{"record":{"id":"9d7e2d767fd06536","repo":"ytdl-org/youtube-dl","slug":"unsupported-compression-format-r","errorCode":null,"errorMessage":"Unsupported compression format %r","messagePattern":"Unsupported compression format %r","errorType":"exception","errorClass":"NotImplementedError","httpStatus":null,"severity":"error","filePath":"youtube_dl/swfinterp.py","lineNumber":23,"sourceCode":"import zlib\n\nfrom .compat import (\n    compat_str,\n    compat_struct_unpack,\n)\nfrom .utils import (\n    ExtractorError,\n)\n\n\ndef _extract_tags(file_contents):\n    if file_contents[1:3] != b'WS':\n        raise ExtractorError(\n            'Not an SWF file; header is %r' % file_contents[:3])\n    if file_contents[:1] == b'C':\n        content = zlib.decompress(file_contents[8:])\n    else:\n        raise NotImplementedError(\n            'Unsupported compression format %r' %\n            file_contents[:1])\n\n    # Determine number of bits in framesize rectangle\n    framesize_nbits = compat_struct_unpack('!B', content[:1])[0] >> 3\n    framesize_len = (5 + 4 * framesize_nbits + 7) // 8\n\n    pos = framesize_len + 2 + 2\n    while pos < len(content):\n        header16 = compat_struct_unpack('<H', content[pos:pos + 2])[0]\n        pos += 2\n        tag_code = header16 >> 6\n        tag_len = header16 & 0x3f\n        if tag_len == 0x3f:\n            tag_len = compat_struct_unpack('<I', content[pos:pos + 4])[0]\n            pos += 4\n        assert pos + tag_len <= len(content), \\\n            ('Tag %d ends at %d+%d - that\\'s longer than the file (%d)'","sourceCodeStart":5,"sourceCodeEnd":41,"githubUrl":"https://github.com/ytdl-org/youtube-dl/blob/956b8c585591b401a543e409accb163eeaaa1193/youtube_dl/swfinterp.py#L5-L41","documentation":"Error \"Unsupported compression format %r\" thrown in ytdl-org/youtube-dl.","triggerScenarios":"Thrown at youtube_dl/swfinterp.py:23 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["The SWF uses an unsupported compression; decompress it or update youtube-dl."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"956b8c585591b401a543e409accb163eeaaa1193","analyzedAt":"2026-08-14T18:59:47.863Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}