AVFormat property start_time_realtime available in input container.

av/__main__.py

@@ -2,7 +2,6 @@
 
 
 def main():
-
     parser = argparse.ArgumentParser()
     parser.add_argument("--codecs", action="store_true")
     parser.add_argument("--version", action="store_true")
@@ -11,7 +10,6 @@ def main():
     # ---
 
     if args.version:
-
         import av
         import av._core
 

av/container/input.pyx

@@ -93,6 +93,18 @@ cdef class InputContainer(Container):
             if self.ptr.start_time != lib.AV_NOPTS_VALUE:
                 return self.ptr.start_time
 
+    property start_time_realtime:
+        """
+        Start time of the RTSP stream, expressed as microseconds since the UNIX epoch.
+
+        This property might not be set by FFmpeg for the first packets.
+
+        :type: int
+        """
+        def __get__(self):
+            if self.ptr.start_time_realtime != lib.AV_NOPTS_VALUE:
+                return self.ptr.start_time_realtime
+
     property duration:
         def __get__(self):
             if self.ptr.duration != lib.AV_NOPTS_VALUE:

av/datasets.py

@@ -9,7 +9,6 @@
 
 
 def iter_data_dirs(check_writable=False):
-
     try:
         yield os.environ["PYAV_TESTDATA_DIR"]
     except KeyError:
@@ -45,7 +44,6 @@ def iter_data_dirs(check_writable=False):
 
 
 def cached_download(url, name):
-
     """Download the data at a URL, and cache it under the given name.
 
     The file is stored under `pyav/test` with the given name in the directory

include/libavformat/avformat.pxd

@@ -184,6 +184,7 @@ cdef extern from "libavformat/avformat.h" nogil:
 
         int flags
         int64_t max_analyze_duration
+        int64_t start_time_realtime
 
         void *opaque
 

tests/test_rtspstarttimerealtime.py

@@ -0,0 +1,28 @@
+import av
+
+from .common import TestCase
+
+
+# RTSP stream server, thanks https://github.com/rtspstream
+RTSP_STREAM = "rtsp://rtsp.stream/pattern"
+UNIX_TIMESTAMP_2022_01_01_00_00 = 1640995200000000  # microseconds
+
+
+class TestRTSPStartTimeRealtime(TestCase):
+    def test_rtsp_start_time_realtime(self):
+        stream_options = {
+            'rtsp_transport': 'tcp',  # preferred stable connection
+            'stimeout': '5000000'  # socket timeout to 5s (default is unlimited)
+        }
+        with av.open(RTSP_STREAM, mode="r", options=stream_options) as container:
+            # wait for proper value set by RTSP in libavformat
+            while container.demux(container.streams.video[0]):
+                # it is okay to have None type at first dozens packets
+                if container.start_time_realtime is None:
+                    continue
+                # Now value is ready, check this and go outside loop
+                else:
+                    self.assertIsInstance(container.start_time_realtime, int)
+                    break
+
+            self.assertGreater(container.start_time_realtime, UNIX_TIMESTAMP_2022_01_01_00_00)