Prepping for video shooting

Brief background prep for shooting video

 

Video frames are wrapped in containers that become the media file. This process starts in the video camera. Some video cameras give users the option of choosing which file format they wish to use to save the video frames. Good quality and professional cameras will package their video in a file format that leans towards archival. This means minimal or no compression, so file sizes will be large.

All the major file formats that are considered suitable for archival purposes are at least semi-open source, including the Microsoft AVI (.avi) and Apple Quicktime (.mov) formats. MPEG-4 (.mp4), MXF (.mfx) and Motion JPEG 2000 (.mj2, .mjp2) are fully open source. The quality of the original video is not affected by the file type wrapper where it is left uncompressed. It is basically how widespread players are, that can read the file format that determines the format popularity. All file formats can be converted to other ones but this requires further technology such as software in the form of codec converters.

Consider codecs as a name to identify the encoding method used to contain the video in a media file. The encoding process is necessary to compress or reduce the media file size. So while the video does not change, the way it is compressed into the media file does. The file is then given an extension associated with the codec used.

Motion JPEG 2000 and MXF offer options for lossless (as much as lossless can be) compression, to reduce file size while minimising quality loss, but may not be able to be read by common players like Quicktime or Windows Media Player. A copy of a MXF file can be made and converted to something like WMV so it can be run on Windows Media Player. This provides a professional quality master file and a small home consumer quality copy for immediate web distribution and viewing. The drawback is the post-production involved to create this second copy requires time, resources and some degree of expertise!

The methods of viewing video include directly via a compatible video player, or through web technologies. Web technology involves downloading the video, so the size of the video file impacts on the performance of web technologies. Large files consume more time and bandwidth in downloading. To reduce delays, the video player starts playing while the download is still in progress. This can lead to problems of freezing where the download is slower than the media player.

There are three methods of viewing video over the web: direct link, embedded player and live streaming. Direct link requires a link to the video file and the video player. This is the basis for YouTube, where the embedded link in a web page acts as an instruction to the host (YouTube) to stream the video. No local player is needed. Other video material is based on utilising an embedded player. The embedded player could be embedded as code in a web page, but is more likely to call on a player embedded into the browser, or plugged into the browser. One of the most common ones being Adobe Flash.

Even if no local player is installed, the video can still be viewed using the resources available from a browser with a Flash plugin. An embedded player removes the need to rely on a stand-alone local media player. The embedded media player is also matched to the video file format. Adobe’s Flash player plays MPEG-encoded video contained in a .flv file. Video that is encoded with .flv codecs requires a browser to have a Flash plugin installed to run it.

Web technology is currently going through changes with a new html5 standard in the making. This new html5 technology offers new alternatives to playing video files in web pages which are predicted to supercede Flash. HTML5 compatible browsers will play video in a range of codecs without the need for plugin extensions like Flash. It is a move towards the direct system.

It should be noted that digital technology is a very fluid field, where new things come and go and older things often get reinvented into new versions. Adobe Flash now has a new identity, being marketed as Adobe Animate. It is Adobe Flash that outputs to HTML5 documents, rather than Flashes own document, as in the past (http://blogs.adobe.com/animate/welcome-adobe-animate-cc-a-new-era-for-flash-professional/).

YouTube is a very popular video gallery website that has moved from reliance on embedded Flash to the new HTML5 video technology (http://www.theverge.com/2015/1/27/7926001/youtube-drops-flash-for-html5-video-default).

One of the problems with Flash is that it does not support current smartphone and tablet technology that now accounts for at least 50% of internet use. The operating systems and browser combinations used in today’s smartphone and tablet technologies are not the same as those for PCs, so new software technologies are continuously evolving to accommodate new hardware technologies—it’s a vicious circle for manufacturers and software technology creators!

With embedded video player technology the video downloaded is held in dynamic memory until it has finished playing, or the browser is closed, after which it is cleared. As with the direct method, it is never saved and is not accessible as a user file by default.

In summary, plan to shoot video where the resulting digital files can be archived. Don’t compress the original files. Save them to a video archive folder for editing later. Open a new project in a video editing program and create a master production file. When complete export the product as a compressed copy of the master in the final container of choice…a codec that compresses the file to reduce its file size that will be recognised by all popular video players. WMV files are good for Microsoft video reader applications as they are quite small in file size and look fine on small screens on devices using Microsoft technologies. With their small footprint they are easy to share and distribute, however their lack of quality will be apparent when viewed on today’s HD tvs. However, not all today’s mobile technologies use Microsoft readers, so some research may be required before using this codec (file type). Consider exporting copies from master files in file types for specific technologies. The h264 packaging (codec) is popular especially where the video file is to be saved to DVD. There is nothing preventing multiple exports in different formats (one at a time), as exports do not alter the project master file in anyway. Like many other technologies, the world patiently awaits for a universal standard that may never evolve with any longevity!


Researched and written by Gavin Lardner (CC BY) 2015.

Advertisements

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s