{"id":11559,"date":"2000-02-08T00:24:02","date_gmt":"2000-02-07T23:24:02","guid":{"rendered":"http:\/\/krabat.menneske.dk\/kkblog\/?p=11559"},"modified":"2015-04-01T00:32:00","modified_gmt":"2015-03-31T23:32:00","slug":"lydoptagelse-paa-macppc","status":"publish","type":"post","link":"https:\/\/krabat.menneske.dk\/kkblog\/2000\/02\/08\/lydoptagelse-paa-macppc\/","title":{"rendered":"lydoptagelse p\u00e5 Mac\/PPC"},"content":{"rendered":"

 <\/p>\n

<\/a>Realtime
\nLYD-optagelse p\u00e5 Mac\/PPC – og ud igen<\/span><\/p>\n

Lydformater<\/a><\/span><\/p>\n

Forberedelse<\/a><\/span><\/p>\n

Programmer<\/a><\/p>\n

Optagelse<\/a><\/p>\n

Efterarbejde<\/a><\/p>\n

Konvertering<\/a><\/p>\n

Broadcast! <\/a><\/p>\n

G\u00f8re sine Real Audio-filer tilg\u00e6ngelige<\/a><\/p>\n

G\u00f8re sine Mp3-filer tilg\u00e6ngelige<\/a><\/p>\n

 <\/p>\n

Note:
\nMp3 og RealAudio p\u00e5 68K-Macintosh<\/a><\/span><\/p>\n

Audio File
\nFormats FAQ<\/a> (1995)<\/span> <\/span><\/p>\n

dden danske tekst \u00a9 Kenneth Krabat<\/p>\n

8. februar 2000<\/p>\n

rev. 10. oktober 2000<\/p>\n

\n

<\/a>LYDFORMATER<\/span><\/b><\/span>
\ntil top<\/a><\/span><\/span><\/p>\n

Jeg er ikke teoretisk vidende om lydformater. L\u00e6ngere nede i dette dokument\u00a0er en \u00e6ldre FAQ over de enkelte formater – Audio File\u00a0Formats FAQ<\/a> – og dens hjemsted p\u00e5 nettet finder du h\u00e9r<\/a>.
\nEn nyere finder du h\u00e9r<\/a>. Men jeg kan\u00a0sige s\u00e5 meget, at<\/p>\n

Mp3<\/b> er et komprimeret format, ca. 1:8\/1:10 i forhold til originalen,\u00a0med lille eller minimalt kvalitetstab. Kan streames*1+3\u00a0<\/span>fra en server.
\nteam-mp3.com<\/a>\u00a0har en glimrende teknisk FAQ om Mp3-formatet og h\u00e9r<\/a>\u00a0en mere generel. Mp3rightnow.com\u00a0<\/a>har\u00a0en masse programmer, information og links. Og h\u00e9r<\/a>\u00a0er flere – dog mest til Windows (man kan jo klage…)<\/p>\n

Real Audio<\/b> er et komprimeret format, ca. 1:100 i forhold til originalen,\u00a0hvis den skal kunne hentes og h\u00f8res via et 28.8 modem, med et vist\u00a0kvalitetstab, men kvaliteten kan h\u00e6ves ved at s\u00e6tte st\u00f8rre\u00a0krav til modtagerens modemhastighed. Kan streames*1<\/span>.<\/p>\n

AIFF<\/b> er (s\u00e5 vidt jeg ved) ukomprimerede, og derfor kvalitetsm\u00e6ssigt\u00a0intakte.<\/p>\n

QuickTime<\/b> movies er et komprimeret format med lille eller ringe kvalitetstab.
\nKan streames*1+2<\/span>, men d.d. fungerer det ikke til Netscape\u00a0p\u00e5 Macintosh. Filen kan dog downloades og h\u00f8res efter download.
\nCa. 1:10 i forhold til originalen.<\/p>\n

H\u00e9r<\/a>
\nkan du l\u00e6se en lang udredning om de mest popul\u00e6re formater, deres\u00a0fordele og ulemper b\u00e5de ved streaming af lyd og billede.<\/span><\/p>\n

Der findes andre lydformater – .WAV, .au, system7 (til Mac) og MIDI ikke mindst\u00a0– men ovenst\u00e5ende er at foretr\u00e6kke, hvis man vil dele med flest\u00a0muligt og have flest programmer at v\u00e6lge fra.<\/p>\n

*1 Streaming
\nbetyder b\u00e5de, at filen kan h\u00f8res “fra serveren” uden\u00a0at blive downloadet til klient-computeren (hvilket er smart, hvis man vil\u00a0undg\u00e5 at f\u00e5 sine lydfiler i oml\u00f8b, som det er tilf\u00e6ldet\u00a0med Mp3-filer) og at man kan “spole” i den komprimerede fil, pr\u00e6cis\u00a0som p\u00e5 en CD. Forvirrende, men s\u00e5dan er det.<\/span><\/span><\/p>\n

*2 QuickTime-filer bliver <\/b>downloadede.<\/p>\n

*3 Dog kun i Mp1-formatet; kvaliteten er ikke s\u00e5 h\u00f8j; sikkert\u00a0som RealAudio<\/p>\n

\n

<\/a>FORBEREDELSE<\/span>
\n<\/span><\/b>til
\ntop<\/a><\/span><\/span><\/span><\/p>\n

Man \u00e5bner sit program\u00a0og finder i dets indstillinger ud af, hvilken placering der bruges som scratchdisc\u00a0– mellemlager – og derefter om der er plads p\u00e5 den p\u00e5g\u00e6ldende
\nHD til den m\u00e6ngde lyd, man vil optage.<\/span><\/p>\n

640Mb svarer til 74 minutter – det giver (mumle mumle) 8,6486486486\u00a0Mb lyd pr. minut. Det er nu ikke altid rigtigt, fordi 74 minutter er lig de\u00a0640 Mb p\u00e5 en CD, hvad enten det er stereo eller mono – men regn med\u00a08.7 Mb i Stereo, og 5Mb i mono.<\/p>\n

\n

<\/a>PROGRAMMER
\ntil lydoptagelse<\/span>
\n<\/span><\/b>til
\ntop<\/a><\/span><\/span><\/span><\/p>\n

Der er mange amat\u00f8rprogrammer,\u00a0man kan bruge til at optage med fra ekstern kilde (og mange professionelle,\u00a0som kr\u00e6ver manual og stor lydteoretisk viden).<\/span><\/p>\n

Her er et sted<\/a>\u00a0(Hitsquad), som rummer mange, mange programmer – dog ingen “payware”-programmer.
\nG\u00e5 direkte til Mac-siden<\/a>\u00a0eller til Audio\u00a0converters<\/a> til Mac<\/span><\/p>\n

AIFF-filer<\/b><\/span><\/span><\/p>\n

 <\/p>\n

Coaster<\/b> (v. 1.1.2<\/a>\u00a0d.d. – det har den fordel, at man – n\u00e5r man har fundet indspillestyrken\u00a0– kan optage fra en LP\/CD\/MC eller mikrofon,\u00a0 og s\u00e5 bare “klippe”\u00a0efter hvert nummer; s\u00e5 f\u00e5r man en selvst\u00e6ndig lydfil for\u00a0hvert nummer uden at skulle stoppe programmet. Det kr\u00e6ver dog at man\u00a0sidder parat og kender sin plade rimelig godt)<\/p>\n

FeltTip Sound Studio<\/a><\/b>
\n– lille sharewareprogram med gode filtre – hjemmeside<\/span><\/a><\/p>\n

SoundEdit 16<\/a><\/b>
\nfra Macromedia (v 2.0.7 til brug for iMac\/OS 8.5 +\u00a0 – stort program fra\u00a0Macromedia, som har 50 effektfiltre til at lege lydmand med – med lidt \u00f8velse\u00a0kan man g\u00f8re det samme som ovenst\u00e5ende). Payware<\/p>\n

SoundMaker<\/b> (sidste version 1.0.3<\/a>
\n– derefter ingen opdateringer; lille program med 100-vis af supergode og sjove\u00a0effekt-, redigerings- og editeringsmuligheder; fungerer i princippet som SoundEdit,\u00a0men er ikke helt s\u00e5 overskueligt. Men det er hurtigere end SE16)<\/p>\n

Real\u00a0Audio<\/span><\/b><\/span><\/p>\n

RealProducer<\/a><\/b>
\n(pt. v. 6 etellerandet – kan producere b\u00e5de god kvalitet RealAudiofiler\u00a0og optage real-time<\/em> til RealAudio-formatet fra extern indgang, CD\u00a0eller mikrofon) – hjemmeside<\/span><\/a><\/p>\n

Mp3<\/b><\/span><\/span><\/p>\n

MPEG Audio Creator<\/a><\/b>
\n(pt. v. 2.0 – er prim\u00e6rt en hurtig AIFF->Mp3->AIFF-converter,\u00a0men kan optage real-time<\/em> til Mp2 – har dog ikke den store betydning\u00a0for kvaliteten. Kr\u00e6ver dog, at maskinen underst\u00f8tter 44Khz\/16bit\u00a0optagelse og har mindst en180MHz 604 processor eller 603\/200MHz+. “Payware”<\/p>\n

\n

<\/a>OPTAGELSE<\/span><\/b>
\ntil top<\/a><\/span> <\/span><\/p>\n

Man tr\u00e6kker en\u00a0ledning fra sit stereonal\u00e6gs b\u00e5ndoptagerudgang til Mac’ens mikrofon-indgang;\u00a0en phono til minijack, hvis man har phono-udgang p\u00e5 stereoen. Man kan<\/i>
\nogs\u00e5 tr\u00e6kke en ledning fra stereoanl\u00e6ggets hovedtelefonudgangen,\u00a0men s\u00e5 v\u00e6r MEGET varsom med udgangsniveauet – og det er heller\u00a0ikke altid, at det lyder godt, fordi dette signal er et forst\u00e6rket signal\u00a0(og s\u00e5 ved jeg ikke mere…)<\/span><\/p>\n

Man \u00e5bner sit program,\u00a0g\u00f8r de n\u00f8dvendige fagter for at f\u00e5 magien til at virke,\u00a0og vupti… er man i gang med at optage (l\u00e6s de medf\u00f8lgende ReadMe-filer,\u00a0men ovenforn\u00e6vnte programmer er superenkle og ligetil).<\/span><\/p>\n

Hvis man vil sikre sig,\u00a0at filen har den optimale lydkvalitet, INDEN man konverter den til Mp3, RealAudio\u00a0(eller et andet format), skal man optage den i CDkvalitet, dvs. 44 kHz\/16bit.\u00a0Jo h\u00f8jere frekvens og bit-rate, desto flere informationer = bedre lyd.
\n<\/span><\/p>\n

Hvis man vil optage flere\u00a0lydfiler fra den samme kilde, og man ikke kan lave det hele i samme session,\u00a0er det klogt at skrive ned hvad indstillingerne i program og evt. ekstern\u00a0mixer st\u00e5r p\u00e5; man kan ogs\u00e5 tage et screenshot af programmets\u00a0indstillinger og gemme dette og evt. nedskrevne informationer i samme mappe\u00a0som lydfilerne. Har man et godt \u00f8re, kan man evt. lave en referencefil,\u00a0som holder d\u00e9t niveau, man vil have – og s\u00e5 indstille niveau\u00a0p\u00e5 den nye fil indtil den matcher afspilningsnu\u00edveauet p\u00e5
\nreferencefilen.<\/span><\/p>\n

\n

<\/a>EFTERARBEJDE<\/span>
\n<\/span><\/b>til\u00a0top<\/a><\/span><\/span><\/span><\/p>\n

Dette g\u00e6lder “kun” AIFF-filer, og andre, “l\u00f8st” komprimerede,\u00a0lydformater; det er dog muligt at fikse “pops’n’cracks” p\u00e5\u00a0Mp3 filer, men programmer til d\u00e9t form\u00e5l findes vist endnu kun\u00a0til Windows.<\/p>\n

Med SoundEdit16 og SoundManager\u00a0og mange sharewareprogrammer<\/a>\u00a0kan man efterbehandle lyden – dvs. stille niveau op og ned, equalize og lege\u00a0sine numre s\u00f8nder og sammen.<\/span>
\n<\/span><\/p>\n

Anbefalede shareware-programmer\u00a0listes gerne h\u00e9r, hvis man skriver en kort forklaring<\/a>
\np\u00e5 sit elskede programs genialitet. <\/span><\/p>\n

\n

<\/a>KONVERTERING<\/span>
\n<\/span><\/b><\/span><\/b>til
\ntop<\/a><\/span><\/span><\/span><\/span><\/p>\n

AIFF->Mp3->AIFF<\/span><\/b>:
\n<\/span> <\/span><\/p>\n

MPEG
\nAudio Creator<\/a><\/b> “for the latest versions of both encoder and player”<\/span><\/p>\n

AudioCatalyst\u2122 2.0.0<\/b> – hurtig – hjemmeside<\/span><\/a><\/p>\n

SoundJam<\/b> – er ogs\u00e5 en udm\u00e6rket Mp3-player – hjemmeside<\/span><\/a><\/p>\n

SoundApp
\n2.7<\/a><\/b> – kan konvertere mellem alle lydformater, minimumssystemkrav 68020\/OS7; SoundApp kr\u00e6ver dog en hurtig processor (200MHz+) for at afspille\u00a0<\/b><\/em>MPEG’formatet – hjemmeside<\/a><\/span><\/p>\n

AIFF->RealAudio<\/b><\/span><\/span><\/p>\n

RealProducer<\/a><\/b>
\n– som ovenst\u00e5ende<\/span><\/p>\n

RealAudio Encoder<\/b> – \u00e6ldre udgave af RealProducer, der ikke fylder\u00a0s\u00e5 meget, er hurtig, men giver “knap” s\u00e5 gode RA-filer som den\u00a0nyere udgave (OBS: den kan v\u00e6re sv\u00e6r at finde)<\/p>\n

(Der findes programmer, ikke lavet af Real.com, sim kan producere RA-filer,\u00a0men jeg kender dem ikke; fort\u00e6l mig gerne, hvis du ved noget eller finder\u00a0ud af det – krabat@menneske.dk<\/span><\/a>)<\/p>\n

Real\u00a0Audio->AIFF<\/span><\/b><\/span><\/p>\n

Real Audio->Mp3<\/p>\n

 <\/p>\n

(jeg kender ikke nogen\u00a0programmer, der kan g\u00f8re dette, men er MEGET<\/a>\u00a0<\/b>interesseret!!)<\/span><\/p>\n

\n

<\/a>BROADCAST!<\/b><\/span><\/p>\n

For at man kan\u00a0streame Mp3 eller RealAudio fra sin server eller sin desktop (sin egen computer)\u00a0beh\u00f8ves programmer, der kan d\u00e9n slags (…!). Mere f\u00f8lger\u00a0senere, men tjeck forel\u00f8big Icecast<\/a>\u00a0eller MacCast<\/a> (Mp3), RealAudio<\/a>\u00a0(RealAudio)<\/span><\/p>\n

\n

<\/a>G\u00f8re\u00a0Sine RealAudio-filer Tilg\u00e6ngelige<\/b><\/span>
\ntil top<\/a><\/span><\/span><\/p>\n

G\u00e5 til\u00a0realAudio’s site og indtast de relevante oplysninger <\/span><\/p>\n

http:\/\/realguide.real.com\/info\/?page=submit<\/a><\/p>\n

\n

<\/a>G\u00f8re\u00a0Sine Mp3-filer Tilg\u00e6ngelige<\/b><\/span>
\ntil top<\/a><\/span><\/span><\/p>\n

Limewire<\/span><\/a>,\u00a0Macster, Carracho<\/a>, Hotline<\/span><\/p>\n

\n

<\/a>NOTE:
\nMp3 og RealAudio p\u00e5 68K-Macintosh<\/b> <\/span>
\n<\/span><\/b>til
\ntop<\/a><\/span><\/span><\/span><\/p>\n

For at en maskine kan\u00a0afvikle disse hyperkomprimerede filer – l\u00e6se dem fra harddiske, pakke\u00a0dem ud og afvikle dem – beh\u00f8ver maskinen en FPU (Floating Point Processor);\u00a0det er en matematisk co-processor, som assisterer CPU’en med at beregne –\u00a0og CPU’ens hastighed og maskinens bushastighed skal ogs\u00e5 v\u00e6re\u00a0af en vis st\u00f8rrelse.<\/span><\/p>\n

REAL\u00a0AUDIO<\/span><\/b><\/span><\/p>\n

Jeg har testet en \u00e6ldre model RealAudio Player (v. 3.0) sammen med en\u00a0software FPU (SoftFPU 3.04) p\u00e5 en Performa 475\/25MHz. Resultat var som\u00a0f\u00f8lger<\/p>\n

14.4 RealAudio-filer<\/b> kunne godt afvikles, men lydkvaliteten var ikke\u00a0noget at skrive hjem om. Og om man kunne h\u00f8re dem streaming over nettet\u00a0tvivler jeg p\u00e5, da CPU’en da vil have rigeligt at g\u00f8re med at\u00a0holde netforbindelse og browser k\u00f8rende samtidig.<\/p>\n

28.8 RealAudio-filer\u00a0<\/b>– nul putte<\/span><\/p>\n

 <\/p>\n

Min konklusion er, at\u00a0maskinen skal op omkring 40-50MHz, f\u00f8r den kan afvikle en RealAudiofil\u00a0af en t\u00e5lelig kvalitet. Hvordan det ville forl\u00f8be med en hardwareFPU
\np\u00e5 en 68K maskine kan jeg kun g\u00e6tte om – men jeg formoder at det\u00a0g\u00e5r; i dette tilf\u00e6lde skal CPU’en ikke l\u00e6se b\u00e5de lydfil\u00a0og software FPU fra maskinen samtidig.<\/span><\/p>\n

Mp3\u00a0<\/span><\/b><\/p>\n

Glem det.<\/p>\n

\n

<\/a>Audio\u00a0File Formats FAQ<\/span><\/b><\/a>
\n<\/span><\/b>til\u00a0top<\/a><\/span><\/span><\/span><\/p>\n

THIS IS AN OLD\u00a0LIST – 1995, but apart from realAudio documentation, it kind of still stands.<\/span><\/p>\n

 <\/p>\n

SoundApp<\/b>
\nsupports many different file formats, but what exactly are they? The following
\nis a brief description of the various sound formats that SoundApp supports:<\/span><\/p>\n

SoundCap<\/b>:
\nThis is a Macintosh sound format created for use with an early audio digitizer.
\nVersion 4.3 of the application circa 1986 is the latest I’ve seen. It was
\nwritten by Mark Zimmer and Tom Hedges from Fractal Software. It supported
\ntwo basic flavors of sounds, compressed and uncompressed. Both types had ‘FSSD’
\nas the file type and ‘FSSC’ as the creator. Uncompressed files are just a
\nseries of 8-bit unsigned bytes in the data fork. Compressed files store information
\npertaining to sampling rate and a checksum. Sampling rates are limited to
\n5.6, 7.4, 11.1 and 22.2 kHz, and compression is done with a Huffman algorithm.
\nCompressed files are sometimes referred to as HCOM files because that is the
\nfirst four characters of the file.<\/span><\/p>\n

SoundEdit<\/b>:
\nThis is the same file type as uncompressed SoundCap for mono sounds. In addition,
\nit adds to the resource fork some information about colors, labels, looping
\nsegments and the format. The most useful for playback is the ‘INFO’ resource,
\nwhich stores the sampling rate, limited to the same four as SoundCap. Stereo
\nfiles consist of the left and right channels stored back-to-back in the data
\nfork. The ‘INFO’ resource specifies the lengths of each channel, which can
\nbe different. SoundEdit came with the MacRecorder sound digitizer from Farallon
\nand later by MacroMedia. SoundEdit Pro and SoundEdit 16 are more recent incarnations,
\nand they support a much larger format suite, including up to 48-kHz samples
\nand 16-bit resolution. They shed the limitations inherent in the original
\nformat. SoundApp does not currently support SoundEdit Pro or SoundEdit 16
\nfiles. (it does now – 2000\/02)<\/span><\/p>\n

Studio Session
\nInstrument<\/b>: This format is primarily used with Super Studio Session and
\nstores digitally sampled instruments. There are two types: compressed and
\nuncompressed. Compressed instruments have the same format as compressed SoundCap
\nfiles, and uncompressed instruments are likewise similar to uncompressed SoundCap
\nfiles, with the addition of an eight-byte header.<\/span><\/p>\n

AIFF<\/b>
\nand AIFF-C<\/b>: AIFF stands for Audio Interchange File Format and was developed
\nby Apple for storage of sounds in the data fork. It has been adopted by SGI
\nand some other specialized applications. The Macintosh OS includes support
\nfor playing and creating AIFF files. More information about the format can
\nbe found in Inside Macintosh VI or Inside Macintosh: Sound. In addition, the
\nformat specification can be found at various places on the Internet. AIFF
\nis a very flexible file format, allowing the specification of arbitrary sampling
\nrates, sample size, number of channels, and application-specific format chunks
\nwhich can be ignored by other applications. AIFF-C is basically AIFF with
\ncompressed samples. Apple supports two types of compression on the Macintosh,
\nMACE 3-to-1 and MACE 6-to-1. Both are lossy compression algorithms, but provide
\nreasonable quality with a great space savings. In addition, the Apple II GS
\nuses ACE 2-to-1 and ACE 8-to-3 compression, but SoundApp only supports MACE-compressed
\nfiles. Unlike SoundCap\/Edit, samples are stored as two’s complement values.
\nLossy compression means the compressed sound will not sound exactly like the
\noriginal sound, much like JPEGs do not look exactly like the original picture.<\/span><\/p>\n

System 7<\/b>
\nand ‘snd<\/b> ‘: System 7 sound files are simply type 1 ‘snd ‘ resources
\nstored with a type of ‘sfil’ and a creator of ‘movr’. System 7 provides the
\nfamiliar icon for them and permits playback in the Finder by double-clicking
\non them. A ‘snd ‘ is a type of resource which consists of a series of commands
\nfor use by the Sound Manager. In addition to digitized sound samples, ‘snd
\n‘ resources can contain direct frequency-modulated and wave table-based sounds.
\nAny number of the three types can be combined with various effects to produce
\ncomplex sound files. Simple Beep is an example of a non-digitized ‘snd ‘.
\nThere are two types of ‘snd ‘ resources, amazingly called type 1 and type
\n2. Type 1 is the format described above and is referred to as the System sound
\nformat. Type 2 is for use with HyperCard and can contain only a sampled (digitized)
\nsound. SoundApp can play both types but will only convert sampled sounds.
\nFor more information on ‘snd ‘ files consult Inside Macintosh VI or Inside
\nMacintosh: Sound. A familiarity with the Resource Manager would also be helpful.
\n8-bit samples are stored as unsigned bytes, like SoundCap\/Edit, but 16-bit
\nsamples are signed, like AIFF. Stereo ‘snd ‘ resources are also possible,
\nbut Sound Manager 3.0 is required to play 16-bit samples directly. The two
\ntypes of compression for ‘snd ‘ resources are the same MACE types used in
\nAIFF files.<\/span><\/p>\n

Sun Audio (.au)<\/b>
\nand NeXT: Internally, these are the same formats. SoundApp differentiates
\nbetween them by file type or suffix merely for the user’s benefit. The format
\nspecifies arbitrary sampling rates and multi-channel sounds. It supports a
\nnumber of sound encodings, including \u00b5-law, a-law, various linear formats
\nof varying sample sizes, floating point samples, native DSP samples and G.72x
\nADPCM compression. SoundApp supports \u00b5-law, a-law, 8-bit signed, 16-bit
\nsigned, G.721 ADPCM and both versions of G.723 ADPCM. Each \u00b5-law sample
\nis stored in 8 bits, but the meaning of the sample is different. Normal sound
\nformats use a linear encoding, whereas \u00b5-law and a-law are logarithmic.
\nThis means that the spacing between the different sound levels grow progressively
\nlarger as the values increase. This format provides a larger dynamic range
\nthan normal 8-bit samples, approximately equivalent to 12-bit samples. However,
\nit suffers from more noise than linear encodings. The G.721, G.723-24 and
\nG.723-40 ADPCM formats are CCITT standards for compression of 8000-Hz 14-bit
\nsamples into a 32-, 24- or 40-kbps data stream. These compressed formats are
\nnot very popular due to the extremely slow decompression rates. Most files
\nstart with the four-character signature, ‘.snd’, but there are some older
\nheaderless AU files. These are assumed to be \u00b5-law encoded, mono at 8000
\nHz. A “.al” suffix will force the sound to be a-law, if it does not have a
\nheader. The U.S. telephone system uses \u00b5-law encoding for digitization,
\nwhereas the European telephone systems use a-law encoding.<\/span><\/p>\n

PSION<\/b>
\nsound file: This format consists of a short header followed by a-law encoded
\nsamples at 8000 Hz. It is used by the PSION Series 3 palmtop personal information
\nmanager and uses a “.WVE” suffix.<\/span><\/p>\n

Windows WAVE<\/b>:
\nThis format was created by Microsoft and IBM, and it has unfortunately become
\na popular standard. Like AU, it specifies an arbitrary sampling rate, number
\nof channels and sample size. It also specifies a number of application-specific
\nblocks within the file. It has a plethora of different compression formats,
\nalthough the Microsoft ADPCM is the most popular. SoundApp only supports 8-,
\n16-bit and MS ADPCM-compressed sounds. MS ADPCM provides 4-to-1 compression.
\nAll data fields and 16-bit samples are stored in little-endian notation, as
\nIntel processors require. All other formats supported by SoundApp use big-endian
\nnotation which means the high-bytes come first in the data stream.<\/span><\/p>\n

Sound Blaster
\nVOC<\/b>: This is the format used by the Creative Voice SoundBlaster hardware
\nused in IBM-compatible computers and is optimized for that hardware. It specifies
\nsampling rate as a multiple of an internal clock and is not as flexible as
\nthe other general formats. Data can be segmented and portions of silence can
\nbe added. SoundApp supports both of these features, but not the looping feature.<\/span><\/p>\n

Amiga IFF (8SVX<\/b>):
\nThis is the dominant format on the Commodore Amiga platform. It can specify
\nan arbitray sampling rate but ony supports mono 8-bit sounds. It also supports
\na 2-to-1 lossy compression format which uses a unique Fibonacci delta compression.<\/span><\/p>\n

Sound Designer
\nII (SDII)<\/b>: This is a format for professional sound editing on the Macintosh.
\nIt can specify arbitrary sampling rates and supports multiple channels and
\ndata sizes. Information regarding the specifics of the sound are stored in
\nthree ‘STR ‘ resources. Like VOC, 8SVX and WAVE, samples are encoded as signed
\nvalues. More information about this format can be obtained from Digidesign.
\nSoundApp only supports version II files.<\/span><\/p>\n

DVI ADPCM<\/b>:
\nThis is the Intel\/DVI ADPCM (Adaptave Differential Pulse Code Modulation)
\nformat. It is a 4-to-1 compressed 16-bit file format. It is unique among the
\nvarious ADPCM formats in that it’s very fast, and like all ADPCM formats it
\nis lossy. The version of the format that SoundApp supports plays at a 8000-Hz
\nsampling rate.<\/span><\/p>\n

Amiga MOD<\/b>:
\nThis is not really a sound format but a music format. It stores digitized
\ninstruments and contains a musical score which produces a lengthy composition
\nwith a very small amount of data. There have been various extensions to this
\nformat, but SoundApp only supports those which Sound Trecker 2.2 supports.
\nThese include Amiga SoundTracker, StarTracker, NoiseTracker, ProTracker (4-track),
\nAmiga StarTracker (4- and 8-track), Oktalyzer (4-8 track), Amiga MED\/OctaMED
\n(4-16 track MMD0\/1\/2 formats), IBM FastTracker (4-, 6- and 8-track), IBM TakeTracker
\n(1-32 track). SoundApp does not support MTM or S3M formats. Native code will
\nbe used for MOD playback on a Power Macintosh.<\/span><\/p>\n

QuickTime
\nMovies<\/b>: This is the Apple standard for time-based multimedia files. Versions
\n1.x support moving pictures, sound and later versions support text. QuickTime
\n2.0 supports MIDI tracks; however, conversion of MIDI data to other sound
\nformats is not supported by QuickTime 2.0. QuickTime 2.0 or later and the
\nQuickTime Musical Instruments extension must be installed in order to play
\nQuickTime MIDI files. It is highly advisable to install the Apple Multimedia
\nTuner version 2.0.1 or later as well. This extension is freely available from
\nApple’s online support services and makes QuickTime and Sound Manager 3.0
\nmemory management considerably more robust.<\/span><\/p>\n

MIDI<\/b>:
\nMusical Instrument Digitial Interface is primarily a standard for communication
\nbetween musical instruments. General MIDI is a standard for storing compositions
\nbased on what events happened during the performance. It does not contain
\ndigitized audio data; instead, it stores only the information about which
\nnotes were played in a time-line format. This is similar to the MOD format
\nbut without the digitized instrument samples. QuickTime 2.0 or later supports
\nGeneral MIDI data in QuickTime movies. In order to listen to MIDI files with
\nSoundApp, they must first be converted to QuickTime files. This can be done
\nvia the Import QuickTime menu item in the File menu.<\/span><\/p>\n

Audio CD
\nTracks<\/b>: A lot of programs can “rip” CD’s – and the format is
\nAIFF. Audio tracks take up a huge amount of space.<\/span><\/p>\n


\n<\/span><\/b>til\u00a0top<\/a><\/span><\/span><\/span><\/p>\n

 <\/p><\/blockquote>\n