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A chunk begins with the chunk type , a four-byte string whose value is either MThd for a header chunk or MTrk for a track chunk. The chunk length follows this string, and indicates the number of bytes remaining in the chunk. The chunk length is a 32-bit unsigned integer in big-endian format, i.e., the most-significant byte is first.

Header chunk

The header chunk begins with the string MThd , and is followed by a fixed chunk length value of 6; as a 32-bit unsigned integer this is 0x00_00_00_06.

The file type follows, and is a 16-bit unsigned integer that takes on one of three possible values: 0 (0x00_00) indicates single track data, 1 (0x00_01) indicates multi-track data which is vertically synchronous (i.e., they are parts of the same song), and 2 (0x00_02) indicates multi-track data with no implied timing relationship between tracks. Type 1 is by far the most common, where each track contains MIDI messages on a single channel. In this way tracks can be associated with a single instrument and recorded individually

Next is the number of tracks , a 16-bit unsigned integer. The number of tracks can range from one (0x00_01) to 65,535 (0xFF_FF). In practice the number of tracks is typically about 20 or so.

The last value in the header chunk is the division , a 16-bit unsigned integer that indicates the number of ticks per quarter note . The tick is a dimensionless unit of time, and is the smallest grain of time used to indicate the interval between events. A typical value of division is 120 (0x00_78).

Track chunk

The track chunk begins with the string MTrk , and is followed by the track length , a 32-bit unsigned integer that indicates the number of bytes remaining in the track. In theory a track could be as long as 4 Gbytes!

The remainder of the track is composed of pairs of delta-times and events. A delta-time is in units of tics, and indicates the time interval between events. An event is either a MIDI message or a meta-event . Meta-events are unique to the standard MIDI file, and indicate information such as track name, tempo, copyright notice, lyric text, and so on.

A delta time uses variable-length format ( VLF ), and can be anywhere from one to four bytes in length. Short delta times require only one byte, and long delta times can require up to four bytes. Since short delta times tend to dominate the standard MIDI file (think of a chord hit that generates a burst of Note-On messages with very little time between events), most of the delta times are only one byte long and the overall file size is thus minimized. However, since very long delta times must be accommodated as well, the variable-length format can use up to four bytes to represent very long time intervals.

Variable-length format

Variable-length format ( VLF ) is used to represent delta times and the length of meta-events (to be described below). A numerical value represented in VLF requires from one to four bytes, depending on the size of the numerical value. Since the standard MIDI file is parsed one byte at a time, some type of scheme is required to let the parser know the length of the VLF number. A naïve approach would be to include an additional byte at the beginning of the VLF to indicate the number of bytes remaining in the value. However, this approach would mean that a delta time always requires a minimum of two bytes. Instead, the VLF uses the most-significant bit (MSB) as a flag to indicate whether more bytes follow.

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Musical signal processing with labview -- midi for synthesis and algorithm control. OpenStax CNX. Nov 09, 2007 Download for free at http://cnx.org/content/col10487/1.2
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