Prepare for publish

README.md

@@ -0,0 +1,27 @@
+# Bad Apple!! for Sansa Clip+ (Rockbox Lua)
+
+Bad Apple!! video player implemented in Lua for Rockbox, designed to run on the Sansa Clip+ MP3 player.
+
+Video data assumes a 128x64 display with a 2px gap between visible regions.
+
+## Files for playing:
+- badapple.lua: main script, copy to player storage or SD card
+- vid.mp3 (download in Releases): audio data, MP3 format, copy to main script location
+- vid.bin (download in Releases): video data, display native format, copy to main script location
+
+## Additional files:
+- vidsrc.mp4 (not provided): 30fps video source, 2:1 aspect ratio
+- vidextract.bat: extracts vidsrc.mp4 to frame images and vid.mp3, requires ffmpeg
+- writedata.py: converts frame images to display native format, vid.bin
+- vidframes: frame image target for vidextract/writedata
+
+## Theory of operation:
+Audio is played natively by the Rockbox MP3 codec.
+
+Video data is stored at pre-dithered 1-bit-per-pixel, in native display order. It is dithered at 100fps.
+The data is read from the file and blitted directly to the display.
+Each frame is delayed approximately 1/100th of a second, which achieves rough speed sync, then frames are skipped to maintain time sync.
+As the source data is only 30fps before dithering, these skips are not noticeable.
+I wanted to do some kind of compression, but both ends of the process use strings to store the binary data, and Lua's string manipulation is too slow for this.
+
+The Lua script also performs some extra functions like setting the display to maximum brightness, and clearing some settings to ensure the audio plays at the right speed/pitch.

badapple.lua

@@ -0,0 +1,81 @@
+require("actions")
+require("rbsettings")
+require("settings")
+--mathex=require("math_ex")
+do_play=true
+
+datafile = nil
+
+function prepare_data(vidfn,audfn)
+	-- video
+	root = rb.current_path()
+	datafile = io.open(root..vidfn,"rb")
+	rb.sleep(rb.HZ/10)
+	-- audio
+	audfile=io.open(root..'_.m3u','w')
+	audfile:write(root..audfn..'\n')
+	audfile:close()
+	rb.playlist('create',root,'_.m3u')
+	rb.yield()
+	rb.playlist('start',0,0*1000,0)
+	rb.audio("pause") -- immediately pause - add silence at the start to avoid click
+end
+
+function play()
+	if datafile == nil then return end
+	do_play = true
+	-- get that data flowing! not sure why this helps. cache?
+	for i = 1,50 do
+		datafile:read(1024)
+	end
+	datafile:seek("set",0)
+	rb.lcd_clear_display() -- blank screen
+	rb.lcd_update()
+	rb.sleep(rb.HZ/2)
+	rb.yield()
+	collectgarbage("collect")
+	lastframe = -1
+	dat = nil
+	rb.audio("resume")
+	while do_play do
+		if rb.get_plugin_action(0)==rb.actions.PLA_CANCEL then break end -- kill on button
+		if rb.audio("status") == 0 then break end -- kill on stop
+		playtime = rb.audio("elapsed")
+		if playtime == nil then break end
+		timeframe = (playtime / 10) + 20 -- 100fps data
+		if timeframe >= 0 then
+			if lastframe > timeframe then break end -- kill on repeat
+			if lastframe < timeframe then
+				while lastframe < timeframe-20 do -- pos sync
+					datafile:seek("cur",1024)
+					lastframe = lastframe + 1
+				end
+				dat = datafile:read(1024)
+				lastframe = lastframe + 1
+			end
+			if dat == nil then break end -- kill on data end
+			rb.lcd_blit_mono(dat,nil,0,0,128,8,128)
+			rb.sleep(rb.HZ/100) -- rate sync
+		end
+	end
+	datafile:close()
+end
+
+--MAIN PROGRAM
+rb.backlight_force_on() -- disable timeout
+rb.cpu_boost(true) -- enable overclock
+rb.audio('stop') -- clear currently playing
+rb.sound_set_pitch(10000) -- reset pitch to +0
+rb.lcd_clear_display() -- blank screen
+rb.lcd_update()
+rb.lcd_set_contrast(999) -- full brightness
+prepare_data("vid.bin","vid.mp3") -- get files ready
+play() -- play video
+rb.audio('stop') -- stop music
+os.remove(rb.current_path()..'_.m3u') -- remove temp playlist
+rb.lcd_set_contrast(rb.settings.read("global_settings",rb.system.global_settings.contrast,"system")) -- restore brightness
+rb.backlight_use_settings() -- restore timeout
+rb.lcd_clear_display() -- blank screen
+rb.lcd_update()
+rb.sleep(20) -- wait a moment
+rb.cpu_boost(false) -- disable overclock

vidextract.bat

@@ -0,0 +1,6 @@
+@echo off
+del /Q vidframes\*
+del vid.mp3
+ffmpeg -i vidsrc.mp4 -s 132x66 -sws_flags neighbor vidframes/frame%%04d.png
+ffmpeg -i vidsrc.mp4 -q:a 0 -map a vid.mp3
+pause

writedata.py

@@ -0,0 +1,49 @@
+from PIL import Image
+import os
+import sys
+import random
+
+def itoxy(i):
+    ipage = i&1023
+    x = ipage/8
+    y = 7-ipage&7
+    y += (i//1024)*8
+    if y >= 16:
+        y += 2
+    x += 2
+    return (x,y)
+
+f = open('vid.bin', 'w+b')
+random.seed("ksk2020")
+frame_multiplier = 4 # 30 -> 120
+frame_skip_every = 6 # 120 -> 100
+frame_limit = -1
+fcnt = 0
+scnt = 0
+for filename in os.listdir("vidframes"):
+    if filename.endswith(".png"):
+        sys.stdout.write(filename+"\n")
+        fi = Image.open(os.path.join("vidframes", filename)).convert("RGB")
+        px = fi.load()
+        for fm in range(frame_multiplier):
+            scnt = (scnt + 1) % frame_skip_every
+            if scnt == 0:
+                continue
+            byte_arr = [0]*1024
+            for i in range(1024):
+                byte = 0
+                for j in range(8):
+                    k = i*8+j
+                    pv = px[itoxy(k)][1]
+                    pv /= 255
+                    pv = (pv * 1.04) - 0.02
+                    #pv = 0.5
+                    pv = 1 if pv >= random.random() else 0
+                    byte += byte + pv
+                byte_arr[i] = byte
+            binary_format = bytearray(byte_arr)
+            f.write(binary_format)
+        fcnt += 1
+        if fcnt == frame_limit:
+            break
+f.close()