Linux Multi-Media Basics

   When I first got into Linux (mid 90s with Slackware 2.0) there were very few multi-media applications available. Linux was pretty much limited to very basic audio file playing with non-interactive command line programs and a very limited motif based CD player program. If you wanted to watch video or listen to real music you pretty much had to use Windows. Luckily over the years Linux has moved from a server and developer OS to one that can also handle desktop functionality like multi-media. Linux even does a very good job of and in most cases a modern Linux distro is even better at multi-media than Windows is.

   The exception to this is DRM. Multi-media applications that use "Digital Rights Management" are often still limited to the Windows environment where they can enjoy the proprietary nature of the OS and prevent the user from enjoying their own data.

• xmms: Xmms is primarily a GUI audio file player. However, there are plugins available to make it play video if you really want it to. There are also plugins for just about every audio file format and audio related device out there. There are even control plugins that allow you to control xmms in some creative ways. Here are the xmms plugins that I often use:
• xmms-flac: Plays lossless .flac audio files. The xmms plugin is included with the main flac codec and tools.
• xmms-mpg123: Plays .mp3 files and streams. Comes with xmms.
• xmms-vorbis: Plays .ogg files and streams. Comes with xmms.
• modplug-xmms: Plays various old tracked module formats (.mod .it .xm .s3m). Modplug-xmms is the highest quality tracked music player because of its heavy use of oversampling. This is what I normally use for playing tracked music files.
• dumb-xmms: Plays various old tracked module formats (.mod .it .xm .s3m). Dumb is the most accurate tracked music player so use it if something just doesn't sound right in modplugxmms.
• xmms-mad: Plays .mp3 files. Generally sounds better than xmms-mpg123 however it doesn't support streaming and is less stable. I tend to only use it when using headphones.
• xmms-wav: Plays plain old uncompressed .wav files. Comes with xmms. I had trouble using both xmms-sndfile and xmms-audiofile so I use this instead.
• xmms-musepack: Plays Musepack (.mpc) audio files. These are rare but are out there. The format isn't a bad one it is just uncommon.
• xmms-midi: Plays .midi synth music. Uses timidity++ and its patches to do it.
• xmms-cdaudio: Plays audio CDROM discs (uses the DAC on the CDROM drive). Comes with xmms.
• xmms-a52dec: Plays a52 .ac3 audio files. These are the standard audio format that is on DVD discs.
• xmmsctrl: This isn't really a plugin but a command line utility for controlling xmms. It provides more controls than the standard xmms command.
• mplayer: Mplayer is primarily a command line video file player. It has support for many audio file formats and it can use xmms to play others if installed. It does have a GUI but not a very good one. I use mplayer to play almost all of my video data both on the monitor and on my TV set. I also have some scripts to automate some of its capabilities.
• xine: Xine is primarily a GUI video file player. It has a very nice GUI and works pretty much like a DVD player appliance that can also handle local files. I use this when I want to play a DVD in Linux because it handles the DVD menus very well (unlike mplayer which doesn't even support them).
• vlc: Vlc is another GUI video player. It isn't quite as nice as xine or as handy as mplayer but it has also been ported to Windows which means you can have a pretty good common app on both systems if you choose to use them.
• Audacity: Audacity is a nice GUI sound editing program. It is somewhat like SoundForge under Windows but better.
• amarok: Amarok is a complete multi-media library GUI in addition to a player. It is somewhat patterned after iTunes.

• normalize: Normalizes the volume level in a .wav file or a set of them. The purpose of normalizing is to attempt to adjust the volume level of a set of files so that they are all the same. This is especially important if you are making a mix CD or are playing songs randomly from a large pool from various sources. I use the --peak option for my music collection because that normalizes everything to the max it can take instead of trying to normalize them all to a specific amount.
• lame: The best mp3 encoder. Used as a back end by most GUI rippers.
• id3v2: A command line program for changing id3v2 tags in mp3 files.
• flac: This is the program for encoding and decoding flac files.
• Vorbis tools: Tools for working with ogg/vorbis files. Including oggenc and oggdec.
• mkvtoolnix: Tools for manipulating .mkv files (mkvmerge, mkvextract).
• sox: "The swiss army knife of sound processing programs". Sox can convert between a bunch of audio formats and can do some processing on them in the conversion.
• cdparanoia: Rips audio CDs and is very careful to make sure it gets a good copy.
• madplay: A command line decoder and play for all MPEG audio formats including mp3. It generally sounds better than mpg123.
• mpg321: A drop in replacement for mpg123. It uses the mad library so it sounds better than mpg123. It also hasn't had the security problems that mpg123 has had.
• ogmtools: Utilities for manipulating .ogm files.
• shntool: More utilities for .wav files. This can split up a large .wav file according to a .cue sheet.
• timidity++: Converts .mid files to .wav files (or plays them) using a patch set instead of synth hardware.
• avidemux: A GUI for working with .avi files.
• DVD::Rip: A GUI front end for DVD ripping using transcode.
• mpgtx: Tools for manipulating .mpg files.
• transcode: Converts between various video codecs.
• vcdimager: Manipulates VCD files and properly rips VCD discs.
• grip: A popular GUI CD audio ripping/encoding front end. Uses cdparanoia and lame. I personally don't like it because if there is an error during the ripping process you never see it unless you stare at the window the entire time.

• Alsa is better than OSS unless you just plain can't make it work with your hardware.
• I have written a script called tcode that transcodes between various audio codecs and the ones that I like to make. You can download it from: http://www.sanitarium.net/unix_stuff/mp3_scripts/tcode.txt. Even if you don't use it you can look at it to see all the command line arguments that I use for various things.
• Organize! Create a file and directory naming convention and layout. Stick to it. Keep id tags consistent with the file names. This will make finding what you want so much easier. When you are blasting music you want to keep it playing not spend 2 minutes scrolling around with a mouse looking for "that song". For example, my mp3 files are stored as: /mp3/[genre]/[artist]/[album]/[artist] - [album] - [tracknum] - [title].mp3
• Make playlists. They keep you from queuing up a bunch of stuff by hand.
• Xmms can read a playlist from a text file. The format is simply 1 filename per line. This means that it is real easy to write a perl (or whatever) script to generate a list of what you want to hear and hand it to xmms.
• If you have the disk space go with .flac files. At least for the stuff you really like. That way when the next wizz bang, saves 2% but gives 5% more quality codec comes out you don't have to re-rip all those CDs just to be happy again.
• Normalize! There is nothing worse than random playing a bunch of songs that are at completely different volume levels.
• Look through the list of xmms plugins. There are some real nice ones. I only listed the ones that I use but there are many others that you might like.
• I have had good luck with sound cards using the CM8738 chipset. Of course I haven't really tried all of the chipsets. Make sure you get one that can handle multiple sampling rates (some ONLY do 48k).
• 2 sound cards in one system has its benefits. I have a set of nice loud speakers that I use for music however they aren't normally on. I have another pair of old low power speakers that I leave on all the time connected to my second sound card to play notification sounds (like "you have mail" but not that lame). Sox can play a track to the second sound card with 'soxplay -d /dev/dsp1 file.wav'.
• Get good speakers. These are the most critical part of your sound system. A top of the line sound card or amp doesn't mean squat if your speakers suck. Luckily speakers tend to last a long time so if you invest in really good speakers you probably won't have to worry about it for 10 years or so.
• Computer sound doesn't have to go through wimpy little computer speakers. A simple adapter cable will connect you to a real sound system with really big speakers. As I write this I am listening to an Iced Earth song in a .flac file using xmms. It is playing through my CM8738 integrated sound chip to my JVC 400W amp. From there it goes to 2 Sony 3-way (dual 8"+3.5"+1") front speakers, 2 Infinity 6" 2-way rear speakers, and a 12" Infinity powered sub woofer. It sounds great and it shakes the floor :)
• Remap keys. Even though xmms is a GUI it can be controlled from the command line (it has plugins to give more commands). Those silly Windows keys that you have to get these days when you buy a keyboard can be very useful if mapped to control xmms. This is a window manager specific configuration though so I am not going to tell you how unless you want to know how to do it in fvwm-1.24r.

• Mplayer has a bunch of output options. It can display in X, the framebuffer console, SVGAlib, probably others. Some of those even have multiple modes. Some video cards even have their own drivers within mplayer (like xmga for Matrox cards). Experiment and see what works best for your hardware and setup.
• I prefer the Matrox G450 or G550 cards for displaying video on a monitor because of the xmga driver and /dev/mga_vid which uses the Matrox hardware for scaling. Matrox cards aren't very good for games but they are the best for video and have the best, most compatible, and completely open drivers.
• Video cards with the nVidia GeForce4 MX 4000 chipset and a TV-out jack are perfect for displaying video on a standard TV. You just tell X to run at 640x480 with the TV-out enabled, use the XV output in mplayer and it just works.
• Matroska files are smaller (slightly) than avi files. When you download an avi file you can convert it to a Matroska file with 'mkvmerge -o file.mkv file.avi'. This is not a transcode so there is no loss of quality and it doesn't take long. Just be sure to verify that the audio is still synchronized before you delete the .avi file. This also works for .ogm files but it doesn't save quite as many bytes.
• Xvid is better than DivX or SVCD. SVCD is better than VCD. PAL is higher resolution than NTSC.
• If you download an .avi file that has a 2-channel ac3 audio track you can save some space (and normalize the audio) by converting to a vorbis track and an .mkv file like this:
1. mplayer -dumpaudio -dumpfile file.ac3 file.ac3.avi
2. tcode ogg tv file.ac3 #assuming you have my tcode script and want to use TV quality
3. mkvmerge -o file.mkv -A file.ac3.avi file.ogg
   -or-
   mkvmerge -o file.mkv -A file.ac3.avi file.ogg file.ac3 #if you want to keep both audio tracks.
• If you have a file with the audio slightly out of sync you can use the + and - keys in mplayer to adjust it slightly in either direction. Once you figure out how much to change it and which way you can use mkvmerge -y to make a new .mkv file with the audio in sync.

• If you are storing a bunch of large video files (like TV shows or movies) use xfs. It handles large files much better than any other filesystem.
• If you are storing a bunch of medium sized files (like .flac, .vorbis, .mp3) and have them organized into directories use xfs. It handles them very well.
• If you are storing a bunch of tiny files (.mod, etc) or have a very large number of files all in one directory use reiserfs. It handles large directories and small files better than any other filesystem.
• If you are burning a CD or DVD use par2cmdline to pad out the disc with par2 recovery blocks. These will allow you to recover damaged data from the disc at a later date (assuming you have more good par2 blocks than bad data blocks). I have written a script called par2calc that calculates how many to make and makes them. You can download par2calc at http://www.sanitarium.net/unix_stuff/par2calc.txt.
• Backup! I can't mention storage without reminding you that if you didn't back it up you may as well consider it temporary.