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Acknowledgements

This project is assembled on other people's work, and much of what looks like original engineering here is really the result of having good references to check against. Listed in full — not only where attribution is legally required, but everywhere something was genuinely leaned on.

Code this is built from

  • Koen De Vleeschauwer — mpeg2fpga (2007), the hardware MPEG-2 decoder at the centre of this core. Nearly the entire video datapath is his.
  • mrchrisster — MiSTer_MPEG2, the MiSTer port this forks: the framework integration, SD streaming, and DDR3 frame buffer that made a working starting point.
  • The MiSTer project (MiSTer-devel) — the framework in sys/, hps_io, and the ascal scaler. The N64 core additionally supplied the interlaced sync model that the native 15 kHz CRT raster is built on, after a from-scratch approach failed to lock.

Design guidance

  • Anime0t4ku — the custom-MiSTer-Main approach for physical-disc cores (a core-specific main= binary that reads and serves the disc's own sectors). That guidance shaped MiSTer_DVDcss and is what unlocked physical-disc support here. The CSS and reader code is our own, developed independently.

Specifications

  • ATSC A/52 — Digital Audio Compression (AC-3): normative frame syntax and the per-stage algorithms for the in-fabric decoder.
  • ISO/IEC 13818-1 and 13818-2 — MPEG-2 Systems (Program Stream, pack and PES headers) and MPEG-2 Video.
  • ISO/IEC 11172-2 and 11172-3 — MPEG-1 Video (the decoder's MPEG-1 mode) and MPEG-1 Audio (the Layer II decoder's tables and algorithms).
  • IEC 61937-3 / 61937-5 / 60958-1 — AC-3 and DTS over S/PDIF and HDMI, and the channel-status non-PCM flag that makes receivers lock onto a bitstream.
  • DVD Demystified, Jim Taylor — the practical DVD-Video reference for VOB/IFO structure. Repeatedly the fastest route to understanding how discs are actually authored, as opposed to how the spec says they could be.
  • mpucoder's DVD documentation — the long-standing public reference for DVD sector, NAV pack and IFO layout.

Behavioural references and verification oracles

Much of this core was built by checking its behaviour against known-good implementations rather than by reading specs alone.

  • libdvdnav — the reference the DVD virtual machine was validated against command-by-command (decoder.c, vmcmd.c). Where this core and libdvdnav disagreed, libdvdnav was usually right; where it wasn't, the disagreement itself was informative.
  • libdvdread — ifo_types.h and nav_types.h were the authority for every IFO and NAV pack offset the in-fabric parsers use.
  • liba52 0.8.0 — the golden reference for the AC-3 decoder's co-simulation. Every coding tool is checked against it to a bounded error, and it caught bugs (a mis-decoded dynamic-range exponent among them) that listening tests did not.
  • ffmpeg (ac3dec.c, ac3_fixed) — second opinion and fixed-point cross-check for AC-3, and the float reference the MP2 golden model is gated against.
  • pl_mpeg (Dominic Szablewski, MIT) — compact C reference for MPEG-1/MP2; the Layer II synthesis-window table (tools/mp2_window.py in the repository) is extracted from it, as vendored by MiSTer-devel/CDi_MiSTer, whose serial-MAC filterbank was the reference spec for the fabric MP2 decoder's architecture.
  • Han, Dapeng (2017), FPGA Implementation of an AC3 Decoder, MSc thesis, Linköping University — stage-by-stage pseudocode for exponent decode, bit allocation, mantissa and IMDCT.
  • libdvdcss — not used in the core, but it is what makes the PC-side rip step work, and the reason a decrypted image can be produced at all.
  • The MiSTer CD cores (PCE-CD, MegaCD, Saturn) — prior art for partitioning work between the ARM and the fabric, studied while designing the audio path.

Test material

The DVD-Video discs used for hardware verification are commercial releases, ripped from owned copies for testing. No disc content appears in this repository.