fix(macos): fix broken streaming on MacOS (#2485)

src/platform/macos/av_img_t.h

@@ -11,42 +11,56 @@
 
 namespace platf {
   struct av_sample_buf_t {
+    CMSampleBufferRef buf;
+
     explicit av_sample_buf_t(CMSampleBufferRef buf):
         buf((CMSampleBufferRef) CFRetain(buf)) {}
 
     ~av_sample_buf_t() {
-      CFRelease(buf);
+      if (buf != nullptr) {
+        CFRelease(buf);
+      }
     }
-
-    CMSampleBufferRef buf;
   };
 
   struct av_pixel_buf_t {
-    explicit av_pixel_buf_t(CVPixelBufferRef buf):
-        buf((CVPixelBufferRef) CFRetain(buf)),
-        locked(false) {}
+    CVPixelBufferRef buf;
+
+    // Constructor
+    explicit av_pixel_buf_t(CMSampleBufferRef sb):
+        buf(
+          CMSampleBufferGetImageBuffer(sb)) {
+      CVPixelBufferLockBaseAddress(buf, kCVPixelBufferLock_ReadOnly);
+    }
 
     [[nodiscard]] uint8_t *
-    lock() const {
-      if (!locked) {
-        CVPixelBufferLockBaseAddress(buf, kCVPixelBufferLock_ReadOnly);
-      }
-      return (uint8_t *) CVPixelBufferGetBaseAddress(buf);
+    data() const {
+      return static_cast<uint8_t *>(CVPixelBufferGetBaseAddress(buf));
     }
 
+    // Destructor
     ~av_pixel_buf_t() {
-      if (locked) {
+      if (buf != nullptr) {
         CVPixelBufferUnlockBaseAddress(buf, kCVPixelBufferLock_ReadOnly);
       }
-      CFRelease(buf);
     }
-
-    CVPixelBufferRef buf;
-    bool locked;
   };
 
-  struct av_img_t: public img_t {
+  struct av_img_t: img_t {
     std::shared_ptr<av_sample_buf_t> sample_buffer;
     std::shared_ptr<av_pixel_buf_t> pixel_buffer;
   };
+
+  struct temp_retain_av_img_t {
+    std::shared_ptr<av_sample_buf_t> sample_buffer;
+    std::shared_ptr<av_pixel_buf_t> pixel_buffer;
+    uint8_t *data;
+
+    temp_retain_av_img_t(
+      std::shared_ptr<av_sample_buf_t> sb,
+      std::shared_ptr<av_pixel_buf_t> pb,
+      uint8_t *dt):
+        sample_buffer(std::move(sb)),
+        pixel_buffer(std::move(pb)), data(dt) {}
+  };
 }  // namespace platf