[SSTV] Fixes from cppcheck scan

src/protocols/SSTV/SSTV.cpp

@@ -166,7 +166,7 @@ SSTVClient::SSTVClient(AFSKClient* audio) {
 }
 #endif
 
-int16_t SSTVClient::begin(SSTVMode_t mode, float correction) {
+int16_t SSTVClient::begin(const SSTVMode_t& mode, float correction) {
   if(_audio == nullptr) {
     // this initialization method can only be used in AFSK mode
     return(ERR_WRONG_MODEM);
@@ -175,7 +175,7 @@ int16_t SSTVClient::begin(SSTVMode_t mode, float correction) {
   return(begin(0, mode, correction));
 }
 
-int16_t SSTVClient::begin(float base, SSTVMode_t mode, float correction) {
+int16_t SSTVClient::begin(float base, const SSTVMode_t& mode, float correction) {
   // save mode
   _mode = mode;
 
@@ -278,10 +278,6 @@ void SSTVClient::sendLine(uint32_t* imgLine) {
   }
 }
 
-uint16_t SSTVClient::getPictureHeight() {
-  return(_mode.height);
-}
-
 void SSTVClient::tone(float freq, uint32_t len) {
   uint32_t start = micros();
   if(_audio != nullptr) {

src/protocols/SSTV/SSTV.h

@@ -121,7 +121,7 @@ class SSTVClient {
 
       \param phy Pointer to the wireless module providing PhysicalLayer communication.
     */
-    SSTVClient(PhysicalLayer* phy);
+    explicit SSTVClient(PhysicalLayer* phy);
 
     #if !defined(RADIOLIB_EXCLUDE_AFSK)
     /*!
@@ -129,7 +129,7 @@ class SSTVClient {
 
       \param audio Pointer to the AFSK instance providing audio.
     */
-    SSTVClient(AFSKClient* phy);
+    explicit SSTVClient(AFSKClient* audio);
     #endif
 
     // basic methods
@@ -145,7 +145,7 @@ class SSTVClient {
 
       \returns \ref status_codes
     */
-    int16_t begin(float base, SSTVMode_t mode, float correction = 1.0);
+    int16_t begin(float base, const SSTVMode_t& mode, float correction = 1.0);
 
     /*!
       \brief Initialization method for AFSK.
@@ -156,7 +156,7 @@ class SSTVClient {
 
       \returns \ref status_codes
     */
-    int16_t begin(SSTVMode_t mode, float correction = 1.0);
+    int16_t begin(const SSTVMode_t& mode, float correction = 1.0);
 
     /*!
       \brief Sends out tone at 1900 Hz.
@@ -180,7 +180,7 @@ class SSTVClient {
 
       \returns Picture height of the currently configured SSTV mode in pixels.
     */
-    uint16_t getPictureHeight();
+    uint16_t getPictureHeight() const { return(_mode.height); };
 
 #ifndef RADIOLIB_GODMODE
   private:
@@ -192,9 +192,9 @@ class SSTVClient {
     void* _audio;
     #endif
 
-    uint32_t _base;
-    SSTVMode_t _mode;
-    bool _firstLine;
+    uint32_t _base = 0;
+    SSTVMode_t _mode = Scottie1;
+    bool _firstLine = true;
 
     void tone(float freq, uint32_t len = 0);
 };