Add Avisynth video encoding workflow

tools/video_formatting.py

@@ -0,0 +1,119 @@
+from __future__ import annotations
+
+from fractions import Fraction
+
+
+def join_parts(parts: list[str | None]) -> str:
+    return ", ".join(part for part in parts if part)
+
+
+def video_parts(
+    *,
+    codec: str | None = None,
+    width: int | None = None,
+    height: int | None = None,
+    pixel_format: str | None = None,
+    bit_depth: int | None = None,
+    matrix: str | None = None,
+    bit_rate: int | None = None,
+) -> list[str | None]:
+    return [
+        codec,
+        format_size(width, height),
+        format_chroma(pixel_format),
+        f"{bit_depth}-bit" if bit_depth is not None else None,
+        matrix,
+        format_bitrate(bit_rate),
+    ]
+
+
+def audio_parts(
+    *,
+    codec: str | None = None,
+    channels: int | None = None,
+    sample_rate: int | None = None,
+    bit_rate: int | None = None,
+) -> list[str | None]:
+    return [
+        codec,
+        format_channels(channels),
+        f"{sample_rate} Hz" if sample_rate is not None else None,
+        format_bitrate(bit_rate),
+    ]
+
+
+def format_size(width: int | None, height: int | None) -> str | None:
+    return f"{width}x{height}" if width is not None and height is not None else None
+
+
+def format_chroma(pixel_format: str | None) -> str | None:
+    value = (pixel_format or "").lower()
+    for marker, label in (("420", "4:2:0"), ("422", "4:2:2"), ("444", "4:4:4")):
+        if marker in value:
+            return label
+    if value.startswith(("rgb", "bgr", "gbr")):
+        return "RGB"
+    if value.startswith("gray"):
+        return "gray"
+    return pixel_format
+
+
+def chroma_family(pixel_format: str | None) -> str:
+    value = (pixel_format or "").lower()
+    if "444" in value:
+        return "444"
+    if "422" in value:
+        return "422"
+    return "420"
+
+
+def format_channels(channels: int | None) -> str | None:
+    if channels is None:
+        return None
+    return f"{channels} channel{'s' if channels != 1 else ''}"
+
+
+def format_bitrate(bit_rate: int | None) -> str | None:
+    if bit_rate is None:
+        return None
+    if bit_rate >= 1_000_000:
+        return f"{bit_rate / 1_000_000:.3g} Mbit/s"
+    return f"{bit_rate / 1_000:.3g} kbit/s"
+
+
+def format_seconds(seconds: float | None) -> str:
+    return "unknown" if seconds is None else f"{seconds:.3f}s"
+
+
+def format_frame_count(stream_count: int | None, timestamp_count: int) -> str:
+    if stream_count is not None and stream_count != timestamp_count:
+        return f"{stream_count} stream frames, {timestamp_count} timestamped frames"
+    count = stream_count if stream_count is not None else timestamp_count
+    return f"{count} frames" if count else "unknown frames"
+
+
+def rate_value(value: str | None) -> float | None:
+    if not value:
+        return None
+    try:
+        rate = Fraction(value)
+    except (ValueError, ZeroDivisionError):
+        return None
+    return float(rate) if rate else None
+
+
+def format_framerate(kind: str, value: str | None) -> str:
+    rate = rate_value(value)
+    rate_text = "unknown" if rate is None else f"{rate:.3f} fps"
+    kind = kind.upper()
+    return f"{kind}, average {rate_text}" if kind == "VFR" else f"{kind}, {rate_text}"
+
+
+def matrix_name(matrix: int | None) -> str:
+    if matrix == 1:
+        return "Rec709"
+    if matrix in {5, 6}:
+        return "Rec601"
+    if matrix in {9, 10}:
+        return "Rec2020"
+    return "unknown" if matrix is None else f"unknown ({matrix})"