color: input colorspace auto-detection, HDR export tags, LGG/white balance nodes, more LUT formats, waveform parade

- media color primaries/transfer tags now flow from the FFmpeg probe
  through VideoParams into Footage::get_colorspace_to_use(); precedence
  is user override > media tags > project default
- export nclc tags derive from the output colorspace (PQ/HLG/BT.2020,
  P3, sRGB, Rec.601, Rec.709) instead of hardcoded BT.709
- new OCIO Color Grading (Log) node (lift/gamma/gain) and White Balance
  node (kelvin temperature + tint, HDR-safe)
- LUT whitelist extended to 9 OCIO-supported formats
- waveform scope gains an RGB parade mode (GPU and software paths)
- tests updated for the new colorspace precedence

app/render/lutlibrary.cpp

@@ -29,6 +29,17 @@
 namespace olive
 {
 
+const QStringList &LUTLibrary::supported_extensions()
+{
+	// LUT formats OCIO FileTransform can load
+	static const QStringList extensions = {
+		QStringLiteral("cube"),	 QStringLiteral("3dl"),  QStringLiteral("spi1d"),
+		QStringLiteral("spi3d"), QStringLiteral("spimtx"), QStringLiteral("csp"),
+		QStringLiteral("clf"),	 QStringLiteral("ctf"),  QStringLiteral("cub"),
+	};
+	return extensions;
+}
+
 bool LUTLibrary::is_supported_extension(const QString &suffix)
 {
 	QString s = suffix;
@@ -36,8 +47,7 @@ bool LUTLibrary::is_supported_extension(const QString &suffix)
 		s.remove(0, 1);
 	}
 
-	const QString lower = s.toLower();
-	return lower == QStringLiteral("cube") || lower == QStringLiteral("3dl");
+	return supported_extensions().contains(s.toLower());
 }
 
 QStringList LUTLibrary::get_directories()

app/render/lutlibrary.h

@@ -37,9 +37,16 @@ namespace olive
  */
 class LUTLibrary {
 public:
+	/**
+	 * @brief All LUT file extensions supported by the library
+	 *
+	 * Extensions OCIO FileTransform can load, lowercase, without the dot.
+	 */
+	static const QStringList &supported_extensions();
+
 	/**
 	 * @brief Returns true if the given file suffix is a supported LUT
-	 * extension (.cube or .3dl, case-insensitive, leading dot tolerated)
+	 * extension (case-insensitive, leading dot tolerated)
 	 */
 	static bool is_supported_extension(const QString &suffix);
 

app/render/videoparams.cpp

@@ -419,6 +419,10 @@ void VideoParams::load(QXmlStreamReader *reader)
 		} else if (reader->name() == QStringLiteral("colorrange")) {
 			set_color_range(
 				static_cast<ColorRange>(reader->readElementText().toInt()));
+		} else if (reader->name() == QStringLiteral("colorprimaries")) {
+			set_color_primaries(reader->readElementText().toInt());
+		} else if (reader->name() == QStringLiteral("colortransfer")) {
+			set_color_transfer(reader->readElementText().toInt());
 		} else {
 			reader->skipCurrentElement();
 		}
@@ -463,6 +467,10 @@ void VideoParams::save(QXmlStreamWriter *writer) const
 	writer->writeTextElement(QStringLiteral("colorspace"), colorspace_);
 	writer->writeTextElement(QStringLiteral("colorrange"),
 							 QString::number(color_range_));
+	writer->writeTextElement(QStringLiteral("colorprimaries"),
+							 QString::number(color_primaries_));
+	writer->writeTextElement(QStringLiteral("colortransfer"),
+							 QString::number(color_transfer_));
 }
 
 }

app/render/videoparams.h

@@ -378,6 +378,33 @@ public:
 		color_range_ = color_range;
 	}
 
+	/**
+	 * @brief Color primaries/transfer as reported by the media
+	 *
+	 * Raw FFmpeg AVColorPrimaries/AVColorTransferCharacteristic values
+	 * (0 = unset, 2 = unspecified). Used to auto-detect the input
+	 * colorspace when no explicit colorspace has been set.
+	 */
+	int color_primaries() const
+	{
+		return color_primaries_;
+	}
+
+	void set_color_primaries(int p)
+	{
+		color_primaries_ = p;
+	}
+
+	int color_transfer() const
+	{
+		return color_transfer_;
+	}
+
+	void set_color_transfer(int t)
+	{
+		color_transfer_ = t;
+	}
+
 	int64_t get_time_in_timebase_units(const Rational &time) const;
 
 	void load(QXmlStreamReader *reader);
@@ -425,6 +452,8 @@ private:
 	float x_;
 	float y_;
 	ColorRange color_range_;
+	int color_primaries_ = 0;
+	int color_transfer_ = 0;
 };
 
 }