ffprobe参数show_entries

之前一直没有理解show_entries的意义，实际上show_entries参数的意思是对输出结果进行定制，如果不加的话 就是输出全部信息，添加了就输出指定的信息

这里以format为例

ffprobe -show_entries format -v quiet -of json -i "/root/test/mnt//10.mp4"

会输出

{
    "format": {
        "filename": "/root/test/mnt//10.mp4",
        "nb_streams": 2,
        "nb_programs": 0,
        "format_name": "mov,mp4,m4a,3gp,3g2,mj2",
        "format_long_name": "QuickTime / MOV",
        "start_time": "0.000000",
        "duration": "119.998000",
        "size": "7134116",
        "bit_rate": "475615",
        "probe_score": 100,
        "tags": {
            "major_brand": "isom",
            "minor_version": "512",
            "compatible_brands": "isomiso2avc1mp41",
            "encoder": "Lavf58.20.100"
        }
    }
}

如果使用下面的代码

ffprobe -show_entries format=duration,size,bit_rate -v quiet -of json -i "/root/test/mnt//10.mp4"

就只输出如下信息了

{
    "format": {
        "duration": "119.998000",
        "size": "7134116",
        "bit_rate": "475615"
    }
}