Desktop Test for M4A

Author: pschatzmann

src/AudioTools/AudioCodecs/ContainerM4A.h

@@ -291,8 +291,8 @@ class ContainerM4A : public ContainerDecoder {
     if (header_pos == 8) {
       // Header complete
       header_pos = 0;
-      LOGI("Found box: %s, size: %u, offset: %llu", current_box.type,
-           current_box.size, current_box.absolute_offset);
+      LOGI("Found box: %s, size: %u, offset: %u", current_box.type,
+           current_box.size, (unsigned) current_box.absolute_offset);
 
       // Handle special box sizes
       if (current_box.size == 1) {
@@ -451,7 +451,7 @@ class ContainerM4A : public ContainerDecoder {
     is_alac = true;
     result_codec_type = M4ACodecType::ALAC;
 
-    LOGI("Found ALAC config, size: %d", alac_config_size);
+    LOGI("Found ALAC config, size: %u",(unsigned) alac_config_size);
 
     // Extract basic audio parameters from config
     uint32_t frameLength = readUint32(alac_config, 0);

tests-cmake/codec/m4a/CMakeLists.txt

@@ -0,0 +1,51 @@
+cmake_minimum_required(VERSION 3.20)
+
+# set the project name
+project(m4a)
+set (CMAKE_CXX_STANDARD 11)
+set (DCMAKE_CXX_FLAGS "-Werror")
+
+include(FetchContent)
+option(BUILD_SHARED_LIBS "Build using shared libraries" OFF)
+
+# Build with alac
+FetchContent_Declare(codec-alac GIT_REPOSITORY "https://github.com/pschatzmann/codec-alac.git" GIT_TAG main )
+FetchContent_GetProperties(codec-alac)
+if(NOT codec-alac_POPULATED)
+    FetchContent_Populate(codec-alac)
+    add_subdirectory(${codec-alac_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR}/codec-alac)
+endif()
+
+# Build with libhelix
+FetchContent_Declare(helix GIT_REPOSITORY "https://github.com/pschatzmann/arduino-libhelix.git" GIT_TAG main )
+FetchContent_GetProperties(helix)
+if(NOT helix_POPULATED)
+    FetchContent_Populate(helix)
+    add_subdirectory(${helix_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR}/helix)
+endif()
+
+
+# provide audio-tools
+if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+    add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/../../.. ${CMAKE_CURRENT_BINARY_DIR}/arduino-audio-tools )
+endif()
+
+# build sketch as executable
+set_source_files_properties(m4a.ino PROPERTIES LANGUAGE CXX)
+add_executable (m4a m4a.ino)
+
+# set preprocessor defines
+target_compile_definitions(arduino_emulator PUBLIC -DDEFINE_MAIN)
+target_compile_definitions(m4a PUBLIC -DARDUINO -DIS_DESKTOP)
+target_compile_options(m4a PRIVATE -Wno-multichar)
+
+
+# set compile optioins
+target_compile_options(arduino-audio-tools INTERFACE -Wno-inconsistent-missing-override)
+
+# specify libraries
+target_link_libraries(m4a PRIVATE 
+    codec-alac
+    arduino_emulator 
+    arduino_helix 
+    arduino-audio-tools)

tests-cmake/codec/m4a/m4a.ino

@@ -0,0 +1,63 @@
+/**
+ * @file test-codec-alac.ino
+ * @author Phil Schatzmann
+ * @brief generate sine wave -> encoder -> decoder -> audiokit (i2s)
+ * @version 0.1
+ * 
+ * @copyright Copyright (c) 2025
+ * 
+ */
+#include "AudioTools.h"
+#include "AudioTools/AudioCodecs/CodecALAC.h"
+#include "AudioTools/AudioCodecs/CodecAACHelix.h"
+#include "AudioTools/AudioCodecs/ContainerM4A.h"
+#include "AudioTools/AudioCodecs/MultiDecoder.h"
+#include "SD.h"
+
+MultiDecoder multi_decoder;
+ContainerM4A dec_m4a(multi_decoder);
+AACDecoderHelix dec_aac;
+DecoderALAC dec_alac;
+CsvOutput<int16_t> out(Serial);
+EncodedAudioOutput decoder_output(&out, &dec_m4a); 
+File file;
+StreamCopy copier(decoder_output, file);     
+
+void setup() {
+  Serial.begin(115200);
+  AudioToolsLogger.begin(Serial, AudioToolsLogLevel::Debug);
+
+  if (!SD.begin()){
+    Serial.println("SD Card initialization failed!");
+    return;
+  }
+
+  file = SD.open("/home/pschatzmann/Music/m4a/sample-1.m4a");
+  if (!file.isOpen()) {
+    Serial.println("Failed to open file!");
+    return;
+  }
+
+  // mp4 supports alac and aac
+  multi_decoder.addDecoder(dec_alac,"audio/alac"); 
+  multi_decoder.addDecoder(dec_aac,"audio/aac"); 
+
+  // start decoder output
+  if(!decoder_output.begin()) {
+    Serial.println("Failed to start decoder output!");
+    return;
+  }
+
+  // start csv output
+  if (!out.begin()){
+    Serial.println("Failed to start CSV output!");
+    return;
+  }
+
+  Serial.println("M4A decoding started...");
+}
+
+
+void loop() { 
+  copier.copy();
+}