Compress video files

In Nexus 2.16 and later, the Apply Codec to Video operation takes a video file as input, compresses it and writes the resulting frames to an output file.

You may occasionally need to use the Apply Codec to Video operation to compress video files in the following circumstances:

• If you transcoded your files using the Uncompressed option, and then need to apply a codec to the resulting large files. If you have not retained the original (VVID) video files, this pipeline operation enables you to apply the required codec to the uncompressed AVI files.
• If you want to convert from an old DirectShow codec to h.264. Note that to do this, you need the 64-bit version of the DirectShow codec and that the quality of the resulting video will be affected.

Note also that if you have h.264-encoded video:

• If you simply want to change from AVI to MP4 (or MP4 to AVI) you can use the pipeline operation to quickly change the container and transfer the video frame data without modification. For example, you may want to do this if you have existing h.264 AVI files and want to retain the original video quality and to use Nexus Insight as your reporting tool.
• If you select h.264 encoding without changing the container (that is, you choose to convert h.264 MP4 to h.264 MP4 OR h.264 AVI to h.264 AVI) then Nexus alerts you and no action is taken. If you want to force the compression (but see the note above about compressing video that has already been compressed), use the Advanced option, Force Recompress.

To use the Apply Codec to Video operation:

1. To load a digital video file, with the Camera view selected, click on the desired movie file on the Data Management tab.
2. In the Available Operations section of Pipeline Tools pane, expand the System pipeline operations list.
3. Double-click the Apply Codec to Video pipeline operation.
   The operation is added to the current pipeline and is displayed at the bottom of the list in the Current Pipeline section.
4. In the Current Pipeline section, click on Apply Codec to Video, and then in the Properties section at the bottom of the Pipeline Tools pane:
   

   1. From the drop-down File Output list, select the codec you want to use for file compression.

   2. From the h.624 Compression list, select the required option.
   3. If you want Nexus to create a backup of the original video file, ensure the Keep Backup option is selected.
   4. If you want to force compression of files that are already compressed, ensure you've read the Note above, and if still sure you want to further compress your file(s), use the Advanced option, Force Recompress.

5. Add any other pipeline operations you want to include in the pipeline.

   Tip: The pipeline operations are run in the order they appear in the Current Pipeline list; drag to rearrange the order.

6. In the Current Pipeline configuration management section, click Save to save your settings. (An asterisk (*) is displayed next to the pipeline name if there are unsaved changes.)
7. Run the pipeline.