arch add small 3rd party libs to lvgl (#2569)

* move png, sjpg, bmp, gif, fs_if to extra/libs

* reorganize the examples

* update lv_conf_internal.h

* fix warnings

* add freetype

* remove unused assets

* add the new libs to build tests

* update the docs

scripts/jpg_to_sjpg.py

@@ -0,0 +1,138 @@
+##################################################################
+# sjpeg converter script version 1.0
+# Dependencies: (PYTHON-3)
+##################################################################
+SJPG_FILE_FORMAT_VERSION = "V1.00"  #
+JPEG_SPLIT_HEIGHT   = 16 
+##################################################################
+import math, os, sys, time
+from PIL import Image
+
+
+OUTPUT_FILE_NAME = ""
+INPUT_FILE       = ""
+
+
+if len(sys.argv) == 2:
+    INPUT_FILE = sys.argv[1]
+    OUTPUT_FILE_NAME = INPUT_FILE.split("/")[-1].split("\\")[-1].split(".")[0]
+else:
+    print("usage:\n\t python " + sys.argv[0] + " input_file.jpg")
+    sys.exit(0)
+
+try:
+    im = Image.open(INPUT_FILE)
+except:
+    print("\nFile not found!")
+    sys.exit(0)
+
+
+print("\nConversion started...\n")
+start_time = time.time()
+width, height = im.size
+
+print("Input:")
+print("\t" + INPUT_FILE)
+print("\tRES = " + str(width) + " x " + str(height) + '\n')
+
+
+lenbuf = []
+block_size = JPEG_SPLIT_HEIGHT;
+spilts = math.ceil(height/block_size)
+
+c_code = '''//LVGL SJPG C ARRAY\n#include "lvgl/lvgl.h"\n\nconst uint8_t ''' + OUTPUT_FILE_NAME + '''_map[] = {\n'''
+
+sjpeg_data = bytearray()
+sjpeg = bytearray()
+
+
+row_remaining = height;
+for i in range(spilts):
+    if row_remaining < block_size:
+        crop = im.crop((0, i*block_size, width, row_remaining + i*block_size))
+    else:
+        crop = im.crop((0, i*block_size, width, block_size + i*block_size))
+
+    row_remaining = row_remaining - block_size;
+    crop.save(str(i)+".jpg", quality=90)
+
+
+
+
+for i in range(spilts):
+    f = open(str(i)+".jpg", "rb")
+    a = f.read()
+    f.close()
+    sjpeg_data = sjpeg_data + a
+    lenbuf.append(len(a))
+
+header = bytearray()
+
+#4 BYTES
+header = header + bytearray("_SJPG__".encode("UTF-8"));
+
+#6 BYTES VERSION
+header = header + bytearray(("\x00" + SJPG_FILE_FORMAT_VERSION + "\x00").encode("UTF-8"));
+
+#WIDTH 2 BYTES
+header = header + width.to_bytes(2, byteorder='little');
+
+#HEIGHT 2 BYTES
+header = header + height.to_bytes(2, byteorder='little');
+
+#NUMBER OF ITEMS 2 BYTES
+header = header + spilts.to_bytes(2, byteorder='little');
+
+#NUMBER OF ITEMS 2 BYTES
+header = header + int(JPEG_SPLIT_HEIGHT).to_bytes(2, byteorder='little');
+
+for item_len in lenbuf:
+    # WIDTH 2 BYTES
+    header = header + item_len.to_bytes(2, byteorder='little');
+
+
+data = bytearray()
+
+sjpeg = header + sjpeg_data;
+
+if 1:
+    for i in range(len(lenbuf)):
+        os.remove(str(i) + ".jpg")
+
+
+f = open(OUTPUT_FILE_NAME+".sjpg","wb");
+f.write(sjpeg)
+f.close()
+
+new_line_threshold = 0
+for i in range(len(sjpeg)):
+    c_code = c_code + "\t" + str(hex(sjpeg[i])) + ","
+    new_line_threshold = new_line_threshold + 1
+    if (new_line_threshold >= 16):
+        c_code = c_code + "\n"
+        new_line_threshold = 0
+
+
+c_code = c_code + "\n};\n\nlv_img_dsc_t "
+c_code = c_code + OUTPUT_FILE_NAME + " = {\n"
+c_code = c_code + "\t.header.always_zero = 0,\n"
+c_code = c_code + "\t.header.w = " + str(width) + ",\n"
+c_code = c_code + "\t.header.h = " + str(height) + ",\n"
+c_code = c_code + "\t.data_size = " + str(len(sjpeg)) + ",\n"
+c_code = c_code + "\t.header.cf = LV_IMG_CF_RAW,\n"
+c_code = c_code + "\t.data = " + OUTPUT_FILE_NAME+"_map" + ",\n};"
+
+
+f = open(OUTPUT_FILE_NAME + '.c', 'w')
+f.write(c_code)
+f.close()
+
+
+time_taken = (time.time() - start_time)
+
+print("Output:")
+print("\tTime taken = " + str(round(time_taken,2)) + " sec")
+print("\tbin size = " + str(round(len(sjpeg)/1024, 1)) + " KB" )
+print("\t" + OUTPUT_FILE_NAME + ".sjpg\t(bin file)" + "\n\t" + OUTPUT_FILE_NAME + ".c\t\t(c array)")
+
+print("\nAll good!")