AVELUNE
historical · non-normative

Avelune Container Candidate 0.0

Historical Avelune container experiments, retained for provenance and superseded by Draft Generation 1.

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Current draft

  1. Avelune specification drafts
  2. Avelune Draft Generation 1 Baseline profile
  3. ALV1 video bitstream — Draft Generation 1
  4. Avelune V1 — common integer and entropy coding
  5. Avelune container — Draft Generation 1 (header generation 1, minor 0)
  6. ALA1 audio bitstream — Draft Generation 1
  7. Avelune Draft Generation 1 conformance requirements
  8. Specification changelog

History

  1. Avelune Audio Candidate 0.0
  2. Avelune Container Candidate 0.0
  3. Avelune Video Candidate 0.0
  4. Candidate conformance requirements
On this page
  1. Purpose
  2. Integer encoding
  3. File structure
  4. Fixed header candidate
  5. Packet envelope
  6. Epochs
  7. Time
  8. Streaming requirement
  9. Future index contract
Warning

HISTORICAL / NON-NORMATIVE: superseded by the Draft Generation 1 001-* specification.

Status: EXPERIMENTAL / NOT FROZEN

Purpose

The container is designed for bounded-memory incremental parsing, HTTP byte-range seeking, deterministic A/V epoch restart, and straightforward inspection/repair.

Integer encoding

Unless specified otherwise, fixed-width integers are unsigned little-endian. Variable unsigned integers use unsigned LEB128 with a maximum of ten bytes. Decoders MUST reject overlong encodings and values outside the field’s stated range.

File structure

A file is a sequence:

  1. fixed file header;

  2. stream descriptors;

  3. optional front index reservation/data;

  4. zero or more epochs;

  5. optional final index;

  6. optional footer.

The candidate implementation currently exercises the packet/epoch rules before the full front-index serialization is frozen.

Fixed header candidate

magic[8] = 41 56 45 4c 55 4e 45 00   # "AVELUNE\0"
container_major: u16
container_minor: u16
flags: u32
header_bytes: u32
stream_count: u16
reserved: u16 = 0

A decoder MUST reject unknown major versions. It MAY accept a newer minor version only when all encountered structures are explicitly skippable.

Packet envelope

Every packet is self-bounded:

sync: u32 = 0x4B505641   # bytes "AVPK"
kind: u8
flags: u8
stream_id: u16
pts: u64
payload_len: u32
header_crc32c: u32       # candidate; algorithm not frozen
payload[payload_len]
payload_crc32c: u32      # candidate

payload_len MUST be checked against implementation resource limits before allocation. A conforming decoder profile SHALL publish its maximum accepted packet size.

Epochs

An epoch begins with an EPOCH_START packet. All media dependency state required by media packets in that epoch MUST either be contained in the epoch or be declared static stream configuration.

Video reference pictures MUST NOT cross epochs. Audio adaptive/predictive state MUST reset at an epoch boundary.

This property is normative even if the exact epoch packet payload changes during candidate development.

Time

Each stream descriptor defines a rational time base. Packet pts is expressed in that stream time base. Integer timestamp arithmetic MUST be used for demux synchronization; floating-point conversion is presentation-layer behavior.

Streaming requirement

A conforming demuxer MUST be able to accept arbitrary non-empty byte fragments. It MUST NOT require the complete file to determine packet boundaries after the required header/descriptor bytes have arrived.

Future index contract

A future format may provide an index mapping presentation-time intervals to byte offsets of independently decodable epochs. Front-indexed files should carry that index; live streams may omit it. The index representation is intentionally not frozen in Candidate 0.0.