AudioBuffer: allow setting size of RAM and PSRAM buffer

instead of the fixed buffer size of 300000 for PSRAM and 8000 for
non-PSRAM setup, allow to configure the buffer sizes, example code
for that is
    audio.setBuffersize(32768, 0);
which will set the RAM buffer size to 32k and disable PSRAM usage.
I am investigating "bad WiFi throughput with PSRAM" issues and disabling
PSRAM is one workaround I found.

src/Audio.cpp

@@ -35,22 +35,26 @@ AudioBuffer::~AudioBuffer() {
     m_buffer = NULL;
 }
 
+void AudioBuffer::setBufsize(int ram, int psram) {
+    if (ram > -1) // -1 == default / no change
+        m_buffSizeRAM = ram;
+    if (psram > -1)
+        m_buffSizePSRAM = psram;
+}
+
 size_t AudioBuffer::init() {
     if(m_buffer) free(m_buffer);
     m_buffer = NULL;
-    if(psramInit()) {
+    if(psramInit() && m_buffSizePSRAM > 0) {
         // PSRAM found, AudioBuffer will be allocated in PSRAM
+        m_f_psram = true;
         m_buffSize = m_buffSizePSRAM;
-        if(m_buffer == NULL) {
-            m_buffer = (uint8_t*) ps_calloc(m_buffSize, sizeof(uint8_t));
-            m_buffSize = m_buffSizePSRAM - m_resBuffSizePSRAM;
-            if(m_buffer == NULL) {
-                // not enough space in PSRAM, use ESP32 Flash Memory instead
-                m_buffer = (uint8_t*) calloc(m_buffSize, sizeof(uint8_t));
-                m_buffSize = m_buffSizeRAM - m_resBuffSizeRAM;
-            }
-        }
-    } else {  // no PSRAM available, use ESP32 Flash Memory"
+        m_buffer = (uint8_t*) ps_calloc(m_buffSize, sizeof(uint8_t));
+        m_buffSize = m_buffSizePSRAM - m_resBuffSizePSRAM;
+    }
+    if(m_buffer == NULL) {
+        // PSRAM not found, not configured or not enough available
+        m_f_psram = false;
         m_buffSize = m_buffSizeRAM;
         m_buffer = (uint8_t*) calloc(m_buffSize, sizeof(uint8_t));
         m_buffSize = m_buffSizeRAM - m_resBuffSizeRAM;
@@ -205,20 +209,24 @@ Audio::Audio(bool internalDAC /* = false */, i2s_dac_mode_t channelEnabled /* =
     }
 }
 //---------------------------------------------------------------------------------------------------------------------
+void Audio::setBufsize(int rambuf_sz, int psrambuf_sz) {
+    if(InBuff.isInitialized()) {
+        ESP_LOGE(TAG, "Audio::setBufsize must not be called after audio is initialized");
+        return;
+    }
+    InBuff.setBufsize(rambuf_sz, psrambuf_sz);
+};
+
 void Audio::initInBuff() {
     if(!InBuff.isInitialized()) {
         size_t size = InBuff.init();
-        if(size == m_buffSizeRAM - m_resBuffSizeRAM) {
-            AUDIO_INFO(sprintf(chbuf, "PSRAM not found, inputBufferSize: %u bytes", size - 1);)
-            m_f_psram = false;
-        }
-        if(size == m_buffSizePSRAM - m_resBuffSizePSRAM) {
-            AUDIO_INFO(sprintf(chbuf, "PSRAM found, inputBufferSize: %u bytes", size - 1);)
-            m_f_psram = true;
+        if (size > 0) {
+            AUDIO_INFO(sprintf(chbuf, "PSRAM %sfound, inputBufferSize: %u bytes", InBuff.havePSRAM()?"":"not ", size - 1);)
         }
     }
     changeMaxBlockSize(1600); // default size mp3 or aac
 }
+
 //---------------------------------------------------------------------------------------------------------------------
 esp_err_t Audio::I2Sstart(uint8_t i2s_num) {
     // It is not necessary to call this function after i2s_driver_install() (it is started automatically),
@@ -3043,7 +3051,7 @@ void Audio::processWebStream() {
 
         int16_t bytesAddedToBuffer = 0;
 
-        if(m_f_psram) if(bytesCanBeWritten > 4096) bytesCanBeWritten = 4096; // PSRAM throttle
+        if(InBuff.havePSRAM()) if(bytesCanBeWritten > 4096) bytesCanBeWritten = 4096; // PSRAM throttle
 
         if(m_f_webfile){
             // normally there is nothing to do here, if byteCounter == contentLength

src/Audio.h

@@ -114,6 +114,7 @@ public:
     ~AudioBuffer();                             // frees the buffer
     size_t   init();                            // set default values
     bool     isInitialized() { return m_f_init; };
+    void     setBufsize(int ram, int psram);
     void     changeMaxBlockSize(uint16_t mbs);  // is default 1600 for mp3 and aac, set 16384 for FLAC
     uint16_t getMaxBlockSize();                 // returns maxBlockSize
     size_t   freeSpace();                       // number of free bytes to overwrite
@@ -126,10 +127,11 @@ public:
     uint32_t getWritePos();                     // write position relative to the beginning
     uint32_t getReadPos();                      // read position relative to the beginning
     void     resetBuffer();                     // restore defaults
+    bool     havePSRAM() { return m_f_psram; };
 
 protected:
-    const size_t m_buffSizePSRAM    = 300000; // most webstreams limit the advance to 100...300Kbytes
-    const size_t m_buffSizeRAM      = 1600 * 5;
+    size_t       m_buffSizePSRAM    = 300000;   // most webstreams limit the advance to 100...300Kbytes
+    size_t       m_buffSizeRAM      = 1600 * 5;
     size_t       m_buffSize         = 0;
     size_t       m_freeSpace        = 0;
     size_t       m_writeSpace       = 0;
@@ -143,6 +145,7 @@ protected:
     uint8_t*     m_endPtr           = NULL;
     bool         m_f_start          = true;
     bool         m_f_init           = false;
+    bool         m_f_psram          = false;    // PSRAM is available (and used...)
 };
 //----------------------------------------------------------------------------------------------------------------------
 
@@ -153,6 +156,7 @@ class Audio : private AudioBuffer{
 public:
     Audio(bool internalDAC = false, i2s_dac_mode_t channelEnabled = I2S_DAC_CHANNEL_LEFT_EN); // #99
     ~Audio();
+    void setBufsize(int rambuf_sz, int psrambuf_sz);
     bool connecttohost(const char* host, const char* user = "", const char* pwd = "");
     bool connecttospeech(const char* speech, const char* lang);
     bool connecttoFS(fs::FS &fs, const char* path);
@@ -454,7 +458,6 @@ private:
     bool            m_f_playing = false;            // valid mp3 stream recognized
     bool            m_f_webfile = false;            // assume it's a radiostream, not a podcast
     bool            m_f_tts = false;                // text to speech
-    bool            m_f_psram = false;              // set if PSRAM is availabe
     bool            m_f_loop = false;               // Set if audio file should loop
     bool            m_f_forceMono = false;          // if true stereo -> mono
     bool            m_f_internalDAC = false;        // false: output vis I2S, true output via internal DAC