yt-dlp/yt_dlp/compat/imghdr.py
Simon Sawicki f2a4ea1794
[pp/embedthumbnail] Fix postprocessor (#10248)
* [compat] Improve `imghdr.what` detection
* [pp/embedthumbnail] Improve imghdr fail message
* [pp/embedthumbnail] Fix AtomicParsley error handling

Authored by: Grub4K
2024-06-27 16:12:19 +02:00

22 lines
582 B
Python

def what(file=None, h=None):
"""Detect format of image (Currently supports jpeg, png, webp, gif only)
Ref: https://github.com/python/cpython/blob/3.11/Lib/imghdr.py
Ref: https://www.w3.org/Graphics/JPEG/itu-t81.pdf
"""
if h is None:
with open(file, 'rb') as f:
h = f.read(12)
if h.startswith(b'RIFF') and h.startswith(b'WEBP', 8):
return 'webp'
if h.startswith(b'\x89PNG'):
return 'png'
if h.startswith(b'\xFF\xD8\xFF'):
return 'jpeg'
if h.startswith(b'GIF'):
return 'gif'
return None