教你在Linux中从视频流截取图片帧(ffmpeg)

说明: 使用到的 依赖包  

1. ffmpeg

sudo apt update 
sudo apt-get install ffmpeg

2. imagemagick (选装)
(检测图像边缘信息推断清晰度,如果是简单截取但个图像帧=>用不到<=)

sudo apt-get install imagemagick

备注: 
指令及相关参数说明

#!/bin/bash

# 删除指定目录下已有的图片
rm -f /data/hikuser/handler_video_to_picture/output*.jpg

# 检查是否提供了视频流 URL 参数
if [ "$#" -ne 1 ]; then
    echo "Usage: ${0##*/} <video_stream_url>"
    exit 1
fi

# 视频流 URL
VIDEO_URL="$1"

# 检查输出目录是否存在
if [ ! -d "/data/hikuser/handler_video_to_picture" ]; then
    echo "Directory /data/hikuser/handler_video_to_picture does not exist."
    exit 1
fi

# 执行 ffmpeg 命令提取帧，每10帧选择一帧, 一共提取5张
if ! ffmpeg -i "$VIDEO_URL" -vf "select='not(mod(n,10))'" -frames:v 5 -q:v 1 /data/hikuser/handler_video_to_picture/output_%03d.jpg; then
    echo "ffmpeg command failed."
    exit 1
fi

# 执行检测图片清晰度的脚本
# if [ -f /data/hikuser/handler_video_to_picture/detect_sharpness.sh ]; then
#    /bin/bash /data/hikuser/handler_video_to_picture/detect_sharpness.sh
# else
#    echo "detect_sharpness.sh script not found!"
#    exit 1
# fi

#!/bin/bash

# 初始化最大边缘值和最清晰的图片变量
max_edge_value=0
sharpest_image=""

# 进入图片所在目录
cd /data/hikuser/handler_video_to_picture || exit 1

# 遍历每张图片并计算边缘值
for img in output_*.jpg; do
    # 计算图片的边缘检测值
    edge_value=$(convert "$img" -edge 1 -format "%[mean]" info:)
    echo "$img 边缘检测值: $edge_value"
    
    # 比较边缘值，保留最大值对应的图片
    if (( $(echo "$edge_value > $max_edge_value" | bc -l) )); then
        max_edge_value=$edge_value
        sharpest_image=$img
    fi
done

# 输出最清晰的图片
echo "最清晰的图片是: $sharpest_image"

# 删除其他图片
for img in output_*.jpg; do
    if [ "$img" != "$sharpest_image" ]; then
        rm "$img"
    fi
done

# 将最清晰的图片重命名为 output.jpg
mv "$sharpest_image" /data/hikuser/handler_video_to_picture/output.jpg

echo "已删除其他图片，保留最清晰的图片: $sharpest_image"

#!/bin/bash

# 检查是否提供了文件夹名称参数
if [ "$#" -ne 1 ]; then
    echo "Usage: ${0##*/} <directory_name>"
    exit 1
fi

# 文件夹名称
DIR_NAME="$1"

# 检查文件夹是否存在
if [ -d "$DIR_NAME" ]; then
    echo "Directory '$DIR_NAME' already exists."
else
    # 创建文件夹
    mkdir -p "$DIR_NAME"
    if [ $? -eq 0 ]; then
        echo "Directory '$DIR_NAME' has been created."
    else
        echo "Failed to create directory '$DIR_NAME'."
        exit 1
    fi
fi