ytdl_hook: replace skip_muxed with force_all_formats option

I don't think the skip_muxed option was overlay useful. While it was
nice to filter out the low quality muxed versions (as it happens on the
alphabetic site, I suspect it's compatibility stuff), it's not really
necessary, and just makes for another tricky and rarely used
configuration option. (This was different before muxed tracks were also
delay-loaded, and including the muxed versions slowed down loading.)

Add the force_all_formats option instead, which handles the HLS case.
Set it to true because they are also delay-loaded now, and don't slow
down startup as much.

2 files changed, 43 insertions, 42 deletions

diff --git a/DOCS/man/options.rst b/DOCS/man/options.rst
index d181279a41..fb98a04def 100644
--- a/DOCS/man/options.rst
+++ b/DOCS/man/options.rst
@@ -814,7 +814,6 @@ Program Behavior
     ``--script-opts`` option (using ``ytdl_hook-`` as prefix):
 
     ``try_ytdl_first=<yes|no>``
-
         If 'yes' will try parsing the URL with youtube-dl first, instead of the
         default where it's only after mpv failed to open it. This mostly depends
         on whether most of your URLs need youtube-dl parsing.
@@ -855,22 +854,40 @@ Program Behavior
         slow, which can't be really fixed.) In general, this option is not
         useful, and was only added to show that it's possible.
 
-    ``skip_muxed=<yes|no>``
+        There are two cases that must be considered when doing quality/bandwidth
+        selection:
+
+            1. Completely separate audio and video streams (DASH-like). Each of
+               these streams contain either only audio or video, so you can
+               mix and combine audio/video bandwidths without restriction. This
+               intuitively matches best with the concept of selecting quality
+               by track (what ``all_formats`` is supposed to do).
+
+            2. Separate sets of muxed audio and video streams. Each version of
+               the media contains both an audio and video stream, and they are
+               interleaved. In order not to waste bandwidth, you should only
+               select one of these versions (if, for example, you select an
+               audio stream, then video will be downloaded, even if you selected
+               video from a different stream).
+
+               mpv will still represent them as separate tracks, but will set
+               the title of each track to ``muxed-N``, where ``N`` is replaced
+               with the youtube-dl format ID of the originating stream.
+
+        Some sites will mix 1. and 2., but we assume that they do so for
+        compatibility reasons, and there is no reason to use them at all.
+
+    ``force_all_formats=<yes|no>``
         If set to 'yes', and ``all_formats`` is also set to 'yes', this will
-        skip formats that have both audio and video streams (default: yes).
-
-        Some sites that provide multiple qualities will do so with separated
-        audio and video streams (which is what ``all_formats`` is supposed to
-        make use of), still provide formats that include both audio and video.
-        We assume that they do so for compatibility reasons, and ``skip_muxed``
-        filters them out. This will make loading faster, and potentially avoid
-        wasting bandwidth by using only one stream of a muxed stream. On the
-        other hand, if muxed streams are present, but the separate streams lack
-        either video or audio or do not exist at all, then the stream selection
-        as done by youtube-dl (via ``--ytdl-format``) is used.
-
-        This appears to terribly break with some sites that provide a HLS master
-        playlist on the lowest level.
+        try to represent all youtube-dl reported formats as tracks, even if
+        mpv would normally use the direct URL reported by it (default: yes).
+
+        It appears this normally makes a difference if youtube-dl works on a
+        master HLS playlist.
+
+        If this is set to 'no', this specific kind of stream is treated like
+        ``all_formats`` is set to 'no', and the stream selection as done by
+        youtube-dl (via ``--ytdl-format``) is used.
 
     ``use_manifests=<yes|no>``
         Make mpv use the master manifest URL for formats like HLS and DASH,
diff --git a/player/lua/ytdl_hook.lua b/player/lua/ytdl_hook.lua
index 8951e06c44..7269f3f4b7 100644
--- a/player/lua/ytdl_hook.lua
+++ b/player/lua/ytdl_hook.lua
@@ -7,7 +7,7 @@ local o = {
     try_ytdl_first = false,
     use_manifests = false,
     all_formats = false,
-    skip_muxed = true,
+    force_all_formats = true,
 }
 options.read_options(o)
 
@@ -343,8 +343,6 @@ local function formats_to_edl(json, formats, use_all_formats)
     local duration = as_integer(json["duration"])
     local single_url = nil
     local streams = {}
-    local separate_present = {}
-    local muxed_present = false
 
     for index, track in ipairs(formats) do
         local edl_track = nil
@@ -376,14 +374,10 @@ local function formats_to_edl(json, formats, use_all_formats)
 
         local url = edl_track or track.url
         local hdr = {"!new_stream", "!no_clip", "!no_chapters"}
-        local as_muxed = false
+        local skip = false
         local params = ""
 
         if use_all_formats then
-            if #tracks > 1 and o.skip_muxed then
-                as_muxed = true
-                tracks = {} -- skip
-            end
             for _, sub in ipairs(tracks) do
                 -- A single track that is either audio or video. Delay load it.
                 local codec = map_codec_to_mpv(sub.codec)
@@ -418,10 +412,6 @@ local function formats_to_edl(json, formats, use_all_formats)
                 hdr[#hdr + 1] = "!track_meta,title=" ..
                     edl_escape(title) .. ",byterate=" .. byterate
 
-                if #tracks == 1 then
-                    separate_present[sub.media_type] = true
-                end
-
                 if duration > 0 then
                     params = params .. ",length=" .. duration
                 end
@@ -430,23 +420,12 @@ local function formats_to_edl(json, formats, use_all_formats)
 
         hdr[#hdr + 1] = edl_escape(url) .. params
 
-        if as_muxed then
-            muxed_present = true
-        else
-            streams[#streams + 1] = table.concat(hdr, ";")
-        end
+        streams[#streams + 1] = table.concat(hdr, ";")
         -- In case there is only 1 of these streams.
         -- Note: assumes it has no important EDL headers
         single_url = url
     end
 
-    -- If "skip_muxed" is enabled, we discard formats that have both audio
-    -- and video aka muxed (because it's a pain). But if the single-media
-    -- type formats do not provide both video and audio, then discard them
-    -- and use the muxed streams instead.
-    res.muxed_needed = muxed_present and (not (separate_present["video"] and
-                                               separate_present["audio"]))
-
     -- Merge all tracks into a single virtual file, but avoid EDL if it's
     -- only a single track (i.e. redundant).
     if #streams == 1 and single_url then
@@ -495,8 +474,13 @@ local function add_single_video(json)
     if streamurl == ""  then
         -- possibly DASH/split tracks
         local res = nil
+        local has_requested_formats = requested_formats and #requested_formats > 0
 
-        if all_formats and o.all_formats then
+        -- Not having requested_formats usually hints to HLS master playlist
+        -- usage, which we don't want to split off, at least not yet.
+        if (all_formats and o.all_formats) and
+           (has_requested_formats or o.force_all_formats)
+        then
             format_info = "all_formats (separate)"
             res = formats_to_edl(json, all_formats, true)
             -- Note: since we don't delay-load muxed streams, use normal stream
@@ -506,7 +490,7 @@ local function add_single_video(json)
             end
         end
 
-        if (not res) and requested_formats and #requested_formats > 0 then
+        if (not res) and has_requested_formats then
             format_info = "youtube-dl (separate)"
             res = formats_to_edl(json, requested_formats, false)
         end