InputFile: refactoring seekAtFrame

Clement Champetier · Clement Champetier · commit da5438ea52bb · 2015-02-10T14:42:55.000+01:00
diff --git a/src/AvTranscoder/file/InputFile.cpp b/src/AvTranscoder/file/InputFile.cpp
@@ -143,20 +143,18 @@ bool InputFile::readNextPacket( CodedData& data, const size_t streamIndex )
 
 void InputFile::seekAtFrame( const size_t frame )
 {
-	double fps = 1;
-	// Get Fps from first video stream
-	if( _properties.getNbVideoStreams() )
-		fps = _properties.getVideoProperties().at( 0 ).getFps();
-
-	uint64_t pos = frame / fps * AV_TIME_BASE;
+	uint64_t position = frame / getFps() * AV_TIME_BASE;
+	seek( position );
+}
 
-	// Offset of start time
+void InputFile::seek( uint64_t position )
+{
 	if( (int)_formatContext.getStartTime() != AV_NOPTS_VALUE )
-		pos += _formatContext.getStartTime();
+		position += _formatContext.getStartTime();
 
-	if( av_seek_frame( &_formatContext.getAVFormatContext(), -1, pos, AVSEEK_FLAG_BACKWARD ) < 0 )
+	if( av_seek_frame( &_formatContext.getAVFormatContext(), -1, position, AVSEEK_FLAG_BACKWARD ) < 0 )
 	{
-		std::cerr << "Error during seek at " << frame << " (" << pos << ") in file" << std::endl;
+		std::cerr << "Error during seek at " << position << " seconds in file" << std::endl;
 	}
 
 	for( std::vector<InputStream*>::iterator it = _inputStreams.begin(); it != _inputStreams.end(); ++it )
@@ -186,6 +184,14 @@ InputStream& InputFile::getStream( size_t index )
 	}
 }
 
+double InputFile::getFps()
+{
+	double fps = 1;
+	if( _properties.getNbVideoStreams() )
+		fps = _properties.getVideoProperties().at( 0 ).getFps();
+	return fps;
+}
+
 void InputFile::setProfile( const ProfileLoader::Profile& profile )
 {	
 	for( ProfileLoader::Profile::const_iterator it = profile.begin(); it != profile.end(); ++it )
diff --git a/src/AvTranscoder/file/InputFile.hpp b/src/AvTranscoder/file/InputFile.hpp
@@ -97,6 +97,20 @@ class AvExport InputFile
 	 **/
 	static FileProperties analyseFile( const std::string& filename, IProgress& progress, const EAnalyseLevel level = eAnalyseLevelFirstGop );
 
+private:
+	/**
+	 * @brief Get Fps from first video stream
+	 * @note if there is no video stream, return 1.
+	 */
+	double getFps();
+
+	/**
+	 * @brief Seek at a specific position (in AV_TIME_BASE units)
+	 * @note before seek, add offset of start time
+	 * @note after seek, clear buffering of streams
+	 */
+	void seek( uint64_t position );
+
 protected:
 	FormatContext _formatContext;
 	FileProperties _properties;
