virtualdub question

[drummerduck]

What is the difference between video direct stream copying and audio direct stream copying and video and audio full processing mode?

Also where do i goto to strip the audio with vitrualdub WITHOUT changing the audio format. The audio is AC3 which is what i want it to stay as, not WAV.

Many thanks......

D

[Baldrick]

from the virtualdub help
Video processing modes

VirtualDub has four video processing modes. They are, as follows:

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.

2.Fast repack
Fast repack mode allows a video stream to be recompressed. In this mode, VirtualDub hooks decompressor directly to compressor and tries to find the fastest way from one video format to another.

Advantages:

·Depending on the video codecs involved, recompression might take place in a faster format, such as YUV. This can significantly speed recompression.

Disadvantages:

·May not work if the codecs cannot agree on a common image format.

·Video cannot be viewed during process.

·No image processing possible.

·Some video codecs handle YUV data incorrectly, which can result in upside-down video in this mode.

3.Slow repack
VirtualDub decompresses the input video to RGB and compresses it using the selected video compressor.

Advantages:

·Allows a video stream to be recompressed from any video format to any other, provided compressors and decompressors are available.

·Compatible with more video codecs, because RGB is a very ‘safe’ format.

Disadvantages:

·Often slower than fast repack mode.

·Compressors and decompressors must be compatible; if the decompressor only decompresses to 16-bit RGB, and the compressor only accepts 24-bit RGB, this mode won’t work.

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.

[Baldrick]

Audio->direct stream copy
File->save wav (save as .ac3)

Use beslice(included in besplit) or ac3fix to fix the ac3 (virtualdub adds wav headers).