[examples] Review audio examples audio_raw_stream(split) and audio_sound_loading to add more clarity

examples/Makefile

@@ -707,6 +707,7 @@ AUDIO = \
     audio/audio_module_playing \
     audio/audio_music_stream \
     audio/audio_raw_stream \
+    audio/audio_raw_stream_callback \
     audio/audio_sound_loading \
     audio/audio_sound_multi \
     audio/audio_sound_positioning \

examples/audio/audio_raw_stream.c

@@ -4,7 +4,7 @@
 *
 *   Example complexity rating: [★★★☆] 3/4
 *
-*   Example originally created with raylib 1.6, last time updated with raylib 4.2
+*   Example originally created with raylib 1.6, last time updated with raylib 6.0
 *
 *   Example created by Ramon Santamaria (@raysan5) and reviewed by James Hofmann (@triplefox)
 *
@@ -24,34 +24,6 @@
 #define MAX_SAMPLES               512
 #define MAX_SAMPLES_PER_UPDATE   4096
 
-// Cycles per second (hz)
-float frequency = 440.0f;
-
-// Audio frequency, for smoothing
-float audioFrequency = 440.0f;
-
-// Previous value, used to test if sine needs to be rewritten, and to smoothly modulate frequency
-float oldFrequency = 1.0f;
-
-// Index for audio rendering
-float sineIdx = 0.0f;
-
-// Audio input processing callback
-void AudioInputCallback(void *buffer, unsigned int frames)
-{
-    audioFrequency = frequency + (audioFrequency - frequency)*0.95f;
-
-    float incr = audioFrequency/44100.0f;
-    short *d = (short *)buffer;
-
-    for (unsigned int i = 0; i < frames; i++)
-    {
-        d[i] = (short)(32000.0f*sinf(2*PI*sineIdx));
-        sineIdx += incr;
-        if (sineIdx > 1.0f) sineIdx -= 1.0f;
-    }
-}
-
 //------------------------------------------------------------------------------------
 // Program main entry point
 //------------------------------------------------------------------------------------
@@ -71,8 +43,6 @@ int main(void)
     // Init raw audio stream (sample rate: 44100, sample size: 16bit-short, channels: 1-mono)
     AudioStream stream = LoadAudioStream(44100, 16, 1);
 
-    SetAudioStreamCallback(stream, AudioInputCallback);
-
     // Buffer for the single cycle waveform we are synthesizing
     short *data = (short *)malloc(sizeof(short)*MAX_SAMPLES);
 
@@ -84,7 +54,6 @@ int main(void)
     // Position read in to determine next frequency
     Vector2 mousePosition = { -100.0f, -100.0f };
 
-    /*
     // Cycles per second (hz)
     float frequency = 440.0f;
 
@@ -93,7 +62,6 @@ int main(void)
 
     // Cursor to read and copy the samples of the sine wave buffer
     int readCursor = 0;
-    */
 
     // Computed size in samples of the sine wave
     int waveLength = 1;
@@ -124,8 +92,8 @@ int main(void)
         if (frequency != oldFrequency)
         {
             // Compute wavelength. Limit size in both directions
-            //int oldWavelength = waveLength;
-            waveLength = (int)(22050/frequency);
+            int oldWavelength = waveLength;
+            waveLength = (int)(stream.sampleRate/frequency);
             if (waveLength > MAX_SAMPLES/2) waveLength = MAX_SAMPLES/2;
             if (waveLength < 1) waveLength = 1;
 
@@ -141,11 +109,10 @@ int main(void)
             }
 
             // Scale read cursor's position to minimize transition artifacts
-            //readCursor = (int)(readCursor*((float)waveLength/(float)oldWavelength));
+            readCursor = (int)(readCursor*((float)waveLength/(float)oldWavelength));
             oldFrequency = frequency;
         }
 
-        /*
         // Refill audio stream if required
         if (IsAudioStreamProcessed(stream))
         {
@@ -174,7 +141,6 @@ int main(void)
             // Copy finished frame to audio stream
             UpdateAudioStream(stream, writeBuf, MAX_SAMPLES_PER_UPDATE);
         }
-        */
         //----------------------------------------------------------------------------------
 
         // Draw

examples/audio/audio_raw_stream_callback.c

@@ -0,0 +1,255 @@
+/*******************************************************************************************
+*
+*   raylib [audio] example - raw stream
+*
+*   Example complexity rating: [★★★☆] 3/4
+*
+*   Example originally created with raylib 1.6, last time updated with raylib 6.0
+*
+*   Example created by Ramon Santamaria (@raysan5) and reviewed by James Hofmann (@triplefox)
+*
+*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
+*   BSD-like license that allows static linking with closed source software
+*
+*   Copyright (c) 2015-2025 Ramon Santamaria (@raysan5) and James Hofmann (@triplefox)
+*
+********************************************************************************************/
+
+#include "raylib.h"
+
+#include <stdlib.h>         // Required for: malloc(), free()
+#include <math.h>           // Required for: sinf()
+
+enum Flags { FLAG_CHANNEL_MONO = 1u<<0, FLAG_SAMPLESIZE_SHORT = 1u<<1 };
+static unsigned int gflags = FLAG_CHANNEL_MONO | FLAG_SAMPLESIZE_SHORT; // mono + 16-bit to match initial stream specs
+#define CHANNEL_MONO() ((gflags & FLAG_CHANNEL_MONO) != 0)
+#define SAMPLESIZE_SHORT() ((gflags & FLAG_SAMPLESIZE_SHORT) != 0)
+#define TOGGLE(K, F) do { if (IsKeyPressed(K)) { gflags ^= (F); } } while (0)
+
+#define MAX_SAMPLES               512
+#define MAX_SAMPLES_PER_UPDATE   4096
+
+// Cycles per second (hz)
+float frequency = 440.0f;
+
+// Audio frequency, for smoothing
+float audioFrequency = 440.0f;
+
+// Previous value, used to test if sine needs to be rewritten, and to smoothly modulate frequency
+float oldFrequency = 1.0f;
+
+// Index for audio rendering
+float sineIdx = 0.0f;
+
+// Audio input processing callback
+void AudioInputCallbackMonoShort(void *buffer, unsigned int frames)
+{
+    audioFrequency = frequency + (audioFrequency - frequency)*0.95f;
+
+    float incr = audioFrequency/44100.0f;
+    short *d = (short *)buffer;
+
+    for (unsigned int i = 0; i < frames; i++)
+    {
+        d[i] = (short)(32000.0f*sinf(2*PI*sineIdx));
+        sineIdx += incr;
+        if (sineIdx > 1.0f) sineIdx -= 1.0f;
+    }
+}
+
+void AudioInputCallbackStereoShort(void *buffer, unsigned int frames)
+{
+    audioFrequency = frequency + (audioFrequency - frequency)*0.95f;
+
+    float incr = audioFrequency/44100.0f;
+    short *d = (short *)buffer;
+
+    for (unsigned int i = 0; i < frames; i++)
+    {
+        short s = (short)(32000.0f*sinf(2*PI*sineIdx));
+        d[2*i + 0] = s;   // L
+        d[2*i + 1] = s;   // R
+        sineIdx += incr;
+        if (sineIdx > 1.0f) sineIdx -= 1.0f;
+    }
+}
+
+void AudioInputCallbackMonoFloat(void *buffer, unsigned int frames)
+{
+    audioFrequency = frequency + (audioFrequency - frequency)*0.95f;
+
+    float incr = audioFrequency/44100.0f;
+    float *d = (float *)buffer;
+
+    for (unsigned int i = 0; i < frames; i++)
+    {
+        d[i] = sinf(2*PI*sineIdx);
+        sineIdx += incr;
+        if (sineIdx > 1.0f) sineIdx -= 1.0f;
+    }
+}
+
+void AudioInputCallbackStereoFloat(void *buffer, unsigned int frames)
+{
+    audioFrequency = frequency + (audioFrequency - frequency)*0.95f;
+    float incr = audioFrequency/44100.0f;
+    float *d = (float *)buffer;
+    for (unsigned int i = 0; i < frames; i++)
+    {
+        float s = sinf(2*PI*sineIdx);
+        d[2*i + 0] = s;
+        d[2*i + 1] = s;
+
+        sineIdx += incr;
+        if (sineIdx > 1.0f) sineIdx -= 1.0f;
+    }
+}
+
+//------------------------------------------------------------------------------------
+// Program main entry point
+//------------------------------------------------------------------------------------
+int main(void)
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    const int screenWidth = 800;
+    const int screenHeight = 450;
+
+    InitWindow(screenWidth, screenHeight, "raylib [audio] example - raw stream with callbacks");
+
+    InitAudioDevice();              // Initialize audio device
+
+    SetAudioStreamBufferSizeDefault(MAX_SAMPLES_PER_UPDATE);
+
+    // Init raw audio stream (sample rate: 44100, sample size: 16bit-short, channels: 1-mono)
+    AudioStream stream = LoadAudioStream(44100, 16, 1);
+
+    SetAudioStreamCallback(stream, AudioInputCallbackMonoShort);
+    unsigned int previousSampleSize = stream.sampleSize;
+    unsigned int previousChannels   = stream.channels;
+
+    // Buffer for the single cycle waveform we are synthesizing
+    short *data = (short *)malloc(sizeof(short)*MAX_SAMPLES);
+
+    // Frame buffer, describing the waveform when repeated over the course of a frame
+    short *writeBuf = (short *)malloc(sizeof(short)*MAX_SAMPLES_PER_UPDATE);
+
+    PlayAudioStream(stream);        // Start processing stream buffer (no data loaded currently)
+
+    // Position read in to determine next frequency
+    Vector2 mousePosition = { -100.0f, -100.0f };
+
+    // Computed size in samples of the sine wave
+    int waveLength = 1;
+
+    Vector2 position = { 0, 0 };
+
+    SetTargetFPS(30);               // Set our game to run at 30 frames-per-second
+    //--------------------------------------------------------------------------------------
+
+    // Main game loop
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        TOGGLE(KEY_M, FLAG_CHANNEL_MONO);
+        TOGGLE(KEY_F, FLAG_SAMPLESIZE_SHORT);
+        unsigned int nextSampleSize = (SAMPLESIZE_SHORT())? 16u : 32u;
+        unsigned int nextChannels = (CHANNEL_MONO())? 1u  : 2u;
+        if (nextSampleSize != previousSampleSize || nextChannels != previousChannels)
+        {
+            StopAudioStream(stream);
+            UnloadAudioStream(stream);
+            stream = LoadAudioStream(44100, nextSampleSize, nextChannels);
+            // CORRECT ALIGNMENT
+            if (nextChannels == 1 && nextSampleSize == 16) SetAudioStreamCallback(stream, AudioInputCallbackMonoShort);
+            if (nextChannels == 2 && nextSampleSize == 16) SetAudioStreamCallback(stream, AudioInputCallbackStereoShort);
+            if (nextChannels == 1 && nextSampleSize == 32) SetAudioStreamCallback(stream, AudioInputCallbackMonoFloat);
+            if (nextChannels == 2 && nextSampleSize == 32) SetAudioStreamCallback(stream, AudioInputCallbackStereoFloat);
+
+            // INCORRECT ALIGNMENT TESTS: comment and uncomment or add your own to observe common misconfigurations
+            // if (nextChannels == 1 && nextSampleSize == 16) SetAudioStreamCallback(stream, AudioInputCallbackStereoShort);
+            // if (nextChannels == 1 && nextSampleSize == 32) SetAudioStreamCallback(stream, AudioInputCallbackMonoShort);
+            // if (nextChannels == 2 && nextSampleSize == 32) SetAudioStreamCallback(stream, AudioInputCallbackMonoShort);
+            // if (nextChannels == 2 && nextSampleSize == 16) SetAudioStreamCallback(stream, AudioInputCallbackMonoFloat);
+            // if (nextChannels == 2 && nextSampleSize == 16) SetAudioStreamCallback(stream, AudioInputCallbackStereoFloat);
+
+            PlayAudioStream(stream);
+            previousSampleSize = nextSampleSize;
+            previousChannels = nextChannels;
+        }
+        // Update
+        //----------------------------------------------------------------------------------
+        mousePosition = GetMousePosition();
+
+        if (IsMouseButtonDown(MOUSE_BUTTON_LEFT))
+        {
+            float fp = (float)(mousePosition.y);
+            frequency = 40.0f + (float)(fp);
+
+            float pan = (float)(mousePosition.x)/(float)screenWidth;
+            SetAudioStreamPan(stream, pan);
+        }
+
+        // Rewrite the sine wave
+        // Compute two cycles to allow the buffer padding, simplifying any modulation, resampling, etc.
+        if (frequency != oldFrequency)
+        {
+            // Compute wavelength. Limit size in both directions
+            waveLength = (int)(22050/frequency);
+            if (waveLength > MAX_SAMPLES/2) waveLength = MAX_SAMPLES/2;
+            if (waveLength < 1) waveLength = 1;
+
+            // Write sine wave
+            for (int i = 0; i < waveLength*2; i++)
+            {
+                data[i] = (short)(sinf(((2*PI*(float)i/waveLength)))*32000);
+            }
+            // Make sure the rest of the line is flat
+            for (int j = waveLength*2; j < MAX_SAMPLES; j++)
+            {
+                data[j] = (short)0;
+            }
+
+            oldFrequency = frequency;
+        }
+
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+            ClearBackground(RAYWHITE);
+
+            DrawText(TextFormat("sine frequency: %i",(int)frequency), GetScreenWidth() - 220, 10, 20, RED);
+            DrawText("click mouse button to change frequency or pan", 10, 10, 20, DARKGRAY);
+            DrawText("press M to SWAP channels [ M ]:", 250, 366, 20, BLUE);
+            DrawText((CHANNEL_MONO())? "MONO" : "STEREO", 600, 366, 20, (CHANNEL_MONO())? GREEN : RED);
+            DrawText("press F to SWAP Sample Size [ F ]:", 250, 400, 20, BLUE);
+            DrawText((SAMPLESIZE_SHORT())? "16" : "32", 620, 400, 20, (SAMPLESIZE_SHORT())? GREEN : RED);
+
+            // Draw the current buffer state proportionate to the screen
+            for (int i = 0; i < screenWidth; i++)
+            {
+                position.x = (float)i;
+                position.y = 250 + 50*data[i*MAX_SAMPLES/screenWidth]/32000.0f;
+
+                DrawPixelV(position, RED);
+            }
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+    free(data);                 // Unload sine wave data
+    free(writeBuf);             // Unload write buffer
+
+    UnloadAudioStream(stream);   // Close raw audio stream and delete buffers from RAM
+    CloseAudioDevice();         // Close audio device (music streaming is automatically stopped)
+
+    CloseWindow();              // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}