G.719
Encyclopedia
G.719 is an ITU-T standard audio codec
providing high quality, moderate bit rate (32 to 128 kbit/s) wideband
(20 Hz - 20 kHz audio bandwidth, 48 kHz audio sample rate) audio coding at low computational load. It was produced through a collaboration between Polycom
and Ericsson
.
G.719 incorporates elements of Polycom's Siren22
codec (22 kHz) and Ericsson codec technology, as well as Polycom's Siren7 and Siren14 codecs (G.722.1 and G.722.1 Annex C), which have been used in videoconferencing systems for many years. As ITU-T Recommendation G.719, it was approved on June 13, 2008.
G.719 is optimized for both speech and music. It is based on transform coding with adaptive time-resolution, adaptive bit-allocation and low complexity lattice vector quantization. The computational complexity is quite low (18 floating-point MIPS) for an efficient high-quality compressor. The codec operates on 20 ms frames, and the algorithmic delay end-to-end is 40 ms. The encoder input and decoder output are sampled at 48 kHz.
In addition to the nominal bit rates of 32, 48 and 64 kbit/s, the G.719 codec has an inherent feature of flexible rate selection. In fact, it is possible to accommodate any rate between 32 kbit/s and 64 kbit/s by steps of 4 kbit/s. Moreover, the codec can also provide higher rates than 64 kbit/s and up to 128 kbit/s.
Amendment 1 of the ITU-T G.719 specification defined the use of the ISO base media file format
(ISO/IEC 14496-12 a.k.a. MPEG-4
Part 12) as container for the G.719 bitstream. It also defined stereo and multichannel use of G.719 bitstreams in the ISO base media file format. It addresses non-conversational use cases of the codec (e.g. call waiting music playback and recording of teleconferencing sessions, voice mail messages). Thus, media file formats such as MP4 (audio/mp4 or video/mp4) and 3GP
(audio/3GPP and video/3GPP) can contain G.719-encoded audio.
RFC 5404 defined media type audio/G719.
Audio codec
All codecs are devices or computer programs capable of coding or decoding a digital data stream or signal.The term audio codec has two meanings depending on the context:...
providing high quality, moderate bit rate (32 to 128 kbit/s) wideband
Wideband Audio
Wideband audio is an audio technology used in telephony. It extends the frequency range of audio signals transmitted over telephone lines, resulting in higher quality speech. The range of the human voice extends from 80 Hz to 14 kHz but traditional, voiceband or narrowband telephone calls limit...
(20 Hz - 20 kHz audio bandwidth, 48 kHz audio sample rate) audio coding at low computational load. It was produced through a collaboration between Polycom
Polycom
Polycom is a multinational corporation with approximately 3,200 employees worldwide and an annual revenue of approximately $1.2 billion in 2010. The company manufactures and sells telepresence and voice communications solutions.-Company History 1990:...
and Ericsson
Ericsson
Ericsson , one of Sweden's largest companies, is a provider of telecommunication and data communication systems, and related services, covering a range of technologies, including especially mobile networks...
.
G.719 incorporates elements of Polycom's Siren22
Siren Codec
Siren is a family of patented, transform-based, wideband audio codecs developed and licensed by PictureTel Corporation . There are three Siren codecs: Siren 7, Siren 14 and Siren 22....
codec (22 kHz) and Ericsson codec technology, as well as Polycom's Siren7 and Siren14 codecs (G.722.1 and G.722.1 Annex C), which have been used in videoconferencing systems for many years. As ITU-T Recommendation G.719, it was approved on June 13, 2008.
G.719 is optimized for both speech and music. It is based on transform coding with adaptive time-resolution, adaptive bit-allocation and low complexity lattice vector quantization. The computational complexity is quite low (18 floating-point MIPS) for an efficient high-quality compressor. The codec operates on 20 ms frames, and the algorithmic delay end-to-end is 40 ms. The encoder input and decoder output are sampled at 48 kHz.
In addition to the nominal bit rates of 32, 48 and 64 kbit/s, the G.719 codec has an inherent feature of flexible rate selection. In fact, it is possible to accommodate any rate between 32 kbit/s and 64 kbit/s by steps of 4 kbit/s. Moreover, the codec can also provide higher rates than 64 kbit/s and up to 128 kbit/s.
Amendment 1 of the ITU-T G.719 specification defined the use of the ISO base media file format
ISO base media file format
ISO base media file format defines a general structure for time-based multimedia files such as video and audio. It is used as the basis for other media file formats...
(ISO/IEC 14496-12 a.k.a. MPEG-4
MPEG-4
MPEG-4 is a method of defining compression of audio and visual digital data. It was introduced in late 1998 and designated a standard for a group of audio and video coding formats and related technology agreed upon by the ISO/IEC Moving Picture Experts Group under the formal standard ISO/IEC...
Part 12) as container for the G.719 bitstream. It also defined stereo and multichannel use of G.719 bitstreams in the ISO base media file format. It addresses non-conversational use cases of the codec (e.g. call waiting music playback and recording of teleconferencing sessions, voice mail messages). Thus, media file formats such as MP4 (audio/mp4 or video/mp4) and 3GP
3GP
3GP is a multimedia container format defined by the Third Generation Partnership Project for 3G UMTS multimedia services. It is used on 3G mobile phones but can also be played on some 2G and 4G phones....
(audio/3GPP and video/3GPP) can contain G.719-encoded audio.
RFC 5404 defined media type audio/G719.
Licensing
G.719 is licensed by Polycom, Inc. and by Ericsson; both licenses are necessary 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 equivalent).External links
- Polycom Siren/G 722.1 Page
- Polycom Siren14 G.722.1C Page
- Official ITU-T G.719 standard
- RFC 5404 - RTP Payload Format for G.719