[YoutubeDL] Make postprocessors declarative

Instead of having to configure PPs in code, this allows us and embedding programs not to worry about imports or finer details, similarly to how we handle IEs.

youtube_dl/__init__.py

@@ -40,16 +40,6 @@ from .downloader import (
 )
 from .extractor import gen_extractors
 from .YoutubeDL import YoutubeDL
-from .postprocessor import (
-    AtomicParsleyPP,
-    FFmpegAudioFixPP,
-    FFmpegMetadataPP,
-    FFmpegVideoConvertor,
-    FFmpegExtractAudioPP,
-    FFmpegEmbedSubtitlePP,
-    XAttrMetadataPP,
-    ExecAfterDownloadPP,
-)
 
 
 def _real_main(argv=None):
@@ -212,6 +202,43 @@ def _real_main(argv=None):
     any_printing = opts.geturl or opts.gettitle or opts.getid or opts.getthumbnail or opts.getdescription or opts.getfilename or opts.getformat or opts.getduration or opts.dumpjson or opts.dump_single_json
     download_archive_fn = compat_expanduser(opts.download_archive) if opts.download_archive is not None else opts.download_archive
 
+    # PostProcessors
+    postprocessors = []
+    # Add the metadata pp first, the other pps will copy it
+    if opts.addmetadata:
+        postprocessors.append({'key': 'FFmpegMetadata'})
+    if opts.extractaudio:
+        postprocessors.append({
+            'key': 'FFmpegExtractAudio',
+            'preferredcodec': opts.audioformat,
+            'preferredquality': opts.audioquality,
+            'nopostoverwrites': opts.nopostoverwrites,
+        })
+    if opts.recodevideo:
+        postprocessors.append({
+            'key': 'FFmpegVideoConvertor',
+            'preferedformat': opts.recodevideo,
+        })
+    if opts.embedsubtitles:
+        postprocessors.append({
+            'key': 'FFmpegEmbedSubtitle',
+            'subtitlesformat': opts.subtitlesformat,
+        })
+    if opts.xattrs:
+        postprocessors.append({'key': 'XAttrMetadata'})
+    if opts.embedthumbnail:
+        if not opts.addmetadata:
+            postprocessors.append({'key': 'FFmpegAudioFix'})
+        postprocessors.append({'key': 'AtomicParsley'})
+    # Please keep ExecAfterDownload towards the bottom as it allows the user to modify the final file in any way.
+    # So if the user is able to remove the file before your postprocessor runs it might cause a few problems.
+    if opts.exec_cmd:
+        postprocessors.append({
+            'key': 'ExecAfterDownload',
+            'verboseOutput': opts.verbose,
+            'exec_cmd': opts.exec_cmd,
+        })
+
     ydl_opts = {
         'usenetrc': opts.usenetrc,
         'username': opts.username,
@@ -297,32 +324,10 @@ def _real_main(argv=None):
         'encoding': opts.encoding,
         'exec_cmd': opts.exec_cmd,
         'extract_flat': opts.extract_flat,
+        'postprocessors': postprocessors,
     }
 
     with YoutubeDL(ydl_opts) as ydl:
-        # PostProcessors
-        # Add the metadata pp first, the other pps will copy it
-        if opts.addmetadata:
-            ydl.add_post_processor(FFmpegMetadataPP())
-        if opts.extractaudio:
-            ydl.add_post_processor(FFmpegExtractAudioPP(preferredcodec=opts.audioformat, preferredquality=opts.audioquality, nopostoverwrites=opts.nopostoverwrites))
-        if opts.recodevideo:
-            ydl.add_post_processor(FFmpegVideoConvertor(preferedformat=opts.recodevideo))
-        if opts.embedsubtitles:
-            ydl.add_post_processor(FFmpegEmbedSubtitlePP(subtitlesformat=opts.subtitlesformat))
-        if opts.xattrs:
-            ydl.add_post_processor(XAttrMetadataPP())
-        if opts.embedthumbnail:
-            if not opts.addmetadata:
-                ydl.add_post_processor(FFmpegAudioFixPP())
-            ydl.add_post_processor(AtomicParsleyPP())
-
-        # Please keep ExecAfterDownload towards the bottom as it allows the user to modify the final file in any way.
-        # So if the user is able to remove the file before your postprocessor runs it might cause a few problems.
-        if opts.exec_cmd:
-            ydl.add_post_processor(ExecAfterDownloadPP(
-                verboseOutput=opts.verbose, exec_cmd=opts.exec_cmd))
-
         # Update version
         if opts.update_self:
             update_self(ydl.to_screen, opts.verbose)