[external/FFmpeg] Fix and improve --ffmpeg-location handling

* pass YoutubeDL (FileDownloader) to FFmpegPostProcessor constructor
* consolidate path search in FFmpegPostProcessor
* make availability of FFmpegFD depend on existence of FFmpegPostProcessor
* detect ffmpeg executable on instantiation of FFmpegFD
* resolves #32735

test/test_downloader_external.py

@@ -18,6 +18,7 @@ from test.helper import (
 )
 from youtube_dl import YoutubeDL
 from youtube_dl.compat import (
+    compat_contextlib_suppress,
     compat_http_cookiejar_Cookie,
     compat_http_server,
     compat_kwargs,
@@ -35,6 +36,9 @@ from youtube_dl.downloader.external import (
     HttpieFD,
     WgetFD,
 )
+from youtube_dl.postprocessor import (
+    FFmpegPostProcessor,
+)
 import threading
 
 TEST_SIZE = 10 * 1024
@@ -227,7 +231,17 @@ class TestAria2cFD(unittest.TestCase):
             self.assertIn('--load-cookies=%s' % downloader._cookies_tempfile, cmd)
 
 
-@ifExternalFDAvailable(FFmpegFD)
+# Handle delegated availability
+def ifFFmpegFDAvailable(externalFD):
+    # raise SkipTest, or set False!
+    avail = ifExternalFDAvailable(externalFD) and False
+    with compat_contextlib_suppress(Exception):
+        avail = FFmpegPostProcessor(downloader=None).available
+    return unittest.skipUnless(
+        avail, externalFD.get_basename() + ' not found')
+
+
+@ifFFmpegFDAvailable(FFmpegFD)
 class TestFFmpegFD(unittest.TestCase):
     _args = []
 

youtube_dl/compat.py

@@ -2421,29 +2421,26 @@ except ImportError:  # Python 2
 compat_urllib_request_urlretrieve = compat_urlretrieve
 
 try:
+    from HTMLParser import (
+        HTMLParser as compat_HTMLParser,
+        HTMLParseError as compat_HTMLParseError)
+except ImportError:  # Python 3
     from html.parser import HTMLParser as compat_HTMLParser
-except ImportError:  # Python 2
-    from HTMLParser import HTMLParser as compat_HTMLParser
-compat_html_parser_HTMLParser = compat_HTMLParser
-
-try:  # Python 2
-    from HTMLParser import HTMLParseError as compat_HTMLParseError
-except ImportError:  # Python <3.4
     try:
         from html.parser import HTMLParseError as compat_HTMLParseError
     except ImportError:  # Python >3.4
-
-        # HTMLParseError has been deprecated in Python 3.3 and removed in
+        # HTMLParseError was deprecated in Python 3.3 and removed in
         # Python 3.5. Introducing dummy exception for Python >3.5 for compatible
         # and uniform cross-version exception handling
         class compat_HTMLParseError(Exception):
             pass
+compat_html_parser_HTMLParser = compat_HTMLParser
 compat_html_parser_HTMLParseError = compat_HTMLParseError
 
 try:
-    from subprocess import DEVNULL
-    compat_subprocess_get_DEVNULL = lambda: DEVNULL
-except ImportError:
+    _DEVNULL = subprocess.DEVNULL
+    compat_subprocess_get_DEVNULL = lambda: _DEVNULL
+except AttributeError:
     compat_subprocess_get_DEVNULL = lambda: open(os.path.devnull, 'w')
 
 try:
@@ -2943,6 +2940,51 @@ else:
     compat_socket_create_connection = socket.create_connection
 
 
+try:
+    from contextlib import suppress as compat_contextlib_suppress
+except ImportError:
+    class compat_contextlib_suppress(object):
+        _exceptions = None
+
+        def __init__(self, *exceptions):
+            super(compat_contextlib_suppress, self).__init__()
+            # TODO: [Base]ExceptionGroup (3.12+)
+            self._exceptions = exceptions
+
+        def __enter__(self):
+            return self
+
+        def __exit__(self, exc_type, exc_val, exc_tb):
+            return exc_val is not None and isinstance(exc_val, self._exceptions or tuple())
+
+
+# subprocess.Popen context manager
+# avoids leaking handles if .communicate() is not called
+try:
+    _Popen = subprocess.Popen
+    # check for required context manager attributes
+    _Popen.__enter__ and _Popen.__exit__
+    compat_subprocess_Popen = _Popen
+except AttributeError:
+    # not a context manager - make one
+    from contextlib import contextmanager
+
+    @contextmanager
+    def compat_subprocess_Popen(*args, **kwargs):
+        popen = None
+        try:
+            popen = _Popen(*args, **kwargs)
+            yield popen
+        finally:
+            if popen:
+                for f in (popen.stdin, popen.stdout, popen.stderr):
+                    if f:
+                        # repeated .close() is OK, but just in case
+                        with compat_contextlib_suppress(EnvironmentError):
+                            f.close()
+                popen.wait()
+
+
 # Fix https://github.com/ytdl-org/youtube-dl/issues/4223
 # See http://bugs.python.org/issue9161 for what is broken
 def workaround_optparse_bug9161():
@@ -3263,6 +3305,7 @@ __all__ = [
     'compat_http_cookiejar_Cookie',
     'compat_http_cookies',
     'compat_http_cookies_SimpleCookie',
+    'compat_contextlib_suppress',
     'compat_ctypes_WINFUNCTYPE',
     'compat_etree_fromstring',
     'compat_filter',
@@ -3298,6 +3341,7 @@ __all__ = [
     'compat_struct_pack',
     'compat_struct_unpack',
     'compat_subprocess_get_DEVNULL',
+    'compat_subprocess_Popen',
     'compat_tokenize_tokenize',
     'compat_urllib_error',
     'compat_urllib_parse',

youtube_dl/downloader/external.py

@@ -11,8 +11,14 @@ from .common import FileDownloader
 from ..compat import (
     compat_setenv,
     compat_str,
+    compat_subprocess_Popen,
 )
-from ..postprocessor.ffmpeg import FFmpegPostProcessor, EXT_TO_OUT_FORMATS
+
+try:
+    from ..postprocessor.ffmpeg import FFmpegPostProcessor, EXT_TO_OUT_FORMATS
+except ImportError:
+    FFmpegPostProcessor = None
+
 from ..utils import (
     cli_option,
     cli_valueless_option,
@@ -361,13 +367,14 @@ class FFmpegFD(ExternalFD):
 
     @classmethod
     def available(cls):
-        return FFmpegPostProcessor().available
+        # actual availability can only be confirmed for an instance
+        return bool(FFmpegPostProcessor)
 
     def _call_downloader(self, tmpfilename, info_dict):
-        url = info_dict['url']
-        ffpp = FFmpegPostProcessor(downloader=self)
+        # `downloader` means the parent `YoutubeDL`
+        ffpp = FFmpegPostProcessor(downloader=self.ydl)
         if not ffpp.available:
-            self.report_error('m3u8 download detected but ffmpeg or avconv could not be found. Please install one.')
+            self.report_error('ffmpeg required for download but no ffmpeg (nor avconv) executable could be found. Please install one.')
             return False
         ffpp.check_version()
 
@@ -396,6 +403,7 @@ class FFmpegFD(ExternalFD):
         # if end_time:
         #     args += ['-t', compat_str(end_time - start_time)]
 
+        url = info_dict['url']
         cookies = self.ydl.cookiejar.get_cookies_for_url(url)
         if cookies:
             args.extend(['-cookies', ''.join(
@@ -483,21 +491,25 @@ class FFmpegFD(ExternalFD):
 
         self._debug_cmd(args)
 
-        proc = subprocess.Popen(args, stdin=subprocess.PIPE, env=env)
-        try:
-            retval = proc.wait()
-        except BaseException as e:
-            # subprocess.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':
-                process_communicate_or_kill(proc, b'q')
-            else:
-                proc.kill()
-                proc.wait()
-            raise
+        # From [1], a PIPE opened in Popen() should be closed, unless
+        # .communicate() is called. Avoid leaking any PIPEs by using Popen
+        # as a context manager (newer Python 3.x and compat)
+        # Fixes "Resource Warning" in test/test_downloader_external.py
+        # [1] https://devpress.csdn.net/python/62fde12d7e66823466192e48.html
+        with compat_subprocess_Popen(args, stdin=subprocess.PIPE, env=env) as proc:
+            try:
+                retval = proc.wait()
+            except BaseException as e:
+                # subprocess.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':
+                    process_communicate_or_kill(proc, b'q')
+                else:
+                    proc.kill()
+                raise
         return retval
 
 

youtube_dl/postprocessor/ffmpeg.py

@@ -96,6 +96,7 @@ class FFmpegPostProcessor(PostProcessor):
 
         self._paths = None
         self._versions = None
+        location = None
         if self._downloader:
             prefer_ffmpeg = self._downloader.params.get('prefer_ffmpeg', True)
             location = self._downloader.params.get('ffmpeg_location')
@@ -118,32 +119,17 @@ class FFmpegPostProcessor(PostProcessor):
                     location = os.path.dirname(os.path.abspath(location))
                     if basename in ('ffmpeg', 'ffprobe'):
                         prefer_ffmpeg = True
+        self._paths = dict(
+            (p, p if location is None else os.path.join(location, p))
+            for p in programs)
+        self._versions = dict(
+            x for x in (
+                (p, get_ffmpeg_version(self._paths[p])) for p in programs)
+            if x[1] is not None)
 
-                self._paths = dict(
-                    (p, os.path.join(location, p)) for p in programs)
-                self._versions = dict(
-                    (p, get_ffmpeg_version(self._paths[p])) for p in programs)
-        if self._versions is None:
-            self._versions = dict(
-                (p, get_ffmpeg_version(p)) for p in programs)
-            self._paths = dict((p, p) for p in programs)
-
-        if prefer_ffmpeg is False:
-            prefs = ('avconv', 'ffmpeg')
-        else:
-            prefs = ('ffmpeg', 'avconv')
-        for p in prefs:
-            if self._versions[p]:
-                self.basename = p
-                break
-
-        if prefer_ffmpeg is False:
-            prefs = ('avprobe', 'ffprobe')
-        else:
-            prefs = ('ffprobe', 'avprobe')
-        for p in prefs:
-            if self._versions[p]:
-                self.probe_basename = p
+        for p in ('ffmpeg', 'avconv')[::-1 if prefer_ffmpeg is False else 1]:
+            if self._versions.get(p):
+                self.basename = self.probe_basename = p
                 break
 
     @property

youtube_dl/utils.py

@@ -45,6 +45,7 @@ from .compat import (
     compat_casefold,
     compat_chr,
     compat_collections_abc,
+    compat_contextlib_suppress,
     compat_cookiejar,
     compat_ctypes_WINFUNCTYPE,
     compat_datetime_timedelta_total_seconds,
@@ -1855,25 +1856,18 @@ def write_json_file(obj, fn):
     try:
         with tf:
             json.dump(obj, tf)
-        if sys.platform == 'win32':
-            # Need to remove existing file on Windows, else os.rename raises
-            # WindowsError or FileExistsError.
-            try:
+        with compat_contextlib_suppress(OSError):
+            if sys.platform == 'win32':
+                # Need to remove existing file on Windows, else os.rename raises
+                # WindowsError or FileExistsError.
                 os.unlink(fn)
-            except OSError:
-                pass
-        try:
             mask = os.umask(0)
             os.umask(mask)
             os.chmod(tf.name, 0o666 & ~mask)
-        except OSError:
-            pass
         os.rename(tf.name, fn)
     except Exception:
-        try:
+        with compat_contextlib_suppress(OSError):
             os.remove(tf.name)
-        except OSError:
-            pass
         raise
 
 
@@ -2033,14 +2027,13 @@ def extract_attributes(html_element):
     NB HTMLParser is stricter in Python 2.6 & 3.2 than in later versions,
     but the cases in the unit test will work for all of 2.6, 2.7, 3.2-3.5.
     """
-    parser = HTMLAttributeParser()
-    try:
-        parser.feed(html_element)
-        parser.close()
-    # Older Python may throw HTMLParseError in case of malformed HTML
-    except compat_HTMLParseError:
-        pass
-    return parser.attrs
+    ret = None
+    # Older Python may throw HTMLParseError in case of malformed HTML (and on .close()!)
+    with compat_contextlib_suppress(compat_HTMLParseError):
+        with contextlib.closing(HTMLAttributeParser()) as parser:
+            parser.feed(html_element)
+            ret = parser.attrs
+    return ret or {}
 
 
 def clean_html(html):
@@ -2241,7 +2234,8 @@ def _htmlentity_transform(entity_with_semicolon):
             numstr = '0%s' % numstr
         else:
             base = 10
-        # See https://github.com/ytdl-org/youtube-dl/issues/7518
+        # See https://github.com/ytdl-org/youtube-dl/issues/7518\
+        # Also, weirdly, compat_contextlib_suppress fails here in 2.6
         try:
             return compat_chr(int(numstr, base))
         except ValueError:
@@ -2348,11 +2342,9 @@ def make_HTTPS_handler(params, **kwargs):
         # Some servers may (wrongly) reject requests if ALPN extension is not sent. See:
         # https://github.com/python/cpython/issues/85140
         # https://github.com/yt-dlp/yt-dlp/issues/3878
-        try:
+        with compat_contextlib_suppress(AttributeError, NotImplementedError):
+            # fails for Python < 2.7.10, not ssl.HAS_ALPN
             ctx.set_alpn_protocols(ALPN_PROTOCOLS)
-        except (AttributeError, NotImplementedError):
-            # Python < 2.7.10, not ssl.HAS_ALPN
-            pass
 
     opts_no_check_certificate = params.get('nocheckcertificate', False)
     if hasattr(ssl, 'create_default_context'):  # Python >= 3.4 or 2.7.9
@@ -2362,12 +2354,10 @@ def make_HTTPS_handler(params, **kwargs):
             context.check_hostname = False
             context.verify_mode = ssl.CERT_NONE
 
-        try:
+        with compat_contextlib_suppress(TypeError):
+            # Fails with Python 2.7.8 (create_default_context present
+            # but HTTPSHandler has no context=)
             return YoutubeDLHTTPSHandler(params, context=context, **kwargs)
-        except TypeError:
-            # Python 2.7.8
-            # (create_default_context present but HTTPSHandler has no context=)
-            pass
 
     if sys.version_info < (3, 2):
         return YoutubeDLHTTPSHandler(params, **kwargs)
@@ -3176,12 +3166,10 @@ def parse_iso8601(date_str, delimiter='T', timezone=None):
     if timezone is None:
         timezone, date_str = extract_timezone(date_str)
 
-    try:
+    with compat_contextlib_suppress(ValueError):
         date_format = '%Y-%m-%d{0}%H:%M:%S'.format(delimiter)
         dt = datetime.datetime.strptime(date_str, date_format) - timezone
         return calendar.timegm(dt.timetuple())
-    except ValueError:
-        pass
 
 
 def date_formats(day_first=True):
@@ -3201,17 +3189,13 @@ def unified_strdate(date_str, day_first=True):
     _, date_str = extract_timezone(date_str)
 
     for expression in date_formats(day_first):
-        try:
+        with compat_contextlib_suppress(ValueError):
             upload_date = datetime.datetime.strptime(date_str, expression).strftime('%Y%m%d')
-        except ValueError:
-            pass
     if upload_date is None:
         timetuple = email.utils.parsedate_tz(date_str)
         if timetuple:
-            try:
+            with compat_contextlib_suppress(ValueError):
                 upload_date = datetime.datetime(*timetuple[:6]).strftime('%Y%m%d')
-            except ValueError:
-                pass
     if upload_date is not None:
         return compat_str(upload_date)
 
@@ -3240,11 +3224,9 @@ def unified_timestamp(date_str, day_first=True):
         date_str = m.group(1)
 
     for expression in date_formats(day_first):
-        try:
+        with compat_contextlib_suppress(ValueError):
             dt = datetime.datetime.strptime(date_str, expression) - timezone + datetime.timedelta(hours=pm_delta)
             return calendar.timegm(dt.timetuple())
-        except ValueError:
-            pass
     timetuple = email.utils.parsedate_tz(date_str)
     if timetuple:
         return calendar.timegm(timetuple) + pm_delta * 3600 - compat_datetime_timedelta_total_seconds(timezone)