# oxideav-mpegts
Pure-Rust, clean-room **MPEG-TS** (Transport Stream) demuxer per
[ISO/IEC 13818-1](https://www.iso.org/standard/74427.html). The crate
is scoped at the bytes Blu-ray Disc ships inside a `.m2ts` file once the
BDAV `TP_extra_header` has been stripped — i.e. the 188-byte MPEG-TS
packets [`oxideav_bluray::iter_source_packets`] yields.
The motivating downstream is the workspace's `oxideav remux bluray://`
path: a Blu-ray title comes out of `oxideav-bluray` as a decrypted
192-byte-source-packet stream, the BDAV envelope gets stripped, this
crate demuxes each elementary stream's PES payloads, and the MKV
writer in `oxideav-mkv` lays them down as one MKV per unique title with
language-tagged tracks and chapter marks.
## Phase 1 surface
| Module | What it parses |
|------------------|-----------------------------------------------------------------------------|
| `packet` | 188-byte TS packet — sync byte, flags, PID, adaptation field (PCR + OPCR + splice_countdown + transport_private_data + adaptation_field_extension with ltw / piecewise_rate / seamless_splice), payload. |
| `psi` | PAT + PMT + CAT (Conditional Access Table, §2.4.4.6) + TSDT (Transport Stream Description Table, §2.4.4.12 — TS-wide descriptor loop on PID 0x0002 / table_id 0x03) + SDT (DVB Service Description Table, ETSI EN 300 468 §5.2.3 — service loop on PID 0x0011 / table_id 0x42 actual + 0x46 other, with typed `RunningStatus`) + EIT (DVB Event Information Table, EN 300 468 §5.2.4 — event loop on PID 0x0012 / table_id 0x4E/0x4F present-following + 0x50–0x6F schedule, with MJD/BCD `start_time` + BCD `duration` decoded per annex C) section parsers, plus `PsiSectionAssembler` — per-PID reassembler that joins long sections across multiple 188-byte TS packets (§2.4.4 pointer_field + PUSI continuation). Handles up-to-1024-byte sections, stuffing terminators, CC-skip detection, and back-to-back sections in one payload. |
| `descriptor` | §2.6 TLV descriptors — registration / ISO-639 language / CA / video / audio / hierarchy / AVC / HEVC / data-stream-alignment / target-background-grid / video-window / system-clock / multiplex-buffer-utilization / copyright / maximum-bitrate / smoothing-buffer / STD / IBP — plus the DVB `service_descriptor` (tag 0x48, EN 300 468 §6.2.33) carrying the service / provider names and the DVB `short_event_descriptor` (tag 0x4D, EN 300 468 §6.2.37) carrying the event name + short text. |
| `pes` | PES packet reassembler — joins TS payloads per-PID into complete PES units. Decodes every Table 2-17 optional header field: PES_scrambling_control / PES_priority / data_alignment_indicator / copyright / original_or_copy on flags1, plus the flag-gated bodies ESCR (42-bit 27 MHz tick), ES_rate (50 bytes/s units), DSM_trick_mode (raw 8-bit), additional_copy_info, previous_PES_packet_CRC, and the full PES_extension body (16-byte private data, raw pack_header bytes, program_packet_sequence_counter, P-STD buffer scale/size, PES_extension_field_2). |
| `stream_type` | `stream_type` byte → BD-relevant codec class enum. |
| `clock` | Per-PCR-PID 27 MHz clock recovery + per-PID continuity-counter classification (§2.4.2.2 / §2.4.3.3 / §2.4.3.5). |
No decoders. No re-multiplexing. Every payload byte stays as a
borrowed slice unless reassembly forces a copy.
`ProgramMapTable::iter_program_descriptors` and
`PmtStream::iter_descriptors` lift the raw descriptor bytes carried
inside a PMT into typed [`Descriptor`] records (TLV envelope + a
decoded body for the most common tags). Unrecognised tags surface as
`DescriptorBody::Raw` so downstream callers still see the payload
bytes verbatim. `ConditionalAccessTable::iter_descriptors` exposes
the same view over a CAT's CA_descriptor block.
`ServiceDescriptionTable::parse` reads a DVB SDT section into typed
`SdtService` entries — `service_id` (equal to the PMT
`program_number` for normal services), the two EIT-presence flags, a
typed `RunningStatus` (EN 300 468 Table 6), `free_CA_mode`, and a
per-service descriptor loop. `SdtService::iter_descriptors` lifts that
loop, and the `service_descriptor` (tag 0x48) it usually carries
decodes to `DescriptorBody::Service` exposing the `service_type` byte
plus the raw service / provider name runs. That name is what the
`oxideav remux bluray://` path needs to label an MKV title when the
source TS carries an SDT. DVB text strings keep their original bytes —
the EN 300 468 annex-A character-table selection is deliberately left
to the caller rather than decoded here.
`EventInformationTable::parse` reads a DVB EIT section (EN 300 468
§5.2.4) into typed `EitEvent` entries. The EIT lives on the fixed PID
`0x0012` and comes in four `table_id` classifications — present/
following on the actual TS (`0x4E`) or another TS (`0x4F`), and the
event schedule on the actual TS (`0x50`–`0x5F`) or another TS
(`0x60`–`0x6F`); `parse` accepts all four and records
`other_transport_stream` / `schedule`. Each `EitEvent` carries its
`event_id`, a decoded `start_time` (`EitDateTime` — the 40-bit field's
16-bit Modified Julian Date is converted to a Gregorian
`(year, month, day)` via the annex-C integer formula, and the 24-bit
BCD UTC time is decoded alongside; the all-ones "undefined" sentinel
surfaces as `None`), a `duration` (`EitDuration` — BCD hours/minutes/
seconds with `as_seconds`), a typed `RunningStatus`, `free_CA_mode`,
and a per-event descriptor loop. `EitEvent::iter_descriptors` lifts
that loop, where the `short_event_descriptor` (tag `0x4D`) decodes to
`DescriptorBody::ShortEvent` exposing the language code plus the raw
event-name and short-text runs. Since `service_id` equals the PMT
`program_number` for normal services, the EIT lets the
`oxideav remux bluray://` path attach human-readable event names and
time ranges to each title. The spec's worked examples
(`0xC0 7912 4500` → 1993-10-13 12:45:00 and `0x01 4530` → 01:45:30)
are pinned as tests.
`PsiSectionAssembler` is the building block that turns a stream of
TS-packet payloads on a single PSI PID into a stream of complete
sections. The §2.4.4 wire rules are enforced in one place: a PUSI=1
TS payload begins with a `pointer_field` that completes whatever
section was in flight; a PUSI=0 payload contributes continuation
bytes; `0xFF` table_id terminates iteration inside a single payload;
and a `continuity_counter` skip discards the in-flight buffer rather
than concatenating misordered bytes. The demuxer's PAT and PMT
discovery loops both drive an assembler so a PMT with rich descriptor
blocks (multi-language PGS + multi-codec audio + HEVC + … ) can grow
past the ~184-byte single-TS payload budget without losing the
trailing streams.
`PcrTracker` consumes one adaptation field per packet on the
configured `PCR_PID` and emits `PcrEvent::Sample { pcr, jitter_27mhz,
bitrate_bps }` for normal flow or
`PcrEvent::Discontinuity { reason }` when either (a) the adaptation
field carries `discontinuity_indicator = 1` (§2.4.3.5) or (b) the
observed PCR jump exceeds the configured tolerance window. Jitter is
the signed residual in 27 MHz ticks between the observed PCR delta
and the delta predicted by the previous pair's bitrate. Default
window is 100 ms — well above the ±500 ns spec tolerance but tight
enough to catch a clean time-base reset that didn't bother to set the
indicator.
`ContinuityTracker` is a sibling observer for the 4-bit
`continuity_counter` per §2.4.3.3 — emits `Continuous` / `Duplicate`
/ `NoPayload` / `Dropped { gap }` / `Discontinuity`. Duplicate-cap
enforcement (max one repeat per CC) is built in: a second identical
CC reads as a drop, not a second duplicate.
## License
MIT — see [`LICENSE`](LICENSE).