[utils] Popen: Refactor to use contextmanager

Fixes https://github.com/yt-dlp/yt-dlp/issues/3531#issuecomment-1156223597

yt_dlp/downloader/external.py

@@ -34,6 +34,7 @@ class Features(enum.Enum):
 class ExternalFD(FragmentFD):
     SUPPORTED_PROTOCOLS = ('http', 'https', 'ftp', 'ftps')
     SUPPORTED_FEATURES = ()
+    _CAPTURE_STDERR = True
 
     def real_download(self, filename, info_dict):
         self.report_destination(filename)
@@ -128,24 +129,25 @@ class ExternalFD(FragmentFD):
         self._debug_cmd(cmd)
 
         if 'fragments' not in info_dict:
-            p = Popen(cmd, stderr=subprocess.PIPE)
-            _, stderr = p.communicate_or_kill()
-            if p.returncode != 0:
-                self.to_stderr(stderr.decode('utf-8', 'replace'))
-            return p.returncode
+            _, stderr, returncode = Popen.run(
+                cmd, text=True, stderr=subprocess.PIPE if self._CAPTURE_STDERR else None)
+            if returncode and stderr:
+                self.to_stderr(stderr)
+            return returncode
 
         fragment_retries = self.params.get('fragment_retries', 0)
         skip_unavailable_fragments = self.params.get('skip_unavailable_fragments', True)
 
         count = 0
         while count <= fragment_retries:
-            p = Popen(cmd, stderr=subprocess.PIPE)
-            _, stderr = p.communicate_or_kill()
-            if p.returncode == 0:
+            _, stderr, returncode = Popen.run(cmd, text=True, stderr=subprocess.PIPE)
+            if not returncode:
                 break
+
             # TODO: Decide whether to retry based on error code
             # https://aria2.github.io/manual/en/html/aria2c.html#exit-status
-            self.to_stderr(stderr.decode('utf-8', 'replace'))
+            if stderr:
+                self.to_stderr(stderr)
             count += 1
             if count <= fragment_retries:
                 self.to_screen(
@@ -180,6 +182,7 @@ class ExternalFD(FragmentFD):
 
 class CurlFD(ExternalFD):
     AVAILABLE_OPT = '-V'
+    _CAPTURE_STDERR = False  # curl writes the progress to stderr
 
     def _make_cmd(self, tmpfilename, info_dict):
         cmd = [self.exe, '--location', '-o', tmpfilename, '--compressed']
@@ -204,16 +207,6 @@ class CurlFD(ExternalFD):
         cmd += ['--', info_dict['url']]
         return cmd
 
-    def _call_downloader(self, tmpfilename, info_dict):
-        cmd = [encodeArgument(a) for a in self._make_cmd(tmpfilename, info_dict)]
-
-        self._debug_cmd(cmd)
-
-        # curl writes the progress to stderr so don't capture it.
-        p = Popen(cmd)
-        p.communicate_or_kill()
-        return p.returncode
-
 
 class AxelFD(ExternalFD):
     AVAILABLE_OPT = '-V'
@@ -500,24 +493,23 @@ class FFmpegFD(ExternalFD):
         args.append(encodeFilename(ffpp._ffmpeg_filename_argument(tmpfilename), True))
         self._debug_cmd(args)
 
-        proc = Popen(args, stdin=subprocess.PIPE, env=env)
-        if url in ('-', 'pipe:'):
-            self.on_process_started(proc, proc.stdin)
-        try:
-            retval = proc.wait()
-        except BaseException as e:
-            # subprocces.run would send the SIGKILL signal to ffmpeg and the
-            # mp4 file couldn't be played, but if we ask ffmpeg to quit it
-            # produces a file that is playable (this is mostly useful for live
-            # streams). Note that Windows is not affected and produces playable
-            # files (see https://github.com/ytdl-org/youtube-dl/issues/8300).
-            if isinstance(e, KeyboardInterrupt) and sys.platform != 'win32' and url not in ('-', 'pipe:'):
-                proc.communicate_or_kill(b'q')
-            else:
-                proc.kill()
-                proc.wait()
-            raise
-        return retval
+        with Popen(args, stdin=subprocess.PIPE, env=env) as proc:
+            if url in ('-', 'pipe:'):
+                self.on_process_started(proc, proc.stdin)
+            try:
+                retval = proc.wait()
+            except BaseException as e:
+                # subprocces.run would send the SIGKILL signal to ffmpeg and the
+                # mp4 file couldn't be played, but if we ask ffmpeg to quit it
+                # produces a file that is playable (this is mostly useful for live
+                # streams). Note that Windows is not affected and produces playable
+                # files (see https://github.com/ytdl-org/youtube-dl/issues/8300).
+                if isinstance(e, KeyboardInterrupt) and sys.platform != 'win32' and url not in ('-', 'pipe:'):
+                    proc.communicate_or_kill(b'q')
+                else:
+                    proc.kill(timeout=None)
+                raise
+            return retval
 
 
 class AVconvFD(FFmpegFD):