Certain types of audio content will ‘take’ a watermark better than others. The basic rule is that you want almost continual noise, with few silences as possible.
Examples of audio that works well with watermarking:
- TV and radio ads with speech and/or music
- Pop and rock music
Examples of audio to avoid:
- Commentary during a golf broadcast
- Solo instrumental music
- Recordings of sparse conversation
- Audio files that do not meet the technical specs below
The audio file formats that work with watermarking are:
- *.wav (preferred)
- Minimum length: 10 seconds
- Maximum length: 10 minutes
- File extension must be in lowercase.
- Sample rate: 44.1kHz or 48kHz
- Bits per sample: 16 or 24
- Bit rate: 128kbps or higher
- File size: Under 150MB
Tip: How To Check the ‘Sample Rate’ of a File
Many audio players and most audio editors can show you advanced details of a file. For example, you can use the free Quicktime player as follows:
- Load the audio file
- Choose “Show Movie Inspector” from the Window menu.
- The Format listing will display the sampling rate, bit rate and other technical information.