mendevi.utils
Provide simple tools.
Classes
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Measure the computer activity of a section. |
Functions
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Compute the checksum of the video. |
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Alias to cutcutcodec func. |
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Alias to cutcutcodec func. |
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Alias to cutcutcodec func. |
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Convert the md5 binary hash value into an urlsafe string. |
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Convert the string signature into the md5 checksum. |
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Explore recursively the folders to find the video path. |
Details
- class mendevi.utils.Activity(sleep: Real = 0.05)[source]
Measure the computer activity of a section.
Examples
>>> import pprint, time >>> from mendevi.utils import Activity >>> with Activity() as activity: ... time.sleep(1) ... >>> pprint.pprint(activity) >>>
Initalize the perf context.
Parameters
- sleepfloat, default=50e-3
The time interval between 2 measures (in s).
- mendevi.utils.compute_video_hash(videos: str | bytes | Path | Iterable[str | bytes | Path]) bytes | dict[Path, bytes][source]
Compute the checksum of the video.
For \(n\) hash of \(b\) bits, the proba of the colision \(C\) is \(p(C) = 1 - \left(\frac{2^k-1}{2^k}\right)^{\frac{n(n-1)}{2}}\).
The md5 hash uses \(b = 128\) bits. If we add one video per second durring 10 years, the proba of colision is about \(p(C) \approx 1.46*10^{-22}\).
That’s why the md5 hash is used to identify the video files.
Parameters
- videospathlike or list[pathlike]
The single or set of video you want to compute the signature.
Returns
- signatures
The md5 checksum of the video file. In the case of a multiple file, a dictionary containing the file and the hash is returned rather a single hash. If the file does not exists, return None.
- mendevi.utils.get_pix_fmt(*args)[source]
Alias to cutcutcodec func.
- mendevi.utils.get_rate_video(*args)[source]
Alias to cutcutcodec func.
- mendevi.utils.get_resolution(*args)[source]
Alias to cutcutcodec func.
- mendevi.utils.hash_to_signature(checksum: bytes) str[source]
Convert the md5 binary hash value into an urlsafe string.
Bijection of
signature_to_hash().Parameters
- checksumbytes
The 128 bit binary hash value.
Returns
- signaturestr
The 26 ascii [2-7a-z] symbols string of the converted checksum.
Examples
>>> from mendevi.utils import hash_to_signature >>> hash_to_signature(b"\xd4\x1d\x8c\xd9\x8f\x00\xb2\x04\xe9\x80\t\x98\xec\xf8B~") '2qoyzwmpaczaj2mabgmoz6ccpy' >>>
- mendevi.utils.signature_to_hash(signature: str) bytes[source]
Convert the string signature into the md5 checksum.
Bijection of
hash_to_signature().Parameters
- signaturestr
The 26 ascii [2-7a-z] symbols string of the converted checksum.
Returns
- checksumbytes
The 128 bit binary hash value.
Examples
>>> from mendevi.utils import signature_to_hash >>> signature_to_hash("2qoyzwmpaczaj2mabgmoz6ccpy") b'\xd4\x1d\x8c\xd9\x8f\x00\xb2\x04\xe9\x80\t\x98\xec\xf8B~' >>>