Voice Codec Comparison - birdapplications’s diary

The following tables compare general and technical information for a variety of audio coding formats. For listening tests comparing the perceived audio quality of.
Codec Quality Comparison. Warning: these are machine-generated results not from real listeners and hence should be taken with a grain of salt. Codec Feature Comparison.
Codec Landscape Quality vs Bitrate The figure below illustrates the quality of various codecs as a function of the bitrate. It attempts to summarize results from a.

Codecs are used to convert an analog voice signal to digitally encoded version. Codecs vary in the sound quality, the bandwidth required, the computational.

Introduction. Audio codec is a small chip measuring 0.25 x 0.25 inches 7 x 7 mm located on the motherboard in charge of the analog audio functions.

Explanation of Terms

Codec Bit Rate Kbps

Based on the codec, this is the number of bits per second that need to be transmitted to deliver a voice call. codec bit rate codec sample size / codec sample interval.

Codec Sample Size Bytes

Based on the codec, this is the number of bytes captured by the Digital Signal Processor DSP at each codec sample interval. For example, the G.729 coder operates on sample intervals of 10 ms, corresponding to 10 bytes 80 bits per sample at a bit rate of 8 Kbps. codec bit rate codec sample size / codec sample interval.

Codec Sample Interval ms

This is the sample interval at which the codec operates. For example, the G.729 coder operates on sample intervals of 10 ms, corresponding to 10 bytes 80 bits per sample at a bit rate of 8 Kbps. codec bit rate codec sample size / codec sample interval.

MOS

MOS is a system of grading the voice quality of telephone connections. With MOS, a wide range of listeners judge the quality of a voice sample on a scale of one bad to five excellent. The scores are averaged to provide the MOS for the codec.

Voice Payload Size Bytes

The voice payload size represents the number of bytes or bits that are filled into a packet. The voice payload size must be a multiple of the codec sample size. For example, G.729 packets can use 10, 20, 30, 40, 50, or 60 bytes of voice payload size.

Voice Payload Size ms

The voice payload size can also be represented in terms of the codec samples. For example, a G.729 voice payload size of 20 ms two 10 ms codec samples represents a voice payload of 20 bytes 20 bytes 8 / 20 ms 8 Kbps

PPS

PPS represents the number of packets that need to be transmitted every second in order to deliver the codec bit rate. For example, for a G.729 call with voice payload size per packet of 20 bytes 160 bits, 50 packets need to be transmitted every second 50 pps 8 Kbps / 160 bits per packet.

Robust to corruption at the bit level, as found on wireless networks

Special Features

Speex supports intensity stereo encoding and 32 kHz sampling

iLBC

iLBC frames are encoded completely independently; while this provides better quality when 10 or more of the packets are being dropped, this makes the codec suboptimal for clean line conditions.

The Xiph OSC and the Speex Parrot logos are trademarks of Xiph.Org.

Last Modified.

Introduction to comparison. The following characteristics are compared in video codecs comparisons: Video quality per bitrate or range of bitrates.