Retire motion_mp(), which never worked

CHANGELOG.md

@@ -5,6 +5,22 @@ All notable changes to MGT-python will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Removed
+- `motion_mp()` is retired. It rendered a motion video across several processes, coordinating them
+  with a socket server and an argparse child process, and it raised on its first call: two fields
+  were read as one between the parent and the workers, and behind that failure it called
+  `save_txt` and `save_analysis` with arguments in the wrong positions. It therefore produced
+  nothing for anyone who tried it, and had no test. `motion()` does the same work in one process
+  and is tested. The method remains as a stub that says all this and points there; the two modules
+  behind it are gone. Closes #370.
+
+### Changed
+- Internal typing, issue #350: `mypy musicalgestures/` is at 17 errors in 9 files, from 90 when
+  this work started. Retiring `motion_mp()` accounts for nine of the reduction, since typing code
+  that cannot run would have been effort spent hiding a breakage.
+
 ## [1.13.0] — 2026-08-23
 
 ### Fixed

docs/MODULES.md

@@ -41,8 +41,6 @@ Each page is rendered from the source docstrings by
 - [Motiontempo](musicalgestures/_motiontempo.md)
 - [Motionvectors](musicalgestures/_motionvectors.md)
 - [Motionvideo](musicalgestures/_motionvideo.md)
-- [Motionvideo Mp Render](musicalgestures/_motionvideo_mp_render.md)
-- [Motionvideo Mp Run](musicalgestures/_motionvideo_mp_run.md)
 - [Movementbeats](musicalgestures/_movementbeats.md)
 - [Peaks](musicalgestures/_peaks.md)
 - [Physio](musicalgestures/_physio.md)

docs/musicalgestures/index.md

@@ -49,8 +49,6 @@ module.
 - [Motiontempo](_motiontempo.md)
 - [Motionvectors](_motionvectors.md)
 - [Motionvideo](_motionvideo.md)
-- [Motionvideo Mp Render](_motionvideo_mp_render.md)
-- [Motionvideo Mp Run](_motionvideo_mp_run.md)
 - [Movementbeats](_movementbeats.md)
 - [Peaks](_peaks.md)
 - [Physio](_physio.md)

docs/user-guide/results.md

@@ -131,7 +131,7 @@ motion plot only if `motionplots()` has been called.
 
 | method | stores |
 |---|---|
-| `motion()`, `motiongrams()`, `motion_mp()` | `motion_video`, `motion_plot_image`, `motiongram_vertical_image`, `motiongram_horizontal_image`, `ssm_figure` |
+| `motion()`, `motiongrams()` | `motion_video`, `motion_plot_image`, `motiongram_vertical_image`, `motiongram_horizontal_image`, `ssm_figure` |
 | `motionvideo()` | `motion_video` |
 | `videograms()` | `videogram_vertical_image`, `videogram_horizontal_image` |
 | `history()` | `history_video` |

docs/user-guide/video-analysis.md

@@ -35,7 +35,7 @@ commonly confused pairs, one line each:
 
 Most analysis methods stream frames straight through FFmpeg and run on any container, including MP4, e.g. `motion()`, `motiongrams()`, `average()`/`blend()`, `videograms()`, `heatmap()`, `eulerian()`, `motiontempo()`, `sonomotiongram()`, `grid()`, `subtract()`, and `history()`.
 
-A few methods that decode frame-by-frame with OpenCV first convert the input to an all-intra **MJPEG `.avi`** (cached once as `self.as_avi`) for frame-accurate decoding: `flow.dense()`/`flow.sparse()`, `directograms()`, `impacts()`, `motion_mp()`, and `history_cv2()`. The motion **video output** keeps the source container: an mp4 in gives `_motion.mp4` out.
+A few methods that decode frame-by-frame with OpenCV first convert the input to an all-intra **MJPEG `.avi`** (cached once as `self.as_avi`) for frame-accurate decoding: `flow.dense()`/`flow.sparse()`, `directograms()`, `impacts()`, and `history_cv2()`. The motion **video output** keeps the source container: an mp4 in gives `_motion.mp4` out.
 
 If your MP4 decodes reliably and you want to skip that conversion (faster, no extra file), pass `convert=False`: