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Convert MPA to AMR
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Total Audio MP3 Converter converts MPA 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 MPA Files
Click "Add Files" to choose MPA files and then add them to conversion
list.
Choose one or more MPA files you want to convert and then click Open.
- Choose "to AMR"
- Convert MPA to AMR
Click button "Convert" to convert all MPA files to AMR format.
The software is converting MPA 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 MPA?
MPA is compressed audio file using MPEG Layer I, II or III compression. There
are three "layers" in the MPEG-1 Audio specification. In MPEG Audio
Layer-1, a simple 32-subband audio compressor using a floating point representation
for subband samples. Resolution and scale factor are stored for groups of 12 subsamples.
MP1 is only used for Philips DCC Digital Compact cassette with data rates of 384
kbps. Both MPEG-1 and MPEG-2 files use MPEG-1 Audio Layer-2. MPEG-1 Audio Layer-3
becomes the widely popular MP3.
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 MPA to AMR Related Topics:
WV to AMR,
XVID to AMR,
SWF to AMR,
FLAC to AMR,
SPX to AMR,
AMR Converter,
VCD to AMR,
CAF to AMR,
MLP to AMR,
DIF to AMR,
DAT to AMR,
DVD to AMR,
DV to AMR,
XA to AMR,
WAV to AMR,
MKV to AMR,
DIVX to AMR,
OGG to AMR,
MPE to AMR,
MPGA to AMR,
AU to AMR,
AMR to AAC,
MOD to AMR,
F4A to AMR,
MTV to AMR,
FLIC to AMR,
EVO to AMR,
SND to AMR,
MVI to AMR,
AMR to M4B,
WM to AMR,
DXA to AMR,
AMR to WAV,
SMK to AMR,
M2A to AMR,
VQF to AMR,
CDA to AMR,
MKA to AMR,
H264 to AMR,
AMR to MP4
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