AVISource / OpenDMLSource / AVIFileSource / WAVSource

AVISource (string filename [, ...], bool "audio" = true, string "pixel_type" = YV12, [string fourCC])
OpenDMLSource (string filename [, ...], bool "audio" = true, string "pixel_type" = YV12, [string fourCC])
AVIFileSource (string filename [, ...], bool "audio" = true, string "pixel_type" = YV12, [string fourCC])
WAVSource (string filename [, ...])

AVISource takes as argument one or more file name in quotes, and reads in the file(s) using either the Video-for-Windows "AVIFile" interface, or AviSynth's built-in OpenDML code (taken from VirtualDub). This filter can read any file for which there's an AVIFile handler. This includes not only AVI files but also WAV files, AVS (AviSynth script) files, and VDR (VirtualDub frameserver) files. If you give multiples filenames as arguments, the clips will be spliced together with UnalignedSplice. The bool argument is optional and defaults to true.

The AVISource filter examines the file to determine its type and passes it to either the AVIFile handler or the OpenDML handler as appropriate. In case you have trouble with one or the other handler, you can also use the OpenDMLSource and AVIFileSource filters, which force the use of one or the other handler. Either handler can read ordinary (< 2GB) AVI files, but only the OpenDML handler can read larger AVI files, and only the AVIFile handler can read other file types like WAV, VDR and AVS.

Up to v2.04, WAVSource was an alias to AVIFileSource. In later versions, WAVSource doesn't try to open the video stream anymore. It can be useful if you want to retrieve the audio stream from an AVI file but the video stream is damaged or its compression method is not supported on your system.

From v2.04 up there is built-in support for ACM (Audio Compression Manager) audio (e.g. mp3-AVIs). AVISource is also no longer able to open WAV-files, which must be accessed by using WAVSource.

From v2.06 the pixel_type parameter (default YUY2) allows you to choose the output format of the decompressor. Valid values are "YUY2", "RGB32" and "RGB24". If omitted, AviSynth will use the first format supported by the decompressor (in the following order: YUY2, RGB32, RGB24). This parameter has no effect if the video is in an uncompressed format (YUY2, RGB32 or RGB24), because no decompressor will be used in that case. From v2.5 the default pixel_type parameter is changed to YV12. To put it in different words: if you don't specify something it will try to output the AVI as YV12, if that isn't possible it tries YUY2 and if that isn't possible it tries RGB.

Sometimes the colors will be distorted when loading a DivX clip in AviSynth v2.5 (the chroma channels U and V are swapped), due to a bug in DivX (5.02 and older). You can use SwapUV to correct it.

From v2.53 AVISource can also open DV type 1 video input (only video, not audio).

From v2.55, an option fourCC is added. FourCC, is a FOUR Character Code in the beginning of media file, mostly associated with avi, that tells what codec your system should use for decoding the file. You can use this to force AviSource to open the avi file using a different codec. A list of FOURCCs can be found here. By default, the fourCC of the avi is used.

Some MJPEG/DV codecs do not give correct CCIR 601 compliant output when using AVISource. The problem could arise if the input and output colorformat of the codec are different. For example if the input colorformat is YUY2, while the output colorformat is RGB, or vice versa. There are two ways to resolve it:

1) Force the same output as the input colorformat. Thus for example (if the input is RGB):

AVISource("file.avi", pixel_type="RGB32")

2) Correct it with the filter ColorYUV:


Some reference threads:
MJPEG codecs
DV codecs


# C programmers note: backslashes are not doubled; forward slashes work too

# the following is the same as AVISource("cap1.avi") + AVISource("cap2.avi"):
AVISource("cap1.avi", "cap2.avi")

# disables audio and request RGB32 decompression
AVISource("cap.avi", false, "RGB32")

# opens a DV using the Canopus DV Codec
AviSource("cap.avi", false, fourCC="CDVC")

# opens an avi (for example DivX3) using the XviD Codec
AviSource("cap.avi", false, fourCC="XVID")

# splicing two clips where one of them contains no audio.
# when splicing the clips must be compatible (have the same video and audio properties):
A = AviSource("FileA.avi")
B = AviSource("FileB.avi") # No audio stream
A ++ AudioDub(B, BlankClip(A))

Some compression formats impose a limit to the number of AviSource() calls that can be placed in a script. Some people have experienced this limit with fewer than 50 AviSource() statements. See discussion.


v2.55 Added fourCC option.

$Date: 2008/07/11 18:20:45 $