Convert M4R to AMR
Total Audio MP3 Converter converts M4R 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
- Launch Total Audio MP3 Converter
- Choose M4R Files
Click "Add Files" to choose M4R files and then add them to conversion
Choose one or more M4R files you want to convert and then click Open.
- Choose "to AMR"
- Convert M4R to AMR
Click button "Convert" to convert M4R files to AMR format.
The software is converting M4R files to AMR format.
- Play and Browse AMR File
When conversion completes, you could right-click converted AMR file and choose
"Play Destination" to play the outputted AMR file; or choose "Browse
Destination Folder" to open Windows Explorer to browse the AMR file.
What is M4R?
M4R is the standard file format for Apple iPhone ringtones. The M4R is encoded
with Advanced Audio Coding (AAC). The AAC is a standardized, lossy compression
and encoding scheme for digital audio. AAC has been standardized by ISO and IEC,
as part of the MPEG-2 and MPEG-4 specifications.
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
- Sampling frequency 8 kHz/13-bit (160 samples for 20 ms frames), filtered to
- 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
- 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
- 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 M4R to AMR Related Topics:
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SDP to AMR,
DAT to AMR,
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FLV to AMR,
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WAVE64 to AMR,
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DIVX to AMR,
MKA to AMR,
MLP to AMR,
MTV to AMR,
MKV to AMR,
DTS to AMR,
ALAW to AMR,
PVA to AMR,
ROQ to AMR,
CD to AMR,
M2T to AMR,
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TS to AMR,
RPL to AMR,
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