doc.go

/*
Package fourcc is a Go implementation of FOURCC (four character code) (4CC) identifiers for a video codecs, compression formats, colors, and pixel format used in media files.


Introduction

FOURCC, also sometimes written as FourCC and 4CC, are all short for “four character code”.

FOURCC, is a sequence of 4 8-bit bytes packed into an unsigned 32-bit integer which, uniquely identifies a data format.

(A character in this context is a 1 byte (i.e., 8 bit) value. Thus a FOURCC always takes up exatly 32 bits (i.e., 4 bytes).)

These data formats tend to be video codecs, compression formats, colors, and pixel format used in media files.


Samples

Here are some sample FOURCC.

	┏━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
	┃ Label ┃ Hexadecimal (unsigned integer) ┃
	┡━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┩
	│ PAL8  │ 0x384C4150                     │
	┼───────┼────────────────────────────────┤
	│ VP80  │ 0x30385056                     │
	┼───────┼────────────────────────────────┤
	│ H264  │ 0x34363248                     │
	┼───────┼────────────────────────────────┤
	│ MJPG  │ 0x47504A4D                     │
	└───────┴────────────────────────────────┘

The way you can understand how these labels get turned in unsigned integers is, if we consider the FOURCC “PAL8”, then:

	ASCII ‘P’ = hexadecimal 0x50
	ASCII ‘A’ = hexadecimal 0x41
	ASCII ‘L’ = hexadecimal 0x4C
	ASCII ‘8’ = hexadecimal 0x38

And then these 8-bit bytes as packed into an unsigned integer in reverse order.

I.e.,:

	var value uint32 = (uint32('P') | (uint32('A') << 8) | (uint32('L') << 16) | (uint32('8') << 24))


Examples

Here is an example usage:

	var colorspace fourcc.Type = fourcc.FOURCC('P','A','L','8')

Here is a constant:

	const (
		VP8 = fourcc.Const("VP80")
	)

A fourcc.Const needs to be turned into a fourcc.Type before using it. So:

	var datum fourcc.Type
	var err error
	
	datum, err = VP8.FOURCC()

Some uses of Scan:

	var colorspace fourcc.Type
	
	err := colorspace.Scan("PAL8")

And:

	var p [4]byte = [4]byte{'P','A','L','8'}
	
	var colorspace fourcc.Type
	
	err := colorspace.Scan(p)

And:

	var p []byte = []byte{'P','A','L','8'}
	
	var colorspace fourcc.Type
	
	err := colorspace.Scan(p)


See Also

More information about FOURCC can be found at: https://www.fourcc.org/

*/
package fourcc