Disambiguate export formats with different encoder settings

Disambiguate export formats with different encoder
qualities, sample-formats or settings (wav/bwav).

This allows to export multipe mp3 with different bitrates.

libs/ardour/ardour/export_format_specification.h

@@ -80,6 +80,7 @@ class LIBARDOUR_API ExportFormatSpecification : public ExportFormatBase {
 
 	void set_format (std::shared_ptr<ExportFormat> format);
 	bool is_format (std::shared_ptr<ExportFormat> format) const;
+	bool operator== (ExportFormatSpecification const&) const;
 
 	void set_name (std::string const & name) { _name = name; }
 

libs/ardour/export_format_specification.cc

@@ -581,6 +581,27 @@ ExportFormatSpecification::is_complete () const
 	return true;
 }
 
+bool ExportFormatSpecification::operator== (ExportFormatSpecification const& other) const
+{
+	const int a = format_id() | sample_format() | endianness();
+	const int b = other.format_id() | other.sample_format() | other.endianness();
+	if (a != b) {
+		return false;
+	}
+
+	/* BWF has the same format id with wav, so we need to check this. */
+	if (has_broadcast_info () != other.has_broadcast_info ()) {
+		return false;
+	}
+
+	if (_has_codec_quality && other._has_codec_quality) {
+		if (_codec_quality != other._codec_quality) {
+			return false;
+		}
+	}
+	return true;
+}
+
 bool
 ExportFormatSpecification::is_format (std::shared_ptr<ExportFormat> format) const
 {

libs/ardour/export_graph_builder.cc

@@ -327,7 +327,9 @@ ExportGraphBuilder::Encoder::destroy_writer (bool delete_out_file)
 bool
 ExportGraphBuilder::Encoder::operator== (FileSpec const & other_config) const
 {
-	return get_real_format (config) == get_real_format (other_config);
+	ExportFormatSpecification const& a = *config.format;
+	ExportFormatSpecification const& b = *other_config.format;
+	return a == b;
 }
 
 int
@@ -649,7 +651,21 @@ ExportGraphBuilder::SFC::operator== (FileSpec const& other_config) const
 	ExportFormatSpecification const& a = *config.format;
 	ExportFormatSpecification const& b = *other_config.format;
 
-	bool id = a.sample_format() == b.sample_format();
+	bool id;
+	if (a.analyse () || b.analyse ()) {
+		/* Show dedicated analysis result for files with different
+		 * quality or wav/bwav. This adds a dedicated SFC for each
+		 * format, rater than only running dedicated Encoders as 
+		 * childs of of the same SFC.
+		 *
+		 * TODO: separate normalizer, and limiter into a dedicated
+		 * graph-node, so that it can be shared.
+		 */
+		id = a == b;
+	} else {
+		/* delegate disambiguation to Encoder::operator== */
+		id = a.sample_format() == b.sample_format();
+	}
 
 	if (a.normalize_loudness () == b.normalize_loudness ()) {
 		id &= a.normalize_lufs () == b.normalize_lufs ();