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Convert M1A to AMR
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Total Audio MP3 Converter converts M1A files to AMR format.
The software is an all in one audio converter that supports more than 90 audio
and video files as input, and converts to popular formats such as MP3, WAV, AAC,
M4A, OGG, WMA, and AMR.
Total Audio MP3 Converter also supports batch conversion, and is full compatible
with Vista and Windows
7.
- Free Download
Total Audio MP3 Converter here and then install the software
by instructions
- Launch Total Audio MP3 Converter
- Choose M1A Files
Click "Add Files" to choose M1A files and then add them to conversion
list.
Choose one or more M1A files you want to convert and then click Open.
- Choose "to AMR"
- Convert M1A to AMR
Click button "Convert" to convert all M1A files to AMR format.
The software is converting M1A files to AMR format.
- Play & Browse
When conversion completes, you could right-click converted item and choose "Play
Destination" to play the destination file; or choose "Browse Destination
Folder" to open Windows Explorer to browse the destination file.
Top
What is M1A?
MPEG-1 Audio Layer I. MPEG-1 Layer I is nothing more than a simplified version
of Layer II. Layer I uses a smaller 384-sample frame size for very low delay,
and finer resolution. This is advantageous for applications like teleconferencing,
studio editing, etc. It has lower complexity than Layer II to facilitate real-time
encoding on the hardware available circa 1990.
Layer I saw limited adoption in its time, and most notably was used on Philips'
defunct Digital Compact Cassette at a bitrate of 384 kbit/s. With the substantial
performance improvements in digital processing since its introduction, Layer I
quickly became unnecessary and obsolete.
What is AMR?
Adaptive Multi-Rate (AMR) is an audio data compression scheme optimized for speech
coding. AMR was adopted as the standard speech codec by 3GPP in October 1998 and
is now widely used in GSM and UMTS. It uses link adaptation to select from one
of eight different bit rates based on link conditions. AMR is also a file format
for storing spoken audio using the AMR codec. Many modern mobile telephone handsets
will allow you to store short recordings in the AMR format. There also exists
another storage format for AMR that is suitable for applications with more advanced
demands on the storage format, like random access or synchronization with video.
This format is the 3GPP-specified 3GP container format based on ISO base media
file format.
Key Features:
- Sampling frequency 8 kHz/13-bit (160 samples for 20 ms frames), filtered to
200-3400 Hz.
- The AMR codec uses eight source codecs with bit-rates of 12.2, 10.2, 7.95,
7.40, 6.70, 5.90, 5.15 and 4.75 kbit/s.
- Generates frame length of 95, 103, 118, 134, 148, 159, 204, or 244 bits for
bit rates 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), with Voice Activity Detection
(VAD) and Comfort Noise Generation (CNG) to reduce bandwidth usage during silence
periods
- Algorithmic delay is 20 ms per frame. For bit-rates of 12.2, there is no 'algorithm'
look-ahead delay. For other rates, look-ahead delay is 5 ms. Note that there is
5 ms 'dummy' look-ahead delay, to allow seamless frame-wise mode switching with
the rest of rates.
- AMR is a hybrid speech coder which uses Algebraic Code Excited Linear Prediction
(ACELP)
- The complexity of the algorithm is rated at 5, using a relative scale where
G.711 is 1 and G.729a is 15.
- PSQM testing under ideal conditions yields Mean Opinion Scores of 4.14 for
AMR (12.2 kbit/s), compared to 4.45 for G.711 (u-law)
- PSQM testing under network stress yields Mean Opinion Scores of 3.79 for AMR
(12.2 kbit/s), compared to 4.13 for G.711 (u-law)
Convert M1A to AMR Related Topics:
OGA to AMR,
WM to AMR,
MKA to AMR,
M1A to AMR,
MJ2 to AMR,
XA to AMR,
3GP2 to AMR,
MOD to AMR,
ASF to AMR,
AMR to AWB,
ALAW to AMR,
MP4 to AMR,
OMA to AMR,
MVI to AMR,
QT to AMR,
3G2 to AMR,
EVO to AMR,
M4B to AMR,
MP1 to AMR,
DV to AMR,
AC3 to AMR,
OGM to AMR,
NUT to AMR,
3GPP to AMR,
CD to AMR,
SMK to AMR,
QCP to AMR,
S3M to AMR,
SPX to AMR,
DIVX to AMR,
F4B to AMR,
W64 to AMR,
M4V to AMR,
AWB to AMR,
GSM to AMR,
FLIC to AMR,
MPEG to AMR,
VCD to AMR,
M1V to AMR,
SWF to AMR
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