Video File Formats – What is best?

One of the many powerful tools available for use in litigation is video. Video can be used to tell a story, depict a day in the life of someone, see the actual event happening, see a witness’s demeanor during examination, substitute for a witness who cannot attend the trial in person, impeachment and the list goes on. From the early days of 8mm film, followed by VHS tapes to today’s digital video, this tool is an essential part of almost every trial.

When an attorney used 8mm film, VHS tapes or LaserDisc, the setup and use was straightforward. Someone would hook up the player to a projector or TV and when they needed it, they pressed the play button. Pretty easy. Once digital video came into the mix, things started to get complicated. While you still hook up to a projector or TV and press the play button, digital video has some potential complications that can add a degree of difficulty you really don’t need at trial.

Digital Formats: One of the most common digital formats and the focus of this blog is MPEG. MPEG is an acronym for Moving Pictures Experts Group. This group of authorities set the standards for audio/video compression and transmission of the digital files that everyone “abides” by. These standards set the compressed data format to a standard video compression specification. Creation of these digital files requires software known as a “video codec” that includes an encoder that can compress the video into a smaller file size and a decoder that will decompress the files for playback. More on video codecs later. The original MPEG standard that was first developed and released in 1993 was called MPEG-1. This standard is still very much in use today and has continuously been recommended, especially in litigation, because MPEG-1 doesn’t require anything special to make it work. Using an MPEG-1 video compression algorithm, a 120-minute video would be compressed to about 1.2 GB. MPEG-2 is a standard that has been adopted by most of the movie producing companies because of the higher visual quality of video available during playback. The compression algorithm of MPEG-2 would take a 120-minute video and compress it to about 4GB – 8GB, but with a much higher quality than MPEG-1. With the eruption of the internet, MPEG-4 has steadily become the standard of choice thanks to its high level of compression while maintaining a high level of quality during playback. One of the many reasons that MPEG-4 has become popular is that its compression algorithm will compress a 120-minute video to about 300MB and maintain a very high quality. Choosing a video format essentially becomes a comparison between power, speed, storage capacity and fidelity or quality of the video and the requirements to play the video, i.e. video codecs.

Issues: When it comes to working with digital video files, the number one culprit that causes issues is the video codec. If you have ever had audio play, but not the video or had some MPEG files play but not others, it is because the video codec is incompatible. Video playback software that came pre-installed or was installed after the fact may install their own codec and you can have multiple codecs installed on the same computer. When this happens there are potential conflicts and it is unknown what codec will be used with what video. The problem is consistently found when dealing with MPEG-2 video files and less of an issue with the other MPEG formats. There are several packages commercially available that can be used to determine what codecs are installed and what may or may not be conflicting. A secondary issue when dealing with digital video that may be encountered is that not all digital video is created equally. Just because the format is MPEG-1 or MPEG-2 doesn’t mean that it is compliant or compatible with the player. One thing to verify is if the video was created using a constant bit rate or a variable bit rate. Another possible area to check is if within the file format, standards or “parts” have been included. For example, MPEG-4 Part 8, is video formatted using a method to carry the content on IP networks. Another would be MPEG-4 – H.264 or Part 10 that supports video resolutions up to 4096×2304 or 4K UHD. Making sure that your video codec supports constant or variable bit rates and parts or variants to a format will help alleviate some of the potential issues you may encounter.

Conclusion: When it comes to working with video files and having issues, find out who/what created the video, if there are any non-standard or non-compliant issues and what video codecs are installed on the computer. Taking these steps to resolve any issues beforehand is critical to a smooth presentation and keeping your focus where it needs to be at trial.