ADX (file Format) - Technical Description - File Header

File Header

The ADX disk format is defined in big-endian. The identified sections of the main header are outlined below:

0 1 2 3 4 5 6 7 8 9 A B C D E F
0x0 0x80 0x00 Copyright Offset Encoding Type Block Size Sample Bitdepth Channel Count Sample Rate Total Samples
0x10 Highpass Frequency Version Flags Unknown Loop Enabled (v3) Loop Begin Sample Index (v3)
0x20 Loop Begin Byte Index (v3) Loop Enabled (v4)

Loop End Sample Index (v3)

Loop Begin Sample Index (v4)

Loop End Byte Index (v3)

Loop Begin Byte Index (v4)
0x30 Loop End Sample Index (v4) Loop End Byte Index (v4) Zero or more bytes empty space
??? ASCII (unterminated) string: "(c)CRI"
... Audio data starts here

Fields labelled "Unknown" contain either unknown data or are apparently just reserved (i.e. filled with null bytes). Fields labelled with 'v3' or 'v4' but not both are considered "Unknown" in the version they are not marked with. It should also be noted that this header may be as short as 20 bytes (0x14), as determined by the copyright offset, which implicitly removes support for a loop since those fields are not present.

The "Encoding Type" field should contain one of:

  • 0x03 for Standard ADX
  • 0x04 for ADX with an exponential scale
  • 0x10 or 0x11 for AHX

The "Version" field should contain one of:

  • 0x02 for a variant of 'version 3' with a different fixed decoder
  • 0x03 for ADX 'version 3'
  • 0x04 for ADX 'version 4'
  • 0x05 for a variant of ADX 4 without looping support

When decoding AHX audio, the version field does not appear to have any meaning and can be safely ignored.

Read more about this topic:  ADX (file Format), Technical Description

Other articles related to "file, files":

Files-11 - Index File: INDEXF.SYS
... The index file contains the most basic information about a Files-11 volume set ... of the extents comprising the remainder of the index file, the volume owner's UIC, and the volume protection information ... These structures are not included in INDEXF.SYS, and the blocks of the INDEXF.SYS file are unused ...
Resource Interchange File Format - Compatibility Issues - INFO Chunk Placement Problems
... the optimal position for the INFO chunk is near the beginning of the file ... from the detailed specifications of individual file formats, leading to some confusion over the correct position for this chunk within a file ... When dealing with large media files, the expansion or contraction of the INFO chunk during tag-editing can result in the following "data" section of the file having to be read and rewritten back ...

Famous quotes containing the word file:

    I have been a soreheaded occupant of a file drawer labeled “Science Fiction” ... and I would like out, particularly since so many serious critics regularly mistake the drawer for a urinal.
    Kurt Vonnegut, Jr. (b. 1922)