Encoding video

In this use case, the clock.avi which comes as preinstalled on all Microsoft Windows XP installations is used to demonstrate the conversion process by converting it into mobile-compliant 3GP format. Clock.avi is a 12-second long video clip that can be found in the WINNT directory. The file is highly compressed initially so do not be alarmed by the apparent lack of further file size reduction over the course of this example.

For this example, you can use the clock.avi or your own video file.

1. Download and install MediaCoder or similar video encoding software, and run it. Click File > Add File and find clock.avi.

2. Set the correct encoding settings. Start from the Audio tab, which is open by default.

   Mobile devices generally support at least AMR, AAC, and MP3 audio formats. In this use case, AAC is used. To further save space on the target device, you can lower the bitrate and sampling rates to achieve a smaller file size.

   

   Figure 20: MediaCoder audio settings

3. After audio, you can start configuring video settings, which are found by clicking the Video tab on the right side of the Audio tab.

   Video formats have more variety than audio formats. They are divided into actual video codecs that handle compression among other features and container formats that tie the video and audio together into one file.

   Mobile devices generally support H.263, MPEG4, RealVideo video formats and 3GP and MP4 containers. In this use case, H.263/3GP combination is used as it is the most common mobile device video format. The video bitrate is set as 48 kbps, which is quite low but sufficient enough for such a simple video file.

   

   Figure 21: MediaCoder video settings

4. Open the Picture tab. From here you can set the size of the video resolution.

   3GP/H.263 combination only supports resolutions up to 176x144px, so it is used in this use case. The frame rate can be lowered to get an even smaller file. If the video is not shown correctly, you may need to set the rotation as well.

   

   Figure 22: MediaCoder resolution settings

5. Choose your output folder in the upper right corner and click Start. MediaCoder encodes the video in the chosen location. Note that only the suffix of the filename is changed. If you want to have a file other than clock.3gp, you need to change it.