SDRdaemonFEC plugin: fixed CM256 library init and simplify code

plugins/samplesource/sdrdaemonfec/sdrdaemonfecbuffer.h

@@ -139,19 +139,17 @@ private:
 
     struct DecoderSlot
     {
-        ProtectedBlock       m_blockZero;
-        ProtectedBlock       m_recoveryBlocks[m_nbOriginalBlocks]; // max size
-        cm256_block          m_cm256DescriptorBlocks[m_nbOriginalBlocks];
-        int                  m_totalCount;         //!< total number of blocks received for this frame
-        int                  m_blockCount;         //!< number of blocks usable for decode in this frame
+        ProtectedBlock       m_originalBlocks[m_nbOriginalBlocks];        //!< Original blocks retrieved directly or by later FEC
+        ProtectedBlock       m_recoveryBlocks[m_nbOriginalBlocks];        //!< Recovery blocks (FEC blocks) with max size
+        cm256_block          m_cm256DescriptorBlocks[m_nbOriginalBlocks]; //!< CM256 decoder descriptors (block addresses and block indexes)
+        int                  m_blockCount;         //!< number of blocks received for this frame
         int                  m_originalCount;      //!< number of original blocks received
-        int                  m_recoveryStartIndex; //!< block number start of recovery blocks
         int                  m_recoveryCount;      //!< number of recovery blocks received
         bool                 m_decoded;            //!< true if decoded
         bool                 m_metaRetrieved;      //!< true if meta data (block zero) was retrieved
     };
 
-    MetaDataFEC m_currentMeta;                   //!< Stored current meta data
+    MetaDataFEC          m_currentMeta;          //!< Stored current meta data
     cm256_encoder_params m_paramsCM256;          //!< CM256 decoder parameters block
     DecoderSlot          m_decoderSlots[nbDecoderSlots]; //!< CM256 decoding control/buffer slots
     BufferFrame          m_frames[nbDecoderSlots];       //!< Samples buffer
@@ -165,7 +163,6 @@ private:
     int                  m_readIndex;            //!< current byte read index in frames buffer
     int                  m_wrDeltaEstimate;      //!< Sampled estimate of write to read indexes difference
     int                  m_readNbBytes;          //!< Nominal number of bytes per read (50ms)
-    int                  m_blockIndex;           //!< Stored block index for verification
 
 	uint32_t m_throttlemsNominal;  //!< Initial throttle in ms
     uint8_t* m_readBuffer;         //!< Read buffer to hold samples when looping back to beginning of raw buffer
@@ -177,6 +174,7 @@ private:
     int      m_nbWrites;      //!< Number of buffer writes since start of auto R/W balance correction period
     int      m_balCorrection; //!< R/W balance correction in number of samples
     int      m_balCorrLimit;  //!< Correction absolute value limit in number of samples
+    bool     m_cm256_OK;      //!< CM256 library initialized OK
 
     void initDecodeAllSlots();
     void initReadIndex();