The Video Standards Report – 2011 has been released by the Australian Flexible Learning Framework. This report provides recommendations for the formats and settings to use with video for vocational education. The report is intended to help the vocational education sector, but may be of use for higher education and schools as well.
The report's author's have tried to do to much, with a primer on video uses and video technologies, as well as formats and implementation issues. The result is a report which will be hard to understand for those new to digital video and too superficial for those who are. A short summary of recommendations would be better, leaving the primer material to the many good guides to digital video available (some of which are referenced in the report). The introduction strays away from the topic of digital video into the role of the NBN, Korean broadband and mobile devices.
The report is available in PDF (1 MB) and Word (3.4 MB) formats. As the report is about online education, it would have been better provided as a HTML document, for ease of reading and referencing on-line. I converted the Word version to HTML and here are some excerpts:
Video Standards Report v1.0
E-standards for Training
Table of Contents
- Table of Contents 3
- Introduction 1
- The changing digital environment 2 ...
- Key considerations 4 ...
- Video encoding 5 ...
- Video production for encoding 10 ...
- Encoding parameters 13 ...
- Players/Container formats ...
- Codecs 25 ...
- Streaming servers 31 ...
- Screen recording and sharing 36 ...
- Relevant findings 37 ...
- Recommendations 40 ...
- Appendix 1: Standards recommendation 42
- Appendix 2: Players/container formats and codecs 43
- Appendix 3: Video codec table 45
- Appendix 4: Bit rates 47
- Appendix 5: Screen resolutions 50
- Contacts 51
...
A screen size of 640 x 480 is still a good standard for SD (4:3) video.
For HD video, the dimensions 512 x 288 are a good size. This screen size is half the PAL HD standard of 1024 x 576 (which is good for pixel doubling). The dimensions 512 x 288 are good for a web page, but they are a little too big for mobile phones.
The most common screen size for mobile phones is 320 x 240 (QVGA).
See Appendix 5 (Screen resolutions) for an overview.
Video can be interlaced or progressive.The use of interlacing helps to achieve good visual quality in narrow bandwidth contexts. Fields are alternating half frames that are horizontally "interlaced" (odd and even) lines of the image. This approach was developed as a solution to the issue of the duration of phosphor glow with television cathode ray tubes. Footage shot with interlacing can appear to have a "comb" effect on a computer screen when there is quick horizontal movement. If this effect is evident, make sure the video master is rendered with a deinterlacing filter.
Abbreviated video resolution specifications may include an "i" or a "p". For example, "1080i" refers to 1080 horizontal lines interlaced (drawn odd and then even), whereas "1080p" means the lines are progressive (drawn from 1 to 1080).
Video can consist of 25 (PAL), 30 (NTSC) or 60 (HD) fps. Halving the frame rate can reduce the data rate without loss of image quality. PAL, for example, can be reduced to 12.5 fps, although at 12 fps motion may begin to look a little jerky.
Players/Container formats
This section provides a list of common players and plug-ins, along with some information on associated licences, tools, severs and platforms. A final recommendation is provided for each player/plug-in. Information on supported codecs can be found in Appendix 1 (Standards recommendation) and Appendix 2 (Players/container formats and codecs).
An overview of available players can be found at: http://en.wikipedia.org/wiki/List_of_media_players
Remember, the licence for a player only pertains to the distribution of the player software. A publisher is constrained by the licensing requirements of any codecs used by content, regardless of the player licence.
.wmv ...
Recommendation
While Windows Media Player is always available on Windows machines, the complicated breadth of versions, and the fact that it only supports Microsoft"s version of MPEG-4 make it complicated to use to produce cross-platform content.
The WMV format includes its own Digital Rights Management (DRM), which has been subject to much criticism.
Note that Windows 7 ships with an H.264 decoder (licence included in OS fee).
.flv, .f4v, .f4p, .f4a, .f4b ...
RecommendationFlash may lose ground as HTML5 becomes more popular, but it currently has an enormous installed base. It can be used in concert with HTML5.
.mov, .moov, .mp4, .mp3, etc. ...
RecommendationQuickTime offers broad codec support and can be confidently installed on PCs. The plug-in supports H.264 in browsers without native support, for example Internet Explorer (pre-9).
...
RecommendationVLC is highly recommended as a powerful, free video tool. In addition, it is an open-source, cross-platform, all-purpose video player. VLC can transcode to popular formats and play regionalised DVDs.
The VLC plug-in supports H.263 in browsers without native support. Also see Section 11.3 (HTML5 and the video tag).
...
RecommendationIt is difficult to recommend WebM due to the potential technical and licensing issues, plus its uneven support (despite Google"s backing).
...
Recommendation
In comparison to H.264, Ogg"s file size/quality balance is inferior. This format is unlikely to become a broad standard.
.rm ...
RecommendationAs RealNetwork"s influence continues to wane, its future is unclear. It is difficult to recommend this format with any confidence. However, as a media-streaming solution, it has a strong track record.
...
RecommendationSilverlight is new, it has not been tested and uptake is still limited. It is therefore impossible to recommend Silverlight at the time of writing this report.
...
RecommendationThe AVI container should probably be phased out. It is not recommended.
Codecs
This section gives an overview of the main codecs, including information on associated licences, tools and platforms. See Appendix 1 (Standards recommendation) for a table summary of this information. For an overview of lossy video codecs, see Appendix 3 (Video codec table).
...
Some comparisons
WebM vs H.264
Currently, H.264 and WebM (which share much code) produce the best results with restricted data rate.
The following table and quote come from: http://www.streamingmedia.com/Articles/ReadArticle.aspx?ArticleID=68594&PageNum=4
... Additional comparison data of video codecs can be found at: http://en.wikipedia.org/wiki/Comparison_of_video_codecs
...
Streaming serversUnder some circumstances, a dedicated media-streaming server may be required to deliver audio-visual content. ...
...
Appendix 1: Standards recommendationCodec overview: most recommended to least recommended
Codec
Licence
Platforms
Web
Tools
H.264
Commercial distribution requires licence
Mac, PC, LINUX, iOS, Android
HTML5 on WebKit, QuickTime plug-in
Major platforms have good commercial tools, which are free
WebM/VP8
Free, but it shares patentable code with H.264
No hardware support for mobile devices
YouTube
Free, but requires an understanding of binaries
Ogg Theora
No limitation
Does not have wide support
Mozilla - Firefox, etc
Free, but requires an understanding of binaries
WMV
Free to use, DRM for content
Windows integration only
Not recommended
Commercial and free bare-bones version
On2
Open source
All platforms
Various versions supported by various plug-ins including WebM
Major platforms have good commercial tools, which are free
Overview: players/container formats and codec support
Player
H.264
WebM/VP8
Ogg Theora
WMV
On2
Windows Media
*
no
no
yes
no
Flash
yes
no
no
no
VP6
QuickTime
yes
*
yes
*
yes
VLC
yes
no
yes
yes
VP3/5/6
Real
yes
yes
yes
no
VP3/5/8
Silverlight
yes
no
no
yes
no
* requires software installation
From: Video Standards Report – 2011, Australian Flexible Learning Framework, May 2011
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