updated output-capture for JSON parsing

MkvOpusEnc.py

@@ -108,11 +108,14 @@ def convert_audio_track(stream_index, channels, temp_dir, source_file, should_do
     
     # Read stderr and print progress updates. The Tee class now handles '\r' correctly.
     stderr_output = ""
-    for line in iter(process.stderr.readline, ''):
+    with process.stderr as pipe:
+        for line in iter(pipe.readline, ''):
             stderr_output += line # Buffer the full output for parsing
             # Print the line to stdout, clearing the line and using a carriage return.
             # This will be handled by the Tee class.
             sys.stdout.write(line.strip() + '\x1B[K\r')
+        # After the loop, read any remaining data (the JSON block)
+        stderr_output += pipe.read()
     
     process.wait() # Wait for the process to terminate
     if process.returncode != 0: