Pass output options to avio_open2()

Author: ANDYwyLEE

CHANGELOG.rst

@@ -35,6 +35,7 @@ v19.1.0 (Unreleased)
 Fixes:
 
 - Audio encoding now correctly passes the codec's ``thread_count`` to its internal :class:`.AudioResampler`, which takes a new ``threads`` argument, as video encoding does for its reformatter. Audio codecs without threading (e.g. MP3) resolve ``thread_count`` to ``1``, but the resampler ignored it and started an idle thread per CPU. By :gh-user:`tonyay163`.
+- Output containers now pass their options to ``avio_open2()`` before ``avformat_write_header()``, as the ``ffmpeg`` program does, so protocol options (``rtmp_flush_interval``, ``rw_timeout``, ``tcp_nodelay``, SRT's ``latency``, HTTP ``headers``, ...) reach the protocol instead of being reported as unused. By :gh-user:`ANDYwyLEE`.
 
 
 v19.0.1

av/container/output.py

@@ -630,6 +630,9 @@ def start_encoding(self):
         self.start_timeout()
         self._blocking_depth += 1
         try:
+            all_options = Dictionary(self.options, self.container_options)
+            options = all_options.copy()
+            options_ptr = cython.address(options.ptr)
             if (
                 self.ptr.pb == cython.NULL
                 and not self.ptr.oformat.flags & lib.AVFMT_NOFILE
@@ -642,17 +645,14 @@ def start_encoding(self):
                         name,
                         lib.AVIO_FLAG_WRITE,
                         cython.address(self.ptr.interrupt_callback),
-                        cython.NULL,
+                        options_ptr,
                     )
                 err_check(ret)
                 opened_pb = True
 
             # Copy the metadata dict.
             dict_to_avdict(cython.address(self.ptr.metadata), self.metadata)
 
-            all_options = Dictionary(self.options, self.container_options)
-            options = all_options.copy()
-            options_ptr = cython.address(options.ptr)
             with cython.nogil:
                 ret = lib.avformat_write_header(self.ptr, options_ptr)
             try: