Add FFmpegSlice postprocessor

youtube_dl/__init__.py

@@ -252,6 +252,12 @@ def _real_main(argv=None):
             'preferredquality': opts.audioquality,
             'nopostoverwrites': opts.nopostoverwrites,
         })
+    if opts.slicestart or opts.sliceend:
+        postprocessors.append({
+            'key': 'FFmpegSlice',
+            'slice_start_time': opts.slicestart,
+            'slice_end_time': opts.sliceend,
+        })
     if opts.recodevideo:
         postprocessors.append({
             'key': 'FFmpegVideoConvertor',

youtube_dl/options.py

@@ -756,6 +756,14 @@ def parseOpts(overrideArguments=None):
         '--recode-video',
         metavar='FORMAT', dest='recodevideo', default=None,
         help='Encode the video to another format if necessary (currently supported: mp4|flv|ogg|webm|mkv|avi)')
+    postproc.add_option(
+        '--slice-start',
+        metavar='START_TIME', dest='slicestart', default=None,
+        help='Slice start time')
+    postproc.add_option(
+        '--slice-end',
+        metavar='END_TIME', dest='sliceend', default=None,
+        help='Slice end time')
     postproc.add_option(
         '--postprocessor-args',
         dest='postprocessor_args', metavar='ARGS',

youtube_dl/postprocessor/__init__.py

@@ -12,6 +12,7 @@ from .ffmpeg import (
     FFmpegMetadataPP,
     FFmpegVideoConvertorPP,
     FFmpegSubtitlesConvertorPP,
+    FFmpegSlicePP,
 )
 from .xattrpp import XAttrMetadataPP
 from .execafterdownload import ExecAfterDownloadPP
@@ -33,6 +34,7 @@ __all__ = [
     'FFmpegMergerPP',
     'FFmpegMetadataPP',
     'FFmpegPostProcessor',
+    'FFmpegSlicePP',
     'FFmpegSubtitlesConvertorPP',
     'FFmpegVideoConvertorPP',
     'MetadataFromTitlePP',

youtube_dl/postprocessor/ffmpeg.py

@@ -278,7 +278,7 @@ class FFmpegExtractAudioPP(FFmpegPostProcessor):
 
         prefix, sep, ext = path.rpartition('.')  # not os.path.splitext, since the latter does not work on unicode in all setups
         new_path = prefix + sep + extension
-        
+
         information['filepath'] = new_path
         information['ext'] = extension
 
@@ -577,3 +577,25 @@ class FFmpegSubtitlesConvertorPP(FFmpegPostProcessor):
                 }
 
         return sub_filenames, info
+
+
+class FFmpegSlicePP(FFmpegPostProcessor):
+
+    def __init__(self, downloader, slice_start_time, slice_end_time):
+        super(FFmpegSlicePP, self).__init__(downloader)
+        self.slice_start_time = slice_start_time
+        self.slice_end_time = slice_end_time
+
+    def run(self, info):
+        filename = info['filepath']
+        temp_filename = prepend_extension(filename, 'temp')
+        start_time = self.slice_start_time or "0"
+        end_time = self.slice_end_time or "{}".format(info['duration'])
+        options = ['-ss', start_time, '-to', end_time]
+        self.run_ffmpeg(filename, temp_filename, options)
+        msg = '[ffmpeg] Sliced: from ({}) seconds to ({}) seconds'.format(
+            start_time, end_time)
+        self._downloader.to_screen(msg)
+        os.remove(encodeFilename(filename))
+        os.rename(encodeFilename(temp_filename), encodeFilename(filename))
+        return [], info