[YoutubeDL] Use a progress hook for progress reporting

Instead of every downloader calling two helper functions, let our progress report be an ordinary progress hook like everyone else's.
Closes #4875.

1 files changed, 10 insertions, 3 deletions

diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index 3658332ec..b087d356f 100755
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -199,18 +199,25 @@ class YoutubeDL(object):
                        postprocessor.
     progress_hooks:    A list of functions that get called on download
                        progress, with a dictionary with the entries
-                       * status: One of "downloading" and "finished".
+                       * status: One of "downloading", "error", or "finished".
                                  Check this first and ignore unknown values.
 
-                       If status is one of "downloading" or "finished", the
+                       If status is one of "downloading", or "finished", the
                        following properties may also be present:
                        * filename: The final filename (always present)
+                       * tmpfilename: The filename we're currently writing to
                        * downloaded_bytes: Bytes on disk
                        * total_bytes: Size of the whole file, None if unknown
-                       * tmpfilename: The filename we're currently writing to
+                       * total_bytes_estimate: Guess of the eventual file size,
+                                               None if unavailable.
+                       * elapsed: The number of seconds since download started.
                        * eta: The estimated time in seconds, None if unknown
                        * speed: The download speed in bytes/second, None if
                                 unknown
+                       * fragment_index: The counter of the currently
+                                         downloaded video fragment.
+                       * fragment_count: The number of fragments (= individual
+                                         files that will be merged)
 
                        Progress hooks are guaranteed to be called at least once
                        (with status "finished") if the download is successful.