switch-frame-tap
Copyright (C) 2026 Tomas Uribe
Contact: Some_Potato_1@protonmail.com  /  reddit u/Papux200

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License version 2, as published by the Free
Software Foundation. See LICENSE for the full text.

GPL-2.0 is not an arbitrary choice: tier4/applet-mitm is a libstratosphere
sysmodule. It is compiled inside an Atmosphère checkout, links libstratosphere,
and ships a patch against it (tier4/applet-mitm/patch_libstrat.py). Atmosphère
is GPL-2.0, so anything built this way is too.


Third-party material this project depends on but does not redistribute
----------------------------------------------------------------------

Nothing under ref/ is committed to this repository; see ref/README.md for what
belongs there and where to fetch it.

  Atmosphère        GPL-2.0   https://github.com/Atmosphere-NX/Atmosphere
  SysDVR            GPL-2.0   https://github.com/exelix11/SysDVR
  SysDVR-UVC-Capture GPL-2.0  https://github.com/Insektaure/SysDVR-UVC-Capture
  libdrm (tegra)    MIT       https://gitlab.freedesktop.org/mesa/drm
  libnx             ISC       https://github.com/switchbrew/libnx
  switchbrew wiki             https://switchbrew.org/wiki/


Derived work
------------

tier4/applet-mitm/source/vic40_config.hpp transcribes the VIC 4.0 register
methods and configuration-struct layout from libdrm's Tegra backend
(vic.h / vic40.h, Copyright (c) 2018 NVIDIA Corporation, MIT). Every one of the
nine config structs in it was diffed field-for-field and bit-for-bit against
those headers.

tier4/applet-mitm/source/applet_mitm_uvc.cpp (v0.4 webcam mode) follows
Insektaure's SysDVR-UVC-Capture (GPL-2.0, source/uvc/uvc_device.c and
docs/RESEARCH.md): the UVC descriptor layout, the EP0 control-transfer handling
on usb:ds (manual status stages, StallCtrl), probe/commit negotiation and the
bulk payload rules (2-byte headers, FID toggling, zero-length packets,
cancel-and-reap on timeout). Adapted to two frame sizes at 60 fps and a sender
fed by this project's NVENC stream.

tier4/applet-mitm/source/nvjpg_dec_control.h, generated by
tools/nvjpg_dec_control.py, is a test job for the NVJPG engine. Its decode
picture-info record is laid out at the field offsets of the T210 hardware's
record as averne's oss-nvjpg documents it (GPL-3.0,
include/nvjpg/nv/registers.hpp): the offsets describe the hardware; no code
from oss-nvjpg is in this tree. It runs only in a test install armed with
"jpgdec".

tier4/applet-mitm/patch_libstrat.py backports Atmosphère commit b05166d50
(GPL-2.0): mitm ForwardRequest closes the request's copy handles.

tier4/applet-mitm/source/applet_mitm_nv.cpp (FindLibnxNvMaps) and
applet_mitm_audout.cpp rely on libnx's data layouts (ISC): struct NvMap
(nvidia/map.h) and AudioOutBuffer plus the audout:u commands
(services/audout.h). Only the layouts are used; no libnx code is copied.