ASF to AVI: Convert Video from ASF(Advanced Streaming Format) to AVI(Audio Video Interleaved) with River Past Video Cleaner, ASF2AVI converter, conversion

What is ASF?

Advanced Systems Format (formerly Advanced Streaming Format, Active Streaming Format) is Microsoft's proprietary digital audio/digital video container format, especially meant for streaming media. ASF is part of the Windows Media framework.

The format does not specify how (i.e. with which codec) the video or audio should be encoded; it just specifies the structure of the video/audio stream. This is similar to the function performed by the QuickTime, AVI, or Ogg container formats. One of the objectives of ASF was to support playback from digital media servers, HTTP servers, and local storage devices such as hard disk drives.

What is AVI?

Defined by Microsoft, AVI stands for Audio Video Interleave. It is a special case of the RIFF (Resource Interchange File Format). AVI is the most common format for audio/video data on the PC.

AVI is Microsoft's response to Apple's QuickTime technology. Early AVI files were limited on choice of video and audio codecs, quality, and resolution. However, with the introduction of DirectShow, AVI became a very flexible and powerful architecture. Some newer codecs including DivX and XviD enable AVI files to have similar or even better quality than DVD.

Launch River Past Video Cleaner

Once River Past Video Cleaner is installed properly, launch Video Cleaner.

Add File

Click on the "Add File" button on the tool bar. The standard file open dialog appears. Select "ASF - Advanced Streaming Format" in its "Files of type" combo box.

Select the file you want to convert and click "Open". The file will be added to the conversion file list.

River Past Video Cleaner

Select output format

Use the setting panel on the bottom of the window to control the output format. Click on the toggle to the left of the "Output Format" label to expand the panel. Select "AVI - Audio Video Interleave" as the "File Type".

Change Video Settings

Click on the toggle to the left of the "Video Settings" label to expand the panel.

Select "Specify" under "Size" and/or "Frame rate" to enter the video resolution and/or frame rate.

You can change the compressor, quality, size, and frame rate of the video.

The size of the AVI file depend a lot on the chosen video compressor. Microsoft ships some standard codecs with Windows, including MJPEG, Microsoft Video 1 and Cinepak. Those are old codecs and are not very efficient. It is not uncommon that your AVI files will be 10x to 50x bigger than your original files if you are converting from DIVX, MOV, MPEG, WMV or anything encoded with a MPEG based codec.

You can use additional codecs from Microsoft or third party codecs to reduce the file size. DivX and Xvid are two excellent third party codecs, which produces video with excellent quality with smaller file size. Both of them are based on MPEG-4, and both can be used with AVI file format.

However, if you use any non-standard codecs for the AVI file, please keep in mind that the viewer of the video must have the codecs installed on their PC too, and your file may not be compatible with all video editing software.

The file size also depend on the "Quality" setting. Move the slider to the left for smaller file size, at the expense of video quality.

Change Audio Settings

Click on the toggle to the left of the "Audio Settings" label to expand the panel.

Select the audio compressor for the conversion. Depending on the compressor, you may also change the sample rate, channel (stereo or mono), resolution, and bitrate.

Do not use "MPEG Layer-3" as the audio compressor. It does not work correctly in video files and often causes the conversion to abort in the middle. If you prefer to have MP3 audio in the AVI file, download lame_enc.dll instead.