neu_draw.video¶

Finding ffmpeg, encoding frames with it, and the result of an orbit. Standard library only, so it works and is tested without a renderer.

ffmpeg is never declared as a dependency: put one on PATH or name it with $NEU_DRAW_FFMPEG. Without one, the frames are kept and a plain ffmpeg command is printed.

Attributes¶

`ENCODE_ARGS`
`ENCODE_MODES`
`FFMPEG_ENV`
`FRAME_PATTERN`

Classes¶

Orbit

What a render produced: the frames, and the video if one was encoded.

Functions¶

`encode_args`(ffmpeg, directory, fps, output) → list[str]	The argv for an encode, run without a shell, so no path needs quoting.
`find_ffmpeg`([explicit]) → Optional[str]	The ffmpeg to encode with, or `None`. First match wins:
`run_encode`(directory, fps, output, ffmpeg) → str	Run ffmpeg over the frames. Raises with ffmpeg's own last lines if it fails.

Module Contents¶

class neu_draw.video.Orbit¶

What a render produced: the frames, and the video if one was encoded.

command(ffmpeg: str = 'ffmpeg') → str¶: The encode as one line to paste into a shell.

directory: str¶

fps: float¶

frames: int¶

output: str | None = None¶

rendered: int¶

size: tuple[int, int]¶

video: str | None = None¶

neu_draw.video.encode_args(ffmpeg: str, directory: str, fps: float, output: str) → list[str]¶: The argv for an encode, run without a shell, so no path needs quoting.

neu_draw.video.find_ffmpeg(explicit: str | None = None) → str | None¶

The ffmpeg to encode with, or None. First match wins:

explicit: a path, or a name to look up on PATH;
$NEU_DRAW_FFMPEG, the same from the environment;
ffmpeg on PATH (e.g. a site module loaded before starting Jupyter);
imageio-ffmpeg’s bundled binary, if the user has installed that package.

An explicit choice (1 or 2) that is not executable raises rather than falling through, so the binary used is never a different one from the one named.

neu_draw.video.run_encode(directory: str, fps: float, output: str, ffmpeg: str) → str¶: Run ffmpeg over the frames. Raises with ffmpeg’s own last lines if it fails.

neu_draw.video.ENCODE_ARGS = ('-c:v', 'libx264', '-pix_fmt', 'yuv420p', '-crf', '18')¶

neu_draw.video.ENCODE_MODES = ('auto', True, False)¶

neu_draw.video.FFMPEG_ENV = 'NEU_DRAW_FFMPEG'¶

neu_draw.video.FRAME_PATTERN = 'frame_%05d.png'¶