Encoder Options for 3gp Files
This file format is widely used on mobile devices.
3gp files are saved using either H263 or MPEG4 compression.
- H263 is an old compression algorithm; it only supports a fixed set of video resolutions and the quality of compression is worse than MPEG4. However it is supported by most devices.
- MPEG4 compression is better than H263, and can be used with custom resolution. It is not supported by some older devices.
Here you specify the bitrate the video is encoded at. The higher the value, the better the quality of the picture and the less artifacts (macro blocks and blurring). You should experiment with this. Please note that higher values result in a larger file size.
- Average bitrate is the mean bit rate, and is the main value that affects quality. Maximum bitrate should generally exceed this, but no set margin is required; the Average and Maximum bitrate can safely be the same.
- Maximum bitrate is the absolute maximum. It does not majorly affect quality but some formats have set values that must not be exceeded (e.g. 10 megabits for DVD video). Sometimes if your maximum bitrate is too low then you will get macro block effects, in which case you should increase BOTH values.
H263 compression can only be used on a fixed set of resolutions. Choose the most suitable resolution from the list.
3gp files are saved using either AMR or AAC compression for sound.
- AMR is a common compression algorithm for mobile phones.
- AAC is an advanced compression algorithm which is only supported by some newer devices. The quality of sound is much better when using this compressor - however you should check if you device supports it.
You can select from a variety of bitrates for the sound to be encoded at. The higher the value the better the quality of sound.