[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
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 25 additions and 16 deletions

View File

@ -752,7 +752,7 @@ Then simply run `make`. You can also run `make yt-dlp` instead to compile only t
(currently supported: srt|ass|vtt|lrc) (currently supported: srt|ass|vtt|lrc)
(Alias: --convert-subtitles) (Alias: --convert-subtitles)
--convert-thumbnails FORMAT Convert the thumbnails to another format --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 --split-chapters Split video into multiple files based on
internal chapters. The "chapter:" prefix internal chapters. The "chapter:" prefix
can be used with "--paths" and "--output" can be used with "--paths" and "--output"

View File

@ -227,7 +227,7 @@ def _real_main(argv=None):
if opts.convertsubtitles not in ('srt', 'vtt', 'ass', 'lrc'): if opts.convertsubtitles not in ('srt', 'vtt', 'ass', 'lrc'):
parser.error('invalid subtitle format specified') parser.error('invalid subtitle format specified')
if opts.convertthumbnails is not None: 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') parser.error('invalid thumbnail format specified')
if opts.date is not None: if opts.date is not None:

View File

@ -1253,7 +1253,7 @@ def parseOpts(overrideArguments=None):
postproc.add_option( postproc.add_option(
'--convert-thumbnails', '--convert-thumbnails',
metavar='FORMAT', dest='convertthumbnails', default=None, 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( postproc.add_option(
'--split-chapters', '--split-tracks', '--split-chapters', '--split-tracks',
dest='split_chapters', action='store_true', default=False, dest='split_chapters', action='store_true', default=False,

View File

@ -77,11 +77,14 @@ class EmbedThumbnailPP(FFmpegPostProcessor):
original_thumbnail = thumbnail_filename = info['thumbnails'][-1]['filepath'] 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:] thumbnail_ext = os.path.splitext(thumbnail_filename)[1][1:]
if thumbnail_ext not in ('jpg', 'png'): if thumbnail_ext not in ('jpg', 'png'):
thumbnail_filename = convertor.convert_thumbnail(thumbnail_filename, 'jpg') thumbnail_filename = convertor.convert_thumbnail(thumbnail_filename, 'png')
thumbnail_ext = 'jpg' thumbnail_ext = 'png'
mtime = os.stat(encodeFilename(filename)).st_mtime mtime = os.stat(encodeFilename(filename)).st_mtime

View File

@ -849,24 +849,30 @@ class FFmpegThumbnailsConvertorPP(FFmpegPostProcessor):
info['__files_to_move'].pop(thumbnail_filename), 'webp') info['__files_to_move'].pop(thumbnail_filename), 'webp')
def convert_thumbnail(self, thumbnail_filename, ext): def convert_thumbnail(self, thumbnail_filename, ext):
if ext != 'jpg': if ext == 'jpg':
raise FFmpegPostProcessorError('Only conversion to jpg is currently supported') 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 # NB: % is supposed to be escaped with %% but this does not work
# for input files so working around with standard substitution # for input files so working around with standard substitution
escaped_thumbnail_filename = thumbnail_filename.replace('%', '#') escaped_thumbnail_filename = thumbnail_filename.replace('%', '#')
os.rename(encodeFilename(thumbnail_filename), encodeFilename(escaped_thumbnail_filename)) os.rename(encodeFilename(thumbnail_filename), encodeFilename(escaped_thumbnail_filename))
escaped_thumbnail_jpg_filename = replace_extension(escaped_thumbnail_filename, 'jpg') escaped_thumbnail_conv_filename = replace_extension(escaped_thumbnail_filename, ext)
self.to_screen('Converting thumbnail "%s" to JPEG' % escaped_thumbnail_filename) self.to_screen('Converting thumbnail "%s" to %s' % (escaped_thumbnail_filename, format_name))
self.run_ffmpeg(escaped_thumbnail_filename, escaped_thumbnail_jpg_filename, ['-bsf:v', 'mjpeg2jpeg']) self.run_ffmpeg(escaped_thumbnail_filename, escaped_thumbnail_conv_filename, opts)
thumbnail_jpg_filename = replace_extension(thumbnail_filename, 'jpg') thumbnail_conv_filename = replace_extension(thumbnail_filename, ext)
# Rename back to unescaped # Rename back to unescaped
os.rename(encodeFilename(escaped_thumbnail_filename), encodeFilename(thumbnail_filename)) os.rename(encodeFilename(escaped_thumbnail_filename), encodeFilename(thumbnail_filename))
os.rename(encodeFilename(escaped_thumbnail_jpg_filename), encodeFilename(thumbnail_jpg_filename)) os.rename(encodeFilename(escaped_thumbnail_conv_filename), encodeFilename(thumbnail_conv_filename))
return thumbnail_jpg_filename return thumbnail_conv_filename
def run(self, info): def run(self, info):
if self.format != 'jpg': if self.format not in ('jpg', 'png'):
raise FFmpegPostProcessorError('Only conversion to jpg is currently supported') raise FFmpegPostProcessorError('Only conversion to either jpg or png is currently supported')
files_to_delete = [] files_to_delete = []
has_thumbnail = False has_thumbnail = False