|
|
Using Windows Media Encoder, you can crop the edges of your input video image. For example, noise often occurs at the edges of an image, so you can crop one or more edges to eliminate the affected rows. You can specify how much to crop from each side of an image, or you can use default values for cropping. After cropping, you can resize the height and width of the output video. By default, the output video image is stretched to match the frame size specified in the profile. However, you can resize the video so that the output image matches the dimensions of the cropped image. Or, you can have the video resize automatically to make use of the bandwidth specified in the profile. You can also specify custom resize dimensions.
If you are encoding MBR video, you can resize the output frame size for each bit rate separately. This means that an MBR file or stream can contain video images of varying sizes.
If you have multiple sources in a session, the output dimensions of the first source determine those of the subsequent sources. Therefore, it is only possible to resize the first source in a multisource session.
When you source from a file, the encoder can detect the size of the source video before encoding begins; when you source from devices or screen captures, the input size cannot be detected before encoding. For this reason, when sourcing from devices or screen captures, you should specify the input size when you crop and resize video. When you do so, the encoder will detect the actual input size when encoding begins. If the actual input size is different than the size you specified, the percentage of cropping you specified (rather than the actual pixel values) will be applied to the actual input size.
For example, assume you indicated that the input size was 100 x 200 pixels, and specified the following crop values:
If the encoder detected that the actual input size is 200 x 400, the actual crop values would match the percentage of cropping, as follows:
If your capture card supports hardware cropping, it is recommended that you use the hardware to crop the video. Refer to the documentation for your capture card for information about hardware cropping.
If your capture card does not support hardware cropping, or if you are sourcing from a file, the cropped video will not be displayed in the Input area on the Video panel until you start encoding.
For best results, do not resize your output video. Resizing can result in suboptimal output. However, if you are encoding to a file by using the Windows Media Video 9 codec, and the time required to encode is not important, you can improve the quality of resized content by adjusting the encoder performance setting for the Encode to file option to better quality. Note that the encoding time increases significantly if you use this method.
Caution