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95bb7c50ee
Publish and subscribe over wss://livekit.uni-wh.de:7800 and refuse cleartext ws://. Conference room is uwh-telhai. Includes the uncommitted encoded H.264 publish path, Rally hairpin, and KMS wall overlay.
73 lines
1.8 KiB
Python
73 lines
1.8 KiB
Python
"""Split Annex-B H.264 into access units."""
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from __future__ import annotations
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def _start_at(buf: bytes, i: int) -> int:
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n = len(buf)
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while i + 2 < n:
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if buf[i] == 0 and buf[i + 1] == 0:
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if buf[i + 2] == 1:
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return i
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if i + 3 < n and buf[i + 2] == 0 and buf[i + 3] == 1:
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return i
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i += 1
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return -1
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def nal_unit_type(nal: bytes) -> int:
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"""First NAL type in an AU (5 = IDR)."""
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i = _start_at(nal, 0)
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if i < 0:
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return 0
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hdr = i + (4 if i + 3 < len(nal) and nal[i + 2] == 0 else 3)
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if hdr >= len(nal):
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return 0
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return nal[hdr] & 0x1F
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def is_keyframe(au: bytes) -> bool:
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i = 0
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n = len(au)
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while True:
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s = _start_at(au, i)
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if s < 0:
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return False
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hdr = s + (4 if s + 3 < n and au[s + 2] == 0 else 3)
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if hdr >= n:
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return False
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ntype = au[hdr] & 0x1F
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if ntype == 5:
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return True
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i = hdr + 1
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class AnnexBSplitter:
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"""Feed byte-stream; yield complete AUs (including start codes)."""
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def __init__(self) -> None:
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self._buf = bytearray()
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def push(self, data: bytes) -> list[bytes]:
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if data:
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self._buf.extend(data)
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out: list[bytes] = []
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buf = self._buf
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first = _start_at(bytes(buf), 0)
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if first < 0:
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if len(buf) > 1_000_000:
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del buf[: len(buf) - 8]
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return out
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if first:
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del buf[:first]
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pos = 0
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while True:
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nxt = _start_at(bytes(buf), pos + 3)
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if nxt < 0:
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break
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au = bytes(buf[:nxt])
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if au:
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out.append(au)
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del buf[:nxt]
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pos = 0
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return out
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