A Codec is a device or software capable of encoding or decoding a digital stream or a signal for transmission over a data network. There are video and audio codecs. Codecs are divided into two categories. Lossless codecs and Lossy codecs. Lossless codecs retain all the information contained in the original stream thus preserving the audio/video quality in a signal, while lossy codecs reduce the quality to achieve compression but also use lower data bandwidth.
The following is a list of Codecs that are in common use today:
Audio Codecs:
- GSM – 13 Kbps (full rate), 20ms frame size.
- iLBC – 15Kbps,20ms frame size: 13.3 Kbps, 30ms frame size.
- ITU G.711 – 64 Kbps, sample-based. Also known as A-law/μ-law.
- ITU G719 – 32/48/64/128 Kbps, 28 ms Frame Size.
- ITU G.722 – 48/56/64 Kbps.
- ITU G.723.1 – 5.3/6.3 Kbps, 30ms frame size.
- ITU G.726 – 16/24/32/40 Kbps.
- ITU G.728 – 16 Kbps.
- ITU G.729 – 8 Kbps, 10ms frame size.
- Speex – 2.15 to 44.2 Kbps.
- LPC10 – 2.5 Kbps.
- DoD CELP – 4.8 Kbps.
Video Codecs:
- VP8 is codec used for the encoding and decoding of high definition video as a either a file or a bit-stream for viewing. The VP8 codec is – in contrast to the H.264 codec – free for use.
- H.264/MPEG-4 Part 10 or AVC (Advanced Video Coding) is currently one of the most commonly used formats for the recording, compression, playback of high definition video. In contrast to VP8, H.264 is not free.
