rockbox/apps/plugins/lua_scripts/random_playlist.lua
William Wilgus 7200b738a5 lua random_playlist generator
uses the database to create random playlists of specified size

with the advanced GUI you can..
set the number of songs (up to max playlist buffer)
set the number of tracks before a repeat is allowed
play the tracks when finished

-- fix a parsing bug where first and last entry in database
   were corrupted

-- Incremental loading for very large databases, allows decent speed and lower ram usage

Change-Id: Ia95469b6a04625b621129ec61e5db4b2b00adc5e
2021-12-03 16:56:12 -05:00

464 lines
16 KiB
Lua

--[[ Lua RB Random Playlist -- random_playlist.lua V 1.0
/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2021 William Wilgus
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
]]
require ("actions")
require("dbgettags")
get_tags = nil -- unneeded
-- User defaults
local playlistpath = "/Playlists"
local max_tracks = 500; -- size of playlist to create
local min_repeat = 500; -- this many songs before a repeat
local play_on_success = true;
-- Random integer function
local random = math.random; -- ref random(min, max)
math.randomseed(rb.current_tick()); -- some kind of randomness
-- Button definitions
local CANCEL_BUTTON = rb.actions.PLA_CANCEL
local OK_BUTTON = rb.actions.PLA_SELECT
local ADD_BUTTON = rb.actions.PLA_UP
local ADD_BUTTON_RPT = rb.actions.PLA_UP_REPEAT or ADD_BUTTON
local SUB_BUTTON = rb.actions.PLA_DOWN
local SUB_BUTTON_RPT = rb.actions.PLA_DOWN_REPEAT or SUB_BUTTON
-- remove action and context tables to free some ram
rb.actions = nil
rb.contexts = nil
-- Program strings
local sINITDATABASE = "Initialize Database"
local sHEADERTEXT = "Random Playlist"
local sPLAYLISTERROR = "Playlist Error!"
local sREMOVEPLAYLIST = "Removing Dynamic Playlist"
local sSEARCHINGFILES = "Searching for Files.."
local sERROROPENFMT = "Error Opening %s"
local sINVALIDDBFMT = "Invalid Database %s"
local sPROGRESSHDRFMT = "%d \\ %d Tracks"
local sGOODBYE = "Goodbye"
-- Gets size of text
local function text_extent(msg, font)
font = font or rb.FONT_UI
return rb.font_getstringsize(msg, font)
end
local function _setup_random_playlist(tag_entries, play, min_repeat, trackcount)
-- Setup string tables
local tPLAYTEXT = {"Play? [ %s ] (up/dn)", "true = play tracks on success"}
local tREPEATTEXT = {"Repeat hist? [ %d ] (up/dn)","higher = less repeated songs"}
local tPLSIZETEXT = {"Find [ %d ] tracks? (up/dn)",
"Warning overwrites dynamic playlist",
"Press back to cancel"};
-- how many lines can we fit on the screen?
local res, w, h = text_extent("I")
h = h + 5 -- increase spacing in the setup menu
local max_w = rb.LCD_WIDTH / w
local max_h = rb.LCD_HEIGHT - h
local y = 0
-- User Setup Menu
local action, ask, increment
local t_desc = {scroll = true} -- scroll the setup items
-- Clears screen and adds title and icon, called first..
function show_setup_header()
local desc = {icon = 2, show_icons = true, scroll = true} -- 2 == Icon_Playlist
rb.lcd_clear_display()
rb.lcd_put_line(1, 0, sHEADERTEXT, desc)
end
-- Display up to 3 items and waits for user action -- returns action
function ask_user_action(desc, ln1, ln2, ln3)
if ln1 then rb.lcd_put_line(1, h, ln1, desc) end
if ln2 then rb.lcd_put_line(1, h + h, ln2, desc) end
if ln3 then rb.lcd_put_line(1, h + h + h, ln3, desc) end
rb.lcd_hline(1,rb.LCD_WIDTH - 1, h - 5);
rb.lcd_update()
local act = rb.get_plugin_action(-1); -- Blocking wait for action
-- handle magnitude of the increment here so consumer fn doesn't need to
if act == ADD_BUTTON_RPT and act ~= ADD_BUTTON then
increment = increment + 1
if increment > 1000 then increment = 1000 end
act = ADD_BUTTON
elseif act == SUB_BUTTON_RPT and act ~= SUB_BUTTON then
increment = increment + 1
if increment > 1000 then increment = 1000 end
act = SUB_BUTTON
else
increment = 1;
end
return act
end
-- Play the playlist on successful completion true/false?
function setup_get_play()
action = ask_user_action(tdesc,
string.format(tPLAYTEXT[1], tostring(play)),
tPLAYTEXT[2]);
if action == ADD_BUTTON then
play = true
elseif action == SUB_BUTTON then
play = false
end
end
-- Repeat song buffer list of previously added tracks 0-??
function setup_get_repeat()
if min_repeat >= trackcount then min_repeat = trackcount - 1 end
if min_repeat >= tag_entries then min_repeat = tag_entries - 1 end
action = ask_user_action(t_desc,
string.format(tREPEATTEXT[1],min_repeat),
tREPEATTEXT[2]);
if action == ADD_BUTTON then
min_repeat = min_repeat + increment
elseif action == SUB_BUTTON then -- MORE REPEATS LESS RAM USED
if min_repeat < increment then increment = 1 end
min_repeat = min_repeat - increment
if min_repeat < 0 then min_repeat = 0 end
elseif action == OK_BUTTON then
ask = setup_get_play;
setup_get_repeat = nil
action = 0
end
end
-- How many tracks to find
function setup_get_playlist_size()
action = ask_user_action(t_desc,
string.format(tPLSIZETEXT[1], trackcount),
tPLSIZETEXT[2],
tPLSIZETEXT[3]);
if action == ADD_BUTTON then
trackcount = trackcount + increment
elseif action == SUB_BUTTON then
if trackcount < increment then increment = 1 end
trackcount = trackcount - increment
if trackcount < 1 then trackcount = 1 end
elseif action == OK_BUTTON then
ask = setup_get_repeat;
setup_get_playlist_size = nil
action = 0
end
end
ask = setup_get_playlist_size; -- \!FIRSTRUN!/
repeat -- SETUP MENU LOOP
show_setup_header()
ask()
rb.lcd_scroll_stop() -- I'm still wary of not doing this..
collectgarbage("collect")
if action == CANCEL_BUTTON then rb.lcd_scroll_stop(); return nil end
until (action == OK_BUTTON)
return play, min_repeat, trackcount;
end
--[[ Given the filenameDB file [database]
creates a random dynamic playlist with a default savename of [playlist]
containing [trackcount] tracks, played on completion if [play] is true]]
function create_random_playlist(database, playlist, trackcount, play)
if not database or not playlist or not trackcount then return end
if not play then play = false end
local file = io.open('/' .. database or "", "r") --read
if not file then rb.splash(100, string.format(sERROROPENFMT, database)) return end
local fsz = file:seek("end")
local fbegin
local posln = 0
local tag_len = TCHSIZE
local anchor_index
local ANCHOR_INTV
local track_index = setmetatable({},{__mode = "v"}) --[[ weak table values
this allows them to be garbage collected as space is needed / rebuilt as needed ]]
-- Read character function sets posln as file position
function readchrs(count)
if posln >= fsz then return nil end
file:seek("set", posln)
posln = posln + count
return file:read(count)
end
-- Check the header and get size + #entries
local tagcache_header = readchrs(DATASZ) or ""
local tagcache_sz = readchrs(DATASZ) or ""
local tagcache_entries = readchrs(DATASZ) or ""
if tagcache_header ~= sTCHEADER or
bytesLE_n(tagcache_sz) ~= (fsz - TCHSIZE) then
rb.splash(100, string.format(sINVALIDDBFMT, database))
return
end
local tag_entries = bytesLE_n(tagcache_entries)
play, min_repeat, trackcount = _setup_random_playlist(
tag_entries, play, min_repeat, trackcount);
_setup_random_playlist = nil
collectgarbage("collect")
-- how many lines can we fit on the screen?
local res, w, h = text_extent("I")
local max_w = rb.LCD_WIDTH / w
local max_h = rb.LCD_HEIGHT - h
local y = 0
rb.lcd_clear_display()
function get_tracks_random()
local tries, idxp
local tracks = 0
local str = ""
local t_lru = {}
local lru_widx = 1
local lru_max = min_repeat
if lru_max >= tag_entries then lru_max = tag_entries / 2 + 1 end
function do_progress_header()
rb.lcd_put_line(1, 0, string.format(sPROGRESSHDRFMT,tracks, trackcount))
rb.lcd_update()
--rb.sleep(300)
end
function show_progress()
local sdisp = str:match("([^/]+)$") or "?" --just the track name
rb.lcd_put_line(1, y, sdisp:sub(1, max_w));-- limit string length
y = y + h
if y >= max_h then
do_progress_header()
rb.lcd_clear_display()
y = h
end
end
-- check for repeated tracks
function check_lru(val)
if lru_max <= 0 or val == nil then return 0 end --user wants all repeats
local rv
local i = 1
repeat
rv = t_lru[i]
if rv == nil then
break;
elseif rv == val then
return i
end
i = i + 1
until (i == lru_max)
return 0
end
-- add a track to the repeat list (overwrites oldest if full)
function push_lru(val)
t_lru[lru_widx] = val
lru_widx = lru_widx + 1
if lru_widx > lru_max then lru_widx = 1 end
end
function get_index()
if ANCHOR_INTV > 1 then
get_index =
function(plidx)
local p = track_index[plidx]
if p == nil then
parse_database_offsets(plidx)
end
return track_index[plidx][1]
end
else -- all tracks are indexed
get_index =
function(plidx)
return track_index[plidx]
end
end
end
get_index() --init get_index fn
-- Playlist insert loop
while true do
str = nil
tries = 0
repeat
idxp = random(1, tag_entries)
tries = tries + 1 -- prevent endless loops
until check_lru(idxp) == 0 or tries > fsz -- check for recent repeats
posln = get_index(idxp)
tag_len = bytesLE_n(readchrs(DATASZ))
posln = posln + DATASZ -- idx = bytesLE_n(readchrs(DATASZ))
str = readchrs(tag_len) or "\0" -- Read the database string
str = str:match("^(%Z+)%z$") -- \0 terminated string
-- Insert track into playlist
if str ~= nil then
tracks = tracks + 1
show_progress()
push_lru(idxp) -- add to repeat list
if rb.playlist("insert_track", str) < 0 then
rb.splash(rb.HZ, sPLAYLISTERROR)
break; -- ERROR, PLAYLIST FULL?
end
end
if tracks >= trackcount then
do_progress_header()
break
end
-- check for cancel non-blocking
if rb.get_plugin_action(0) == CANCEL_BUTTON then
break
end
end
end -- get_files
function build_anchor_index()
-- index every n files
ANCHOR_INTV = 1 -- for small db we can put all the entries in ram
local ent = tag_entries / 1000 -- more than 10,000 will be incrementally loaded
while ent >= 10 do -- need to reduce the size of the anchor index?
ent = ent / 10
ANCHOR_INTV = ANCHOR_INTV * 10
end -- should be power of 10 (10, 100, 1000..)
--grab an index for every ANCHOR_INTV entries
local aidx={}
local acount = 0
local next_idx = 1
local index = 1
local tlen
if ANCHOR_INTV == 1 then acount = 1 end
while index <= tag_entries and posln < fsz do
if next_idx == index then
acount = acount + 1
next_idx = acount * ANCHOR_INTV
aidx[index] = posln
else -- fill the weak table, we already did the work afterall
track_index[index] = {posln} -- put vals inside table to make them collectable
end
index = index + 1
tlen = bytesLE_n(readchrs(DATASZ))
posln = posln + tlen + DATASZ
end
return aidx
end
function parse_database_offsets(plidx)
local tlen
-- round to nearest anchor entry that is less than plidx
local aidx = (plidx / ANCHOR_INTV) * ANCHOR_INTV
local cidx = aidx
track_index[cidx] = {anchor_index[aidx] or fbegin};
-- maybe we can use previous work to get closer to the desired offset
while track_index[cidx] ~= nil and cidx <= plidx do
cidx = cidx + 1 --keep seeking till we find an empty entry
end
posln = track_index[cidx - 1][1]
while cidx <= plidx do --[[ walk the remaining entries from the last known
& save the entries on the way to our desired entry ]]
tlen = bytesLE_n(readchrs(DATASZ))
posln = posln + tlen + DATASZ
track_index[cidx] = {posln} -- put vals inside table to make them collectable
if posln >= fsz then posln = fbegin end
cidx = cidx + 1
end
end
if trackcount ~= nil then
rb.splash(10, sSEARCHINGFILES)
fbegin = posln --Mark the beginning for later loops
tag_len = 0
anchor_index = build_anchor_index() -- index track offsets
if ANCHOR_INTV == 1 then
-- all track indexes are in ram
track_index = anchor_index
anchor_index = nil
end
rb.splash(10, sREMOVEPLAYLIST)
rb.audio("stop")
os.remove( playlistpath .. "/" .. playlist)
rb.playlist("remove_all_tracks")
rb.playlist("create", playlistpath .. "/", playlist)
--[[ --profiling
local starttime = rb.current_tick();
get_tracks_random()
local endtime = rb.current_tick();
rb.splash(1000, (endtime - starttime) .. " ticks");
end
if (false) then
--]]
get_tracks_random()
end
file:close()
collectgarbage("collect")
if trackcount and rb.playlist("amount") >= trackcount and play == true then
rb.playlist("start", 0, 0, 0)
end
end -- create_playlist
local function main()
if not rb.file_exists(rb.ROCKBOX_DIR .. "/database_4.tcd") then
rb.splash(rb.HZ, sINITDATABASE)
os.exit(1);
end
if rb.cpu_boost then rb.cpu_boost(true) end
rb.backlight_force_on()
if not rb.dir_exists(playlistpath) then
luadir.mkdir(playlistpath)
end
rb.lcd_clear_display()
rb.lcd_update()
collectgarbage("collect")
create_random_playlist(rb.ROCKBOX_DIR .. "/database_4.tcd",
"random_playback.m3u8", max_tracks, play_on_success);
rb.splash(rb.HZ * 2, sGOODBYE)
-- Restore user backlight settings
rb.backlight_use_settings()
if rb.cpu_boost then rb.cpu_boost(false) end
--[[
local used, allocd, free = rb.mem_stats()
local lu = collectgarbage("count")
local fmt = function(t, v) return string.format("%s: %d Kb\n", t, v /1024) end
-- this is how lua recommends to concat strings rather than ..
local s_t = {}
s_t[1] = "rockbox:\n"
s_t[2] = fmt("Used ", used)
s_t[3] = fmt("Allocd ", allocd)
s_t[4] = fmt("Free ", free)
s_t[5] = "\nlua:\n"
s_t[6] = fmt("Used", lu * 1024)
s_t[7] = "\n\nNote that the rockbox used count is a high watermark"
rb.splash_scroller(10 * rb.HZ, table.concat(s_t)) --]]
end --MAIN
main() -- BILGUS