimming) is to be done, such as fades, filters, cropping, compressing to a codec such as DiVX, compressing the audio to a particular codec, etc. You would only use this when you need to do things in VirtualDub that you can't do in TMPEGEnc. This mode is slow, depending on your computer processor. Most people just want to record a movie off the TV and cut out the commercials. If this is what you are doing, you don't need to use this mode.

Here is Virtual Dubs comment:

"4. Full processing (default)

The full video processing pipeline is enabled. This involves a full conversion to 32-bit RGB and back, and the video runs through the current set of video filters.

Advantages:

· All filtering options are functional.
· Any decompressor-compressor pair can be used as long as the decompressor outputs some form of RGB and the compressor accepts 16- or 24-bit RGB.

Disadvantages:

· The slowest mode.
· Requires the most memory, since all images must be decompressed to 32-bit RGB, and then converted back to a form suitable for the compressor."




Graham