Make exception args tuple; refactor visiblity of context stuff

Author: scotts

src/torchcodec/decoders/_core/AVIOContextHolder.h

@@ -10,10 +10,6 @@
 
 namespace facebook::torchcodec {
 
-// These signatures are defined by FFmpeg.
-using AVIOReadFunction = int (*)(void*, uint8_t*, int);
-using AVIOSeekFunction = int64_t (*)(void*, int64_t, int);
-
 // The AVIOContextHolder serves several purposes:
 //
 //   1. It is a smart pointer for the AVIOContext. It has the logic to create
@@ -33,7 +29,7 @@ using AVIOSeekFunction = int64_t (*)(void*, int64_t, int);
 //           write callback functions.
 //      While it's not required, it is natural for the derived classes to make
 //      all of the above members. Base classes need to call
-//      createAVIOContext(), ideally in there constructor.
+//      createAVIOContext(), ideally in their constructor.
 //  3. A generic handle for those that just need to manage having access to an
 //     AVIOContext, but aren't necessarily concerned with how it was customized.
 class AVIOContextHolder {
@@ -47,6 +43,10 @@ class AVIOContextHolder {
   // enforced by having a pure virtual methods, but we don't have any.)
   AVIOContextHolder() = default;
 
+  // These signatures are defined by FFmpeg.
+  using AVIOReadFunction = int (*)(void*, uint8_t*, int);
+  using AVIOSeekFunction = int64_t (*)(void*, int64_t, int);
+
   // Deriving classes should call this function in their constructor.
   void createAVIOContext(
       AVIOReadFunction read,

src/torchcodec/decoders/_core/AVIOFileLikeContext.h

@@ -15,18 +15,6 @@ namespace py = pybind11;
 
 namespace facebook::torchcodec {
 
-// Necessary to make sure that we hold the GIL when we delete a py::object.
-struct PyObjectDeleter {
-  inline void operator()(py::object* obj) const {
-    if (obj) {
-      py::gil_scoped_acquire gil;
-      delete obj;
-    }
-  }
-};
-
-using UniquePyObject = std::unique_ptr<py::object, PyObjectDeleter>;
-
 class AVIOFileLikeContext : public AVIOContextHolder {
  public:
   explicit AVIOFileLikeContext(py::object fileLike);
@@ -43,6 +31,16 @@ class AVIOFileLikeContext : public AVIOContextHolder {
   // and that's, at least, hard. For all of the common pitfalls, see:
   //
   //   https://pybind11.readthedocs.io/en/stable/advanced/misc.html#common-sources-of-global-interpreter-lock-errors
+  struct PyObjectDeleter {
+    inline void operator()(py::object* obj) const {
+      if (obj) {
+        py::gil_scoped_acquire gil;
+        delete obj;
+      }
+    }
+  };
+
+  using UniquePyObject = std::unique_ptr<py::object, PyObjectDeleter>;
   UniquePyObject fileLike_;
 };
 

src/torchcodec/decoders/_core/ops.py

@@ -54,7 +54,7 @@ def load_torchcodec_extension():
         except Exception as e:
             # TODO: recording and reporting exceptions this way is OK for now as  it's just for debugging,
             # but we should probably handle that via a proper logging mechanism.
-            exceptions.append(ffmpeg_major_version, e)
+            exceptions.append((ffmpeg_major_version, e))
 
     traceback = (
         "\n[start of libtorchcodec loading traceback]\n"