G.719

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G.719 is an audio codec standardized by ITU-T , which encodes broadband audio signals (20 kHz audio bandwidth, 48 kHz sampling rate) with high quality and moderately high bit rate (32 to 128 kbit / s) with low Calculation effort enabled. It was created in a collaboration between Polycom and Ericsson .

G.719 combines Ericsson codec technology and elements of Polycom's Siren codecs that have been used in video conferencing systems for many years. It was recognized on June 13, 2008 as the ITU-T Recommendation "G.719".

G.719 is designed for both voice and music signals. It is based on transform coding with adaptive time resolution, adaptable bit allocation and low-complexity lattice vector quantization. The computational effort is quite low (18 floating point MIPS) for an efficient high quality audio compressor. The codec works with 20 millisecond blocks and the algorithmic end-to-end delay is 40 milliseconds. The input signal for the encoder and the output of the decoder are sampled at 48 kHz.

In addition to the nominal bit rates of 32, 48 and 64 kbit / s, the G.719 codec is capable of flexible bit rate selection. In fact, it can adjust the bit rate in steps of 4 kbit / s between 32 and 64 kbit / s. The codec can also use higher bit rates up to 128 kbit / s.

The addition 1 to the G.719 specification of the ITU-T defines the use of the ISO base media file format (ISO / IEC 14496-12, also known as MPEG-4 Part 12) as the container format for G.719 data streams. It also defines stereo and multi-channel use of G.719 data streams within the ISO base media file format. It also covers use cases for the codec beyond conversations (e.g. music on hold and recording of telephone conference sessions, voice messages). Therefore, multimedia file formats such as MP4 (audio / mp4 or video / mp4) and 3gp (audio / 3GPP and video / 3GPP) can contain G.719 encoded audio material.

RFC 5404 defines the media type audio/G719.

Licensing

G.719 is licensed from Polycom Inc. and Ericsson; both licenses are required for use. Polycom licensees also receive the right to use G.722.1 (Siren7, Polycom's 7 kHz codec) and G.722.1 Annex C (Siren14, the 14 kHz counterpart).

Web links

Individual evidence

  1. ↑ Polycom Siren 22 . Polycom, Inc .. Retrieved September 7, 2009.
  2. ^ G.719: The First ITU-T Standard for Full-Band Audio (PDF; 542 kB) Polycom, Inc. April 2009. Retrieved September 7, 2009.
  3. ↑ ITU-T (2009) ITU-T Recommendation G.719 accessed on June 17, 2009
  4. ↑ RFC 5404 - RTP Payload Format for G.719 , p. 18, accessed on June 17, 2009