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Preferences
Supported Video Formats
Making Videos

Select this to choose the video file to play back as your wallpaper. You can browse through the entire file system of your phone. The <go up to ...> option goes one directory back. Your SD card's home directory can be found in the top most directory (it is usually /sdcard/) and is colored red.

You can choose a single file or an entire directory for play back. If you select the entire directory, then all videos from that directory (and possibly subdirectories) will be played, according to the preferences below.

Recursive directory

This option enables all subdirectories in addition to the selected directory.

This option is disabled if a single video file is chosen for play back, rather than a directory.

Random file

If you enable this option then video files are played in a random order. If you disable this option then video files are played in an alphabetical order.

This option is disabled if a single video file is chosen for play back, rather than a directory.

Swiping smoothness

You can choose what you want smoother when swiping between home screens. Smoother swiping animation makes all the icons and widgets appear to slide smoother, but freezes the video in the background. Smoother video does the opposite: it doesn't freeze the video, but the widgets and icons may not slide as smooth.

This effect is only visible on some home screen replacement apps, like Launcher Pro.

Do not skip frames

Sometimes videos are too complex to be played back smoothly. They are either too big in resolution or have a frame rate that is too high. If this option is disabled then the live wallpaper will attempt to skip frames to play the video as close to the original speed as possible. Enable this option if you prefer smooth animation and don't care much about slow speed.

Shift video

If this option is enabled then the video will shift left and right when swiping between home screens. If this option is disabled then the video will stay centered.

This effect is only visible if the video is wider than the screen.

Swiping lag

This setting tells the live wallpaper how fast it should shift the video when swiping. You can select one of five stages, ranging from instant which shifts the video at the same time as swiping occurs, to slow which makes the shifting animation very slow.

This setting has no effect if the video is not wider than the screen. This setting is disabled if video shifting is disabled.

Debug mode

If this option is enabled then the current/wanted FPS value is displayed at the center of the wallpaper. Also, the device's logcat is filled with all kinds of debugging information. Keep this option disabled unless you are making a video and want to see the FPS or you are instructed to turn it on by the support/developer.

Supported Video Formats

This live wallpaper uses FFmpeg to decode videos. This means that every video format that FFmpeg supports is also supported here. These include:

.avi
.mp4
.3gp
.mpg
.flv
.3g2
.asf
.dv
.mov
.mpeg
.rm
.vcd
.vob
.wmv

Many video codecs are also supported. Please refer to the FFmpeg documentation for the complete list.

Audio is not supported as this is a live wallpaper and is not supposed to emit sounds.

Making Videos

A word about bitrate

When you are reencoding video, you are often asked to provide a bitrate. A bitrate is a number which tells the codec how much storage space on average it is allowed to spend on a single second of video. The unit is bits per second or just bps. This number is usually very large so it is often shortened by a factor of 1000. Such a value has a unit called kilobits per second or kbps.

The bitrate is used to find a compromise between the video file's size and the video quality. With a small bitrate, the file is small but the video is of very bad quality. As the bitrate is increased, the quality gets better but the file size gets bigger.

If you don't care much about file size, then a high bitrate like 3000 kbps should be more than enough to produce nice quality videos at the recommended resolutions and frame rates. Generally, the bitrate gives an estimate of the resulting file size. The formula involved is:

video_size_in_MB = bitrate_in_kbps * 128 * video_length_in_seconds

This holds true if there is no audio and if the bitrate is not too small for the given resolution.

You should also consider what codec you use. Some codecs need more bitrate to generate a nice quality image than others. 3000 kbps should be more than enough for mpeg4 for example, but might not be enough for mjpeg or mpeg1video.

Do not go overboard with the bitrate. Keep in mind that storage memory in phones and other embedded devices is slower than on most bigger machines. A 100 MB file for a minute of a video is probably too much!

Reencoding video with FFmpeg

FFmpeg is a free tool that can be used to reencode your videos to a more appropriate codec/format for the live wallpaper. FFmpeg can be found all over the internet and is available for Windows, Linux and Mac. Search for "ffmpeg executable for windows/linux/mac" to find it. If you are using linux then FFmpeg is probably already included with your setup.

FFmpeg is a console executable. On Windows you access it via the Command Prompt (cmd.exe), on Linux or Mac you use a terminal. Usage of cmd or terminal is beyond the scope of this help so search the internet if you need additional help. Alternatively, you can look for graphical frontends to FFmpeg but then this chapter will probably not be of much use to you.

To get information about your existing video file, use the following command:

ffmpeg -i "video file"

This command will output all the information about the video file. Look for the video stream, where you will be able to find the duration, bitrate, codec, resolution and frame rate (fps or tbr). If everything fits the recommended values in the previous chapters then the video doesn't need reencoding and is ready. If such a video contains audio and you would like to get rid of it as it is not needed, the following command does this quickly:

ffmpeg -i "video file" -an -vcodec copy "output file"

This command will make an output file that only contains video from the video file.

To fully reencode the video, use the following command:

ffmpeg [options_1] -i "video file" -an [options_2] -vcodec <video_codec> -vb <bitrate> "output file"

Substitute [options_1] with zero, one or more of the following:

-ss time_in_seconds
if you wish to skip to time_in_seconds and start encoding from there
-t time_in_seconds
if you wish to encode only time_in_seconds seconds of the video

Substitute [options_2] with zero, one or more of the following:

-s size
if you wish to resize the video (for example to 640x480)
-r framerate
if you wish to set a new frame rate in FPS (for example to 25 or 23.976)

Substitute <video_codec> with one of the supported video codecs, for example mpeg1video or mpeg4.

Substitute <bitrate> with the wanted bitrate in bits per second, for example 1000000 or 1000k, which is the same.

If you wish to keep the sound (which will NOT be played as the live wallpaper), substitute -an with -acodec copy.

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An example of a full command would be:

ffmpeg -ss 15 -i "myvideo.avi" -an -s 640x360 -vcodec mpeg4 -vb 1500k "result.avi"

This command would:

start at the 15th second of the original video
encode until the end of the original video (because -t option is missing)
encode the myvideo.avi file (the "original" video)
cut out and disable the sound from the result (the -an flag)
resize the result to 640x360
keep the same frame rate as in the original video (because -r option is missing)
use the mpeg4 (DivX/XviD/3ivX) video codec to encode
use the bitrate of 1.500.000 bits per second
save the result into the file named result.avi

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The FFmpeg supports much more options than are mentioned and explained here. Please refer to the documentation of FFmpeg to find out more.

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Last Saved: December 11th, 2010