Add option `--convert-thumbnails`

Closes: https://github.com/yt-dlp/yt-dlp/issues/99 https://github.com/yt-dlp/yt-dlp/issues/102

README.md

@@ -639,24 +639,24 @@ Then simply run `make`. You can also run `make yt-dlp` instead to compile only t
                                      Specify the postprocessor/executable name
                                      and the arguments separated by a colon ":"
                                      to give the argument to the specified
-                                     postprocessor/executable. Supported
+                                     postprocessor/executable. Supported PP are:
-                                     postprocessors are: SponSkrub,
+                                     Merger, ExtractAudio, SplitChapters,
-                                     ExtractAudio, VideoRemuxer, VideoConvertor,
+                                     Metadata, EmbedSubtitle, EmbedThumbnail,
-                                     EmbedSubtitle, Metadata, Merger,
+                                     SubtitlesConvertor, ThumbnailsConvertor,
-                                     FixupStretched, FixupM4a, FixupM3u8,
+                                     VideoRemuxer, VideoConvertor, SponSkrub,
-                                     SubtitlesConvertor, EmbedThumbnail and
+                                     FixupStretched, FixupM4a and FixupM3u8. The
-                                     SplitChapters. The supported executables
+                                     supported executables are: AtomicParsley,
-                                     are: SponSkrub, FFmpeg, FFprobe, and
+                                     FFmpeg, FFprobe, and SponSkrub. You can
-                                     AtomicParsley. You can also specify
+                                     also specify "PP+EXE:ARGS" to give the
-                                     "PP+EXE:ARGS" to give the arguments to the
+                                     arguments to the specified executable only
-                                     specified executable only when being used
+                                     when being used by the specified
-                                     by the specified postprocessor.
+                                     postprocessor. Additionally, for
-                                     Additionally, for ffmpeg/ffprobe, "_i"/"_o"
+                                     ffmpeg/ffprobe, "_i"/"_o" can be appended
-                                     can be appended to the prefix optionally
+                                     to the prefix optionally followed by a
-                                     followed by a number to pass the argument
+                                     number to pass the argument before the
-                                     before the specified input/output file. Eg:
+                                     specified input/output file. Eg: --ppa
-                                     --ppa "Merger+ffmpeg_i1:-v quiet". You can
+                                     "Merger+ffmpeg_i1:-v quiet". You can use
-                                     use this option multiple times to give
+                                     this option multiple times to give
                                      different arguments to different
                                      postprocessors. (Alias: --ppa)
     -k, --keep-video                 Keep the intermediate video file on disk
@@ -697,6 +697,8 @@ Then simply run `make`. You can also run `make yt-dlp` instead to compile only t
     --convert-subs FORMAT            Convert the subtitles to another format
                                      (currently supported: srt|ass|vtt|lrc)
                                      (Alias: --convert-subtitles)
+    --convert-thumbnails FORMAT      Convert the thumbnails to another format
+                                     (currently supported: jpg)
     --split-chapters                 Split video into multiple files based on
                                      internal chapters. The "chapter:" prefix
                                      can be used with "--paths" and "--output"

yt_dlp/__init__.py

@@ -230,6 +230,9 @@ def _real_main(argv=None):
     if opts.convertsubtitles is not None:
         if opts.convertsubtitles not in ('srt', 'vtt', 'ass', 'lrc'):
             parser.error('invalid subtitle format specified')
+    if opts.convertthumbnails is not None:
+        if opts.convertthumbnails not in ('jpg', ):
+            parser.error('invalid thumbnail format specified')
 
     if opts.date is not None:
         date = DateRange.day(opts.date)
@@ -332,6 +335,13 @@ def _real_main(argv=None):
             # Run this before the actual video download
             'when': 'before_dl'
         })
+    if opts.convertthumbnails:
+        postprocessors.append({
+            'key': 'FFmpegThumbnailsConvertor',
+            'format': opts.convertthumbnails,
+            # Run this before the actual video download
+            'when': 'before_dl'
+        })
     if opts.extractaudio:
         postprocessors.append({
             'key': 'FFmpegExtractAudio',

yt_dlp/options.py

@@ -1109,10 +1109,11 @@ def parseOpts(overrideArguments=None):
         help=(
             'Give these arguments to the postprocessors. '
             'Specify the postprocessor/executable name and the arguments separated by a colon ":" '
-            'to give the argument to the specified postprocessor/executable. Supported postprocessors are: '
+            'to give the argument to the specified postprocessor/executable. Supported PP are: '
-            'SponSkrub, ExtractAudio, VideoRemuxer, VideoConvertor, EmbedSubtitle, Metadata, Merger, '
+            'Merger, ExtractAudio, SplitChapters, Metadata, EmbedSubtitle, EmbedThumbnail, '
-            'FixupStretched, FixupM4a, FixupM3u8, SubtitlesConvertor, EmbedThumbnail and SplitChapters. '
+            'SubtitlesConvertor, ThumbnailsConvertor, VideoRemuxer, VideoConvertor, '
-            'The supported executables are: SponSkrub, FFmpeg, FFprobe, and AtomicParsley. '
+            'SponSkrub, FixupStretched, FixupM4a and FixupM3u8. '
+            'The supported executables are: AtomicParsley, FFmpeg, FFprobe, and SponSkrub. '
             'You can also specify "PP+EXE:ARGS" to give the arguments to the specified executable '
             'only when being used by the specified postprocessor. Additionally, for ffmpeg/ffprobe, '
             '"_i"/"_o" can be appended to the prefix optionally followed by a number to pass the argument '
@@ -1204,6 +1205,10 @@ def parseOpts(overrideArguments=None):
         '--convert-subs', '--convert-sub', '--convert-subtitles',
         metavar='FORMAT', dest='convertsubtitles', default=None,
         help='Convert the subtitles to another format (currently supported: srt|ass|vtt|lrc) (Alias: --convert-subtitles)')
+    postproc.add_option(
+        '--convert-thumbnails',
+        metavar='FORMAT', dest='convertthumbnails', default=None,
+        help='Convert the thumbnails to another format (currently supported: jpg)')
     postproc.add_option(
         '--split-chapters', '--split-tracks',
         dest='split_chapters', action='store_true', default=False,

yt_dlp/postprocessor/__init__.py

@@ -13,6 +13,7 @@ from .ffmpeg import (
     FFmpegVideoConvertorPP,
     FFmpegVideoRemuxerPP,
     FFmpegSubtitlesConvertorPP,
+    FFmpegThumbnailsConvertorPP,
     FFmpegSplitChaptersPP,
 )
 from .xattrpp import XAttrMetadataPP
@@ -40,6 +41,7 @@ __all__ = [
     'FFmpegMetadataPP',
     'FFmpegPostProcessor',
     'FFmpegSubtitlesConvertorPP',
+    'FFmpegThumbnailsConvertorPP',
     'FFmpegVideoConvertorPP',
     'FFmpegVideoRemuxerPP',
     'MetadataFromFieldPP',

yt_dlp/postprocessor/embedthumbnail.py

@@ -13,8 +13,10 @@ try:
 except ImportError:
     has_mutagen = False
 
-from .ffmpeg import FFmpegPostProcessor
+from .ffmpeg import (
-
+    FFmpegPostProcessor,
+    FFmpegThumbnailsConvertorPP,
+)
 from ..utils import (
     check_executable,
     encodeArgument,
@@ -23,7 +25,6 @@ from ..utils import (
     PostProcessingError,
     prepend_extension,
     process_communicate_or_kill,
-    replace_extension,
     shell_quote,
 )
 
@@ -35,7 +36,7 @@ class EmbedThumbnailPPError(PostProcessingError):
 class EmbedThumbnailPP(FFmpegPostProcessor):
 
     def __init__(self, downloader=None, already_have_thumbnail=False):
-        super(EmbedThumbnailPP, self).__init__(downloader)
+        FFmpegPostProcessor.__init__(self, downloader)
         self._already_have_thumbnail = already_have_thumbnail
 
     def run(self, info):
@@ -46,44 +47,21 @@ class EmbedThumbnailPP(FFmpegPostProcessor):
             self.to_screen('There aren\'t any thumbnails to embed')
             return [], info
 
-        initial_thumbnail = original_thumbnail = thumbnail_filename = info['thumbnails'][-1]['filepath']
+        thumbnail_filename = info['thumbnails'][-1]['filepath']
-
         if not os.path.exists(encodeFilename(thumbnail_filename)):
             self.report_warning('Skipping embedding the thumbnail because the file is missing.')
             return [], info
 
-        def is_webp(path):
-            with open(encodeFilename(path), 'rb') as f:
-                b = f.read(12)
-            return b[0:4] == b'RIFF' and b[8:] == b'WEBP'
-
         # Correct extension for WebP file with wrong extension (see #25687, #25717)
-        _, thumbnail_ext = os.path.splitext(thumbnail_filename)
+        convertor = FFmpegThumbnailsConvertorPP(self._downloader)
-        if thumbnail_ext:
+        convertor.fixup_webp(info, -1)
-            thumbnail_ext = thumbnail_ext[1:].lower()
+
-            if thumbnail_ext != 'webp' and is_webp(thumbnail_filename):
+        original_thumbnail = thumbnail_filename = info['thumbnails'][-1]['filepath']
-                self.to_screen('Correcting extension to webp and escaping path for thumbnail "%s"' % thumbnail_filename)
-                thumbnail_webp_filename = replace_extension(thumbnail_filename, 'webp')
-                if os.path.exists(thumbnail_webp_filename):
-                    os.remove(thumbnail_webp_filename)
-                os.rename(encodeFilename(thumbnail_filename), encodeFilename(thumbnail_webp_filename))
-                original_thumbnail = thumbnail_filename = thumbnail_webp_filename
-                thumbnail_ext = 'webp'
 
         # Convert unsupported thumbnail formats to JPEG (see #25687, #25717)
-        if thumbnail_ext not in ['jpg', 'png']:
+        _, thumbnail_ext = os.path.splitext(thumbnail_filename)
-            # NB: % is supposed to be escaped with %% but this does not work
+        if thumbnail_ext not in ('jpg', 'png'):
-            # for input files so working around with standard substitution
+            thumbnail_filename = convertor.convert_thumbnail(thumbnail_filename, 'jpg')
-            escaped_thumbnail_filename = thumbnail_filename.replace('%', '#')
-            os.rename(encodeFilename(thumbnail_filename), encodeFilename(escaped_thumbnail_filename))
-            escaped_thumbnail_jpg_filename = replace_extension(escaped_thumbnail_filename, 'jpg')
-            self.to_screen('Converting thumbnail "%s" to JPEG' % escaped_thumbnail_filename)
-            self.run_ffmpeg(escaped_thumbnail_filename, escaped_thumbnail_jpg_filename, ['-bsf:v', 'mjpeg2jpeg'])
-            thumbnail_jpg_filename = replace_extension(thumbnail_filename, 'jpg')
-            # Rename back to unescaped for further processing
-            os.rename(encodeFilename(escaped_thumbnail_filename), encodeFilename(thumbnail_filename))
-            os.rename(encodeFilename(escaped_thumbnail_jpg_filename), encodeFilename(thumbnail_jpg_filename))
-            thumbnail_filename = thumbnail_jpg_filename
             thumbnail_ext = 'jpg'
 
         mtime = os.stat(encodeFilename(filename)).st_mtime
@@ -194,9 +172,6 @@ class EmbedThumbnailPP(FFmpegPostProcessor):
 
         files_to_delete = [thumbnail_filename]
         if self._already_have_thumbnail:
-            info['__files_to_move'][original_thumbnail] = replace_extension(
-                info['__files_to_move'][initial_thumbnail],
-                os.path.splitext(original_thumbnail)[1][1:])
             if original_thumbnail == thumbnail_filename:
                 files_to_delete = []
         elif original_thumbnail != thumbnail_filename:

yt_dlp/postprocessor/ffmpeg.py

@@ -816,3 +816,73 @@ class FFmpegSplitChaptersPP(FFmpegPostProcessor):
             destination, opts = self._ffmpeg_args_for_chapter(idx + 1, chapter, info)
             self.real_run_ffmpeg([(info['filepath'], opts)], [(destination, ['-c', 'copy'])])
         return [], info
+
+
+class FFmpegThumbnailsConvertorPP(FFmpegPostProcessor):
+    def __init__(self, downloader=None, format=None):
+        super(FFmpegThumbnailsConvertorPP, self).__init__(downloader)
+        self.format = format
+
+    @staticmethod
+    def is_webp(path):
+        with open(encodeFilename(path), 'rb') as f:
+            b = f.read(12)
+        return b[0:4] == b'RIFF' and b[8:] == b'WEBP'
+
+    def fixup_webp(self, info, idx=-1):
+        thumbnail_filename = info['thumbnails'][idx]['filepath']
+        _, thumbnail_ext = os.path.splitext(thumbnail_filename)
+        if thumbnail_ext:
+            thumbnail_ext = thumbnail_ext[1:].lower()
+            if thumbnail_ext != 'webp' and self.is_webp(thumbnail_filename):
+                self.to_screen('Correcting thumbnail "%s" extension to webp' % thumbnail_filename)
+                webp_filename = replace_extension(thumbnail_filename, 'webp')
+                if os.path.exists(webp_filename):
+                    os.remove(webp_filename)
+                os.rename(encodeFilename(thumbnail_filename), encodeFilename(webp_filename))
+                info['thumbnails'][idx]['filepath'] = webp_filename
+                info['__files_to_move'][webp_filename] = replace_extension(
+                    info['__files_to_move'].pop(thumbnail_filename), 'webp')
+
+    def convert_thumbnail(self, thumbnail_filename, ext):
+        if ext != 'jpg':
+            raise FFmpegPostProcessorError('Only conversion to jpg is currently supported')
+        # NB: % is supposed to be escaped with %% but this does not work
+        # for input files so working around with standard substitution
+        escaped_thumbnail_filename = thumbnail_filename.replace('%', '#')
+        os.rename(encodeFilename(thumbnail_filename), encodeFilename(escaped_thumbnail_filename))
+        escaped_thumbnail_jpg_filename = replace_extension(escaped_thumbnail_filename, 'jpg')
+        self.to_screen('Converting thumbnail "%s" to JPEG' % escaped_thumbnail_filename)
+        self.run_ffmpeg(escaped_thumbnail_filename, escaped_thumbnail_jpg_filename, ['-bsf:v', 'mjpeg2jpeg'])
+        thumbnail_jpg_filename = replace_extension(thumbnail_filename, 'jpg')
+        # Rename back to unescaped
+        os.rename(encodeFilename(escaped_thumbnail_filename), encodeFilename(thumbnail_filename))
+        os.rename(encodeFilename(escaped_thumbnail_jpg_filename), encodeFilename(thumbnail_jpg_filename))
+        return thumbnail_jpg_filename
+
+    def run(self, info):
+        if self.format != 'jpg':
+            raise FFmpegPostProcessorError('Only conversion to jpg is currently supported')
+        files_to_delete = []
+        has_thumbnail = False
+
+        for idx, thumbnail_dict in enumerate(info['thumbnails']):
+            if 'filepath' not in thumbnail_dict:
+                continue
+            has_thumbnail = True
+            self.fixup_webp(info, idx)
+            original_thumbnail = thumbnail_dict['filepath']
+            _, thumbnail_ext = os.path.splitext(original_thumbnail)
+            if thumbnail_ext:
+                thumbnail_ext = thumbnail_ext[1:].lower()
+            if thumbnail_ext == self.format:
+                self.to_screen('Thumbnail "%s" is already in the requested format' % original_thumbnail)
+                continue
+            thumbnail_dict['filepath'] = self.convert_thumbnail(original_thumbnail, self.format)
+            files_to_delete.append(original_thumbnail)
+            info['__files_to_move'][thumbnail_dict['filepath']] = replace_extension(
+                info['__files_to_move'][original_thumbnail], self.format)
+
+        if not has_thumbnail:
+            self.to_screen('There aren\'t any thumbnails to convert')
+        return files_to_delete, info