#!/usr/bin/env python3
"""Find pixel format of a video stream."""
import collections
import pathlib
import typing
import cv2 # pip install opencv-contrib-python-headless
from cutcutcodec.core.analysis._helper_properties import _check_pathexists_index, _mix_and_check
from cutcutcodec.core.analysis.ffprobe import _estimate_pix_fmt_ffmpeg, _map_index_rel_to_abs
from cutcutcodec.core.exceptions import MissingStreamError, MissingInformation
def _estimate_pix_fmt_cv2(filename: str, index: int) -> tuple[int, int]:
"""Retrieve via cv2, the metadata concerning the pixel format.
This function is fast because it reads only the header of the file.
Examples
--------
>>> from cutcutcodec.core.analysis.video.properties.pix_fmt import _estimate_pix_fmt_cv2
>>> from cutcutcodec.utils import get_project_root
>>> media = str(get_project_root() / "media" / "video" / "intro.webm")
>>> _estimate_pix_fmt_cv2(media, 0)
'yuv420'
>>>
"""
cap = cv2.VideoCapture(filename, index)
if not cap.isOpened():
raise MissingStreamError(f"impossible to open '{filename}' stream {index} with 'cv2'")
if (code := cap.get(cv2.CAP_PROP_CODEC_PIXEL_FORMAT)) == -1.0:
raise MissingInformation(
f"'cv2' did not find the pixel format of '{filename}' stream {index}"
)
PIXEL_FORMAT_MAP = {
134230855.0: "gbrp",
168440665.0: "yuv422p10le",
168506201.0: "yuv420p10le",
808596553.0: "yuv420",
}
if code not in PIXEL_FORMAT_MAP:
raise MissingInformation(
f"the 'cv2' pixel format code {code} is unknown '{filename}' stream {index}"
)
return PIXEL_FORMAT_MAP[code]
[docs]
def get_pix_fmt(
filename: pathlib.Path | str | bytes,
index: int = 0,
*,
backend: typing.Optional[str] = None
) -> str:
"""Read in the metadata, the pixel format.
Parameters
----------
filename : pathlike
The pathlike of the file containing a video stream.
index : int
The relative index of the video stream being considered,
by default the first stream encountered is selected.
backend : str, optional
- None (default) : Try to read the stream by trying differents backends.
- 'ffmpeg' : Uses the modules ``pip install ffmpeg-python``
which are using the ``ffmpeg`` program in the background.
- 'cv2' : Uses the module ``pip install opencv-contrib-python-headless``.
Returns
-------
pix_fmt : int
The name of the pixel format.
Raises
------
MissingStreamError
If the file does not contain a playable video stream.
MissingInformation
If the information is unavailable.
Examples
--------
>>> from cutcutcodec.core.analysis.video.properties.pix_fmt import get_pix_fmt
>>> from cutcutcodec.utils import get_project_root
>>> media = get_project_root() / "media" / "video" / "intro.webm"
>>> get_pix_fmt(media)
'yuv420p'
>>>
"""
_check_pathexists_index(filename, index)
return _mix_and_check(
backend, False, (str(pathlib.Path(filename)), index),
collections.OrderedDict([
(
(
lambda filename, index: _estimate_pix_fmt_ffmpeg(
filename, _map_index_rel_to_abs(filename, index, "video")
)
),
{"accurate": False, "backend": "ffmpeg"},
),
(_estimate_pix_fmt_cv2, {"accurate": False, "backend": "cv2"}),
])
)