The capture window has options to change the encoding method that is used while capturing the movie. The encoding method is referred to as a codec. Codec stands for compression / decompression and is the way in which the data is stored (compressed) and presented (decompressed).
For many capture workflows, the native codec used by the source might not produce the optimal results, so a different codec might be chosen to use during capture. This is common to reduce the file size. For example, the DV codec produces very good quality video, but the file size is quite large. So, as a way of reducing the file size, capture using the H.264 or MPEG-4 codec option. While the quality is not as good, it is much easier to transfer and store the smaller files.
While choosing different codecs from the native ones is a great option, be aware that it requires more CPU to recompress the files on the fly. We recommend doing a lot of testing to guarantee that the options used during capture will work through the entire span of the video workflow. You might find that your computer is not powerful enough to handle capture, recompression and coding at the same time. You could also find that the chosen video codec will not work in some third party software involved in your workflow.
There are 3 codec choices for the video component of capture apart from the device’s native video codec. These are designed by Apple to produce the best results possible. The video codec options can be accessed by clicking on the drop down menu to the right of the video source drop down.
Device Native – The capture will use the settings that are coming from the source. We recommend using this option in most cases as it reduces the load on the cpu and results in the highest quality possible. A common native codec is DV. DV files will be 13.76GB per hour.
Apple Intermediate – This is a codec designed by Apple to be an intermediate format in an HDV workflow. This codec produces very large and high quality video files while not requiring a lot of cpu work to do so. Files are roughly 20GB per hour. This is a great codec to use when you want a high quality master that will be used to create other videos such as for iPod or streaming over the internet.
H.264 – This option compresses the video into the H.264 codec, a derivative of MPEG- There are 4 options while using this codec, the options only change the frame size thus reducing the file size. We recommend using the H.264 SD for standard definition video sources or H.264 HD 720 option for high definition video sources for most occasions. The data rate will vary according to images being processed.
MPEG-4 – This option compresses into the MPEG-4 codec. Like H.264, there are 3 options, each one uses a different frame thus resulting in a smaller file. This has traditionally been the codec of choice for capturing good quality files with relatively small file sizes. Files will be roughly 2GB per hour. H.264 will supersede this codec in the future.
And there are 3 choices for the audio component of capture apart from the device’s native audio codec. Generally speaking, audio codec settings are largely ignored as when compared to video, mainly because the size of the audio component is insignificant to that of video. For the most part using the Device Native settings will be perfect. However to save a little space, using AAC High Quality is a good option.
Next to the audio source drop down menu are the compression options. By default, the menu selection is set to Device Native.
- Device Native – This will capture using whatever the device is outputting.
- AAC High Quality – This delivers a CD quality audio track at 128kbps.
- AAC Voice Quality – This delivers a low quality audio track at 32kbps.
- Apple Lossless – This delivers a very high quality audio track that is quite large in size depending on the audio that is being recorded. This is a good option to use if recording using external microphones and audio is really important to the video.