制作图片墙

今天我用各种工具组合，制作了一个图片墙，效果如下图： wall.jpg

大致过程如下

1. 去youtube下载视频，https://www.youtube.com/watch?v=9_OSXkatlEs
2. 用正则表达式解析视频的时长，使用了ffmepg，安装方法是brew install ffmpeg
3. 根据时长和想截取的图片数量，确定fps(截图频率)，使用ffmepg截图并保存图片
4. 使用pillow库将图片遍历，组合成一张大图

直接上代码：

import PIL
from PIL import Image, ImageFilter, ImageDraw, ImageFont
from random import randint
import glob
import ffmpeg
import subprocess
import re
from decimal import Decimal

video_path = '../data/video.mp4'
origin_cat = '../data/origin_cat.jpeg'
back_ground_path = '../data/back_ground.png'
frame_path = '../frames'

def get_video_length(path):
    """ffmpeg -i file_path生成的字符串中含有视频的时长：
    .....
    Duration: 00:03:58.98, start: 0.000000, bitrate: 709 kb/s
    .....
    通过正则表达式将其中的时分秒提取出来，转化为秒
    """
    process = subprocess.Popen(['/usr/local/bin/ffmpeg', '-i', path], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    stdout, stderr = process.communicate()
    matches = re.search(r"Duration:\s{1}(?P<hours>\d+):(?P<minutes>\d+):(?P<seconds>\d+\.\d+),", stdout.decode('utf-8'),
                        re.DOTALL).groupdict()

    hours = Decimal(matches['hours'])
    minutes = Decimal(matches['minutes'])
    seconds = Decimal(matches['seconds'])

    total = 0
    total += 60 * 60 * hours
    total += 60 * minutes
    total += seconds
    return float(total)


def capture_video(video_path, num):
    """将视频截取num张图片
    每10秒生成一个图片的语法
    ffmpeg -i ./data/video.mp4 -vf fps=1/10 ./frames/pic%4d.jpg
    """
    seconds = get_video_length(video_path)
    pfs = num / seconds  # 计算要截取num张图片，fps是多少(每秒几张图)
    cmd = f'ffmpeg -i {video_path} -vf fps={pfs} ../frames/pic%4d.jpg'  # 截取num张图片，放到'../frames/'目录下
    subprocess.run(cmd, shell=True)


def plot_pic_wall(saved_name):
    w_num = 10
    h_num = 10
    pics = sorted(glob.glob(frame_path + '/*'))
    im = Image.open(pics[0])
    w, h = im.size
    print(w, h, w*h)
    big_img = Image.new('RGB', (w * 10, h * 10), (255, 255, 255))
    positions = [(w * j, h * i) for i in range(w_num) for j in range(h_num)]
    count = 0
    for pic, position in zip(pics, positions):
        count += 1
        img = Image.open(pic)
        big_img.paste(img, position)
        if count > 0 and count % 10 == 0:
            big_img.save(saved_name)
            big_img = Image.open(saved_name)
            print('保存了一行')
    big_img = big_img.resize((w*5, h*5), PIL.Image.ANTIALIAS)  # 图像太大了，还是做小一点吧
    big_img.save(saved_name)
    print("图片墙保存成功")