From 7ec1e417ca28a7c76ee116138e80e5744806ac14 Mon Sep 17 00:00:00 2001
From: Alexandre L <alex131089@msn.com>
Date: Sun, 5 Nov 2017 01:58:03 +0100
Subject: [PATCH] Allow embedding thumbnail in MKV as attachment

To fix rg3#10359, use `-attach` to embed the thumbnail as attachment.
In this version, the attached filename follow the https://matroska.org/technical/cover_art/index.html convention, as pointed in #6046.
The image dimensions are probably not going to respect the convention though, and we assume the thumbnail is in landscape orientation.
As only 2 images type seems to be recognized by the convention, they are hardcoded (mimetypes module would match on extension too).
---
 youtube_dl/postprocessor/embedthumbnail.py | 37 ++++++++++++++++++++--
 1 file changed, 35 insertions(+), 2 deletions(-)

diff --git a/youtube_dl/postprocessor/embedthumbnail.py b/youtube_dl/postprocessor/embedthumbnail.py
index e606a58de..1a1ca1ae6 100644
--- a/youtube_dl/postprocessor/embedthumbnail.py
+++ b/youtube_dl/postprocessor/embedthumbnail.py
@@ -40,7 +40,40 @@ class EmbedThumbnailPP(FFmpegPostProcessor):
                 'Skipping embedding the thumbnail because the file is missing.')
             return [], info
 
-        if info['ext'] == 'mp3':
+        if info['ext'] == 'mkv':
+            if thumbnail_filename.endswith(('.jpe', '.jpeg', '.jpg', '.jfif')):
+                mimetype = 'image/jpeg'
+                extension = 'jpg'
+            elif thumbnail_filename.endswith('.png'):
+                mimetype = 'image/png'
+                extension = 'png'
+            else:
+                self._downloader.report_warning(
+                    'Skipping embedding the thumbnail because the thumbnail extension is unknown.')
+                return [], info
+
+            options = [
+                '-c', 'copy',
+                '-attach', thumbnail_filename,
+                # https://matroska.org/technical/cover_art/index.html as pointed in #6046
+                # No orientation detection nor dimensions checking/convertion
+                '-metadata:s:t', 'filename=cover_land.{}'.format(extension),
+                # If not given : "[matroska @ 000001458de38840] Attachment stream 2 has no mimetype tag and it cannot be deduced from the codec id."
+                '-metadata:s:t', 'mimetype={}'.format(mimetype),
+                # Use metadata "title" so it is set as MATROSKA_ID_FILEDESC - optional
+                # https://github.com/FFmpeg/FFmpeg/blob/9cfdf0e3322b9a451277cf36406ac4a8e4e3da74/libavformat/matroskaenc.c#L1762
+                '-metadata:s:t', 'title=Thumbnail']
+
+            self._downloader.to_screen('[ffmpeg] Adding thumbnail to "%s"' % filename)
+
+            self.run_ffmpeg(filename, temp_filename, options)
+
+            if not self._already_have_thumbnail:
+                os.remove(encodeFilename(thumbnail_filename))
+            os.remove(encodeFilename(filename))
+            os.rename(encodeFilename(temp_filename), encodeFilename(filename))
+
+        elif info['ext'] == 'mp3':
             options = [
                 '-c', 'copy', '-map', '0', '-map', '1',
                 '-metadata:s:v', 'title="Album cover"', '-metadata:s:v', 'comment="Cover (Front)"']
@@ -87,6 +120,6 @@ class EmbedThumbnailPP(FFmpegPostProcessor):
                 os.remove(encodeFilename(filename))
                 os.rename(encodeFilename(temp_filename), encodeFilename(filename))
         else:
-            raise EmbedThumbnailPPError('Only mp3 and m4a/mp4 are supported for thumbnail embedding for now.')
+            raise EmbedThumbnailPPError('Only mp3, m4a/mp4 and mkv are supported for thumbnail embedding for now.')
 
         return [], info