Avelune Container Candidate 0.0
Historical Avelune container experiments, retained for provenance and superseded by Draft Generation 1.
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Warning
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HISTORICAL / NON-NORMATIVE: superseded by the Draft Generation 1 |
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:
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fixed file header;
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stream descriptors;
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optional front index reservation/data;
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zero or more epochs;
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optional final index;
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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 = 0A 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 # candidatepayload_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.