Implement the prefer_free_formats in YoutubeDL

test/test_YoutubeDL.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python
+
+import sys
+import unittest
+
+# Allow direct execution
+import os
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from helper import FakeYDL, parameters
+
+class YDL(FakeYDL):
+    def __init__(self):
+        super(YDL, self).__init__()
+        self.downloaded_info_dicts = []
+    def process_info(self, info_dict):
+        self.downloaded_info_dicts.append(info_dict)
+
+class TestFormatSelection(unittest.TestCase):
+    def test_prefer_free_formats(self):
+        # Same resolution => download webm
+        ydl = YDL()
+        ydl.params['prefer_free_formats'] = True
+        formats = [{u'ext': u'webm', u'height': 460},{u'ext': u'mp4',  u'height': 460}]
+        info_dict = {u'formats': formats, u'extractor': u'test'}
+        ydl.process_ie_result(info_dict)
+        downloaded = ydl.downloaded_info_dicts[0]
+        self.assertEqual(downloaded[u'ext'], u'webm')
+
+        # Different resolution => download best quality (mp4)
+        ydl = YDL()
+        ydl.params['prefer_free_formats'] = True
+        formats = [{u'ext': u'webm', u'height': 720},{u'ext': u'mp4',u'height': 1080}]
+        info_dict[u'formats'] = formats
+        ydl.process_ie_result(info_dict)
+        downloaded = ydl.downloaded_info_dicts[0]
+        self.assertEqual(downloaded[u'ext'], u'mp4')
+
+        # No prefer_free_formats => keep original formats order
+        ydl = YDL()
+        ydl.params['prefer_free_formats'] = False
+        formats = [{u'ext': u'webm', u'height': 720},{u'ext': u'flv',u'height': 720}]
+        info_dict[u'formats'] = formats
+        ydl.process_ie_result(info_dict)
+        downloaded = ydl.downloaded_info_dicts[0]
+        self.assertEqual(downloaded[u'ext'], u'flv')
+
+if __name__ == '__main__':
+    unittest.main()

youtube_dl/YoutubeDL.py

@@ -484,6 +484,15 @@ class YoutubeDL(object):
         format_limit = self.params.get('format_limit', None)
         if format_limit:
             formats = [f for f in formats if f['format_id'] <= format_limit]
+        if self.params.get('prefer_free_formats'):
+            def _free_formats_key(f):
+                try:
+                    ext_ord = [u'flv', u'mp4', u'webm'].index(f['ext'])
+                except ValueError:
+                    ext_ord = -1
+                # We only compare the extension if they have the same height and width
+                return (f.get('height'), f.get('width'), ext_ord)
+            formats = sorted(formats, key=_free_formats_key)
 
         req_format = self.params.get('format', 'best')
         formats_to_download = []