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| Preparing
Linx Files for Streaming on the Internet |
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| Introduction |
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Linx
provides functionality that you can use to optimize
your output .swf files for web streaming.
Just to clarify, .swf files (which Linx exports)
do not technically stream – they use what
is known as “progressive download”.
This means that the file downloads to the viewer’s
computer as it plays – it is cached on
the viewer’s computer. However, as long
as your files conform to the viewer’s connection
speed (the file is the appropriate file size
for the viewer’s internet connection speed)
the file will play uninterrupted – so for
the viewer it is indistinguishable from streaming.
If you don’t want your files to be cached
on the viewer’s computer, there is code
you can place in your HTML to prevent caching.
For more information on that, check out these
links:
http://www.macromedia.com/support/flash/ts/documents/prevent_caching.htm
http://www.macromedia.com/support/flash/ts/documents/no_caching.htm
If you are outputting your project to be played
from a CD or a local hard drive, you don’t
have to worry about whether the file will stream
(though you do have other concerns that are covered
below). But if you want to post your output .swf
file on the Internet for others to view, you
have to take into account the way your output
will play for viewers on different speed connections.
There is a little bit of an art form to preparing
Linx output files for streaming, but in a nutshell
it comes down to 2 key factors:
- the Linx play modes you
select
- file size
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| Play
Modes |
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When
you import a file into Linx, there are three
different available play modes:
- Play on the main timeline
- Play independently in a sprite
- Play with LoadMovie
You must select one of the three.
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| Quick
Answer: Which play mode should I use? |
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There
is a quick answer that you can use if you don’t
want to delve too deeply into what the different
play modes in Linx do and how they work:
- If your imported file is larger than 50KB
and smaller than 2 MB set it to the “Play
on the main timeline” play mode.
- If your imported file is larger than 2
MB set it to the “Play with LoadMovie” play
mode.
- If your imported file is smaller than
50KB set it to the “Play independently
in a sprite” play mode.
(If you are importing audio or image files for
Linx to convert to .swf the size of the file
referred to above is the size of the .swf file
created once the file is imported – not
the size of the source file.) |
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| Changing
the play mode |
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Files
that you import into Linx by dragging them onto
the interface, or by right-clicking on the Linx
timeline are automatically set to play in the
default play mode.
Dragging a file into Linx. |
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| Right-clicking
on an empty space in the Linx timeline: |
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| In
the Import menu item you can import a file and
set it to play to any of the three play modes. |
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| You
may change the play mode of a .swf in Linx at
any time in either the Play tab of the .swf properties
window |
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by right clicking on the .swf in the Linx timeline
and selecting the option you want. |
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| You
can change the default play mode settings of
imported files in the Options window (View>Options). |
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| What
are the play modes? |
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| Linx's
three play modes each have different characteristics
and can be used for different purposes based
on what you are trying to create. (Keep in mind
that certain features in Linx and certain types
of .swf’s that you import require specific
play modes for them to work.) |
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Using Linx's Play Modes
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Play on the main timeline
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Play independently in a sprite
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Play with Load Movie
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Use with .swf's of size?
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Over 50KB
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Under 50KB
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Over 50KB. Recommended for files larger
than 2 MB.
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Does the .swf stream or preload
100%?
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Streams
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Does not stream. Preloads 100%.
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Streams
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Is the .swf part of or external
to the Linx project?
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Internal
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Internal
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External file that is loaded into the
main file.
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Mouse-overs are enabled?
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No
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Yes
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No
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Actions in .swf affect the main
timeline?
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Yes
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No
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Yes
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.swf's loop automatically?
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No
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Yes
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No
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.swf's can be reused without
increasing final file size
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No
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Yes
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No
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| What
is the main timeline? |
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| Linx’s
play modes reflect the three different ways Linx
can set imported files to play in your output
.swf file and they have to do with how the Flash
player plays Flash movies. This reflects the
Flash’s background as a frame-based animation
format that uses sprites (more on this below).
Every Flash movie has a main timeline which represents
the internal timeline of the .swf file you are
creating (this is not the same as the physical
Linx timeline in the Main window). You can place
.swf’s onto the main timeline for playback.
You can also play .swf’s in a sprite which
is in the .swf file you are creating, but plays
independently of the main timeline. And you can
also load external .swf’s into your project
(.swf’s played with LoadMovie are also
independent of the main timeline). |
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| Linx's
three play modes |
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| Play
on main timeline |
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This
option will cause imported files to be played
on your .swf output’s main timeline. Files
played on the main timeline will stream when
posted on the Web (this is not an issue for files
played from CD or your hard drive).
You should be aware that any actions in a file
played on the main timeline will affect the entire
project you are creating. For instance, if there
is a stop action at the end of a file you import
onto the main timeline, it will stop the entire
project when the Flash player reaches that stop
action. Likewise, if there is a loop at the end
of the file, it will cause your whole movie to
loop and so on. You may remove the stop or loop
actions from the last frame of an imported Flash
file using the "remove stop/loop action
from last frame" options in the Play tab
of the .swf Properties window.
Using image fade in and/or image fade-out with
certain .swf’s set to the main timeline
play mode may result in increasing file size.
If this occurs you may want to use either the
sprite or LoadMovie play modes. |
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| Another
factor to consider is that if you layer multiple
files set to the “Play on main timeline” play
mode on top of each other, they may have elements
which conflict with one another. In this case
you will then have to change one or more of the
files’ play modes. |
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| Play
independently (sprite) |
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This
option will cause imported files to be played
independently in what is known as a sprite. While
files played in a sprite are incorporated into
the .swf file you are creating (they are not
external), they do not affect any other file
in your Linx project – they play independently.
This means that if those files loop or contain
stop actions, those actions will only affect
that .swf, and not the main project or any other
files in the project.
You should be aware that files played independently
in a sprite do not stream when posted on the
Web, they preload 100% - which means they must
download completely before they begin to play
(this is not an issue for files played locally).
This is fine for small files, like still images
or text effects, however, it may be an issue
with larger Flash files, such as video and audio,
because the end user will have to wait for the
entire .swf to download before it starts to play.
If you want those larger files to stream on the
Internet, you should use one of the other two
play modes.
Another thing to keep in mind is that certain
features in Linx can only be applied to files
set to play independently in a sprite - such
as the mouse over option.
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| One
of the great things about sprites is that they
can be reused. In other words you can use the
same file again and again without increasing
the final file size of your output. To reuse
a sprite, simply drag it into your Linx project
from the Linx Library. |
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| Play
with LoadMovie |
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This
option will cause imported files to be played
using LoadMovie. This method can be used to load
external .swf’s into your project. Files
played using LoadMovie will stream when posted
on the Web (this is not an issue for files played
locally). This can be a useful way to play Flash
video and audio files that you want to stream
because they will not stream when played independently
in a sprite.
Loading files into your project is also an excellent
way to get around the .swf format’s 16,000
frame limit and the ram consumption problems
associated with very large Flash files. You can
load an unlimited number of .swf files into your
project. However, files played with LoadMovie
are not included in your Linx output itself,
so you need to remember to have those other files
available in the directory you specified, when
you want to play your output. |
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of which play mode you select, all the files
you import into Linx will appear in the Linx
preview pane of the Main window and can be moved,
resized and cropped in the preview pane. They
will also appear on the Linx timeline in the
Main window, but keep in mind that the Linx timeline
is not the same as the internal "main timeline" of
the .swf file you are creating. |
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| File
Size |
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| When
creating a Linx project you have to keep in mind
the size of the imported .swf files as well as
the size of your total project, and there are
several ways to reduce the size of your imported
files and your final output. |
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| Fades |
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| Using
image fade in and/or image fade-out with certain
.swf’s set to the main timeline play mode
may result in increasing file size. If this occurs
you may want to use either the sprite or LoadMovie
play modes. |
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| Audio |
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| Linx
can directly import .wav and .mp3 audio files
and will convert them to .swf. When you import
audio files Linx will give you a number of options
for encoding. If you want the project to stream
for virtually everyone, we recommend setting
the import settings to 22khz sampling rate and
40kbps bitrate. This will create reasonably good
quality audio that plays without interruption
for listeners on any connection that is 56k and
faster. However, if reducing file size is a major
concern, you can reduce the settings down to
11khz and 8kbps, which will yield the smallest
possible file size. The higher the bitrate the
larger the file gets. You may also consider encoding
the audio at two different settings – one
for listeners on a dial up and one for listeners
on a broadband connection. 44 khz sampling rate
and 128kbps bitrate is generally accepted to
be CD quality audio. |
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| Video |
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| While
Linx does not convert existing video files to
Flash, it can import video .swf files from programs
such as Flix and Macromedia Flash. We generally
recommend encoding your video at two different
settings – one for viewers on a dial up
and one for viewers on a broadband connection.
While you can’t adjust the size of an imported
video, you can add a preloader to a video and
then play it using the LoadMovie play mode. (For
more information on preloaders, see below.) |
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| Images |
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Linx
directly imports most image formats (such as
.jpeg, .bmp, .tif, etc.).
You can reduce file size by reducing the quality
setting when you import the images.
We recommend setting the quality between 30-50.
As the image quality setting increases, file
size increases dramatically. |
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| Wild
FX Effects |
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Wild
FX’s Flash 4 (Dynamic) and Custom effects
are smaller than the Flash 3 (Standard) effects.
If you are using a Flash 3 (standard) effect,
you can use the “export as Flash 4” (or “export
Standard as Dynamic”) option to reduce
the size of the effect.
Another thing to keep in mind is that Wild FX
reuses the same letters created with the same
font – because they are in sprites. So
if you need multiple lines of text, you can reduce
file size by creating multiple lines in the same
Wild FX output .swf and repositioning them in
Linx. |
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| Reuse
sprites whenever possible |
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Any
file you have set to the “Play independently
in a sprite” play mode can be reused without
adding to the final size of your Linx output.
In other words you can use the same file again
and again without increasing the final file size
of your output. To reuse a sprite, simply drag
it into your Linx project from the Linx Library.
This is part of how the Flash format was designed.
While you can’t make an imported .swf file
smaller in file size, there are a number of things
you can do to improve the way it plays that mainly
have to do with the play mode you select, the
ability to use preloaders, and the ability to
reuse sprites. |
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| Actions
in your imported files |
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Any
actions in a file set to the Play on main timeline
play mode will affect the entire project you
are creating. For instance, if there is a stop
action at the end of a file you import, it will
stop the entire project when the Flash player
reaches that stop action. Likewise, if there
is a loop at the end of the file, it will cause
your whole movie to loop and so on. You may remove
the stop or loop actions from the last frame
of an imported Flash file using the "remove
stop/loop action from last frame" options
in the Play tab of the .swf Properties window.
If there are other actions affecting your project
you may need to use the Play independently in
a sprite play mode.
Another factor to consider is that if you layer
multiple files set to the “Play on main
timeline” play mode on top of each other,
they may have elements which conflict with one
another. In this case you will then have to change
one or more of the files play modes. |
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| Preloaders |
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| Linx
has a very useful feature that enables you to
automatically add a preloader to your output
files. |
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The
Preload option allows you to program an automatic
preloader into your Linx output. This is for
web streaming purposes only. Preloaders will
not work on Linx .swf’s played locally
from a hard drive or CD. The purpose of using
preloaders is to ensure smooth playback of
larger .swf’s for viewers on slower connections.
In this way, users on slower speed connections
(e.g., dial up modems) can view larger .swf
files without buffering or the .swf stopping
and starting. For instance, if someone on a
56k connection tries to view a .swf that was
created to stream to a broadband, 256k connection,
the .swf is still going to play, but the amount
of information contained in the .swf will be
much larger than it would be for a .swf specifically
created for a 56k connection. This will cause
an inconsistent and choppy playback experience
for the 56k user. The purpose of a preloader
is to ensure that enough of the .swf has loaded
so that there will be no interruption once
the .swf begins to play. While there is a delay
while the user waits for the .swf to begin
playback, if you preload enough of the file,
once it starts to play, it will continue to
play uninterrupted until it finishes.
The preloaders have a "__% loaded" indicator
that shows how much of the .swf has loaded
until the specified percentage has loaded and
then the .swf begins to play.
There are two types of preloaders included
in Linx:
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| Fixed |
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fixed preloader causes the Flash Player to preload
a specified percentage of your Linx output prior
to beginning playback. You specify the percent
of the movie to load (from 1% - 100%). The Fixed
preloader works with any Flash player version
4 and higher. |
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| Adaptive |
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An
adaptive preloader is an "intelligent" preloader
that will preload a variable amount of your
.swf based on the size of the .swf and the
viewer's internet connection speed so that
the viewer can watch the .swf without stops
and starts - no matter what speed at which
they are connected to the internet. The adaptive
preloader determines the user's connection
speed and based on that figure and the size
of the .swf file you are preloading, it preloads
precisely the amount of the .swf required to
enable the .swf to begin playing as soon as
it possibly can and still not stop at any point
until it is done. In this way, the preload
process is optimized so the amount of time
taken for a .swf to preload is minimized as
much as possible. The Adaptive preloader works
with any Flash player version 5 and higher.
Buffer factor: The buffer
factor will cause the preloader to preload
more (or less) of the .swf than the initial
calculations determine is the minimum amount
of time required. This is useful because
a viewer's connection speed often varies,
even during the course of watching a single
.swf. The time needed to load the .swf file
to the end is multiplied with this factor.
If you don't want to use a buffer you set
the factor to 1.0 (a factor of 1.0 means
no buffer - loadingTime * 1.0 = loadingTime).
To be on the safe side, you may want to use
a factor larger than 1.0. If you think the
viewer's connection will get faster during
the visit (e.g., perhaps a download ends)
then you can change the buffer factor to
a number smaller than 1.0. If you think the
viewer's connection will get slower during
the visit (e.g., because the viewer starts
a new download) you should change the buffer
factor to a number greater than 1.0. As a
general rule, it is a good idea to make the
buffer factor larger than 1.0 to be on the
safe side. The default value is 1.1 which
should provide good results. The buffer factor
can be a number from 0 - 2 in increments
of 0.1
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| Sprites
and preloaders |
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| If
you have files set to the play independently
in a sprite mode, those files will preload 100%
before playing and adding a preloader will not
affect them – and the preloading “__%” indicator
will not work. This is because any file played
in a sprite preloads completely before playing.
If you have a series of sprites in your project
each sprite will preload 100% and then play – but
it won't wait for all the other sprites to preload
before playing. So using the sprite mode can
be fine for a series of small files. |
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| Exporting
to CD or Hard Drive |
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Because
of the way Flash works, when you have a .swf
on CD (or a .swf as part of a Flash projector),
the Flash player loads the entire file into memory
before it starts to play. So, depending on your
computer's speed, ram, CD player speed, etc.
your performance may vary. Consequently, we suggest
not creating files larger than 10-25MB for use
on a CD Rom. You can get around this limit by
chaining a series of smaller .swf’s together
and loading them sequentially using Linx’s “LoadMovie” play
mode (keep in mind that you will have a brief
lag each time you load a new swf).
Linx can automatically output projectors for
both Win and Mac. However, be aware that the
Mac projectors created in Linx compressed and
need to be expanded on a Mac prior to running.
(Also, for Macs, you need to allocate enough
RAM to your projector. All Mac OSs prior to OSX
will not automatically allocate enough RAM. When
preparing a CD-ROM, the projector file needs
to be allocated it's own size plus the biggest
Flix file plus a couple of extra MB to be on
the safe side. When the HFS volume is burnt onto
CD it will inherit the memory settings you've
specified.) |
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| Conclusion |
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| This
tutorial has provided information on optimizing
your Linx projects for deployment on the Internet.
There are many other factors involved, but by
following the guidelines in this tutorial you
should be able to create projects that are well
designed for posting on the Internet. |
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