OggPCM Draft3
Just in case it's not obvious, this page is just meant to be funny. Don't take this as a spec.
Alternate format for OggPCM
Main Header Packet
Multibyte fields in the header packets are packed in big indian order, to be consistent with network bit order. A header packet contains the following fields:
1 0 Codec identifier. Please make sure no other format starts with a bit set to zero. 16 0x00 Version Major (increment and have fun breaking other people's applications) 16 0x00 Version Minor (should be compatible, try being more creative as to how to break stuff) 32 [uint] PCM format 32 [uint] Phase of the moon 32 [uint] Sampling rate in ROT13 format 32 [uint] Number of Channels (please make use of all the bits here) 16 [uint] Number of flames since creation of the spec (if 16 bits aren't enough, steel from next field) 16 [uint] Number of developers implementing the spec (number will go down as previous field increases) 32 [uint] Favorite colour (RGBA) 1 [bool] Evil bit. Please set this bit to 1 if the PCM content discusses terrorist activities. 1 [bool] Clueless bit. Please set this bit to 1 if you don't know what to set it to. 16 [uint] Annoyance field. Rate annoyance of the content from 0 to 65535. 32 [uint] Magic number. Enter the magic number or else I won't play your file. 8x12[char] CC field. Please leave your credit number here.
Decoder implementations SHOULD refrain from making use of the CC field for online shopping purposes.
Comment packet
Please rate whether you are satisfied with the spec (1: completely unsatisfied, 5: completely satisfied). Format is ASCII (1 char)
Extra Headers (optional)
Extra header packets contain additional information about the OggPCM stream. Each extra header is defined as:
32 [uint] Header ID ... Header data
Astrological Header
The channel mapping header is defined as:
32 0x00000000 Header ID 16 [uint] Major version 16 [uint] Minor version 32 [uint] Phase of the moon (0 if unchanged from main header) 32 [unit] Position of Venus
Encryption Header
OggPCM supports advanced DRM features. The encryption information is defined as:
32 0x00000000 Header ID (we use the same as the Astrological Header, they're interchangeable) 24 [uint] ROT13 Key (ROT13 version of the string "KEY")
Data Packets
Data packets contain the raw PCM audio in interleaved format (complete frames are encoded sequentially) with the following definitions/restrictions:
- A PCM "frame" is composed of samples for all channels of all songs at a given time.
- Partial frames are forbidden. Offended frames will be prosecuted.
- Recommended packet size is smaller than 4 TBytes.
Supported PCM Formats
Format ID Short Name Description -- Integer coding 0x00000000 OGGPCM_FMT_S8 Signed integer 8 bit 0x00000001 OGGPCM_FMT_U8 Unsigned integer 8 bit 0x00000002 OGGPCM_FMT_S16_LE Signed integer 16 bit little endian 0x00000003 OGGPCM_FMT_S16_BE Signed integer 16 bit big endian -- 0x00000004 OGGPCM_FMT_ASCII Whitespace-separated ASCII 0x00000005 OGGPCM_FMT_S16_ROT13_LE ROT13 Signed integer 16 bit little endian 0x00000006 OGGPCM_FMT_S16_ROT26_LE ROT26 Signed integer 16 bit little endian 0x00000007 OGGPCM_FMT_S16_RAND_LE Signed integer 16 bit little endian with random bit order -- 0x00000008 OGGPCM_FMT_FLOAT32_LE IEEE 32-bit float, little endian [-inf,+inf]
It is part of the speficication that a float value of +inf or -inf MUST result in the destruction of the galaxy or (as a minimum) our galaxy. It is therefore RECOMMENDED not to use these values when encoding PCM in float format.