Posts Tagged ‘gcc’

How to RIP audio CD and convert to MP3 format on Linux

Thursday, April 11th, 2024

I've been given a very tedious task to Copy music from Audio CD Drive to MP3 / MP4 file format and then copy the content to external Flash drive.
Doing so is pretty trivial, you just need to have a CD / DVD rom on your computer something that becomes rare nowadays and then you need to have installed a bunch of software, if you don't already have it as i've pointed in my previous article Howto craete Music Audio CD from MP3 files, create playable WAV format audio CD Albums from MP3s.

Creating a Audio CD from an MP3 collection is exactly the opposite to what is aim't now (to copy the content of a CD to a computer and prepare it for A Car MP3 player).

1. RIPing audio CDs to WAV and Conver to MP3 from terminal
 

On Linux there is  many ways to do it and many tools that can do it for your both graphical and command line.
But as I prefer command line to do stuff, in this article I'll mention the quickest and most elementary one which is done in 2 steps.

1. Use a tool to dump the CD Audio music to Tracks in WAV format
2. Convert the WAV to MP3 format

We'll need cdparanoia tool installed as well as ffmpeg.

If you don't have them installed do:

# apt-get install –yes cdparanoia dvd+rw-tools cdw cdrdao audiotools cdlabelgen dvd+rw-tools wodim ffmpeg lame normalize-audio libavcodec58

Next create the directory where you want to dump the .wav files.

# mkdir /home/hipo/audiorip/cd1
# cd /home/hipo/audiorip/cd1

Next assumng the Audio CD is plugged in the CD reader, dump its full content into track*.WAV files with cmd:

# paranoia -B

This will produce you the dumped songs into .wav files.

hipo@noah:~/audiorip/cd1$ ls -al *.wav
-rw-r–r– 1 root root  10278284 мар 25 22:49 track01.cdda.wav
-rw-r–r– 1 root root  21666668 мар 25 22:50 track02.cdda.wav
-rw-r–r– 1 root root  88334108 мар 25 22:53 track03.cdda.wav
-rw-r–r– 1 root root  53453948 мар 25 22:55 track04.cdda.wav
-rw-r–r– 1 root root 100846748 мар 25 22:58 track05.cdda.wav
-rw-r–r– 1 root root  41058908 мар 25 22:59 track06.cdda.wav
-rw-r–r– 1 root root 105952940 мар 25 23:02 track07.cdda.wav
-rw-r–r– 1 root root  50074124 мар 25 23:03 track08.cdda.wav
-rw-r–r– 1 root root  92555948 мар 25 23:06 track09.cdda.wav
-rw-r–r– 1 root root  61939964 мар 25 23:07 track10.cdda.wav
-rw-r–r– 1 root root   8521340 мар 25 23:07 track11.cdda.wav

Then you can use a simple for loop with ffmpeg command to conver the .wav files to .mp3s.

hipo@noah:~/audiorip/cd1$  for i in $( ls -1 *); do ffmpeg -i $i $i.wav.mp3; done
 

ffmpeg version 1.2.12 Copyright (c) 2000-2015 the FFmpeg developers
  built on Feb 12 2015 18:03:16 with gcc 4.7 (Debian 4.7.2-5)
  configuration: –prefix=/usr –extra-cflags='-g -O2 -fstack-protector –param=ssp-buffer-size=4 -Wformat -Werror=format-security ' –extra-ldflags='-Wl,-z,relro' –cc='ccache cc' –enable-shared –enable-libmp3lame –enable-gpl –enable-nonfree –enable-libvorbis –enable-pthreads –enable-libfaac –enable-libxvid –enable-postproc –enable-x11grab –enable-libgsm –enable-libtheora –enable-libopencore-amrnb –enable-libopencore-amrwb –enable-libx264 –enable-libspeex –enable-nonfree –disable-stripping –enable-libvpx –enable-libschroedinger –disable-encoder=libschroedinger –enable-version3 –enable-libopenjpeg –enable-librtmp –enable-avfilter –enable-libfreetype –enable-libvo-aacenc –disable-decoder=amrnb –enable-libvo-amrwbenc –enable-libaacplus –libdir=/usr/lib/x86_64-linux-gnu –disable-vda –enable-libbluray –enable-libcdio –enable-gnutls –enable-frei0r –enable-openssl –enable-libass –enable-libopus –enable-fontconfig –enable-libpulse –disable-mips32r2 –disable-mipsdspr1 –dis  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[wav @ 0x66c900] max_analyze_duration 5000000 reached at 5015510 microseconds
Guessed Channel Layout for  Input Stream #0.0 : stereo
Input #0, wav, from 'track01.cdda.wav':
  Duration: 00:00:23.19, bitrate: 1411 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s
Output #0, mp3, to 'track01.cdda.wav.wav.mp3':
  Metadata:
    TSSE            : Lavf54.63.104
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le -> libmp3lame)
Press [q] to stop, [?] for help
size=     363kB time=00:00:23.19 bitrate= 128.2kbits/s    
video:0kB audio:363kB subtitle:0 global headers:0kB muxing overhead 0.058402%
ffmpeg version 1.2.12 Copyright (c) 2000-2015 the FFmpeg developers
  built on Feb 12 2015 18:03:16 with gcc 4.7 (Debian 4.7.2-5)
  configuration: –prefix=/usr –extra-cflags='-g -O2 -fstack-protector –param=ssp-buffer-size=4 -Wformat -Werror=format-security ' –extra-ldflags='-Wl,-z,relro' –cc='ccache cc' –enable-shared –enable-libmp3lame –enable-gpl –enable-nonfree –enable-libvorbis –enable-pthreads –enable-libfaac –enable-libxvid –enable-postproc –enable-x11grab –enable-libgsm –enable-libtheora –enable-libopencore-amrnb –enable-libopencore-amrwb –enable-libx264 –enable-libspeex –enable-nonfree –disable-stripping –enable-libvpx –enable-libschroedinger –disable-encoder=libschroedinger –enable-version3 –enable-libopenjpeg –enable-librtmp –enable-avfilter –enable-libfreetype –enable-libvo-aacenc –disable-decoder=amrnb –enable-libvo-amrwbenc –enable-libaacplus –libdir=/usr/lib/x86_64-linux-gnu –disable-vda –enable-libbluray –enable-libcdio –enable-gnutls –enable-frei0r –enable-openssl –enable-libass –enable-libopus –enable-fontconfig –enable-libpulse –disable-mips32r2 –disable-mipsdspr1 –dis  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[mp3 @ 0x66c900] max_analyze_duration 5000000 reached at 5015510 microseconds
Input #0, mp3, from 'track01.cdda.wav.mp3':
  Metadata:
    encoder         : Lavf54.63.104
  Duration: 00:00:23.22, start: 0.000000, bitrate: 128 kb/s
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p, 128 kb/s
File 'track01.cdda.wav.mp3.wav.mp3' already exists. Overwrite ? [y/N] y
Output #0, mp3, to 'track01.cdda.wav.mp3.wav.mp3':
  Metadata:
    TSSE            : Lavf54.63.104
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p
Stream mapping:
  Stream #0:0 -> #0:0 (mp3 -> libmp3lame)
Press [q] to stop, [?] for help
Trying to remove 1152 samples, but the queue is emptys    
size=     363kB time=00:00:23.24 bitrate= 128.1kbits/s    
video:0kB audio:363kB subtitle:0 global headers:0kB muxing overhead 0.058336%
ffmpeg version 1.2.12 Copyright (c) 2000-2015 the FFmpeg developers
  built on Feb 12 2015 18:03:16 with gcc 4.7 (Debian 4.7.2-5)
  configuration: –prefix=/usr –extra-cflags='-g -O2 -fstack-protector –param=ssp-buffer-size=4 -Wformat -Werror=format-security ' –extra-ldflags='-Wl,-z,relro' –cc='ccache cc' –enable-shared –enable-libmp3lame –enable-gpl –enable-nonfree –enable-libvorbis –enable-pthreads –enable-libfaac –enable-libxvid –enable-postproc –enable-x11grab –enable-libgsm –enable-libtheora –enable-libopencore-amrnb –enable-libopencore-amrwb –enable-libx264 –enable-libspeex –enable-nonfree –disable-stripping –enable-libvpx –enable-libschroedinger –disable-encoder=libschroedinger –enable-version3 –enable-libopenjpeg –enable-librtmp –enable-avfilter –enable-libfreetype –enable-libvo-aacenc –disable-decoder=amrnb –enable-libvo-amrwbenc –enable-libaacplus –libdir=/usr/lib/x86_64-linux-gnu –disable-vda –enable-libbluray –enable-libcdio –enable-gnutls –enable-frei0r –enable-openssl –enable-libass –enable-libopus –enable-fontconfig –enable-libpulse –disable-mips32r2 –disable-mipsdspr1 –dis  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[mp3 @ 0x66c900] max_analyze_duration 5000000 reached at 5015510 microseconds
Input #0, mp3, from 'track01.cdda.wav.mp3.wav.mp3':
  Metadata:
    encoder         : Lavf54.63.104
  Duration: 00:00:23.25, start: 0.000000, bitrate: 128 kb/s
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p, 128 kb/s
Output #0, mp3, to 'track01.cdda.wav.mp3.wav.mp3.wav.mp3':
  Metadata:
    TSSE            : Lavf54.63.104
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p
Stream mapping:
  Stream #0:0 -> #0:0 (mp3 -> libmp3lame)
Press [q] to stop, [?] for help
Trying to remove 1152 samples, but the queue is emptys    
size=     364kB time=00:00:23.27 bitrate= 128.1kbits/s    
video:0kB audio:364kB subtitle:0 global headers:0kB muxing overhead 0.058271%
ffmpeg version 1.2.12 Copyright (c) 2000-2015 the FFmpeg developers
  built on Feb 12 2015 18:03:16 with gcc 4.7 (Debian 4.7.2-5)
  configuration: –prefix=/usr –extra-cflags='-g -O2 -fstack-protector –param=ssp-buffer-size=4 -Wformat -Werror=format-security ' –extra-ldflags='-Wl,-z,relro' –cc='ccache cc' –enable-shared –enable-libmp3lame –enable-gpl –enable-nonfree –enable-libvorbis –enable-pthreads –enable-libfaac –enable-libxvid –enable-postproc –enable-x11grab –enable-libgsm –enable-libtheora –enable-libopencore-amrnb –enable-libopencore-amrwb –enable-libx264 –enable-libspeex –enable-nonfree –disable-stripping –enable-libvpx –enable-libschroedinger –disable-encoder=libschroedinger –enable-version3 –enable-libopenjpeg –enable-librtmp –enable-avfilter –enable-libfreetype –enable-libvo-aacenc –disable-decoder=amrnb –enable-libvo-amrwbenc –enable-libaacplus –libdir=/usr/lib/x86_64-linux-gnu –disable-vda –enable-libbluray –enable-libcdio –enable-gnutls –enable-frei0r –enable-openssl –enable-libass –enable-libopus –enable-fontconfig –enable-libpulse –disable-mips32r2 –disable-mipsdspr1 –dis  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[wav @ 0x66c900] max_analyze_duration 5000000 reached at 5015510 microseconds
Guessed Channel Layout for  Input Stream #0.0 : stereo
Input #0, wav, from 'track02.cdda.wav':
  Duration: 00:02:21.28, bitrate: 1411 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s
Output #0, mp3, to 'track02.cdda.wav.wav.mp3':
  Metadata:
    TSSE            : Lavf54.63.104
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le -> libmp3lame)
Press [q] to stop, [?] for help


Finally remove the old unneded .wav files and enjoy the mp3s with vlc / mplayer / mpg123 or whatever player you like.

hipo@noah:~/audiorip/cd1$  rm -f *.wav


Now mount the flash drive and copy th files into it.

# mkdir /media/usb-drive
# mount /dev/sdc1 /media/usb-drive/
# mkdir -p /media/usb-drive/cd1
# fdisk -l |grep -i sdc1

/dev/sdc1 on /media/usb-drive type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=utf8,shortname=mixed,errors=remount-ro

# cp -rpf ~/audiorip/cd1*.mp3 /mnt/usb-drive/cd1
# umount /dev/sdc1


2. RIPping audio CD on Linux with rip-audio-cds-linux.sh  script
 

#!/bin/bash
# A simple shell script to rip audio cd and create mp3 using lame
# and cdparanoia utilities.
# —————————————————————————-
# Written by Vivek Gite <http://www.cyberciti.biz/>
# (c) 2006 nixCraft under GNU GPL v2.0+
# —————————————————————————-
read -p "Starting in 5 seconds ( to abort press CTRL + C ) " -t 5
cdparanoia -B
for i in *.wav
do
    lame –vbr-new -b 360 "$i" "${i%%.cdda.wav}.mp3"
    rm -f "$i"
done


If you need to automate the task of dumping the audio CDs to WAV and convert them to MP3s you can do it via a small shell script like the one provided by cyberciti.biz that uses paranoia and lame commands in a shell script loop. Script rip-audio-cds-linux.sh is here

3. Dump Audio CD to MP3 with Graphical program ( ripperx ) 

By default most modern Linux distributions including the Debian GNU / Linux based ones has the ripperx in the default repositories, as well as the tool is downloadable and compilable from source from sourceforge.net 

ripping-audio-cds-linux-graphical-program-ripperx-tool

# apt-cache show ripperx|grep -i descript -A3 -B3
Architecture: amd64
Depends: cdparanoia, vorbis-tools (>= 1.0beta3), libatk1.0-0 (>= 1.12.4), libc6 (>= 2.14), libcairo2 (>= 1.2.4), libfontconfig1 (>= 2.12.6), libfreetype6 (>= 2.2.1), libgcc1 (>= 1:3.0), libgdk-pixbuf2.0-0 (>= 2.22.0), libglib2.0-0 (>= 2.16.0), libgtk2.0-0 (>= 2.8.0), libpango-1.0-0 (>= 1.14.0), libpangocairo-1.0-0 (>= 1.14.0), libpangoft2-1.0-0 (>= 1.14.0), libstdc++6 (>= 5.2), libtag1v5 (>= 1.9.1-2.2~)
Suggests: sox, cdtool, mpg321, flac, toolame
Description-en: GTK-based audio CD ripper/encoder
 ripperX is a graphical interface for ripping CD audio tracks (using
 cdparanoia) and then encoding them into the Ogg, FLAC, or MP2/3
 formats using the vorbis tools, FLAC, toolame or other available
 MP3 encoders.
 .
 It includes support for CDDB lookups and ID3v2 tags.
Description-md5: cdeabf4ef72c33d57aecc4b4e2fd5952
Homepage: http://sourceforge.net/projects/ripperx/
Tag: hardware::storage, hardware::storage:cd, interface::graphical,
 interface::x11, role::program, scope::application, uitoolkit::gtk,

# apt install –yes ripperx


https://www.pc-freak.net/images/ripperx-linux-gui-rip-audio-cds-tool

That's all folks.
Enjoy !

Megaraid SAS software installation on CentOS Linux

Saturday, October 20th, 2012

With a standard el5 on a new Dell server, it may be necessary to install the Dell Raid driver, otherwise the OMSA always reports an error and hardware monitoring is therefore obsolete:

Previously, the megaraid_sys package was now called mptlinux

For this we need the following packages in advance:

# yum install gcc kernel-devel
Now the driver stuff:

# yum install dkms mptlinux
That should have built the new module, better test it:

# modinfo mptsas

# dkms status
After a kernel update it may be necessary to build the driver for the new version:

# dkms build -m mptlinux -v 4.00.38.02

# dkms install -m mptlinux -v 4.00.38.02

FreeBSD 10.0 RELEASE is out pkg_add FreeBSD default package manager to be substituted with pkg

Thursday, January 23rd, 2014

freebsd 10 is out logo pkg add to be removed - freebsd big news pkg_add to be substituted by another package manager

New latest version of FreeBSD 10.0-RELEASE is out this. FBSD 10  is the latest stable release of 10 branch. The biggest change in FBSD 10 is removal of long time used pkg_add and its substitute with the newer and more advanced pkg. For BSD users who don't know pkg  stiill check out handbook on pkgng

Key highlights of FreeBSD 10 as taken from FreeBSD-10.0-RELEASE announcement;
 

  • GCC is no longer installed by default on architectures where clang(1) is the default compiler.

  • Unbound has been imported to the base system as the local caching DNS resolver.

  • BIND has been removed from the base system.

  • make(1) has been replaced with bmake(1), obtained from the NetBSD Project.

  • pkg(7) is now the default package management utility.

  • pkg_add(1), pkg_delete(1), and related tools have been removed.

  • Major enhancements in virtualization, including the addition of bhyve(8), virtio(4), and native paravirtualized drivers providing support for FreeBSD as a guest operating system on Microsoft Hyper-V.

  • TRIM support for Solid State Drives has been added to ZFS.

  • Support for the high-performance LZ4 compression algorithm has been added to ZFS.

    There is a big news for Raspberry Pi lovers as from FreeBSD 10 there is an official support for Raspberry Pi
    Happy new release. Cheers to testers 🙂

How to extract Audio Sound and Music from Flash Videos (.flv) files and convert it to (.mp3) on Linux and BSD

Friday, April 15th, 2011

In my quest to know Linux better and use it capabilities to fulfill a multimedia tasks I came across the question:

How can I extract audio sound and music from Flash Videos .flv file format?

After a bit of investigation online I’ve found out in order to achieve this task the quickest way is via the handy ffmpeg conversion tool .

It’s rather easy actually, all necessery to do the conversion is to have the ffmpeg installed.
FFMpeg is part of Debian and Ubuntu repositories, so if you haven’t installed it yet, go straigh and install it with:

debian:~# apt-get install ffmpeg
...

Many modern day Linux distributions already have the ffmpeg pre-installed by default, ffmpeg even have a Windows version so this little tutorial should be directly applied on a Windows host with installed ffmpeg.

Convertion of a .flv file to .mp3 file for example is a real piece of cake to so do issue the command:

debian:~# ffmpeg -i input_file.flv -ab 128 -ar 44100 output_file.mp3

The few mmpeg options meaning is as follows:

-i (specifies input file)
-ab (Set the audio bitrate in bit/s 64k by default)
-ar (Set the audio sampling frequency (default = 44100 Hz).)

For more options checkout the ffmpeg help.

I found ffmpeg to be a bit slower than I expected. A 17 minutes .flv video file is converted to .mp3 for 38 seconds time.

Here is the textual output I got on my Debian Linux while extracting the flash video’s sound and converting it to mp3:

debian:~# time ffmpeg -i g7tvI6JCXD0.flv -ab 128 -ar 44100 output.mp3
FFmpeg version SVN-r25838, Copyright (c) 2000-2010 the FFmpeg developers
built on Jan 21 2011 08:21:58 with gcc 4.4.5
configuration: –enable-libdc1394 –prefix=/usr –extra-cflags=’-Wall -g ‘ –cc=’ccache cc’ –enable-shared –enable-libmp3lame –enable-gpl –enable-libvorbis –enable-pthreads –enable-libfaac –enable-libxvid –enable-postproc –enable-x11grab –enable-libgsm –enable-libtheora –enable-libopencore-amrnb –enable-libopencore-amrwb –enable-libx264 –enable-libspeex –enable-nonfree –disable-stripping –enable-avfilter –enable-libdirac –disable-decoder=libdirac –enable-libschroedinger –disable-encoder=libschroedinger –enable-version3 –enable-libopenjpeg –enable-libvpx –enable-librtmp –extra-libs=-lgcrypt –disable-altivec –disable-armv5te –disable-armv6 –disable-vis
libavutil 50.33. 0 / 50.39. 0
libavcore 0.14. 0 / 0.14. 0
libavcodec 52.97. 2 / 52.97. 2
libavformat 52.87. 1 / 52.87. 1
libavdevice 52. 2. 2 / 52. 2. 2
libavfilter 1.65. 0 / 1.65. 0
libswscale 0.12. 0 / 0.12. 0
libpostproc 51. 2. 0 / 51. 2. 0
[flv @ 0x1336760] Estimating duration from bitrate, this may be inaccurate

Seems stream 0 codec frame rate differs from container frame rate: 2000.00 (2000/1) -> 29.92 (359/12)
Input #0, flv, from ‘g7tvI6JCXD0.flv’:
Metadata:
duration : 1060
starttime : 0
totalduration : 1060
width : 480
height : 360
videodatarate : 76
audiodatarate : 94
totaldatarate : 179
framerate : 30
bytelength : 23723246
canseekontime : true
sourcedata : B5F9E82C6HH1302704673918653
purl :
pmsg :
Duration: 00:17:40.35, start: 0.000000, bitrate: 174 kb/s
Stream #0.0: Video: h264, yuv420p, 480×360 [PAR 1:1 DAR 4:3], 77 kb/s, 29.92 tbr, 1k tbn, 2k tbc
Stream #0.1: Audio: aac, 44100 Hz, stereo, s16, 96 kb/s
WARNING: The bitrate parameter is set too low. It takes bits/s as argument, not kbits/s
Output #0, mp3, to ‘output.mp3’:
Metadata:
duration : 1060
starttime : 0
totalduration : 1060
width : 480
height : 360
videodatarate : 76
audiodatarate : 94
totaldatarate : 179
framerate : 30
bytelength : 23723246
canseekontime : true
sourcedata : B5F9E82C6HH1302704673918653
purl :
pmsg :
TSSE : Lavf52.87.1
Stream #0.0: Audio: libmp3lame, 44100 Hz, stereo, s16, 0 kb/s
Stream mapping:
Stream #0.1 -> #0.0
Press [q] to stop encoding
size= 16576kB time=1060.81 bitrate= 128.0kbits/s
video:0kB audio:16575kB global headers:0kB muxing overhead 0.002404%

real 0m38.489s
user 0m37.126s
sys 0m0.764s

When talking about conversions, another very useful application of ffmpeg is in case if you want to:

Extract Audio from online streams

Let’s say you have a favourite radio, you often listen and there are a podcast you want to capture for later listening, or just catch a few nice songs, using ffmpeg it’s a piece of cake by using the command like:

debian:~# ffmpeg -i http:///xxx.xxx.xxx.xxx/some -ab 128 -ar 44100 captured-radio-sound.mp3

The possible ways of use of ffmpeg is truly versatily, you can use it for instance if you have to convert some kind of audio or video format to another one I have given a very simple example of converting a .flv file to .avi and vice versa in my previous post