Codecs and Audio Formats – Free Software
We may for convenience divide into lossy audio formats (lossy) and no lossy (or lossless, without loss of quality). The idea of lossy formats (popular among the casual user) comes from the idea that not all the sounds present in 44,100 samples per second contained in a standard WAV file are correctly perceived by the human ear.
In this way (as is the case for the jpg image) you are going to cut the high frequencies, which are believed to be less distinct from our ear. More will cut these frequencies, plus the space occupied by our track decreases (for example, 3 MB instead of 6 MB for a passage of a few minutes, or much longer), but also decreases the quality of the result, since the frequencies that are cut are no longer so inaudible.
The conversion to WAV, starting from the lossy formats, does not bring any benefit (unless you have to draw the track and save many times, in this case the quality loss is limited to the first step); There are also programs that are able to give back to our songs some of these high frequencies, such as Steinberg Clean Plus or others (for example, early versions of Easy CD Creator, or other even more professional), however-while doing a decent work-over, so they cannot do.
The lossless (no lossy) instead of trying to reduce the space occupied by track basis without affecting the sound; the compression ratio will be much lower than the lossy, but there will be a loss of quality. If converted to WAV (perhaps to be processed), the sound will be the same as before.
Lossy audio formats (With loss of quality)
WMA (.wma) : windows media audio, compressed and very similar to an mp3. Audio compression format of Microsoft. Files compressed in this format are approximately 20% smaller than MP3.
MP3 (.mp3) is short for MPEG 1 Layer III and identifies the audio files that use this algorithm. It is a standard that eliminates sounds inaudible to the human ear. In this way a song 128 kbps MP3 occupies a space equal to 11.1 over the same .wav or audio CDs.
Some estimate a bit rate to 128 kbps as CD Quality; indeed, the frequencies that are cut to save space on the hard drive are not so much inaudible. At 192 the results are starting to be good, and only to 320 kbps can talk about CD Quality. Until a few years ago mp3 Quality was considered high, but now-with the emergence of more advanced sound cards, 24-bit-it continues to use the mp3 compared to other formats such as ogg or mpc more for its spread and compatibility than for the quality of the result. An album of 600 MB in wav, will occupy about 50 MB in 128 kbps MP3.
To convert an audio track to mp3, you should use the Lame MP3 codec (free), present in all the best conversion programs.
AAC (.aac and .mp4) : Format lossy which allows a high quality (the highest at the time between the lossy formats), at least one step higher than that of mp3. Characteristic of this format is the possibility of being protected by DRM, so it cannot be copied freely from one platform to another (unless using programs that sproteggano).
AC3 (.ac3). And the audio format used by DVD. Usually we find it to 384 kbps (6-channel), but you can also have it in only 2 channels and lower bit rates.
OGG VORBIS (.ogg) : Great open source codec. We can do a better job of mp3 especially at low bit rates (higher quality in less space), ie less than 128 kbps. It is supported by virtually every audio player (both software and audio).
MusePack (.mpc) : Size of high results, especially in high bit rate (192 kbps over and over). The results are much better of mp3: just listen to a track encoded in mp3 at 192 kbps and a mpc in the same bitrate to feel the difference immediately (in some cases, some cases they are left without words …). There were many who consider him the best lossy audio format, at least until the exit of the mp4. It is supported by WinAmp through plugins, and natively by more advanced players as Foobar 2000. An album of 600 MB WAV format will occupy about 100 MB if mpc encoded bit rates around 192 to 256 kbps. Note that gives his best at high bit rates. When it is a size a bit outdated passed since the most recent AAC.
No Lossy audio formats (without loss of quality)
WAV (.wav) format Wave is simply the digital recording of real sounds, sounds that originate from an external source to the PC. In a piece of music WAV, drums, piano, guitar, bass or voice they feel the same way regardless of the PC where the file is heard (at the same sound quality of the hardware).
DSD (DFF, .dsf) are used to digital media such as Super Audio CD. The quality of sampling is very high (the sampling frequency, variable, is about 64 times that of a CD Audio), although according to the various operators of the sector is absolutely to determine whether the final quality is superior to that of the PCM sampling (the one High quality used in Blu-Ray and DVD Audio).
AIFF (.aif). And the audio format used by Apple for the Apple Mac. And basically the equivalent of WAV that is used by Windows.
APE (Monkey Audio: .ape) : no lossy format that reduces by 50% the space occupied by our own music (in some cases even more) without any loss in quality. In this way, an album in wav format takes up about 600 MB, is to occupy an average of 300 MB (much more than about 100MB of mpc to high bitrates, and 60 of an mp3, but the quality is identical to original); I say average because there are certain types of music in which the compression level is even higher. To listen to songs in this format, you can use plugins for WinAmp or Better Yet player that incorporate natively as Foobar 2000. Right now it is probably the best lossless codec, considering a balance between speed and compression.
Apple Lossless Audio Codec – ALAC (.m4a) and a lossless audio codec created by Apple a few years ago and made available as open source from Apple itself as of October 2011. It is supported on Windows (encoding) by some programs, including which dBpoweramp.
FLAC (.flac) : Open Source format, great popularity. It was once extremely popular (among music purists), but lost a bit of land with the emergence of the format bee MonkeyAudio, that same quality, allows better compression. In comparison with others, always it came after the format .ape.
LA (Lossless Audio: .la) : The non-lossy format that compresses more. The conversion in this format is very slow, but gets better compression absolute (continuing the example MonkeyAudio, that album would occupy about 290 MB compared to 300 MB of the EPA). And not widespread, since some MB earned on bees is not worth the long wait for more (and less support from third party programs). However, it is the winner of my comparison lossless formats.
OPTIM FROG (.ofr) : excellent lossless codec, the best after LA as compressibility. The compression -if set to levels somewhat elevati- is about 3 times slower than in Monkey Audio, and the gain in MB is about 2%. Like all other formats of this page, you can be heard with no plugin Foobar 2000.
WavPack (.wv, WVC) : It is a good compression format open source, which allows results to be lossless, lossy and hybrid. The compression speed is high, and the degree of compression good. Also interesting is the hybrid format, in which the lossy joins another file, which will completely reconstruct the original file in a lossless if we wanted to restore.
