Differentiation Between G711 and G729 Codecs

Almost each and every codec differs from one another at some or the other point. But still there are people who cannot differentiate between G711 and G729. Let’s start with the G711 codec first.

G711 Codec:

The G711 codec, the base standard of codecs in many devices, generally helps in converting to 128kbs (64kbs Upload/ 64kbs download). This is the first ITU-T recommendation on speech coding, and was introduced to make sure of international interoperability among carriers. The G.711 standard is also inclusive of Appendix I for Packet Loss Concealment (PLC) and Appendix II for Comfort Noise Payload (CNP). It is also capable of operating in µ-law and A-law.

It’s essentially the data format of how to make transferring of a voice over the internet in its most common format. Primary reason why this codec is so simple is because it doesn’t compress the speech as much as other codecs when transferring over the Internet. Just as your PC/device carries your voice is quite like it’s dissipated over the Internet just as the receiver gets your voice.

Some of the key attributes of the G711 codec are:

Under network stress, PSQM testing renders Mean Opinion Scores of 4.13 for G.711?-law, 4.11 for G.711 A-law

Under ideal conditions, PSQM testing results in Mean Opinion Scores of 4.45 for G.711?-law, 4.45 for G.711 A-law

G.711 Appendix II determines a Discontinuous Transmission (DTX) algorithm that makes use of Comfort Noise Generation (CNG) and Voice Activity Detection (VAD) to bring reduction in the bandwidth usage when there are silence periods

G.711 Appendix I specifies a Packet Loss Concealment (PLC) algorithm to abet to concealing transmission losses in a packetized network

64 kbit/s bitrate (8 kHz sampling frequency x 8 bits per sample)

Typical algorithmic delay is 0.125 ms, without any look-ahead delay

G.711 is a waveform speech coder

Sampling frequency 8 kHz

Some of the Pro’s of G711 codec include:

The G711 codec is the highest quality voice for both ends

Most G711 softphones come free (Like Xlite)

Similarly there are some con’s of the G711 codec

There is major use of bandwidth. If either party is not having sufficient bandwidth, voice could be rough and choppy.

Not all VoIP suppliers offer support for G711 Codec

G729 Codec:

The G729 codec generally helps in converting to 8kbps (8kbps Upload/ 8kbps download)

A G729 coder enables to reduce in size the data of the voice phone call prior to it being sent over the Internet. This results into lower bandwidth employed to making call or much more people being able to call over the similar bandwidth consumption. The receiver end of the VoIP call thereafter helps in converting back to standard size using a G.729 decoder or decompressor.

Some key attributes of G.729 codec include:

It delivers low bit rate (8 kb/s) ITU-T standard including toll quality.

It functions as the most standard codec for all apps, inclusive of wireless.

Bit-accuracy ensures that in spite of implementation, the same level of quality will be maintained.

Quality gets least affected by error transmission as opposed to other low bit rate vocoders.

A mainstream codec of the ITU-T, including existing development as depicted by its annexes:

Annex A: Reduced complexity 8 kb/s

Annex B: VAD/CNG/DTX (Voice Activity Detection/Comfort Noise Generator/Discontinuous Transmission)

Annex C: Floating point version of G.729 and its annexes

Annex D: Extension at 6.4 kb/s

Annex E: Extension at 11.8 kb/s

Some pro’s of G729 include:

Low bandwidth usage for the call.The generic G729 codec comes free for evaluation at used for testing purpose).

Winner: G711 vs G729 codec = G729

Similarly the G729 has some con’s as well:

Patent rights are still enforced.

Not all VoIP providers offer support for G729 Codec

Winner: G711 vs G729 codec = G729

Thus, both the codecs stand a lot apart from one another when it comes to G711 codec specifications and G729 codec specifications. Both the codecs also differ in terms of their features, usages and benefits.

If you are looking for G729 Codec, the author of this article recommends CodecPro.

If you want to know about G729 codec specification, the author of this article recommends CodecPro.