[BOARD/PACKAGE] add FFMPEG to record&play /dev/fb0 + alsa capture (#48)

* [PACKAGE] downgrade FFMPEG(add) & X264
- use ffmpeg-3.1 thus downgrade ver. to working SDL1.2
- downgrade x264 to be inline with former ffmpeg
- uncomment FFSERVER build instructions (it is available in 3.1 version)

* [BOARD] 
- add `ffplay` & `ffmpeg` apps to record&play
- add `arecord` script for AUDIO capture (use alsaloop workaround)
- update appLinks with "params=&" for bg launch
- use `pkill` instead 'killall` for scripts (warning: it also checks for bash running under the same name)
- use FFPROBE to detect media format in `ffplay`
- for X264  use sources.buildroot.net (code.videolan.org src only works with git method)
- rm redundant usb Applink
- add 0003-ffplay-custom-sdlk.patch (to make hotkeys usable in miyoo)

board/miyoo/main/apps/arecord/audio_record.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+if pgrep "arecord" > /dev/null; then
+	killall arecord
+	while (pgrep "arecord"); do
+		sleep 1
+	done
+	rmmod snd-aloop.ko
+	rm /mnt/.asoundrc
+	alsactl init
+else
+#WARNING: This disables audio output to speakers by redirecting it to alsaloop capturing device's card
+	echo 'pcm.!default { type plug slave.pcm "hw:Loopback,0,0" }' > /mnt/.asoundrc
+	modprobe snd-aloop.ko
+	alsactl init
+	mkdir -p /mnt/output
+	arecord -q -c2 -D hw:Loopback,1,0 -f S16_LE "/mnt/output/audio_$(date +%Y%m%d%H%M%S).wav"
+fi

board/miyoo/main/apps/ffmpeg/ffplay_launch.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+if ffprobe -v error -select_streams v:0 -show_entries stream=codec_type "$1" | grep -q "video"; then
+	ffplay -autoexit -i "$1"
+elif ffprobe -v error -select_streams a:0 -show_entries stream=codec_type "$1" | grep -q "audio"; then
+	ffplay -nodisp -autoexit -i "$1"
+else
+	echo -en "Invalid video/audio format!"
+	# We're using SDL terminal to display above echo msg 
+	## because all stdout is parsed to /dev/null from gmenu2x and it's child ps
+	/mnt/apps/st/st -e "/bin/sh" "-c" "echo -e \"\n\n\n\n\n\n          Invalid video or audio format!\"; sleep 2"
+fi

board/miyoo/main/apps/ffmpeg/manual.txt

@@ -0,0 +1,11 @@
+FFPLAY shortcuts:
+-----------------------
+ESCAPE ("Select") = quit
+LSHIFT ("X"); f = fullscreen
+SPACE ("Y"); RETURN ("Start")= pause
+LCTRL ("B"); m = mute
+RSHIFT/RALT ("R3/L3"); 0/9 = increase/decrease volume
+LALT ("A"); s = step to next frame
+LEFT/RIGHT (-) = Seek backward/forward 10 seconds.
+DOWN/UP (-)= Seek backward/forward 1 minute.
+PAGEUP/PAGEDOWN ("L2/R2")= Seek to the previous/next chapter. If there are no chapters seek backward/forward 10 minutes.

board/miyoo/main/apps/ffmpeg/video_record.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+if pgrep "ffmpeg" > /dev/null; then
+	pkill ffmpeg
+else
+	mkdir -p /mnt/output
+	ffmpeg -f fbdev -r 8 -i /dev/fb0 -c:v mpeg4 -framerate 15 "/mnt/output/video_$(date +%Y%m%d%H%M%S).mp4" -nostdin
+fi

board/miyoo/main/gmenu2x/sections/applications/ffplay.launch

@@ -0,0 +1,5 @@
+title=FFPLAY
+description=Play a movie/audio file
+exec=/mnt/apps/ffmpeg/ffplay_launch.sh
+manual=/mnt/apps/ffmpeg/manual.txt
+selectordir=/mnt/output

board/miyoo/main/gmenu2x/sections/applications/record-audio

@@ -0,0 +1,4 @@
+title=AUDIO rec
+description=Start/Stop recording alsa HW audio output
+exec=/mnt/apps/arecord/audio_record.sh
+params=&

board/miyoo/main/gmenu2x/sections/applications/record-video

@@ -0,0 +1,4 @@
+title=VIDEO Rec
+description=Start/Stop recording FB0 video in the background
+exec=/mnt/apps/ffmpeg/video_record.sh
+params=&

board/miyoo/main/gmenu2x/sections/applications/usb-change_primary_partition

@@ -1,3 +0,0 @@
-title=USB change part.
-description=USB switch FAT partition
-exec=/mnt/apps/usb-serial-mass-storage/usb-change_primary_partition.sh