# Compressing MP3 songs in LINUX and Sending it Via BLUETOOTH using LINUX



## paragkalra (Dec 21, 2006)

SOUNDKONVERTER
COMPRESSING & CONVERTING MUSIC FILES FROM ONE FORMAT TO OTHER FORMAT IN LINUX WAS NEVER SO EASY.

HERE ARE THE SCREEN SHORTS:
*discoverlinux.blogspot.com/2006/12/soundkonverter-n-bluetooth.html

AIM:
Compressing MP3 songs in LINUX and Sending it Via BLUETOOTH using LINUX

It feels great to tell you that now I use LINUX to compress my MP3 songs and on the same lines I use LINUX only to send the same song via inbuilt BLUETOOTH facility provided by SUSE LINUX.

PREREQUISITES

1.SUSE LINUX preferably SUSE LINUX 10.2

2.BlueTooth Dongle

3.BlueTooth Compatible Handset. (I am having a L6 Motorola)

4. MP3 Compressor Software.

I received a CD along with my BlueTooth Dongle. But that CD contains drivers only for windows and Nice GUI based software for sending and receiving data.

However coming back to LINUX when I inserted my BlueTooth dongle into one of my USB port in LINUX, It showed no message. Then I clicked kbluetoothd which is nothing but the BlueTooth server or can be treated as BlueTooth daemon in SUSE LINUX, a message was displayed at topmost left corner indicating kbluetoohd – Bluetooth Adaptor found.

Unfortunately My L6 Motorola has only 10 MB internal Memory and no scope for external memory, so I can't afford to listen high quality songs on my cell. Thus I needed a software that could compress my songs. I went to *kde-apps.org/

Then I went to Multimedia section and in Multimedia section I went to Sound section. Fortunately I found a software named soundKonverter right at the top in second position. I downloaded the rpm belonging to SUSE 10.2 RC1 (RELEASE CANDIDATE) version. This is the short cut:

*kde-apps.org/content/download...nt=29024&id=10

Just copy this in your browser's address bar and it will ask you to download or you can download the appropriate rpm depending upon your distro.

I installed the software using:

[root@localhost]# rpm -ivh soundkonverter-0.2.95-1.suse10.2.i686.rpm

Bang it got installed very neatly in one go (pretty rare scene in LINUX, anyways)

Now it was time to run the software, I just fired this at the KONSOLE:

[root@localhost]# soundkonverter

COMPRESSING MP3s

1.There are two options first one is SIMPLE and second one is DETAILED right at the top.

2.It always advisable to select DETAILED.

3.Select the RESAMPLE or SAMPLING FREQUENCY to 32KHz though not a hard fast rule. It depends on the clarity of the song you want. If you want high clarity keep the SAMPLING FREQUENCY less but it will take more time.

4.Make BIT RATE constant (cbr) and set BIT RATE to 128. Bit rate controls the size of the song. Thus more the BIT RATE more will the MP3 size

5.Also make the channel to STEREO

6.Now add the file music file and select the appropriate O/P source directory.

7.Finally start the compression.

8.Once compressed your music file is ready to get transfered.

9.Now click Applications –> Utilities --> Obex File Transfer.

10.Drag the file you are suppose to transfer and Enjoy Music on your Handset using LINUX.

HERE ARE THE SCREEN SHORTS:
*discoverlinux.blogspot.com/20...bluetooth.html


LITTLE THINGS THAT MATTER MUCH

BIT RATES
Bit rate refers to the speed at which a bit stream (compressed audio data in this case) will travel, or the amount of bits per second. With MP3, you usually refer to it in terms of kbps or how many thousands of bits per second. Many MP3 enthusiasts will convert to MP3 at 128 kbps (kilobytes per second) as a good medium in sound quality and file size. However, I recommend 160 kbps , especially if you are a musician or if you have a sensitive ear to musical quality. Bit rate can be used to predict the size of the encoded file. It is simply calculated by whatever bit rate you have chosen to encode with multiplied by the length of the song.


Standard Bit Rates and their qualities:

96kbs: The sound clearly lacks definition: as an example, hall's noises are perceived as some breath. The result is comparable to a good FM radio.

112kbs: The sound seems less present and less natural than the original. The definition is a bit less good, the voice is less clear. Attacks are less spontaneous. The spatialization is different from the original recording: the sound seems to be located more far and more lower. There is however a very noticeable improvement compared to 96kbs.

128kbs: Hall's noises are slightly less defined than the original. The violin is a bit less present and the piano attacks a bit less sharp. The voice is nearly identical to the original recording but sibilants are less pronounced. We can notice the same spatialization problem as with the 112kbs's one although there is again a good improvement compared to the 112kbs rate.

160kbs: The sound is more natural than 128kbs but the improvement is less spectacular than during the two preceding stages. The sound is different from the original, without however being possible to tell in what. I think that the difference resides more in what we feel rather than in what we hear.

192kbs: The sound is not felt as the original recording. It is however totally impossible to tell in what.

256kbs: The sound is indiscernible from the original. It is impossible to make the difference with the original recording.

320kbs: The sound is indiscernible from the original. It is impossible to make the difference with the original recording.

CD Audio : The sound of the burned CD is strictly identical the manufactured CD. This test, although it could appear useless, is however necessary so in order to insure that it is impossible that the burning step introduces differences, that would have falsified tests.


SAMPLING FREQUENCY
The sampling frequency (or sample rate) is the number of samples per second in a Sound. For example: if the sampling frequency is 44100 Hertz, a recording with a duration of 60 seconds will contain 2,646,000 samples. The available sampling frequencies are 32, 44.1 and 48 kHz. 44.1 kHz is almost always used


Relation between Bit Rate and Sampling Frequency
Bit Rate = (Bits/sample) * Sampling Frequency

Now comes the million dollar question, What is more important BIT RATE , SAMPLING FREQUENCY or BIT PER SAMPLE

Any MP3 compressor gives you the option of controlling both BIT RATE & SAMPLING FREQUENCY but it doesn't allow you to play with BITS PER SAMPLE. So how to decide what is important and what is not.

First and Foremost size of any MP3 music file depends solely on is BIT RATE (kbps) and its pretty acceptable because SIZE (kb) = BITRATE (kbps) * TIME (s)

Thus the file's bit rate is simply an indicator of data size. You can, for example, have a 64kbps 44.1kHz stereo sound, or a 64kbps 22.05kHz stereo sound, or a 64kbps 44.1kHz mono sound. All will take up the same amount of disk space.

On the other hand SAMPLING FREQUENCY is the measure of COMPLEXITY of the encoder. Thus more the SAMPLING FREQUENCY less will the BITS PER SAMPLE required to encode , less complex will be the encoding process and lesser will the time required i.e. your song would get compressed much faster but at the cost of clarity.

On the same lines if SAMPLING FREQUENCY is less, more will be the BITS PER SAMPLE required to encode the music file, complexity involved will be more also compression will take comparatively more time but music file will have some what better clarity.

To be very honest SAMPLING FREQUENCY hardly makes any difference. CLARITY is more or less the same in facts its very difficult to make out any difference if at all it exits. It may just control the time it takes for the song to get compressed. Thus more the sampling frequency less would be the time required for compression or encoding process. Hence its a common practice to keep the sampling frequency high usually 44100 Hz

DOCUMENTATION, CONCEPT, COSTUME, REVIEW, STORY, SCREENPLAY, LYRICS, MUSIC, PRODUCED & DIRECTED BY
PARAG.A.KALRA


----------



## Ramakrishnan (Dec 21, 2006)

Mp3 format is already compressed. How can you compress it any further?


----------



## infra_red_dude (Dec 21, 2006)

^^ what he means is lowering the bitrate.


----------



## Ramakrishnan (Dec 22, 2006)

If he lowers the bitrate, the quality will degrade.


----------

