Camera .MOV to .mp4 or .AVI _ Your Considerations?

Chas Tennis wrote:

I do not edit longer videos often.

Recorded with tripod 28 minutes of 1080p x 720 60fps with a camera output file of .MOV

Camera output video file size 1.2 GB

Used a video analysis application that offered only these 3 video file saving options:

1) Matroska (not used)

2) .mp4 (used) - this file took 20-30 minutes to convert and save. ? (Computer speed OK.) It was considerably larger than the original video file.

3) .AVI (used)

When you look at the 3 choices for saving the video file and consider the .MOV original file from the camera, what saving option would you choose and why?

How do you consider Youtube for your decision?

In other words, basically I just pick a familiar file option for saving and have few other considerations. What do you think about when selecting the video file type?

Chas Tennis

There are two main parts to a video file: the containter and the codec.  The container is less important that the codec in terms of video quality, but does have an impact of file size.

.mov, .mp4 and .avi are all containers.  A container can impose some limitations on what type of data is in it, for example, the format of the audio and number of channels.  It's important to understand what the containers do for you.  The .mov container is associated with Apple Quicktime.  The mp4 container is an international, cross-platform standard, and the .avi container is a Microsoft development.

Within any container is video, which is usually compressed with a codec like H.264 (the most popular), common inside the mp4 container, but there are others.  The avi/Microsoft container favors the DIVX codec.  During video encoding and compression the codec is set for several parameters.  Common ones are average bitrate, maximum bitrate, fixed vs variable bitrate, etc.  Codecs may have other limitations, like what types and numbers of audio tracks it handles.  Audio is also run through its own codec, like AAC, which also has compression parameters.  You may never see any of this if your camera doesn't provide options, but some do.

You can also make files with uncompressed video and audio in common containers, which results in no quality hit at all.  Confused yet?

Generally, mp4 is more universal than avi or mov, and avi can end up with bigger files for a given quality.  But the real key to quality is the degree of compression, which directly changes the end bitrate.  Higher is better, lower gets you smaller files.

If the conversion between containers results in a file size change, that's your clue that something else is also going on.  There's been a change in bitrate or codec or audio, or all three.  Good software will expose at least the key parameters for you to adjust before exporting your file.  Limited, or dumbed down software may pick it all for you and hide the tweaks.  In that case you might want to export to the largest file size, then convert with another application that lets you carefully choose your codec and settings.