Video Appears Upside Down When You Use an AVI File as a Source File

When you encode an Audio Video Interleave (AVI) file with the Windows Media Encoder 7, the resultant video may appear upside down. If you play the AVI file with the Media Player, the video is displayed correctly. In addition, if you encode the AVI file with the Windows Media Encoder 4.1, the video is displayed correctly.

Some capture cards and animation programs create AVI files that do not fully conform to published specifications. This problem often occurs with the YUY2 pixel format, but can also occur with other formats. When the pixels are malformatted, they are read out in the wrong order; this results in an upside down video. Most programs (such as Windows Media Encoder 4.1 and Windows Media Player) rely on the capture card drivers to decode the pixel format, so the video comes out right side up when it is fed to the encoder engine. Because Windows Media Encoder 7 uses its own decoder software that conforms to the specifications, the video appears upside down.

To work around this problem, you can create a file with a different pixel format. In the setup dialog box of the capture driver, select a different pixel format, such as RGB or YUV9. The following formats are recommended, in order of preference:

• IYUV (or I420) (12 bits per pixel)
• YV12 (12 bits per pixel)
• RGB 24 (24 bits per pixel)
• RGB 32 (32 bits per pixel)
• RGB 16 (16 bits per pixel)
• YVU9 (9 bits per pixel)
• RGB 8 (8 bits per pixel)

NOTE: The YUV formats listed above are planar YUV formats; this problem only seems to happen with the packed YUV formats, such as YUY2, UYVY, and YVYU.

If you are "live" encoding directly from a capture card, by default the encoder sets the card to a pixel format that does not exhibit this problem.

The newest capture card drivers may include a YUY2 Flip check box in the Driver dialog box so that you can create a file with the YUY2 pixel format that does not exhibit this problem. However, when you view this file in the Windows Media Player and Windows Media Encoder 4.1, the AVI source file now appears upside down, because Windows Media Player and Windows Media Encoder 4.1 still use the old drivers for playback.

If you don't have access to the original source material and cannot recapture it to a different pixel format, you can try to read the AVI file into a third-party video editor and export the video to another AVI file with a different pixel format, such as YUV9 or RGB.