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From: John Foliot - WATS.ca
Date: Apr 1, 2005 7:59AM


dagda1 wrote:
> Hi,
>
> Thanks for all the replies and I do hate to ask further
> questions, but I'm
> trying to put a case to a client as to what our educated
> approach is to
> streaming our multimedia.
>
> I'm going with the approach that we use .mpeg for video and
> mp3 or avi for
> audio.
>

Paul,

Recently, we went through an exercise with a client who had an eLearning
course. One of the tasks in the course was to determine which media players
were installed on the end users machine (and how to download and install if
one was missing - it was a beginners course). There are a few issues to
deal with here, including whether or not there is a requirement for SMIL
(captioned) video - how WCAG compliant must you be?

Issues are:
* Many of the current crop of players support multiple codecs... In fact,
upon installation many will attempt to "hijack" non-native formats that they
are capable of playing. WinAmp for one will try to be the default player
for many different encodings (and does a decent job too), RealPlayer
attempts this as well, and I believe that Windows Media Player will also
attempt to "assume" other file formats. QuickTime less so... (these are the
ones I tested... Remember, there are a slew of other third-party media
players out there). So one of the issues is, we/you cannot "assume" that
any given media player is installed let alone configured as the default
player for a media type, making "embedding" something of an issue (if that
is a requirement)

* SMIL support. Yeesh! SMIL is one of those W3C technologies that is
neither well supported, nor supported in a standard way (which, by it's
reading it doesn't really have to be, but it sure makes it tough on us
developers). RealMedia and QuickTime are the better players in this arena,
but of course SMIL for QuickTime will not play in the RealPlayer, and SMIL
for Real won't play in the QT player... Figures eh? WMP is the worst here,
as it currently does not support the captioning feature-set of SMIL; Windows
SMIL (or SAMI - essentially the same, but different...) appears to be used
primarily as a means to create a playlist, where the SMIL file references
multiple media files and plays them in a predetermined order.

* True Streaming .vs Pseudo Streaming. Are you planning on using the HTTP
protocol, or another, "truer" streaming protocol? Higher overhead for the
client, better results for the user, especially if the media files are
larger video files. Not all formats can be truly "streamed"...

* "Embed-ability": As mentioned above, since many different players will
attempt to play the more popular formats, you might have issues if you need
to embed the media files directly into your pages. Nowhere is this more
true than with MP3 files - arguably the most common audio file format on the
web today (sorry, no hard stats on hand, but given the explosion of stand
alone MP3 players, and the whole peer-to-peer underground file exchange
phenom...). So, if all you want to do is provide an audio download, then
MP3 is certainly your safest bet. However, if you need to "embed" the audio
within a page, avoid MP3 (not even sure if you *can* embed MP3s) because you
just can't be sure what player the end user has configured for MP3s, and
many, if not most of the third part players do not have web plugins; they
launch the player external of the web-page (ie: WinAmp - which is *my*
favorite/default MP3 player)

* DRM - Digital Rights Management. Some content providers have a desire /
requirement to block end users from the ability to locally save the media
file. While there is no 100% fool proof method of stopping a truly
determined user, there are ways of making it much harder; Microsoft have
also done a fair bit of work in the DRM field, and the major players in the
entertainment industry are working hard in this area too. But for the
average small to medium web dev shop, much of this is probably outside their
regular domain. Personally, I have used RealMedia in the past for a client,
as it does have rudimentary means of stopping local file saving... Haven't
dabbled in a while, but as I recall it wasn't too hard. Contact me off list
for more recollections...

So, what's an average punter to do? Well, believe it or not, after spending
a fair bit of time on this myself, I believe the actual answer is.... Flash.
Yep, Flash.

Now there are some caveats here, but the reasons are as follows:

- user base. According to macromedia, they have a 98.2% installed
user base (http://www.macromedia.com/software/player_census/flashplayer/)
*AND* it is available for multiple platforms (unlike, say, Windows Media
Player)
- supports audio only / audio and video / video only (uses MP3
compression for the audio to reduce file size)
- embeddable (with independent user controls - another WCAG
requirement)
- supports captioning for video (requires a third party application,
I believe there are a few: I have used the HiSoftware tool with success -
http://www.hisoftware.com/hmccflash/index.html)

The single largest downside I encountered was degradation in quality of
video (which is due, in part to the number of frames-per-second, as well as
compression algorithms in Flash which seem to concede quality for file
size). Also, to create a Flash movie from live action content requires that
you import the original source material into Flash - in other words it is a
multi-step process. Depending on your source of video, it may be a many
multi-step process. Acceptable import file types are (for video): .avi,
..mov, .mpg/mpeg, .asf/.wmv; (for audio): .wav, .mp3, .aif, .au, ..asf/.wmv

Also, for the captioning component, you must have Flash MX 2004 for
development, plus the aforementioned helper app.


Hope this helps. More than this Paul, and I send out a consulting invoice
(which I do BTW ).

JF
--
John Foliot <EMAIL REMOVED>
Web Accessibility Specialist / Co-founder of WATS.ca
Web Accessibility Testing and Services
http://www.wats.ca 1.866.932.4878 (North America)



>
> What I want is a break down of which:
>
> 1. Format does not work in which version of each player.
> 2. Can I get world wide stats of the percentage of player
> is being used
>
>
> Thanks again for your valuable assistance
>
> Paul
>
>