Incomplete Picture Frame / Photo Slideshow Python code for Raspberry Pi and Touchscreen Display using Framebuffer.

Picture Frame photo slideshow Raspberry Pi Framebuffer working code

import os
import stat
import pygame
import time
import random

# https://learn.adafruit.com/pi-video-output-using-pygame/pointing-pygame-to-the-framebuffer

drivers = ['directfb', 'fbcon', 'svgalib']
background = (255,255,0)

found = False
for driver in drivers:
    if not os.getenv('SDL_VIDEODRIVER'):
        os.putenv('SDL_VIDEODRIVER', driver)
    try:
        pygame.display.init()
    except pygame.error:
        print ('Driver: {0} failed.'.format(driver))
        continue
    found = True
    break

if not found:
   raise Exception('No suitable video driver found!')

def main(startdir="/media/frame/flickr"):
    global file_list, title, waittime

    pygame.init()
    if not pygame.image.get_extended():
        print ("Your Pygame isn't built with extended image support.")
        print ("It's likely this isn't going to work.")

    walktree(startdir, addtolist)  # this may take a while...
    if len(file_list) == 0:
        print ("Sorry. No images found. Exiting.")
        sys.exit(1)
    random.shuffle(file_list)

    modes = pygame.display.list_modes()
#   print (modes)
#   print (max(modes))
#   pygame.display.set_mode(max(modes))
    pygame.display.set_mode((800,480))
    screen = pygame.display.get_surface()
    pygame.display.set_caption(title)
    pygame.display.toggle_fullscreen()

    current = 0
    alpha = 0
    alpha2 = 255
    num_files = len(file_list)

    screen.fill((0,0,0))

    # https://github.com/bradmontgomery/pgSlideShow

    while(True):
        try:
            img = pygame.image.load(file_list[current])
            img = img.convert_alpha()
            # rescale the image to fit the current display
            #img = pygame.transform.scale(img, max(modes))
            scr = (max(modes))
            scr = ((800,480))
            #print (scr[0])
            img = aspect_scale(img,scr[0],scr[1])
            img_rect = img.get_rect(center = screen.get_rect().center)
            while alpha >0 and alpha2 < 255:
               if alpha > 0:
               # Reduce alpha each frame.
                   alpha -= 4
                   alpha = max(0, alpha)  # Make sure it doesn't go below 0.
                   surf = change_alpha(img_old, alpha)
               if alpha2 < 255:
                   alpha2 += 4
                   alpha2 = min(255, alpha2)
                   surf2 = change_alpha(img, alpha2)

               screen.fill((0, 0, 0))
               screen.blit(surf, img_rect_old)
               screen.blit(surf2, img_rect)
               pygame.display.flip()

        #    print ("wait")
        #    time.sleep(waittime)
        except pygame.error as err:
            print ("Failed to display %s: %s" % (file_list[current], err))

        # When we get to the end, re-start at the beginning
        current = (current + 1) % num_files;
        alpha = 255
        alpha2 = 0
        img_old = img
        img_rect_old = img_rect
        screen.blit(img_old, img_rect_old)
        pygame.display.update()
        time.sleep(waittime)

def change_alpha(orig_surf, alpha):
    """Create a copy of orig_surf with the desired alpha value.
    https://stackoverflow.com/questions/47682103/pygame-smooth-transform-of-image-surface
    This function creates another surface with the desired alpha
    value and then blits it onto the copy of the original surface
    with the `BLEND_RGBA_MULT` flag to change the transparency."""
    surf = orig_surf.copy()
    # This surface is used to adjust the alpha of the txt_surf.
    alpha_surf = pygame.Surface(surf.get_size(), pygame.SRCALPHA)
    # alpha_surf = pygame.Surface((800,480), pygame.SRCALPHA)
    alpha_surf.fill((255, 255, 255, alpha))  # Set the alpha value.
    surf.blit(alpha_surf, (0, 0), special_flags=pygame.BLEND_RGBA_MULT)
    return surf


def walktree(top, callback):
    """recursively descend the directory tree rooted at top, calling the
    callback function for each regular file. Taken from the module-stat
    example at: http://docs.python.org/lib/module-stat.html
    """
    for f in os.listdir(top):
        pathname = os.path.join(top, f)
        mode = os.stat(pathname)[stat.ST_MODE]
        if stat.S_ISDIR(mode):
            # It's a directory, recurse into it
            walktree(pathname, callback)
        elif stat.S_ISREG(mode):
            # It's a file, call the callback function
            callback(pathname)
        else:
            # Unknown file type, print a message
            print ('Skipping %s' % pathname)


def addtolist(file, extensions=['.png', '.jpg', '.jpeg', '.gif', '.bmp']):
    """Add a file to a global list of image files."""
    global file_list  # ugh
    filename, ext = os.path.splitext(file)
    e = ext.lower()
    # Only add common image types to the list.
    if e in extensions:
        print ('Adding to list: ', file)
        file_list.append(file)
    else:
        print ('Skipping: ', file, ' (NOT a supported image)')

def aspect_scale(img,bx,by):
    ##http://www.pygame.org/pcr/transform_scale  Scales 'img' to fit into box bx/by.
    ## This method will retain the original image's aspect ratio """
    ix,iy = img.get_size()
    if ix > iy:
        # fit to width
        scale_factor = bx/float(ix)
        sy = scale_factor * iy
        if sy > by:
            scale_factor = by/float(iy)
            sx = scale_factor * ix
            sy = by
        else:
            sx = bx
    else:
        # fit to height
        scale_factor = by/float(iy)
        sx = scale_factor * ix
        if sx > bx:
            scale_factor = bx/float(ix)
            sx = bx
            sy = scale_factor * iy
        else:
            sy = by

    return pygame.transform.scale(img,(int(sx),int(sy)))

title = "test"
waittime = 5
file_list = []
main()

Todo:

• tidy up file list
• mqtt support
• weather / other information overlay (via MQTT)