[YoutubeDL] Make postprocessors declarative

Instead of having to configure PPs in code, this allows us and embedding programs not to worry about imports or finer details, similarly to how we handle IEs.

1 files changed, 28 insertions, 0 deletions

diff --git a/README.md b/README.md
index f10f06ee8..edfcfc223 100644
--- a/README.md
+++ b/README.md
@@ -537,6 +537,34 @@ From a Python program, you can embed youtube-dl in a more powerful fashion, like
 
 Most likely, you'll want to use various options. For a list of what can be done, have a look at [youtube_dl/YoutubeDL.py](https://github.com/rg3/youtube-dl/blob/master/youtube_dl/YoutubeDL.py#L69). For a start, if you want to intercept youtube-dl's output, set a `logger` object.
 
+Here's a more complete example of a program that only outputs errors, and downloads/converts the video as mp3:
+
+
+    import youtube_dl
+
+
+    class MyLogger(object):
+        def debug(self, msg):
+            pass
+
+        def warning(self, msg):
+            pass
+
+        def error(self, msg):
+            print(msg)
+
+    ydl_opts = {
+        'format': 'bestaudio/best',
+        'postprocessors': [{
+            'key': 'FFmpegExtractAudio',
+            'preferredcodec': 'mp3',
+            'preferredquality': '64',
+        }],
+        'logger': MyLogger(),
+    }
+    with youtube_dl.YoutubeDL(ydl_opts) as ydl:
+        ydl.download(['http://www.youtube.com/watch?v=BaW_jenozKc'])
+
 # BUGS
 
 Bugs and suggestions should be reported at: <https://github.com/rg3/youtube-dl/issues> . Unless you were prompted so or there is another pertinent reason (e.g. GitHub fails to accept the bug report), please do not send bug reports via personal email. For discussions, join us in the irc channel #youtube-dl on freenode.