|
|
|
| This is an in-depth guide to understanding the major factors contributing to the final file size of your movies. If you’re looking for brief advice on getting smaller files, don’t worry about reading the detailed stuff and just skip to quick tips for bringing down your file size. |
|
| Movie content and running length |
Key point to remember: file size is based on movie content, not movie running length
Inside your movie, BB FlashBack stores the changes made to the screen. Therefore it’s what you record, not how long you record it for, that really affects your final file size.
For example: someone may record a plain and static screen for one hour. All BB FlashBack has to store in the movie file is the image of the plain screen, and a note that it stayed on screen for one hour. We’d expect the resulting file to be relatively small in size.
However, take another case where someone might record a five minute movie of high quality bitmap pictures. In this case, the movie file must contain all the pictures displayed on screen, of which each could easily be over one megabyte for a high quality photo. This means that even though the movie is only five minutes long, it can produce a relatively large file size. |
|
| Windows graphical effects |
Windows graphical effects are an example where many changes are subtly being made to the screen, but you may not be aware of them. For example, using the ‘fade’ menu transition effect means that the menu is displayed with a few stages of transparency, and these transparent images need to be stored to replay the effect. Using Windows graphical effects can therefore dramatically increase your movie size.
To have BB FlashBack switch off Windows graphical effects temporarily while recording, go to the Display tab of the Recorder Options window and check the option “switch off Windows graphic effects”.
If you want smaller file sizes, avoid using windows graphical effects. Nice as they look, they contribute to large file sizes! |
|
| Sound |
Including sound in your movie will also increase the file size, depending upon the amount of audio used and the format.
If you want to add sounds in the BB FlashBack Player then use MP3 files if possible – they will be much smaller than the same sound file in an uncompressed format (such as .WAV files).
If recording your sounds while recording with the BB FlashBack recorder, select the “use MP3 compression” checkbox in the sound options for a lower file size. This will be selected by BB FlashBack by default. A higher level of compression means smaller files, but also potentially lowers the quality of sound very subtly. |
|
| Movie format |
The file type which you export your movie to has a large bearing on file size, as some formats are much better than others at compressing screen recording footage. As a general “rule of thumb”, file formats will often produce file size in the following order:
| Smallest files |
FBR |
|
|
EXE |
(roughly 400K larger than your FBR file) |
|
Flash |
|
|
WMV |
(heavily dependant on your chosen codec) |
| Largest files |
AVI |
(heavily dependant on your chosen codec) |
However, this is only a very rough guide to file format size performance. The actual ranking will depend on your movie content, so you may find many exceptions to the above.
Exporting to Flash
In the latest version of FlashBack, when exporting to Flash you will be asked if you want to optimise your movie (if you have not already done so). Optimising can add a few seconds to your export time, depending on how long the movie is, but often reduces the file size significantly. Unless you are in a hurry and file size is not important to you, you should always select “yes” to optimising.
On the Flash export options window you should see a tab labelled “compression”. Here you can choose “lossless” compression, for a higher quality movie but higher file size, or “JPEG” for a slight reduction in movie quality but a lower file size. If JPEG compression is selected then you can chose the required balance between smaller files and higher quality replay with a slider bar below.
Also on this screen is the option to “Use MX compression”. This reduces file size considerably, but the resulting movie will require Flash plug-in version 6 or higher in order to play. Most people have, or can very easily download, the latest Flash plug-in so most of the time you’ll want to use MX compression.
Lastly, if you browse to the “more” tab on the Flash export option you will see a drop down menu to select colour depth. The lower the value selected, the smaller your movie but the lower the colour quality.
Exporting to WMV or AVI
When exporting to WMV or AVI formats, you will be asked to select a ‘codec’. These are software programs separate from BB FlashBack, that are used to compress your movie footage and create the final WMV/AVI file. Additional codecs can usually be downloaded from the internet, often for free.
Different codecs produce very different results in terms of exporting speed, movie quality and file size. Experimenting with different codecs is often the best way to find the best quality and file size for your needs, but as a very general rule of thumb Blueberry makes the following codec suggestions:
| WMV format: |
Windows Media Video series 9 |
| AVI format: |
Microsoft video 1, or
XVid |
On the list of codecs, you will also see a "Configure" button. Click this to fine tune the codec settings, which will also have an effect on file size. The options screen shown after pressing “configure” is different depending on the codec selected, and is part of the codec program, not BB FlashBack.
In depth: AVI and WMV codecs |
|
| Optimising Movies |
BB FlashBack contains an “Optimise” function which attempts to reduce the FBR file size. Optimisation is not run automatically because it can take a while. However, if you want smaller files you should definitely use this option.
With your movie open in the BB FlashBack player, to go to the “tools” menu and select “optimise”. After the process is complete, it'll report the percentage reduction in file size. Note that optimisation also reduces the size of Flash exports. If you attempt to export a movie to Flash which has not yet been optimised, BB FlashBack will ask if you want to optimise before exporting. |
|
| Screen Resolution |
The screen resolution setting on your PC determines the size that objects appear on-screen. A higher resolution means more text and objects fits on the screen at once.
You can change your screen resolution by going to the Windows control panel, opening Display and selecting the Settings tab.
The larger the screen resolution with which you record, the more information is recorded and the bigger your resulting movie size. |
|
| Record mode |
Changing recording modes can make a difference to your resulting movie size, but usually won’t affect it as much as the other hints covered in this document.
BB FlashBack supports three different methods of recording the screen. You can select which recording mode to use by going to the Record mode tab of the Recorder Options window. Of the three recording modes, capture driver mode, as a general rule, will produce slightly lower file sizes than DirectX or GDI modes.
If using DirectX or GDI, higher frame rates (FPS) will produce larger files, but doubling the FPS will not necessarily double the size of the movie file - the actual increase in size will likely be a little less than double.
In depth: recording modes |
|
| Key Frames |
Upon recording, it is possible to control how many “key frames” you want BB FlashBack to add into your movie. The more key frames in your movie, the quicker this makes jumping to various points in the movie when viewing it in the BB FlashBack Player. However, the more key frames your movie contains, the larger the file size.
This setting can be found in the Recorder Options window, Advanced tab. |
|
| Quick tips for reducing your movie size |
- Remember that it’s the type of content (such as if the screen is remaining static or consistently changing, or if items displayed on the screen are simple or complex images) in your movie, not the running length, that primarily determines the file size.
- Switch off Windows’ graphical effects before recording: they cause a lot of extra things to be drawn on the screen and can boost your file size significantly. You can set BB FlashBack to do this automatically on the Display tab of the Recorder Options window.
- Always run the Optimise function by selecting the Optimise item from the Tools menu in the BB FlashBack Player. This will reduce the size of your movie where possible.
- Use plain desktop wallpaper, as complex wallpapers can add literally megabytes to your final file size. You can set BB FlashBack to show plain wallpaper while recording via the “Set plain desktop wallpaper” option on the Display tab of the Recorder Options window.
- Record at the lowest screen resolution possible. Higher screen resolutions create larger movie files.
- If possible, avoid recording pictures, photos or animations as these will boost file size significantly.
- If recording sound through BB FlashBack, make sure “use MP3 compression” is selected in the sound recording options, or if you’re adding a sound file into your movie in the player: use MP3 files rather than uncompressed formats such as WAV.
- If exporting to Flash format enable “MX compression” on the Flash export options window: this reduces the size of your Flash file. If perfect movie quality is not vital also consider using JPEG compression on the same screen, and lower the colour depth on the “More” tab. Both these options slightly reduce the image quality of your movie, but can dramatically reduce the Flash movie size.
- If exporting to AVI or WMV, experiment with different codecs to find the best results.
|
|
|
|