i have never looked into mp3 untill recently. i am confused about the file types available. i fully understand the kbps- the higher the more info therefore better sound but i dont know the differences of mp3 , aac, atrac, .wav and many more does anyone know the meanings of these. is there a good site explaining these. which is best??? cheers guys.
confused about music files
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Here's a guide to compressed audio formats.
http://www.hungryhacker.com/articles/audio/audio_formats.html
Lossless formats like wave, apple lossless and ogg vorbis offer nearer CD quality.
http://www.hungryhacker.com/articles/audio/audio_formats.html
Lossless formats like wave, apple lossless and ogg vorbis offer nearer CD quality.
Ogg, AAC, and WMA 9 (not the older varieties) are more sophisticated than MP3, especially at low bit rates, but none of them are CD quality, even at the highest bit rates. A decent CD payer with a CD in relatively good condition is still noticeably better sounding to many people if played back through decent kit.
The lossless formats like FLAC, Monkey's Audio, Apple lossless, Wave, and WMA lossless are all CD quality (or indeed better than CD quality if they were originally recorded with higher sampling rates and bit depths), the problem is they take up a lot of memory, although less than CD and Wave.
The lossy formats such as MP3, Ogg, AAC, WMA MPC etc all use slightly different techniques to achieve the same thing, they try to work out which bits of sound you won't notice much, and they throw that information away (hence lossy). The higher the bit rate, the less information is thrown away, the more true it will be to the original, and the larger the file size, its all about compromise you see. Some simple lossy formats throw away all audio above and below certain frequencies, or only keep the stereo information where there is a significant difference between the 2 channels (MP3 is traditionally especially poor at keeping the high frequency information, even at the highest bit rates, so if you tend to notice a lack of very high frequencies in your music, that could be a problem) The more advanced formats like ogg, aac, and wma 9, all have mathematical models of how an average brain interprets sound based on many experiments, and try to work out what you won't notice missing. Lame encoder for MP3 has also improved the situation for MP3 a lot too.
The lossy formats all have errors (or discrepencies), known as artifacts compared to the original recording. Some artifacts are common to all the formats in differing degrees, some only to certain formats, and not everyone notices the same (if any) artifacts. The important thing however is that you select a format, which produces files that sound "CD quality", and use this format at the minimum bitrate at which the sound becomes acceptable to you. This may in fact mean more than 1 format, as some formats are better at high bit rate, and others the best at low bit rates. The level at which you percieve the sound as identical to the original is known as the transpanrency level.
Where you will listen to the music will also make a difference, what player you have/want, or what media program you use on your computer will also affect the decission depending on what they support, and how good quality they are at playing back your chosen format.
Unfortunately there is no shortcut, we can't tell you what is best, you should listen to the different formats your self, experiment with them, eventually you will settle on 1 (or 2).
Quick word of caution though, don't go deliberately listening for the artifacts and errors i mentioned earlier, don't even look up on the net what they sound like, because if you do start to notice them, they will annoy you forever.
Trust your ears
The lossless formats like FLAC, Monkey's Audio, Apple lossless, Wave, and WMA lossless are all CD quality (or indeed better than CD quality if they were originally recorded with higher sampling rates and bit depths), the problem is they take up a lot of memory, although less than CD and Wave.
The lossy formats such as MP3, Ogg, AAC, WMA MPC etc all use slightly different techniques to achieve the same thing, they try to work out which bits of sound you won't notice much, and they throw that information away (hence lossy). The higher the bit rate, the less information is thrown away, the more true it will be to the original, and the larger the file size, its all about compromise you see. Some simple lossy formats throw away all audio above and below certain frequencies, or only keep the stereo information where there is a significant difference between the 2 channels (MP3 is traditionally especially poor at keeping the high frequency information, even at the highest bit rates, so if you tend to notice a lack of very high frequencies in your music, that could be a problem) The more advanced formats like ogg, aac, and wma 9, all have mathematical models of how an average brain interprets sound based on many experiments, and try to work out what you won't notice missing. Lame encoder for MP3 has also improved the situation for MP3 a lot too.
The lossy formats all have errors (or discrepencies), known as artifacts compared to the original recording. Some artifacts are common to all the formats in differing degrees, some only to certain formats, and not everyone notices the same (if any) artifacts. The important thing however is that you select a format, which produces files that sound "CD quality", and use this format at the minimum bitrate at which the sound becomes acceptable to you. This may in fact mean more than 1 format, as some formats are better at high bit rate, and others the best at low bit rates. The level at which you percieve the sound as identical to the original is known as the transpanrency level.
Where you will listen to the music will also make a difference, what player you have/want, or what media program you use on your computer will also affect the decission depending on what they support, and how good quality they are at playing back your chosen format.
Unfortunately there is no shortcut, we can't tell you what is best, you should listen to the different formats your self, experiment with them, eventually you will settle on 1 (or 2).
Quick word of caution though, don't go deliberately listening for the artifacts and errors i mentioned earlier, don't even look up on the net what they sound like, because if you do start to notice them, they will annoy you forever.
Trust your ears
Alec
Well-known member
rigadig - perhaps im being picky, but you seem to refer to wave in two diferent ways in your second paragrahp...? Also, im sorry to interrupt, but I've a quick pcm question if i may...pcm is somehow used in red book audio isnt it? and in wave? But i was reading about some streamer the other day that takes uncompressed pcm audio...so is it also a format in its own right, and is it used much? I get pretty confused by formats being formats in their ownb right, and "things" (sorry, i struggle with the terminology sometimes) that are simply used to create a format - such as pcm seems to be. Anyway, im confused, and stand to be corrected on any of the above.
Alec
Well-known member
And now your bringin windows into it - im totally confused! But i get your point i think - i just wondered if there was a great new pcm format i didnt know about lol! Many thanks fr0g!
[quote user="al7478"]rigadig - perhaps im being picky, but you seem to refer to wave in two diferent ways in your second paragrahp...? Also, im sorry to interrupt, but I've a quick pcm question if i may...pcm is somehow used in red book audio isnt it? and in wave? But i was reading about some streamer the other day that takes uncompressed pcm audio...so is it also a format in its own right, and is it used much? I get pretty confused by formats being formats in their ownb right, and "things" (sorry, i struggle with the terminology sometimes) that are simply used to create a format - such as pcm seems to be. Anyway, im confused, and stand to be corrected on any of the above.[/quote]
Appologies, I was in a bit of a rush typing that post, and perhaps should have been clearer, (quite a few spelling mistakes which I have just spotted re -reading it too lol)
Frog is once again correct, .wav is a container file format for putting wave type audio data into, think of a container format as sort of like a digital box to but the information into (or as Frog said, a wrapper). .wav is the standard windows container format for wave type audio, other examples of common wave container formats are CD, and .aiff from the macintosh world, . There are loads of other container formats for all sorts of things, some containers can contain many different kinds of audio or video (eg .avi) and sometimes the container is specific to only one kind and the term is used interchangeably with the data inside (eg .mp3 containers contain only mp3 audio)
Wave is a general familly name for a number of different ways of representing audio in digital form (known as a CODEC) , it is known as wave since it stores the sound as a wave form, usually uncompressed.
The most common form of wave audio is PCM (pulse code modulation). PCM is about the most simple CODEC available, it basically measures (samples) the audio volume many times a second (44.1 kHz for the PCM on a CD, about 22kHz for radio) and stores the value of the volume at each sample as a binary number (a 16bit number for CD). If you then play these samples back at the same speed they were recorded, then you get an approximation of the original sound. Generally, the sampling rate must be at least twice the maximum frequency which you wish to record (a very good, young human ear can usually only hear around about 18 Hz to 22kHz hence 44.1kHz for CD). Higher sample rates not only mean higher frequencies are retained, but additionally, the more accurate and detailed ALL recorded sound will be. More bits per sample means more detail in the signal as well. High resolution formats are typically 96 kHz and 24bits ber sample.
Another example of a wave CODEC is ADPCM (which can also be stored in .wav conatiner), which works by only recording the difference in volume between each sample, which means that it can use less bits per sample to achieve passable results (although this only works well on certain types of audio e.g. voice)
Most other CODECs get audio into digital form initally as wave (PCM usually) and then compress it in some way, either losslessly like FLAC, or lossy, like MP3 as described in my first post.
As you may have noticed from the description of PCM, NO digital recording is truly lossless since it is always sampled at a finite number of samples and recorded as finite numbers, whereas sound is continuously varying, However uncompressed PCM at 44 kHz, 16 bit (as in whats on a CD) is usually what people mean when they say lossless.
Lossless CODECs such as FLAC are lossless in the sense that when played back, they always uncompress to the original PCM.
Hope that clears stuff up mate, sorry if its too techy.
Appologies, I was in a bit of a rush typing that post, and perhaps should have been clearer, (quite a few spelling mistakes which I have just spotted re -reading it too lol)
Frog is once again correct, .wav is a container file format for putting wave type audio data into, think of a container format as sort of like a digital box to but the information into (or as Frog said, a wrapper). .wav is the standard windows container format for wave type audio, other examples of common wave container formats are CD, and .aiff from the macintosh world, . There are loads of other container formats for all sorts of things, some containers can contain many different kinds of audio or video (eg .avi) and sometimes the container is specific to only one kind and the term is used interchangeably with the data inside (eg .mp3 containers contain only mp3 audio)
Wave is a general familly name for a number of different ways of representing audio in digital form (known as a CODEC) , it is known as wave since it stores the sound as a wave form, usually uncompressed.
The most common form of wave audio is PCM (pulse code modulation). PCM is about the most simple CODEC available, it basically measures (samples) the audio volume many times a second (44.1 kHz for the PCM on a CD, about 22kHz for radio) and stores the value of the volume at each sample as a binary number (a 16bit number for CD). If you then play these samples back at the same speed they were recorded, then you get an approximation of the original sound. Generally, the sampling rate must be at least twice the maximum frequency which you wish to record (a very good, young human ear can usually only hear around about 18 Hz to 22kHz hence 44.1kHz for CD). Higher sample rates not only mean higher frequencies are retained, but additionally, the more accurate and detailed ALL recorded sound will be. More bits per sample means more detail in the signal as well. High resolution formats are typically 96 kHz and 24bits ber sample.
Another example of a wave CODEC is ADPCM (which can also be stored in .wav conatiner), which works by only recording the difference in volume between each sample, which means that it can use less bits per sample to achieve passable results (although this only works well on certain types of audio e.g. voice)
Most other CODECs get audio into digital form initally as wave (PCM usually) and then compress it in some way, either losslessly like FLAC, or lossy, like MP3 as described in my first post.
As you may have noticed from the description of PCM, NO digital recording is truly lossless since it is always sampled at a finite number of samples and recorded as finite numbers, whereas sound is continuously varying, However uncompressed PCM at 44 kHz, 16 bit (as in whats on a CD) is usually what people mean when they say lossless.
Lossless CODECs such as FLAC are lossless in the sense that when played back, they always uncompress to the original PCM.
Hope that clears stuff up mate, sorry if its too techy.
Alec
Well-known member
Well you told me lol! Only joking. No need to apologise, hope i didnt appear too pompous! I havent delved as far as you and fr0g into this world yet. Many thanks for the reply, hopefully ill get my head around the trickier bits eventually. So waht would be contained in the WAV wrapper used with wmp/windows...? Is a WAV wrapper capable of containing any audio...?
[quote user="al7478"]hope i didnt appear too pompous![/quote]
Not at all, it was a valid question, sorry the reply got so technical.
.wav container usually contains PCM, or ADPCM audio. Pretty much any program and player will play .wav containing PCM, and quite a lot support ADPCM too.
Basically there are 2 aspects to an audio (or video) file, the data, which is in the format of the CODEC used to encode the audio, and the container (or wrapper) which packages the raw data, and contains aditional information like ID3 tags etc.
Some containers support multiple forms of data, encoded with different CODECs (eg m4a, ogg, mp4), others only support a single CODEC (in which case the container and the CODEC are often known by the same name eg wma, mp3).
For you to play back the file, your hardware/software must firstly be able to support the container, and secondly, it must be able to decode the data contained within.
Generally for audio, don't worry about it too much since most players that support a given container tend to support the most common CODECs used with that container (although this is often not the case with video!), so if a player says it supports .ogg for example, it usually means that it supports the ogg container with audio data inside encoded with the vorbis codec.
.wav files containing PCM are not usually used much for music collections since the file size is massive and better lossless CODECs exist (such as FLAC or Monkeys Audio), however PCM is used all the time in applications such as CDs, or sent raw over a coax or optical digital (S/PDIF) connection between CD or MD player to an amplifier etc where there is no container file, it is simply streamed.
As long as your favourite hardware/software supports it, then just choose the format that you like the sound of the best, only worry about the technical bits if things start to go wrong, or if your really interested. Currently my personal favourite format is ogg vorbis, but at different times I end up using all the main formats.
Not at all, it was a valid question, sorry the reply got so technical.
.wav container usually contains PCM, or ADPCM audio. Pretty much any program and player will play .wav containing PCM, and quite a lot support ADPCM too.
Basically there are 2 aspects to an audio (or video) file, the data, which is in the format of the CODEC used to encode the audio, and the container (or wrapper) which packages the raw data, and contains aditional information like ID3 tags etc.
Some containers support multiple forms of data, encoded with different CODECs (eg m4a, ogg, mp4), others only support a single CODEC (in which case the container and the CODEC are often known by the same name eg wma, mp3).
For you to play back the file, your hardware/software must firstly be able to support the container, and secondly, it must be able to decode the data contained within.
Generally for audio, don't worry about it too much since most players that support a given container tend to support the most common CODECs used with that container (although this is often not the case with video!), so if a player says it supports .ogg for example, it usually means that it supports the ogg container with audio data inside encoded with the vorbis codec.
.wav files containing PCM are not usually used much for music collections since the file size is massive and better lossless CODECs exist (such as FLAC or Monkeys Audio), however PCM is used all the time in applications such as CDs, or sent raw over a coax or optical digital (S/PDIF) connection between CD or MD player to an amplifier etc where there is no container file, it is simply streamed.
As long as your favourite hardware/software supports it, then just choose the format that you like the sound of the best, only worry about the technical bits if things start to go wrong, or if your really interested. Currently my personal favourite format is ogg vorbis, but at different times I end up using all the main formats.
Alec
Well-known member
Thanks rigadig, things are becoming much clearer. I will probably do some experimentation at some stage, but im lazy and am tempted by your suggestion to stick with the best format for the software i use. It seems to be something of a dirty word with "computer audiophiles", but i use WMP11, simply as im used to it, and therefore WAV/pcm files (I still have most things in mp3, but ive learned a lot in recent times, so i have some re-encoding to do!).
WMP10 and 11 are fine if thats what you are used to, it is perfectly capable with wma and mp3 out of the box, and if those are the formats you will use, then its media library is OK too, I seriously doubt that anyone could claim to hear a difference between a wma or mp3 playing in media player compared to any other program on the same computer (assuming that all equalisers and effects are turned off of course)
Wav is a little extreme though for a general music collection considering you already have a lossless copy in the form of the CD, I would really suggest you try 1 of the main lossy formats to see if you can notice a difference, since wav will probably take around 10MB per minute! If you want to stick with WMP try MP3 encoded with LAME at around 192kbps VBR, or a wma at 160kbps, if it sounds ok to you, then stick with it (or even try the next bitrate down to see if you can put up with that) it will save you a ton of space.
The other problem you may face with wav files is that there is not really a standard way of putting tags into them (like artist, album etc, which will make managing and organising a large collection a tedious manual process of moving files between folders on your computer. The main lossy (and lossless) formats all support tags of some sort
If you you can't find a lossy format that sounds good enough to you, thenyou could always consider WMA lossless in media player (but it is not supported by much else) or switch to a program like winamp which could support more formats, including the excellent FLAC lossless codec.
I use Winamp to play my files since it is relatively lightweight, supports loads of formats and is free, and I use an awesome program called Media Monkey to organise my music, it is very powerful, supports all kinds of formats, can auto organise your collection in both the library database and your hard drive, catalogue your real CDs, and Auto convert files as it transfers them to a portable player into a format which the player supports, it can also auto generate playlists similar to iTunes etc and finally, it is free for most of those features, with only a few features locked untill you pay for the gold version (which is only about £25 for a lifetime licence to all future versions).
Wav is a little extreme though for a general music collection considering you already have a lossless copy in the form of the CD, I would really suggest you try 1 of the main lossy formats to see if you can notice a difference, since wav will probably take around 10MB per minute! If you want to stick with WMP try MP3 encoded with LAME at around 192kbps VBR, or a wma at 160kbps, if it sounds ok to you, then stick with it (or even try the next bitrate down to see if you can put up with that) it will save you a ton of space.
The other problem you may face with wav files is that there is not really a standard way of putting tags into them (like artist, album etc, which will make managing and organising a large collection a tedious manual process of moving files between folders on your computer. The main lossy (and lossless) formats all support tags of some sort
If you you can't find a lossy format that sounds good enough to you, thenyou could always consider WMA lossless in media player (but it is not supported by much else) or switch to a program like winamp which could support more formats, including the excellent FLAC lossless codec.
I use Winamp to play my files since it is relatively lightweight, supports loads of formats and is free, and I use an awesome program called Media Monkey to organise my music, it is very powerful, supports all kinds of formats, can auto organise your collection in both the library database and your hard drive, catalogue your real CDs, and Auto convert files as it transfers them to a portable player into a format which the player supports, it can also auto generate playlists similar to iTunes etc and finally, it is free for most of those features, with only a few features locked untill you pay for the gold version (which is only about £25 for a lifetime licence to all future versions).
Alec
Well-known member
rigadig - thanks again. I have a really small collection compared to some (about 1000 songs, including some duplicates) so im going to stick with WAV for the time being, but certainly intend to experiment evry so often to see when i can and cant tell the diference between formats. I just tell it to look up the cd in media player and it attatches the info for me, even with WAVs. I think the real problem is that the tags dont stay put if it goes wrong, or if i move the song elsewhere, if you see what i mean. sorry, if i find a way of putting that better ill get back to you lol! ****** fr0g - i downloaded EAC a couple of weeks ago and intended to rip a song in WAV with it and do a comparison to WMP11s WAV ripping, but i had some problems, due to experimenting with too much software i guess, so i had to do a system restore, and to be safe i removed the progs id been playing with. i shouldnt think EAC was the prob, i just havent had time to get it again since, but i shall.
cheers frog and rigadig for your info. i will have to have a listen. i went into the phoneshop and spoke to some yank and he said that the sony walkman phone uses aac, does that mean atrac??? also he said the iphones uses something he called the itunes file. ha. ive never heard of that! do you think he means mp3? i swear these guys in the phone shops know nothing about details, or the majorityof them dont. they all contradict each other. one guy told me a sony walkman could interact with my ps3 by bluetooth. hmmmm not sure and another guy completely disagreed in the o2 shop. what he did say though was sony erricson had a rubbish amplifier inside compared to nokia and apple! which surprised me. maybe im too fussy but they look surprised when i actually ask about sound quality. i guess non hifi addicts just care if it has an mp3 player in it.
Alec
Well-known member
[quote user="vernonkay1984"]the sony walkman phone uses aac, does that mean atrac??? [/quote]
No ATRAC was Sony's proprietory format used in dedicated Walkman until recently...this has now been replaced with WMA, MP3 and AAC (without digital rights management) etc. AAC is the format used by Apple in the iPod. I dont think the SE Walkman phones will support ATRAC as the format has on the whole been withdrawn by Sony in the US and Europe, but is still available in Japan. Generally the sound quality of the Walkman phones is pretty high (but not perhaps as good as a Walkman).
No ATRAC was Sony's proprietory format used in dedicated Walkman until recently...this has now been replaced with WMA, MP3 and AAC (without digital rights management) etc. AAC is the format used by Apple in the iPod. I dont think the SE Walkman phones will support ATRAC as the format has on the whole been withdrawn by Sony in the US and Europe, but is still available in Japan. Generally the sound quality of the Walkman phones is pretty high (but not perhaps as good as a Walkman).
[quote user="oeurf"] I dont think the SE Walkman phones will support ATRAC[/quote]
True. I have a Sony Walkman phone and it supports WMA, MP3 and AAC (without DRM), but not ATRAC.
True. I have a Sony Walkman phone and it supports WMA, MP3 and AAC (without DRM), but not ATRAC.
i think that im gonna go with aac at 320kbps. and my fave music on apple lossless or wav, whichever i find sounds best. obviously that depends on me getting an iphone. i know the files of the previous 2 are massive but i can easily change the music on the hard drive. i will just get a low bit rate files when i go to afghanistan to prevent me getting bored of a small selection. i just hope the phone insurance covers damage by mortar fire
The guy in the phone shop didn't know what he was on about by the sound of it. AAC and MP3 is standard on most modern phones now including nokia, sony ericsson, and of course the iphone. some support wma as well. Itunes music is AAC as someone else has already said, so most phones will support the format, however, if the track was downloaded from itunes and has their copy protection in it, then I think only the iphone can play it.
It is true that the different makes and models of phone will have slightly different amplifiers in, but from my personal experience, Walkman phones, Nokia, and the iphone were all roughly comparable in terms of the sound quality, I think the phone shop bloke was probably just trying to sell you an iphone (to get himself a nice fat commission) when he said walkman phones have inferior amplifiers. The Earphones you use to listen to the phone with will have much more of an impact on sound quality.
I honestly can't think of a good reason to stick with Wav files for your music collection though apart from that you could play them on most portable machines, but the storage required is vast, and you wouldn't have any tags. Many higher capacity players support a decent lossless format which would give you the same quality but take up less space, provide tags etc.
It is true that the different makes and models of phone will have slightly different amplifiers in, but from my personal experience, Walkman phones, Nokia, and the iphone were all roughly comparable in terms of the sound quality, I think the phone shop bloke was probably just trying to sell you an iphone (to get himself a nice fat commission) when he said walkman phones have inferior amplifiers. The Earphones you use to listen to the phone with will have much more of an impact on sound quality.
I honestly can't think of a good reason to stick with Wav files for your music collection though apart from that you could play them on most portable machines, but the storage required is vast, and you wouldn't have any tags. Many higher capacity players support a decent lossless format which would give you the same quality but take up less space, provide tags etc.
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