G.719

G.719 is standardized by the ITU- T audio codec, the encoding of wideband audio signals ( 20 KHz audio bandwidth, 48 kHz sampling rate ), and high quality, standard high bit rate (32 to 128 kbit / s) with low computational effort allows. He was created in a collaboration between Polycom and Ericsson.

G.719 codec technology combined of elements of Ericsson and Polycom Siren codecs which have been used for many years in video conferencing systems. He was recognized as the ITU -T Recommendation " G.719 " on 13 June 2008.

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

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

The modifier 1 specification for G.719 ITU-T defines the use of the ISO base media file format (ISO / IEC 14496-12, also known as MPEG -4 Part 12) 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 discusses use cases for the codec beyond conversations (for example, on-hold music and recording Telephonkonferenz sessions, voice messages ). Therefore, may contain G.719 encoded audio material multimedia file formats, such as MP4 ( audio/mp4 or video/mp4 ) and 3gp ( audio/3gpp and video/3gpp ).

RFC 5404 defines the Media Type " audio/G719 ".

Licensing

G.719 is licensed by Polycom, Inc. and Ericsson; both licenses are required for use. Polycom licensee also get the right to use G.722.1 ( Siren7, Polycom 7 kHz codec) and G.722.1 Annex C ( Siren14, the 14- kHz counterpart ).