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BTC640/Sound

1,738 bytes added, 00:21, 26 November 2011
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44.1kHz was chosen for raw audio because people cannot hear better than half that frequency, thus cannot tell that the reconstructed wave is different from the original. Some claim that they can distinguish a live performance from an Audio CD playback but even such claims are rare.
 
=== WAV/AIFF ===
 
These two are basically identical formats but given that WAV has been the supported-by-default format in windows - it's much more popular.
 
Sound is stored completely uncompressed, similar to how it's stored on Audio CDs. The format is not exactly the same though so conversion is necessary to transfer files from/to audio CDs.
 
Because of their age and lack of encoding/decoding requirement they are usually default formats for audio creation and editing tools.
 
=== FLAC ===
 
Flac is a lossless compressed format. A wav file can be compressed with any generic compression tool so you can understand Flac playback as on-the-fly decompression, but it's been optimised to allow better audio compression, seeking to random places in the file, and storing audio metadata.
 
Playing a flac file is more CPU-intensive than playing a WAV file though so which format you choose is a balance between space required and decoding speed.
 
The speed of the encoder also varies. You can create better compressed Flac files by spending more time encoding them.
 
A flac file can be converted to any other lossless format such as WAV and back without any loss of audio data.
== Compressed Sound ==
There are lots of them out there, see http://en.wikipedia.org/wiki/Comparison_of_audio_codecs for a list. One other worth mentioning here is AAC - a format mostly used by Apple products. It has some benefits over MP3 but is roughly as popular as OGG (both far less used than MP3.
== Uncompressed Electronic Sound == === WAV/AIFF =- MIDI ==
These two are basically identical formats but given that WAV has been the supported-by-default MIDI is actually much more than just a file format in windows - , it's much more popularan interchange format that's used in many electronic sound instruments such as synthesizers.
Sound Instead of recording real sound (and often there is no real sound to record in the first place, the music is electronically generated) the audio is stored completely uncompressedas a set of instructions, similar to how it's stored on Audio CDssomething like sheet music. The format is not exactly instructions include the same though so conversion instrument type, length and amplitude of each note. It is necessary up to transfer files from/the player to audio CDscombine (like an orchestra) all those instructions into a single song.
Because of their age MIDI files on computers were much more popular when the internet was slow and lack of encoding/decoding requirement the harddrives small because they are usually default formats tiny compared even to the best compressed audio file. It was common to hear a MIDI playing when visiting an early webpage. These days support for audio creation MIDI on computers is spotty because they're not a big requirement and editing toolssound cards no longer have MIDI hardware on them like they used to.
=== FLAC =Metadata ==
Flac is a lossless compressed format. A wav file Most image formats (but not WAV and AIFF) can be compressed have metadata associated with any generic compression tool so you can understand Flac playback as on-them. This usually includes the-fly decompressionartist, but it's been optimised to allow better audio compressionalbum, and track name, seeking to random places in the fileyear, and storing audio metadatagenre.
Playing a flac file is more CPU-intensive than playing a WAV file though so which format you choose is a balance between space required and decoding speedMost playback software can be used to edit the metadata. Format conversion software usually also copies the metadata into the appropriate fields.
The speed of the encoder also varies. You can create better compressed Flac files by spending more time encoding them.== Degree Students ==
A flac file can be converted to any other lossless format such as WAV Read the 6 page paper [[Media:Effectiveness of Audio in Instruction.pdf|Effectiveness of Audio on Screen Captures in Software Application Instruction (Veronicas and back without any loss of audio dataMaushak, 2005)]].
== Electronic Sound =Links =
* http://en.wikipedia.org/wiki/Sound* http://en.wikipedia.org/wiki/Note* http://en.wikipedia.org/wiki/Amplitude== Metadata ==* http://en.wikipedia.org/wiki/Sample_rate* http://en.wikipedia.org/wiki/Red_Book_%28CD_standard%29Most image formats (but not * http://en.wikipedia.org/wiki/WAV and AIFF) can have metadata associated with them* http://en. This usually includes the artist, album, and track name, the year, and genrewikipedia.org/wiki/Aiff* http://en.wikipedia.org/wiki/Mp3* http://en.wikipedia.org/wiki/Ogg* http://en.wikipedia.org/wiki/Flac* http://en.wikipedia.org/wiki/Comparison_of_audio_codecs* http://en.wikipedia.org/wiki/Midi* http://en.wikipedia.org/wiki/Advanced_Audio_CodingMost playback software can be used to edit the metadata* http://en. Format conversion software usually also copies the metadata into the appropriate fieldswikipedia.org/wiki/Variable_bitrate
= Lab =
audacity
gz compress wav, mpr, flac
<audio> tags
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