Inserting third-party mp4 content into manim-slides

[svandenhaute]

Is it possible to insert external .mp4 video files into manim-slides? Given that manim-slides is "just" a triggered mp4 player, I am imagining that with some hacking I could get it to work, but I don't know where to start...

[jeertmans]

Hi @svandenhaute, no this is not possible yet. However, I have been thinking of such a feature for a long time, and I think this should be relatively easy to implement, especially if we only want to support adding .mp4 files.

Here is a suggested implementation (to be added to Manim Slides):

1. Add file: Path | None = None config variable to BaseSlideConfig, see

   manim-slides/manim_slides/config.py

   Lines 154 to 162 in ef28230

   	class BaseSlideConfig(BaseModel): # type: ignore
   	"""Base class for slide config."""
   	loop: bool = False
   	auto_next: bool = False
   	playback_rate: float = 1.0
   	reversed_playback_rate: float = 1.0
   	notes: str = ""
   	dedent_notes: bool = True

2. Change start_animation_is_before_end model validator and add (at the very top):

if pre_slide_config.base_slide_config.file is not None and pre_slide_config.start_animation != pre_slide_config.end_animation:
    raise ValueError("A slide cannot have 'file=...' and more than zero animations at the same time.")

see

manim-slides/manim_slides/config.py

Lines 243 to 262 in ef28230

	@model_validator(mode="after")
	@classmethod
	def start_animation_is_before_end(
	cls, pre_slide_config: "PreSlideConfig"
	) -> "PreSlideConfig":
	if pre_slide_config.start_animation >= pre_slide_config.end_animation:
	if pre_slide_config.start_animation == pre_slide_config.end_animation == 0:
	raise ValueError(
	"You have to play at least one animation (e.g., `self.wait()`) "
	"before pausing. If you want to start paused, use the appropriate "
	"command-line option when presenting. "
	"IMPORTANT: when using ManimGL, `self.wait()` is not considered "
	"to be an animation, so prefer to directly use `self.play(...)`."
	)
	raise ValueError(
	"Start animation index must be strictly lower than end animation index"
	)
	return pre_slide_config

3. Edit BaseSlide.next_slide's docstring to include :param url: <...>.
4. Edit BaseSlide.next_slide's body to include a second if check statement:

# previous if ...
if base_slide_config.file is not None:
    # TODO: add also wait between slides
    self._slides.append(
        PreSlideConfig.from_base_slide_config_and_animation_indices(
            self._base_slide_config,
            self._current_animation,
            self._current_animation,
        )
    )

    base_slide_config = BaseSlideConfig()  # default     
    self._current_slide += 1

see

manim-slides/manim_slides/slide/base.py

Lines 447 to 462 in ef28230

	if self._current_animation > self._start_animation:
	if self.wait_time_between_slides > 0.0:
	self.wait(self.wait_time_between_slides) # type: ignore[attr-defined]
	self._slides.append(
	PreSlideConfig.from_base_slide_config_and_animation_indices(
	self._base_slide_config,
	self._start_animation,
	self._current_animation,
	)
	)
	self._current_slide += 1
	self._base_slide_config = base_slide_config
	self._start_animation = self._current_animation

5. Edit BaseSlide._save_slides to copy any video files using file into the assets folder and skip concatenation.

TODOs:

• Handle the case where people call next_slide(notes="...",loop=True);next_slide(url="path") with no animations in between, by raising a warning, as the arguments passed to the first next_slides are not used.

---

I don't have much time to implement this at the moment, so anyone if free to give it a try through a pull request!

[jeertmans]

See #526 for an actual implementation @svandenhaute.