Showing posts with label audio. Show all posts
Showing posts with label audio. Show all posts

Tuesday, 14 November 2006

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Holy ear perforation Batman!

Whether you watch movies through your computer or on a traditional TV you will have noticed that there is often a dramatic contrast between the volume levels of the audio depending on what's happening on screen. The dialog can be so subdued the actors appear to be whispering making it impossible to determine what's being said, whereas the action sequences, explosions, gun shots and so on are loud enough to blow your socks off!

This is done deliberately and is known as 'dynamic range'; it's supposed to provide a more realistic interpretation of the natural soundscape. If you ask me it's enough to make you want to take Spielberg and his ilk by the throat and choke them to death.

In the cinema the projectionist 'works around' this issue by ramping up the volume to ear-splitting levels. Your head is usually ringing by the end of the film, but at least you'll know what it was all about. You're probably used to resorting to the same measures at home too, but not if your media playback software incorporates sound-shaping technology known as 'dynamic range compression'. This operates by standardising the extremes at each end of the auditory spectrum. In other words it amplifies softer sounds and dampens down louder ones so you don't need to keep your thumb poised on your remote control's volume button.

Ticking the 'A/52 dynamic range compression' check-box in VLC's preferences panel is all that is required to enable DRC.

'Normalisation' is another audio-taming feature often built into more advanced media players. It homogenises wave forms by applying a consistent gain ratio in conjunction with an upper volume cap. Within VLC's 'extended controls' panel, located under the 'window' menu, you will find a 'volume normalisation' audio filter. As before it's not difficult to guess how the tool-tipped check-box function operates.

So that's your DVDs covered, but what about the video content you record through your computer's TV tuner? If adding sound effects to a blog wasn't really irritating I'd insert one of me hitting a brick wall here. No audio manipulation gizmos of any kind are to be found in the EyeTV software, though I have an alert configured to give me a nudge the instant this situation changes.

Maybe the TV Volume Regulator could be configured to work with computer audio output. Still I'd rather wait for a software solution.

Saturday, 6 August 2005

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When full blast isn't loud enough

My Creative Rhomba MP3 player came loaded with European firmware (so I'm led to believe). Because some EU directive or other dictates that the volume of portable audio devices has to be restricted (presumably because some people are too feeble-minded to turn it down when their ears start to bleed) I'm unable to listen to certain audiobooks without editing them first.

The problem is that music files are encoded using various 'gain' (i.e. decibel) levels. Some have the maximum volume set very low, while others are set high enough to hollow out your cranium faster than a mutant, flesh-eating virus. If you've ramped up the volume to the maximum and still can't hear your track over the environmental background noise don't trash it just yet - keep reading to discover several potential solutions.

Some manufacturers release multiple, regional firmware updates - US and EU varieties at least. If you are able to flash your EU player with the US firmware you can often eliminate the volume restrictions. Unfortunately this didn't help in my case. I'm told this could be because the US and EU firmware is identical, or that there were no restrictions on the player to begin with - the power output could simply be very mediocre. This coupled with a subdued MP3 track is enough to leave you straining to hear what sounds like a game of Chinese whispers.

The next thing to try if that didn't help is to edit the tracks, turn up the gain (or 'normalise' them) and then re-encode the MP3s. This can be accomplished using the cross-platform audio editor, Audacity.

Here's how:-

- Run the application and open the track you wish to amplify.

- In the left hand panel next to the waveform display there's a slider with a minus symbol at one end, and a plus symbol at the other. Drag the marker which intersects the line towards the right to increase the decibel level. Go overboard and you will create nothing but painful distortion. I chose to boost the gain by 12db. This turned out to offer an ideal balance between sound quality and audibility, but your mileage will vary depending on the track used.

- Select 'File' then 'Export as MP3' to re-encode the corrected track. A new file will be created, leaving the original one intact, so don't worry about corrupting it. You can always try again with different settings if something goes wrong.

Windows users may like to give MP3Gain a shot instead. A Mac port exists known as MacMP3Gain, though it wouldn't behave itself when I tried it - probably because it's not been updated for nearly two years and so doesn't take into account the many OS X changes which have occurred in the mean time.

Another problem I had is that I couldn't get my MP3 player to play the ridiculous number of bitty files my audiobooks were split into in the correct order. They should automatically be organised in alpha-numeric order - should. Hmmf! In reality they play in the order in which they were transferred to the memory, so unless you want your book to read like the disjointed, though head-spinningly superb movie, Memento, you will have to drag each file over individually in sequence. Try doing that with an unabridged, epic novel like Lord of the Rings, split into 1mb chunks!

Luckily help is close at hand in the form of the Mac-only, labour-saving gizmo, ReJoiner. Select the folder containing your serialised audiobook, hit the 'ReJoin' button and the program will launch iTunes and use it to merge them together into a single MP3 file. Note that it can struggle to combine hundreds of files at once (most likely due to memory limitations) so you might like to separate your audiobooks into folders on a per chapter basis and combine them one at a time. Most flash-based MP3 players don't have the capacity to store such huge files in any case so this isn't really much of a drawback.

For Windows users there's Oliver Frietsch's ReOrganize which, if you have a compatible MP3 player, will allow you to re-arrange the playback order of your tracks once they have been transferred to your portable audio device.

Before researching these infuriating design flaws, the other option I seriously considered was hurling my MP3 player at the wall, kicking the furniture and cursing quite a bit. My ickle, oblivious Rhomba doesn't know how close it came to meeting its maker. Who knows? Maybe it could have asked Creative why it was born with half a brain and return from the other side to pass on this newfound, otherworldly knowledge. For now it has been granted a (temporary?) reprieve.

Wednesday, 15 June 2005

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Read Word (and other text) docs with your eyes shut!

Despite first appearances my latest party trick involves no risky eyelid surgery or telepathy of any kind. Rather, this feat can be achieved by running your documents through a text to speech synthesis tool capable of saving the output to an audio file (MP3 being the optimal format for maximum compatibility). These MP3s can be transferred to your portable player allowing you to 'read' web site articles, ebooks, Word documents, emails and so on, on the go.

The Mac is the ideal platform on which to make such conversions since OS X includes as standard very capable speech synthesizer technology incorporating 22 different voices. These range from conservative male and female dialects to wacky robotic and funeral overtone-infused vocalisations.
Because Apple has already done the hard work, it's very easy and cheap for software authors to piggyback this technology in creating text to speech conversion tools. Vox Machina proves my point - it can generate audio files, read text aloud directly and even map the spoken text to an animated representation of a mouth - a technique known as lip-syncing. It's a totally free download of Lilliputian proportions.

Monday, 17 November 2003

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The future's bright, the future's... the past?

Two of my most enduring passions are radio and classic gaming, so imagine my elation upon discovering that the two had been married together in the form of www.retrogamingradio.com. Lovingly crafted by the entertainingly opinionated Shane R. Monroe, the show has been 'on air' since 1998 and is broadcast at monthly intervals. Weaved into the proceedings are retro hardware and software reviews, emulation news, IT fuelled rants and interviews with the people who helped to sculpt the modern gaming industry we all know and l... well let's quit while we're ahead shall we? ;)

Since their inception the shows have consistently been growing lengthier - so much so that the latest edition clocks in at a whopping three hours! Each of these presentations are accessible over the internet for a limited time before being archived and made available for purchase on a series of CDs. As they are encoded using the highly versatile MP3 format, you are free to choose between downloading the complete files to be sampled offline at your convenience, or listening to them there and then as they are streamed over the web.

Computer games, past and present, receive so little coverage on mainstream TV and radio stations here in the UK so it's really refreshing to see this arm of the entertainment industry getting the attention it deserves via alternative mediums. Of special interest to die-hard Amigans this month is the commencement of a new series of Amiga segments which will focus on the history, hardware, emulation, games and demos of this seminal platform. If you want to skip straight to it you can slide Winamp's 'seeking bar' to 127 minutes, 16 seconds.

Shane, not only do you passionately speak your mind unswayed by the media hype-o-babble associated with modern gaming, you're the only person I know over the age of 15 who can impart the idioms, "that game so owns", "x requires tons of leet skillz" and "I'm a slut-pig-whore for genre x", and mean them in all seriousness... and for that, sir, I salute you.

Actually, that's a lie. Stop it, it's irritating! By copying immature, brainless, hacker-wannabe school kiddies, future generations of brainless, immature, hacker-wannabe school kiddies will copy you copying them and soon enough we'll have leet hacker freaks running amok and irritating people who know how to use the English language. :p That minor quibble aside, great show! Keep the retro flag flying!

I'm your host and you've been listening to Kookosity Radio. That was me being a DJ. Nice touch, huh? I'll get my coat *hangs head*

Tuesday, 19 February 2002

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I've downloaded an MP3 track, but it won't play. All I can hear is distortion. Why?

More than likely the file has been 'cooked'. This occurs when the server you are downloading from has been improperly configured and as a result treats binary files as text files. The solution? Well obviously you have to uncook the files. Why didn't you think of that? ;) This can be achieved using a program known as Uncook 95.

Wednesday, 5 September 2001

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MP3: music for the digital age

No internet harvesting training course would be complete without a bit of information on finding and downloading free music, so here's my attempt at guiding you to do just that. First a little bit of background information to give you a rough idea of what I'm talking about. When people use the phrase "free music on the internet" they are referring to MP3 files. MP3 is a fairly recent development in the computer music industry.

Music tracks are encoded from CDs and converted to compressed files with an MP3 extension. These can then be transferred back and forth across the internet, can be stored on your hard drive in the same manner as any other file format and require nothing more than Window's default media player to play them back (although Winamp makes a much better job of it). There's nothing new or revolutionary about this - we have been doing it for years now. The only difference is the transition between file formats.

Until recently, music was encoded in wave format (with a .wav extension) and a typical music track would occupy somewhere between 40 and 50 megabytes of hard disk space, which was obviously very inconvenient for transfer via the internet. So the critical change that the MP3 format brought about was a drastic reduction in file size, allowing much easier distribution over the internet, even for 56k modem users. To give you an example, a typical MP3 file will vary in size between 3 and 4 megabytes (depending on the 'bitrate' or quality in layman's terms) and provides near CD quality sound.

Locating and downloading MP3 tracks

So now the history lesson is over I'll get on with explaining how and where to find your next music fix. Many of the techniques that apply to other kinds of file foraging will also be useful for finding MP3s, so if you've already read my introductory lessons you'll be well equipped to begin your search.

The most dedicated MP3 aficionados tend to bypass more traditional transfer methods, instead opting for much more user friendly file-sharing clients. Of course, before the recent court ruling which imposed new restrictions on the exchange of copyright protected material, Napster ruled the MP3 sharing roost. Those days are, however, long gone. Not that this is likely to spell the end for the sharing of digital music; Napster was just the tip of the iceberg, the granddaddy which gave birth to the modern file sharing client if you like.

While Shaun Fanning deserves full credit for putting the wheels of the free (or at least reasonably priced) music machine in motion, we shouldn't be bowing our heads in silence to commemorate the fallen hero, but saluting his contribution whilst looking ahead at a much more sophisticated range of replacements.

The sheer number of alternative clients is astounding, yet many of them are plagued with problems, the most detrimental ones concerning difficulties in connecting to the networks used to transfer files and store user's file databases. We have all witnessed how vulnerable these centralised networks are to legal action - this is precisely why there has been a marked propensity of late to develop de-centralised systems whereby no single server exists that can be shut down in order to drive the network off-line.

Piolet utilizes such a system and is rapidly shaping up to be the number one Napster replacement. While the current version is still in its infancy, it has the potential to be more popular than Napster ever was and not least because the two programs are so similar. Piolet, as Napster once was, is built on the foundation of simplicity and ease of use, and this is precisely what will attract exiled ex-Napster users by the droves.

To help illustrate the point let me draw your attention to the fact that Piolet requires no installation whatsoever. You download a single file from the program's home page and you're ready to rock; the download is the whole client. Once it has finished downloading you can place it in any folder you like and simply double click on it to get started; the client automatically 'plugs' you into the community where you can begin searching for music tracks.

Also proudly riding the simplicity bandwagon is the anonymity factor. The program doesn't require you to register so you don't have to waste time thinking of a unique username or trying to remember your password before logging on as you would with many of Piolet's competitors. This means you are totally anonymous, a fact which the lack of any integrated spyware will also attest to.

OK, I take it you've had time to download and start the client by now... and if not, why not? Getting this baby up and running is absolute child's play. While it will run perfectly well 'out-of-the-box', it's always a good idea to set your preferences the first time you run any new application. To do this click on the 'config' tab. If your primary language isn't English, now's the time to tell Piolet.

With that precursor taken care of it would be advantageous to inform the client of what sort of connection you are employing to allow other users to estimate how long it is going to take them to download files from your hard drive, and also how long it is going to take you to download files from them.

From within the same 'connection' tab it is also possible to choose a nick name by which people can identify you. This isn't essential and doesn't have to be unique to you, although it's a simple way to introduce yourself to the people you are exchanging files with - it's just a matter of common courtesy really.

With that taken care of, it's time to switch to the 'uploads' tab. This is the area which allows you to select which folders will be made available to other Piolet users. To do this, click on the 'add' button and then use the integrated explorer to choose the folders where your MP3 files are stored. Note that it is advisable to have at least a few files available so that you can begin trading; you're not going to be too popular if you turn up to the party without a bottle!

Below the 'add' folders option are two input boxes. These allow you to restrict the number of files other users can grab from your computer simultaneously. Obviously if you're lumbered with a feeble dial-up modem it would be a good idea to keep this number fairly low (I would suggest setting this to just one or two simultaneous connections, and the maximum number of connections per user to one). If on the other hand you've been blessed with the use of a T1 or faster connection then throw caution to the wind and be as generous as humanly possible.

The final option which requires tweaking is the folder where you wish to store your downloads. You've guessed it; the menu which allows you to do this can be found under the 'downloads' tab, so click on that now and select a drive with plenty of free space available. The other options can be left alone to use the default settings unless you run into difficulties later.

While you were taking care of the formalities, the Blubmeister (it used to be known as Blubster) was busy logging you into the network. You will now have reached the point where you will be allowed to search through and download the collections of other users, in exchange for allowing other users to have access to your files.

So what do you have to do to embark upon your MP3 foraging quest? The first step is to click on the 'search' tab where you will be prompted to fill in a few details relating to your query. You don't have to be a genius to work out what to put in the 'artist' and 'title' boxes so I won't spell it out for you here. Note that these are the only fields which have to be completed to conduct a search.

See, I told you this was child's play didn't I. Having pressed the search button, the results will quickly be presented in the lower window from which it will be possible to reorganise the tracks to narrow down your search. For instance, if you click on the title at the top of the 'bitrate' column, the files will be rearranged according to the sound quality of the tracks.

A useful rule of thumb is not to download anything with a bitrate of less than 128 kb/s. This is the middle of the road setting, which offers a nicely balanced sound quality to file size ratio. Choosing anything less than this figure will result in finding music with a smaller file size, but a lower sound quality, and the converse is true for anything with a higher bitrate. If you've got plenty of hard drive space and a fast connection aim for the highest bitrate tracks available.

Now if you click on 'velocity', the tracks will once again be re-organised, this time according to the connection speed of the user serving the files whilst still taking into account the bitrate value which we specified previously. This is an example of a secondary categorisation. Avoid modem users like the plague, instead set your sights on at least a cable connection, but obviously the faster the connection the better.

Clearly the more people who are connected to a single user's computer at any one time, the smaller the bandwidth limit is for each person. This is why it is wise to download from someone with as fast a connection as possible. Modem users clearly have far less bandwidth available to begin with, which is why such users are best avoided.

'Ping rate', the final option, is much more variable than the preceding two and so will have a lesser effect on your downloads. The ping rate is the length of time it takes for a message to travel from your computer to a remote computer and back again, a bit like a digital boomerang if you like. Note that this figure is not the same as a user's static connection speed (56k for example) because it is dependent on a multitude of other factors. These can include the number of simultaneous connections the user is currently accepting, the number of concurrent downloads he or she is making, and whatever else the user happens to be doing online whilst using the Piolet client.

Although it is advisable to choose the download location with the highest ping rate, since any of these factors can vary at a moment's notice, meddling with this setting will not necessarily yield salient improvements in transfer speeds. So if the range of ping rates offered are very similar don't spend too much time worrying about which download location to choose unless you find that your connections are crawling along at a snail's pace.

Once the track list has been neatly rearranged according to filename, file size, connection speed and so on, downloading is simply a matter of double clicking on whatever takes your fancy. In the same way, other people can download your files without you having to do anything. If you are searching for a particular album, a good tip is to go and find the CD cover for it first (refer to the links at the bottom of the CD burning tutorial for some excellent sources). This way you don't have to wrack your brain trying to recall the names of every track that is on the album because the back cover will contain an official track listing. Armed with a scanned CD inlay you will know exactly which tracks to look for, and in what order they should be burnt to a CD-R if you plan to produce an audio CD later.

The Piolet client also includes an MP3 player and an integrated chat program, which allows you to communicate with your fellow 'Blubsies' via private messages. In short, it is a virtual music community where you can meet new friends, exchange files, run and dance naked in the fields and live happily ever after in a perfect state of melodious bliss! It really is a musical utopia - I've gone too far again haven't I? You really should stop me before I get carried away you know. Trust me though, it's damn good... and if you don't believe me check out some of the independent reviews at Zero Paid. Test driving it yourself and making your own mind up is advisable too however!

Although Piolet is set to revolutionise the way we listen to music, it is not without its problems. Providing you are aware of them, however, the two of you should get along just fine. One of the few stumbling blocks you are likely to encounter is having your transfers cut short. This happens whenever the user you are downloading from disconnects from the internet mid-transfer, moves the files you are downloading, or performs some other action likely to interrupt the download process.

You can slice and dice an MP3 track anywhere you like and the remaining portion will still play correctly, which may lead you to believe everything has gone according to plan despite receiving a 'transfer error' message. That is, until you listen to the end of the track and find that it comes to an abrupt halt without warning. At this point the best thing to do is hit your computer as hard as you possibly can while cursing at your nearest and dearest friends, relatives or partner. It won't help you in the slightest, but it may make you feel a bit better!

To avoid accumulating a collection of half finished MP3s I'd suggest setting Piolet to delete partial downloads from within the preferences menu. That way you can perform a new search for the same track and begin again from scratch; a painful process, but one that pays off in the end. Nevertheless, what's even more annoying is when other people fail to do this and instead leave partially transferred tracks in their shared folder for you to find and waste your time downloading.

The best way to avoid this pitfall is to click on the heading of the file size column to reorganise the tracks into ascending order according to their file size. Providing that the songs listed in your search box are of an equal bitrate and have the same track title, the one with the largest file size will be the most complete of the set. When trying to reduce the likelihood of downloading half finished tracks, biggest is best, so always make a beeline for the ones with the most bytes to avoid having your listening pleasure cut short.

If Piolet doesn't float your boat, fear not, there's a plethora of other options available to you. While none of the competition feature cutesy pixelated Blubsies they will nevertheless get the job done (with widely varying degrees of efficiency) - check out my file sharing tutorial for some inspiration.

Ripping, encoding and creating audio CDs

Now that you have a reasonable sized collection of MP3s you may want to create your own audio CDs that can be played through your hi-fi so that you can make use of your woofers, tweeters and any other house hold pets you can lay your hands on! This is a fairly straightforward process, but you have to keep in mind that you won't be able to fit hundreds of them onto one CD because they will no longer be in MP3 format. Before your hi-fi's CD player can recognise an MP3 file as a music track it must first be converted to wave format; the 40 to 50 megabyte files we discussed at the beginning of this tutorial.

When this conversion process has been taken care of, all that remains to be done is to burn the files to a blank CD-R using an audio CD template. To carry out this operation, open your favourite CD writing program and select 'new CD' from the file menu. Now choose 'new audio CD' and drag the wave files you wish to burn from the source files window to the music CD project window, give the CD a title, fill in the artist name and finally press the 'write CD' button in the usual way. Bear in mind that if you burn your collection of wave files using a data CD template your hi-fi won't have a clue what to do with them, although you will still be able to open the files through your PC using Media Player or a similar audio playback program.

Before you begin creating audio CDs and converting file formats it is important that you understand some of the terminology used in MP3 creation/playback circles. Ripping is the process by which audio CD tracks are converted to wave format and stored on your hard drive. Encoding on the other hand is the art of converting these wave files into MP3 format whilst attempting to minimise any loss of quality which may ensue. There is a glut of so called audio ripping/encoding programs on the market which will take care of these tasks for you, but the difference in terms of the quality of the encoded tracks they produce is vast.

The program used to rip or encode audio tracks is not the only consideration, however - these programs are not standalone, but rely on a particular external encoder to produce MP3 tracks. The two best encoders are Fraunhofer and Lame, and to be of any use, these must be used in conjunction with an audio ripper. Many people use the Xing encoder without really understanding its drawbacks because it is the default encoder found in one of the most commonly used audio rippers, Audio Catalyst. Note that Xing is a very poor substitute for the Lame or Fraunhofer encoder because the sound quality is inferior to that produced through the use of the latter encoders. In short, give it a wide berth if you want to optimise the sound quality of your MP3 tracks.

As I said earlier, there are a broad range of options to choose from in terms of MP3 tools, but my personal favourite is Audiograbber. Audiograbber, when used correctly in conjunction with the Lame encoder will guarantee that your rips are free from pops and clicks every time. Combining these two essential components may sound complicated, but it simply involves placing the freeware Lame DLL encoder file into the directory where the main executable file of Audiograbber resides. Audiograbber is completely idiot-proof so is perfect for beginners, and yet has a myriad of more advanced functions which allow the more experienced encoder to fine tune the conversion process.

The reason Audiograbber produces such high quality MP3s is because it encodes music not via the sound card, but digitally, enabling it to make perfect duplications of audio CDs. It also has the ability to analyse the files it has produced for imperfections, which can then be corrected, in addition to eliminating periods of silence from tracks and performing a normalising function to make sure all the tracks are encoded at the same volume.

The interface is exceptionally user friendly so it is usually fairly obvious how things work from the outset, nevertheless, if you're still struggling to get it to work after going it alone, the Audiograbber home page provides some very comprehensive FAQs and walk-throughs to help out newbies.

If sound quality isn't your top priority, however, an even simpler method would be to let Easy CD Creator take care of the whole process for you. With a few mouse clicks this all purpose program will convert your audio CDs or MP3s to wave files and then burn them to a blank CD-R all in one fluid motion on the fly. If you're planning to take this approach, first ensure that you have plenty of spare disk space available to store the temporary wave files, which will be created behind the scenes before being written to the CD-R.

There are two ways in which you can encode your music tracks. The first, as already covered in detail above, is to download MP3 files from the internet and convert them to wave files, and the second is to turn your own or your friend's CD tracks into wave files (known as 'ripping'). With this antecedent dealt with, it is simply a case of deciding what is going to go where and in what order. To arrange your files, simply drag and drop them using your favourite CD writing software.

Before you all rush off to burn your first audio CD, a final point to note is that most modern CD compilations are stored on 80 minute CDs. This means that to copy a CD track-for-track you will not have enough storage space available on your standard 74 minute CD-Rs, so make sure you stock up on plenty of the fifty-megabytes-extra varieties.

Thought for the day - aka the disclaimer bit

Roll on fairly priced, legal music downloads! It will be a monumental leap forward for consumers when we are at last able to pick and mix the music we wish to purchase without paying a premium for space-fillers, or to subsidise the luxurious lifestyles of fat cat, record label parasites. Hell, let's dispense with them altogether and pay the artists directly. With the advent of forward-thinking, internet-based delivery systems for music, let's also hope that less well established, yet equally talented and hard working artists will be able to penetrate the market and receive the recognition and reward they deserve.

Tuesday, 5 June 2001

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Common movie/audio encoding formats defined

ASF is yet another video format to receive the MPEG4 codec treatment. It stands for Advanced Streaming Format because it was designed to be watched while being transferred from the internet (or to be 'streamed' if you want to use the correct lingo). The quality is nowhere near as good as MPG, DivX or VCD, but is still acceptable for most purposes while maintaining a comparatively favourable size to quality ratio.

AVI is an acronym for Audio Video Interleave. Technically it is a container rather than an encoding format in its own right in that it specifies how audio and video data is structured within the file. The DivX codec is one notable example of an encoding format which makes use of the AVI wrapper.
AVI files contain a four-digit code which is recognised by movie playback tools such as Media Player or VLC, allowing them to determine how to decode the movie.

DivX is the name of the encoding process used to convert DVD, VHS etc movies into a very high-quality AVI video format. This is carried out using a combination of the MP3 format for audio compression and a hacked version of Microsoft's MPEG4 codec for video compression.
A typical DivX movie will fill a standard 650mb CD-R and can be played back using nothing more than Microsoft's trusty (ha!) Media Player providing you have the DivX codec installed (see my movie links page).

The MPEG format was devised by the Motion Picture Experts Group, hence the abbreviation and its variations (MPEG-1, MPEG-2 and so on) form the basis for many other formats (see previous definitions). It combines very high-quality video playback with large file sizes.
Once again keep the VLC Media Player handy.

Musepack is a lossy audio compression format much like MP3 though distinguished by its .mpc extension. The most notable benefits of the MPC format are:- - Superior quality audio at medium to high bit rates - Very fast encoding and decoding - 100% transparency i.e. MPC music tracks sound identical to their CD counterparts Despite the high-quality audio output rendered by Musepack, the format is not widely used because most media players do not support it natively i.e. a plugin is required. Currently the only media player which can handle MPC files 'out of the box' is Foobar.

Also to it's detriment, very few hardware audio players make provisions for MPC playback. In effect, to listen to MPC music on the go, the files first have to be converted. As this entails switching from one lossy format to another, inevitably the quality will deteriorate in the process. Ideally, if you wish to use MPC files in such a way, you would be best advised to re-encode them directly to the destination format, though if this isn't possible you might like to let either the Alive MP3 Wav Converter or 4U WMA MP3 Converter go to work on them.

Burning MPC files directly to CD enabling you to play them in the usual manner is less problematic. To do this using Nero you will need to install Mausau's MPC plugin. Alternatively, you could use the freeware audio CD writing tool, Burrrn, which supports the MPC format by default.

More detailed information relating to the Musepack audio compression format can be found at the official home page.

nAVI is a non-streamable hybrid of the ASF format, which boasts better quality playback due to its adoption of much-improved frame rates.

Ogg Vorbis is a completely free, streamable, open-source audio encoding format. Compared to the more widely known MP3 format, Ogg Vorbis files provide superior sound quality and smaller file size. Since the format is patent-free, software vendors do not need to pay licensing fees to implement the encoding of Ogg Vorbis files into their software. Effectively this means that a greater variety of encoding software will be available for the Ogg Vorbis format.

QuickTime format was conceived by Apple and therefore it is not surprising that these type of movies first appeared on Macintosh computers before being ported to the PC. They comprise high-quality playback and the ability to be streamed over the internet. Many Mac-friendly web sites favour this encoding method, largely due to its association with Apple I don't doubt.

What is most annoying about proprietary codecs is that the authors will have you believe you need to use a specialist tool to play them back - in this case, Apple's QuickTime Player (who'd have thunk it?). A waste of perfectly good hard disk space if you ask me! Use VLC instead.

Real Media is a proprietary, MPEG-2 based streamable format used to encode audio and video data. Small file sizes mean you won't have long to wait for content to begin streaming, or finish downloading if you are transferring the complete .ra or .rm files before attempting to play them back, but quality can leave a lot to be desired. Real Media movies and audio can be played back using Real Network's free RealPlayer application or Real Alternative. Real Media movie clips are very common on mainstream news sites that don't know any better, bless 'em.

VCD stands for Video Compact Disc. These are CD-Roms containing full-motion video encoded using the MPEG1 codec. Because they consist of high-quality stereo sound coupled with reasonable quality video playback (equivalent to the VHS format) you will often find that they occupy two CDs.
VCDs can be played back with Microsoft's Media Player, amongst a host of other more specialist programs simply by locating and opening their '.dat' files.

WMA is an acronym of Windows Media Audio; Microsoft's propriety audio format. WMA files provide CD-quality sound and are slightly more compact than their MP3 equivalents. Like MP3 files they are streamable.

WMV is an acronym of Windows Media Video; again one of Microsoft's propriety formats. WMV is used to encode movie data, which can contain both video and audio streams. Such files offer near broadcast-quality video, and as an added bonus, can be streamed over the internet.

The observant readers among you may have noticed that XviD spells DivX backwards. I would imagine this reflects the wish of its authors to highlight the similarities between the two codecs. Both are MPEG-4 based and are derived from source code written under Project Mayo.

The principal fork in the path can be traced back to their respective software licenses; DivX is commercial and closed source, whereas XviD is open source and released under the GPL license.
It's difficult to definitively answer the question, "which codec is better?" because there are so many factors which can affect the performance and quality of movies encoded using either codec. See www.xvid.org for downloads and further information.

Saturday, 19 May 2001

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How can I stop all that irritating web site music from playing?

Just wait for the page to finish loading and press your browser's stop button (the red circle with the x in the middle). It is also possible to prevent web site music from initiating to begin with - at least it is if you happen to be using Internet Explorer.

The procedure is as follows: click on 'tools' and then select 'internet options' from the drop down menu. Now click on the 'advanced' tab and locate the 'play sounds in web pages' option from within the 'multimedia' group of preferences. If you untick the checkbox adjacent to it, never again will you have to suffer from such auditory intrusion.

Thursday, 13 April 2000

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My game backup CD image is 700mb in size, but when burnt to a CD it only occupies 400mb. Where did the extra 300mb go?

When there is a very large discrepancy between the initial image size and the final size of your burnt CD, it is usually because the image file also contains the game's audio sound track. Because the space occupied by audio tracks isn't represented in the same way as ordinary computer data it appears as though there is much less data on the final CD than there really is.

To witness this effect with your own eyes, try inserting an audio CD into your CD drive and see if you can find out how much space is being utilised by the tracks using the properties menu.

Thursday, 6 January 2000

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I've just burnt a data CD image, but have ended up with a useless audio CD. What am I doing wrong?

Did you load the cue sheet or just the main .bin file before writing the CD? If you've bypassed the cue file stage you've probably confused your CD writing software. Because the cue file lets your software know which mode to use when burning a CD image, if you don't open this file to begin with, it automatically uses the default setting - usually it assumes you want to make an audio CD.

Another possible explanation is that your cue file could contain incorrect file location information. If this is the case you can edit your cue file to check which directory it is pointing to. If your bin file is in a directory other than the one referred to in the cue file, you have two options; you can either relocate the bin file to match the path stated in the cue file, or you can edit the cue file so that it corresponds to the directory in which your bin file is stored. It is often more practical to delete the path reference altogether, leaving just the name of the file. This way, your burning software will assume that the bin file and cue file are situated in the same directory.