admin/repository/nanogong

Nanogong plugin

The Nanogong plugin allows audio-only recording inside the Moodle repositories. The wav files are stored into Moodle using the File API. The sound files can be recorded using the ImaACPCM or Speex codecs. The recorded files and the recording applet are available in all places where the repository is used to select files.

After installing the plugin, you can select the codec used and the quality of the sound for the site-wide recording instance. This instance will be shared by all users of your site (because it only handles recording, and File API handles the rest).

Audio format

This option allows you to select the codec used for recording sound.

ImaADPCM stands for International Multimedia Association (IMA) Adaptive Differential Pulse Code Modulation (ADPCM). It is a lossy compression mechanism that compresses data recorded at various sampling rates. The compression ratio obtained is relatively modest, but it is very fast to encode and decode.

Speex is an Open Source/Free Software patent-free (part of the GNU Project) audio compression format designed for speech. Speex is well-adapted to Internet applications and provides useful features that are not present in most other codecs. The design goals have been to make a codec that would be optimized for high quality speech and low bit rate.

Sampling rate

This option allows you to select the sampling rate used for recording sound. The actual numeric value associated with each level depends on the audio format in use.

Level	ImaADPCM sampling rate (Hz)	Speex sampling rate (Hz)
Low quality	8000	8000
Medium quality	11025	16000
Normal quality	22050	32000
High quality	44100	44100