[youtube] Fixup DASH m4a headers

This fixes #2288, #2506, #2607, #3681, #4741, #4767.

youtube_dl/YoutubeDL.py

@@ -73,6 +73,7 @@
 from .downloader import get_suitable_downloader
 from .downloader.rtmp import rtmpdump_version
 from .postprocessor import (
+    FFmpegFixupM4aPP,
     FFmpegFixupStretchedPP,
     FFmpegMergerPP,
     FFmpegPostProcessor,
@@ -213,7 +214,7 @@ class YoutubeDL(object):
                        - "never": do nothing
                        - "warn": only emit a warning
                        - "detect_or_warn": check whether we can do anything
-                                           about it, warn otherwise
+                                           about it, warn otherwise (default)
     source_address:    (Experimental) Client-side IP address to bind to.
     call_home:         Boolean, true iff we are allowed to contact the
                        youtube-dl servers for debugging.
@@ -1219,11 +1220,12 @@ def dl(name, info):
 
             if success:
                 # Fixup content
-                stretched_ratio = info_dict.get('stretched_ratio')
-                if stretched_ratio is not None and stretched_ratio != 1:
                 fixup_policy = self.params.get('fixup')
                 if fixup_policy is None:
                     fixup_policy = 'detect_or_warn'
+
+                stretched_ratio = info_dict.get('stretched_ratio')
+                if stretched_ratio is not None and stretched_ratio != 1:
                     if fixup_policy == 'warn':
                         self.report_warning('%s: Non-uniform pixel ratio (%s)' % (
                             info_dict['id'], stretched_ratio))
@@ -1237,7 +1239,23 @@ def dl(name, info):
                                 '%s: Non-uniform pixel ratio (%s). Install ffmpeg or avconv to fix this automatically.' % (
                                     info_dict['id'], stretched_ratio))
                     else:
-                        assert fixup_policy == 'ignore'
+                        assert fixup_policy in ('ignore', 'never')
+
+                if info_dict.get('requested_formats') is None and info_dict.get('container') == 'm4a_dash':
+                    if fixup_policy == 'warn':
+                        self.report_warning('%s: writing DASH m4a. Only some players support this container.' % (
+                            info_dict['id']))
+                    elif fixup_policy == 'detect_or_warn':
+                        fixup_pp = FFmpegFixupM4aPP(self)
+                        if fixup_pp.available:
+                            info_dict.setdefault('__postprocessors', [])
+                            info_dict['__postprocessors'].append(fixup_pp)
+                        else:
+                            self.report_warning(
+                                '%s: writing DASH m4a. Only some players support this container. Install ffmpeg or avconv to fix this automatically.' % (
+                                    info_dict['id']))
+                    else:
+                        assert fixup_policy in ('ignore', 'never')
 
                 try:
                     self.post_process(filename, info_dict)

youtube_dl/extractor/youtube.py

@@ -264,9 +264,9 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         '266': {'ext': 'mp4', 'height': 2160, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'vcodec': 'h264'},
 
         # Dash mp4 audio
-        '139': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'vcodec': 'none', 'abr': 48, 'preference': -50},
+        '139': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'vcodec': 'none', 'abr': 48, 'preference': -50, 'container': 'm4a_dash'},
-        '140': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'vcodec': 'none', 'abr': 128, 'preference': -50},
+        '140': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'vcodec': 'none', 'abr': 128, 'preference': -50, 'container': 'm4a_dash'},
-        '141': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'vcodec': 'none', 'abr': 256, 'preference': -50},
+        '141': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'vcodec': 'none', 'abr': 256, 'preference': -50, 'container': 'm4a_dash'},
 
         # Dash webm
         '167': {'ext': 'webm', 'height': 360, 'width': 640, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'preference': -40},

youtube_dl/postprocessor/__init__.py

@@ -7,6 +7,7 @@
     FFmpegEmbedSubtitlePP,
     FFmpegExtractAudioPP,
     FFmpegFixupStretchedPP,
+    FFmpegFixupM4aPP,
     FFmpegMergerPP,
     FFmpegMetadataPP,
     FFmpegVideoConvertorPP,
@@ -25,6 +26,7 @@ def get_postprocessor(key):
     'FFmpegAudioFixPP',
     'FFmpegEmbedSubtitlePP',
     'FFmpegExtractAudioPP',
+    'FFmpegFixupM4aPP',
     'FFmpegFixupStretchedPP',
     'FFmpegMergerPP',
     'FFmpegMetadataPP',

youtube_dl/postprocessor/ffmpeg.py

@@ -564,7 +564,7 @@ class FFmpegFixupStretchedPP(FFmpegPostProcessor):
     def run(self, info):
         stretched_ratio = info.get('stretched_ratio')
         if stretched_ratio is None or stretched_ratio == 1:
-            return
+            return True, info
 
         filename = info['filepath']
         temp_filename = prepend_extension(filename, 'temp')
@@ -577,3 +577,21 @@ def run(self, info):
         os.rename(encodeFilename(temp_filename), encodeFilename(filename))
 
         return True, info
+
+
+class FFmpegFixupM4aPP(FFmpegPostProcessor):
+    def run(self, info):
+        if info.get('container') != 'm4a_dash':
+            return True, info
+
+        filename = info['filepath']
+        temp_filename = prepend_extension(filename, 'temp')
+
+        options = ['-c', 'copy', '-f', 'mp4']
+        self._downloader.to_screen('[ffmpeg] Correcting container in "%s"' % filename)
+        self.run_ffmpeg(filename, temp_filename, options)
+
+        os.remove(encodeFilename(filename))
+        os.rename(encodeFilename(temp_filename), encodeFilename(filename))
+
+        return True, info