AUDIO: Create the audio context and its streams

src/Audio.cc

@@ -2,6 +2,41 @@
 
 using namespace Vivy;
 
+// AudioContext class implementation
+
+// Create an audio contecxt from a file
+AudioContext::AudioContext(const QString &path)
+    : filePath(path)
+{
+    if (!format)
+        throw std::runtime_error("out of memory, can't create allocate the AVFormatContext");
+
+    const std::string filePathStdHolder = filePath.toStdString();
+    const char *filename                = filePathStdHolder.c_str();
+    AVFormatContext *formatPtr          = format.get();
+
+    // Get the format from the audio file
+    if (avformat_open_input(&formatPtr, filename, NULL, NULL) != 0) {
+        [[maybe_unused]] void *relatedOnFailure = format.release(); // freed by avformat_open_input
+        throw std::runtime_error("failed to open file");
+    }
+
+    if (avformat_find_stream_info(formatPtr, NULL) < 0) {
+        throw std::runtime_error("failed to get audio stream info");
+    }
+
+    // Populate all the stream indexes
+    for (uint i = 0; i < format->nb_streams; ++i) {
+        AVStream *itFormat        = format->streams[i];
+        AVCodecParameters *params = itFormat->codecpar;
+        AVCodec *streamCodec      = avcodec_find_decoder(params->codec_id);
+        if (streamCodec && streamCodec->type == AVMEDIA_TYPE_AUDIO) {
+            audioStreamIndexes.push_back(i);
+            audioCodecs.insert(i, std::make_shared<Stream>(formatPtr, itFormat));
+        }
+    }
+}
+
 // AudioContext::Stream class implementation
 
 // Constructor, need an AVFormat and an AVStream

src/Audio.hh

@@ -113,7 +113,7 @@ public:
 
 public:
     AudioContext(const QString &path);
-    ~AudioContext() noexcept;
+    ~AudioContext() noexcept = default;
 
     int getStreamCount() const noexcept;
     StreamWeakPtr getStream(int) const noexcept;
@@ -126,7 +126,7 @@ private:
             avformat_free_context(ptr);
     };
     using AVFormatContextPtr = std::unique_ptr<AVFormatContext, decltype(avFormatContextDeleter)>;
-    AVFormatContextPtr format{ nullptr };
+    AVFormatContextPtr format{ avformat_alloc_context() };
 
     /* Usefull information */
     QString filePath;