readers: added _currentDecoder attribute to easily switch between decoders

Clement Champetier · Clement Champetier · commit 34fef1697424 · 2016-04-08T16:43:47.000+02:00
* If we want to call the generator, no need to call decodeNextFrame on
the other decoder each time. This commit avoids this.
* This is the same solution in StreamTranscoder class.
diff --git a/src/AvTranscoder/reader/AudioReader.cpp b/src/AvTranscoder/reader/AudioReader.cpp
@@ -42,6 +42,7 @@ void AudioReader::init()
     // setup decoder
     _decoder = new AudioDecoder(_inputFile->getStream(_streamIndex));
     _decoder->setupDecoder();
+    _currentDecoder = _decoder;
 
     // generator
     _generator = new AudioGenerator(_inputFile->getStream(_streamIndex).getAudioCodec().getAudioFrameDesc());
diff --git a/src/AvTranscoder/reader/IReader.cpp b/src/AvTranscoder/reader/IReader.cpp
@@ -9,6 +9,8 @@ IReader::IReader(const std::string& filename, const size_t streamIndex, const in
     : _inputFile(NULL)
     , _streamProperties(NULL)
     , _decoder(NULL)
+    , _generator(NULL)
+    , _currentDecoder(NULL)
     , _srcFrame(NULL)
     , _dstFrame(NULL)
     , _transform(NULL)
@@ -25,6 +27,8 @@ IReader::IReader(InputFile& inputFile, const size_t streamIndex, const int chann
     : _inputFile(&inputFile)
     , _streamProperties(NULL)
     , _decoder(NULL)
+    , _generator(NULL)
+    , _currentDecoder(NULL)
     , _srcFrame(NULL)
     , _dstFrame(NULL)
     , _transform(NULL)
@@ -54,8 +58,7 @@ Frame* IReader::readPrevFrame()
 
 Frame* IReader::readFrameAt(const size_t frame)
 {
-    assert(_decoder != NULL);
-    assert(_generator != NULL);
+    assert(_currentDecoder != NULL);
     assert(_transform != NULL);
     assert(_srcFrame != NULL);
     assert(_dstFrame != NULL);
@@ -70,16 +73,17 @@ Frame* IReader::readFrameAt(const size_t frame)
     // decode
     bool decodingStatus = false;
     if(_channelIndex != -1)
-        decodingStatus = _decoder->decodeNextFrame(*_srcFrame, _channelIndex);
+        decodingStatus = _currentDecoder->decodeNextFrame(*_srcFrame, _channelIndex);
     else
-        decodingStatus = _decoder->decodeNextFrame(*_srcFrame);
+        decodingStatus = _currentDecoder->decodeNextFrame(*_srcFrame);
     // if decoding failed
     if(!decodingStatus)
     {
         // generate data (ie silence or black)
         if(_continueWithGenerator)
         {
-           _generator->decodeNextFrame(*_srcFrame);
+            _currentDecoder = _generator;
+            return readFrameAt(frame);
         }
         // or return NULL
         else
diff --git a/src/AvTranscoder/reader/IReader.hpp b/src/AvTranscoder/reader/IReader.hpp
@@ -68,6 +68,7 @@ class AvExport IReader
     const StreamProperties* _streamProperties;
     IDecoder* _decoder;
     IDecoder* _generator;
+    IDecoder* _currentDecoder; ///< Link to _inputDecoder or _generator
 
     Frame* _srcFrame;
     Frame* _dstFrame;
diff --git a/src/AvTranscoder/reader/VideoReader.cpp b/src/AvTranscoder/reader/VideoReader.cpp
@@ -41,6 +41,7 @@ void VideoReader::init()
     // setup decoder
     _decoder = new VideoDecoder(_inputFile->getStream(_streamIndex));
     _decoder->setupDecoder();
+    _currentDecoder = _decoder;
 
     // generator
     _generator = new VideoGenerator(_inputFile->getStream(_streamIndex).getVideoCodec().getVideoFrameDesc());
