Merge pull request #3 from jeertmans/reserve-video-and-more

feat(cli): reverse videos on the fly!

Author: jeertmans

README.md

@@ -3,7 +3,7 @@
 ![PyPI - Downloads](https://img.shields.io/pypi/dm/manim-slides)
 # Manim Slides
 
-Tool for live presentations using either [manim](http://3b1b.github.io/manim/) or [manim-community](https://www.manim.community/).
+Tool for live presentations using either [manim-community](https://www.manim.community/). Currently, support for 3b1b's manim is not planned.
 
 > **_NOTE:_**  This project is a fork of [`manim-presentation`](https://github.com/galatolofederico/manim-presentation). Since the project seemed to be inactive, I decided to create my own fork to deploy new features more rapidly.
 
@@ -65,6 +65,7 @@ Default keybindings to control the presentation:
 | Right Arrow |    Continue/Next Slide   |
 |  Left Arrow |      Previous Slide      |
 |      R      | Re-Animate Current Slide |
+|      V      |   Reverse Current Slide  |
 |   Spacebar  |        Play/Pause        |
 |      Q      |           Quit           |
 
@@ -122,11 +123,10 @@ Here are a few things that I implemented (or that I'm planning to implement) on
 - [x] Only one cli (to rule them all)
 - [x] User can easily generate dummy config file
 - [x] Config file path can be manually set
-- [ ] Play animation in reverse [#9](https://github.com/galatolofederico/manim-presentation/issues/9)
+- [x] Play animation in reverse [#9](https://github.com/galatolofederico/manim-presentation/issues/9)
 - [x] Handle 3D scenes out of the box
-- [ ] Can work with both community and 3b1b versions (not tested)
 - [ ] Generate docs online
-- [ ] Fix the quality problem on Windows platforms with `fullscreen` flag
+- [x] Fix the quality problem on Windows platforms with `fullscreen` flag
 
 ## Contributions and license
 

manim_slides/__version__.py

@@ -1 +1 @@
-__version__ = "3.0.1"
+__version__ = "3.1.0"

manim_slides/config.py

@@ -23,6 +23,7 @@ class Config(BaseModel):
     QUIT: Key = Key(ids=[ord("q")], name="QUIT")
     CONTINUE: Key = Key(ids=[RIGHT_ARROW_KEY_CODE], name="CONTINUE / NEXT")
     BACK: Key = Key(ids=[LEFT_ARROW_KEY_CODE], name="BACK")
+    REVERSE: Key = Key(ids=[ord("v")], name="REVERSE")
     REWIND: Key = Key(ids=[ord("r")], name="REWIND")
     PLAY_PAUSE: Key = Key(ids=[32], name="PLAY / PAUSE")
 
@@ -33,7 +34,7 @@ def ids_are_unique_across_keys(cls, values):
         for key in values.values():
             if len(ids.intersection(key.ids)) != 0:
                 raise ValueError(
-                    f"Two or more keys share a common key code: please make sure each key has distinc key codes"
+                    "Two or more keys share a common key code: please make sure each key has distinc key codes"
                 )
             ids.update(key.ids)
 

manim_slides/main.py

@@ -2,7 +2,7 @@
 from click_default_group import DefaultGroup
 
 from . import __version__
-from .present import present
+from .present import list_scenes, present
 from .wizard import init, wizard
 
 
@@ -13,6 +13,7 @@ def cli():
     pass
 
 
+cli.add_command(list_scenes)
 cli.add_command(present)
 cli.add_command(wizard)
 cli.add_command(init)

manim_slides/present.py

@@ -16,6 +16,7 @@
 from .commons import config_path_option
 from .config import Config
 from .defaults import CONFIG_PATH, FOLDER_PATH
+from .slide import reverse_video_path
 
 
 @unique
@@ -41,7 +42,9 @@ class Presentation:
     def __init__(self, config, last_frame_next: bool = False):
         self.last_frame_next = last_frame_next
         self.slides = config["slides"]
-        self.files = config["files"]
+        self.files = [path for path in config["files"]]
+        self.reverse = False
+        self.reversed_slide = -1
 
         self.lastframe = []
 
@@ -79,19 +82,34 @@ def prev(self):
         self.current_slide_i = max(0, self.current_slide_i - 1)
         self.rewind_slide()
 
-    def rewind_slide(self):
+    def reverse_slide(self):
+        self.rewind_slide(reverse=True)
+
+    def rewind_slide(self, reverse: bool = False):
+        self.reverse = reverse
         self.current_animation = self.current_slide["start_animation"]
         self.current_cap.set(cv2.CAP_PROP_POS_FRAMES, 0)
 
-    def load_this_cap(self, cap_number):
-        if self.caps[cap_number] == None:
+    def load_this_cap(self, cap_number: int):
+        if (
+            self.caps[cap_number] is None
+            or (self.reverse and self.reversed_slide != cap_number)
+            or (not self.reverse and self.reversed_slide == cap_number)
+        ):
             # unload other caps
             for i in range(len(self.caps)):
-                if self.caps[i] != None:
+                if not self.caps[i] is None:
                     self.caps[i].release()
                     self.caps[i] = None
             # load this cap
-            self.caps[cap_number] = cv2.VideoCapture(self.files[cap_number])
+            file = self.files[cap_number]
+            if self.reverse:
+                self.reversed_slide = cap_number
+                file = "{}_reversed{}".format(*os.path.splitext(file))
+            else:
+                self.reversed_slide = -1
+
+            self.caps[cap_number] = cv2.VideoCapture(file)
 
     @property
     def current_slide(self):
@@ -170,7 +188,9 @@ def __init__(self, presentations, config, start_paused=False, fullscreen=False):
 
         if platform.system() == "Windows":
             user32 = ctypes.windll.user32
-            self.screen_width, self.screen_height = user32.GetSystemMetrics(0), user32.GetSystemMetrics(1)
+            self.screen_width, self.screen_height = user32.GetSystemMetrics(
+                0
+            ), user32.GetSystemMetrics(1)
 
         if fullscreen:
             cv2.namedWindow("Video", cv2.WND_PROP_FULLSCREEN)
@@ -283,6 +303,9 @@ def handle_key(self):
             else:
                 self.current_presentation.prev()
                 self.state = State.PLAYING
+        elif self.config.REVERSE.match(key):
+            self.current_presentation.reverse_slide()
+            self.state = State.PLAYING
         elif self.config.REWIND.match(key):
             self.current_presentation.rewind_slide()
             self.state = State.PLAYING
@@ -292,6 +315,31 @@ def quit(self):
         sys.exit()
 
 
+@click.command()
+@click.option(
+    "--folder",
+    default=FOLDER_PATH,
+    type=click.Path(exists=True, file_okay=False),
+    help="Set slides folder.",
+)
+@click.help_option("-h", "--help")
+def list_scenes(folder):
+    """List available scenes."""
+
+    for i, scene in enumerate(_list_scenes(folder), start=1):
+        click.secho(f"{i}: {scene}", fg="green")
+
+
+def _list_scenes(folder):
+    scenes = []
+
+    for file in os.listdir(folder):
+        if file.endswith(".json"):
+            scenes.append(os.path.basename(file)[:-5])
+
+    return scenes
+
+
 @click.command()
 @click.argument("scenes", nargs=-1)
 @config_path_option
@@ -312,6 +360,37 @@ def quit(self):
 def present(scenes, config_path, folder, start_paused, fullscreen, last_frame_next):
     """Present the different scenes."""
 
+    if len(scenes) == 0:
+        scene_choices = _list_scenes(folder)
+
+        scene_choices = dict(enumerate(scene_choices, start=1))
+
+        for i, scene in scene_choices.items():
+            click.secho(f"{i}: {scene}", fg="green")
+
+        click.echo()
+
+        click.echo("Choose number corresponding to desired scene/arguments.")
+        click.echo("(Use comma separated list for multiple entries)")
+
+        def value_proc(value: str):
+            indices = list(map(int, value.strip().replace(" ", "").split(",")))
+
+            if not all(map(lambda i: 0 < i <= len(scene_choices), indices)):
+                raise ValueError("Please only enter numbers displayed on the screen.")
+
+            return [scene_choices[i] for i in indices]
+
+        if len(scene_choices) == 0:
+            raise ValueError("No scenes were found, are you in the correct directory?")
+
+        while True:
+            try:
+                scenes = click.prompt("Choice(s)", value_proc=value_proc)
+                break
+            except ValueError as e:
+                click.secho(e, fg="red")
+
     presentations = list()
     for scene in scenes:
         config_file = os.path.join(folder, f"{scene}.json")

manim_slides/slide.py

@@ -1,12 +1,36 @@
 import json
 import os
+import platform
 import shutil
+import subprocess
 
-from manim import Scene, ThreeDScene, config
+from tqdm import tqdm
+
+try:
+    from .manim import Scene, ThreeDScene, config, logger
+except ImportError:
+    Scene = ThreeDScene = config = logger = None
+    # TODO: manage both manim and manimgl
+
+try:  # For manim<v0.16.0.post0
+    from manim.constants import FFMPEG_BIN as ffmpeg_executable
+except ImportError:
+    ffmpeg_executable = config.ffmpeg_executable
 
 from .defaults import FOLDER_PATH
 
 
+def reverse_video_path(src: str) -> str:
+    file, ext = os.path.splitext(src)
+    return f"{file}_reversed{ext}"
+
+
+def reverse_video_file(src: str, dst: str):
+    command = [config.ffmpeg_executable, "-i", src, "-vf", "reverse", dst]
+    process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    process.communicate()
+
+
 class Slide(Scene):
     def __init__(self, *args, output_folder=FOLDER_PATH, **kwargs):
         super().__init__(*args, **kwargs)
@@ -72,21 +96,54 @@ def render(self, *args, **kwargs):
         scene_name = type(self).__name__
         scene_files_folder = os.path.join(files_folder, scene_name)
 
-        if os.path.exists(scene_files_folder):
-            shutil.rmtree(scene_files_folder)
+        old_animation_files = set()
 
         if not os.path.exists(scene_files_folder):
             os.mkdir(scene_files_folder)
+        else:
+            old_animation_files.update(os.listdir(scene_files_folder))
 
         files = list()
-        for src_file in self.renderer.file_writer.partial_movie_files:
-            dst_file = os.path.join(scene_files_folder, os.path.basename(src_file))
-            shutil.copyfile(src_file, dst_file)
+        for src_file in tqdm(
+            self.renderer.file_writer.partial_movie_files,
+            desc=f"Copying animation files to '{scene_files_folder}' and generating reversed animations",
+            leave=config["progress_bar"] == "leave",
+            ascii=True if platform.system() == "Windows" else None,
+            disable=config["progress_bar"] == "none",
+        ):
+            filename = os.path.basename(src_file)
+            _hash, ext = os.path.splitext(filename)
+
+            rev_filename = f"{_hash}_reversed{ext}"
+
+            dst_file = os.path.join(scene_files_folder, filename)
+            # We only copy animation if it was not present
+            if filename in old_animation_files:
+                old_animation_files.remove(filename)
+            else:
+                shutil.copyfile(src_file, dst_file)
+
+            # We only reverse video if it was not present
+            if rev_filename in old_animation_files:
+                old_animation_files.remove(rev_filename)
+            else:
+                rev_file = os.path.join(scene_files_folder, rev_filename)
+                reverse_video_file(src_file, rev_file)
+
             files.append(dst_file)
 
-        f = open(os.path.join(self.output_folder, "%s.json" % (scene_name,)), "w")
+        logger.info(
+            f"Copied {len(files)} animations to '{os.path.abspath(scene_files_folder)}' and generated reversed animations"
+        )
+
+        slide_path = os.path.join(self.output_folder, "%s.json" % (scene_name,))
+
+        f = open(slide_path, "w")
         json.dump(dict(slides=self.slides, files=files), f)
         f.close()
+        logger.info(
+            f"Slide '{scene_name}' configuration written in '{os.path.abspath(slide_path)}'"
+        )
 
 
 class ThreeDSlide(Slide, ThreeDScene):

setup.py

@@ -2,9 +2,7 @@
 
 import setuptools
 
-sys.path.append("manim_slides")  # To avoid importing manim, which may not be installed
-
-from __version__ import __version__ as version
+from manim_slides import __version__ as version
 
 if sys.version_info < (3, 7):
     raise RuntimeError("This package requires Python 3.7+")