Shulou(Shulou.com)06/02 Report--

This article is about what amr means. Xiaobian thinks it is quite practical, so share it with everyone for reference. Let's follow Xiaobian and have a look.

AMR is a file format that stores AMR voice encoded files; many phones allow users to store short AMR recordings, while some open source and commercial software have programs that convert to other formats; AMR is a voice format that is not optimized for other sounds; the common file extension is ".amr."

AMR is also a file format that stores AMR speech encoded files. Many mobile phones allow users to store AMR recordings for short periods of time, while some open source (see external link) and commercial software have programs for converting and other formats. But AMR is a speech format and is not optimized for other sounds. The normal file extension is.amr.

Because amr is an audio file format, there are many software that can open amr files, such as: commonly used storm video, thunder and other audio and video player software can open amr files, and Nokia mobile phones can also open amr ring files.

characteristics

Sampling rate 8 kHz/13-bit (160 samples every 20ms), only signals in the range of 200-3400 Hz are retained after filtering.

The encoder uses eight bit rates: 12.2, 10.2, 7.95, 7.40, 6.70, 5.90, 5.15 and 4.75 kbit/s.

The resulting frame length is 95, 103, 118, 134, 148, 159, 204, or 244 bits, and the corresponding bit rate is 4.75, 5.15, 5.90, 6.70, 7.40, 7.95, 10.2, or 12.2 kbit/s, respectively.

AMR utilizes Discontinuous Transmission (DTX), Voice Activity Detection (VAD), and Comfort Noise Generation (CNG) to reduce bandwidth during silent periods.

The algorithm delay is 20ms per frame. When the pace is 12.2, there is no lookahead delay. The look-ahead delay for the other rates is 5 ms. Note that there is a simulated look-ahead delay of 5 ms, allowing accurate frame width mode conversion to the remaining rates.

AMR is a hybrid speech encoder that uses Algebraic Code Excited Linear Prediction (ACELP).

If the complexity of the algorithm is 5, then G.711 is 1 and G.729a is 15.

The PSQM tested lossy Mean Opinion Scores AMR (12.2 kbit/s) under ideal conditions was 4.14, compared to 4.45 for G.711 (u-law).

PSQM Mean Opinion Scores AMR (12.2 kbit/s) under network conditions is 3.79, compared to 4.13 for G.711 (u-law).

Thank you for reading! About "amr refers to what file" this article is shared here, I hope the above content can be of some help to everyone, so that everyone can learn more knowledge, if you think the article is good, you can share it to let more people see it!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.