[ThumbnailsConvertor] Support conversion to png and make it the default (#333)

PNG, being a lossless format, should be a better default here compared to JPG since we won't be compressing to a lossy format and losing some of the original image data
PNG is also supported for embedding in all the formats similar to JPEG

Authored by: louie-github
This commit is contained in:
louie-github 2021-05-22 02:09:48 +08:00 committed by GitHub
parent 09f1580e2d
commit a927acb1ec
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5 changed files with 25 additions and 16 deletions

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@ -752,7 +752,7 @@ ## Post-Processing Options:
(currently supported: srt|ass|vtt|lrc)
(Alias: --convert-subtitles)
--convert-thumbnails FORMAT Convert the thumbnails to another format
(currently supported: jpg)
(currently supported: jpg, png)
--split-chapters Split video into multiple files based on
internal chapters. The "chapter:" prefix
can be used with "--paths" and "--output"

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@ -227,7 +227,7 @@ def parse_retries(retries, name=''):
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', ):
if opts.convertthumbnails not in ('jpg', 'png'):
parser.error('invalid thumbnail format specified')
if opts.date is not None:

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@ -1253,7 +1253,7 @@ def _dict_from_options_callback(
postproc.add_option(
'--convert-thumbnails',
metavar='FORMAT', dest='convertthumbnails', default=None,
help='Convert the thumbnails to another format (currently supported: jpg)')
help='Convert the thumbnails to another format (currently supported: jpg, png)')
postproc.add_option(
'--split-chapters', '--split-tracks',
dest='split_chapters', action='store_true', default=False,

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@ -77,11 +77,14 @@ def run(self, info):
original_thumbnail = thumbnail_filename = info['thumbnails'][-1]['filepath']
# Convert unsupported thumbnail formats to JPEG (see #25687, #25717)
# Convert unsupported thumbnail formats to PNG (see #25687, #25717)
# Original behavior was to convert to JPG, but since JPG is a lossy
# format, there will be some additional data loss.
# PNG, on the other hand, is lossless.
thumbnail_ext = os.path.splitext(thumbnail_filename)[1][1:]
if thumbnail_ext not in ('jpg', 'png'):
thumbnail_filename = convertor.convert_thumbnail(thumbnail_filename, 'jpg')
thumbnail_ext = 'jpg'
thumbnail_filename = convertor.convert_thumbnail(thumbnail_filename, 'png')
thumbnail_ext = 'png'
mtime = os.stat(encodeFilename(filename)).st_mtime

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@ -849,24 +849,30 @@ def fixup_webp(self, info, idx=-1):
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')
if ext == 'jpg':
format_name = 'JPEG'
opts = ['-bsf:v', 'mjpeg2jpeg']
elif ext == 'png':
format_name = 'PNG'
opts = []
else:
raise FFmpegPostProcessorError('Only conversion to either jpg or png 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')
escaped_thumbnail_conv_filename = replace_extension(escaped_thumbnail_filename, ext)
self.to_screen('Converting thumbnail "%s" to %s' % (escaped_thumbnail_filename, format_name))
self.run_ffmpeg(escaped_thumbnail_filename, escaped_thumbnail_conv_filename, opts)
thumbnail_conv_filename = replace_extension(thumbnail_filename, ext)
# 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
os.rename(encodeFilename(escaped_thumbnail_conv_filename), encodeFilename(thumbnail_conv_filename))
return thumbnail_conv_filename
def run(self, info):
if self.format != 'jpg':
raise FFmpegPostProcessorError('Only conversion to jpg is currently supported')
if self.format not in ('jpg', 'png'):
raise FFmpegPostProcessorError('Only conversion to either jpg or png is currently supported')
files_to_delete = []
has_thumbnail = False