$c = [
    ["aid" => 8, "did" => 1],
    ["aid" => 2, "did" => 3],
    ["aid" => 3, "did" => 4],
    ["aid" => 5, "did" => 5],
    ["aid" => 2, "did" => 6],
    ["aid" => 2, "did" => 9],
];


 public function retainLargestDid($array) {
        $maxDids = [];
        $filteredArray = [];

        foreach ($array as $item) {
            $aid = $item['aid'];
            $did = $item['did'];

            // 检查是否已经有这个aid的记录，如果没有或者找到了更大的did，则更新记录
            if (!isset($maxDids[$aid]) || $did > $maxDids[$aid]) {
                $maxDids[$aid] = $did;
            }
        }

        // 遍历原始数组，只保留具有最大did的元素
        foreach ($array as $item) {
            if ($item['did'] === $maxDids[$item['aid']]) {
                $filteredArray[] = $item;
            }
        }

        return $filteredArray;
    }

libsvtav1 编码器适应较好

ffmpeg -i input.mp4 -c:v libsvtav1 -b:v 600k output.mp4

B站1080P 下789kbps 的视频码率 196kpbs音频【音频我觉得96kpbs就够了】

动漫 1080P更低

ffmpeg -i gjj.mp4 -c:v libsvtav1 -crf 42 -b:a 96k 42.mp4

DASH切片

ffmpeg -i 42.mp4 -c:v copy  -c:a copy -dash 1 -f dash output.mpd

Dplayer

<div id="dplayer"></div>
<script src="dash.min.js"></script>

DASH必须在Dplayer上面加装
<script src="DPlayer.min.js"></script>

<script>
const dp = new DPlayer({
    container: document.getElementById('dplayer'),
    video: {
        url: 'demo.mpd',
        type: 'dash',
    },
    pluginOptions: {
        dash: {
            // dash config
        },
    },
});
console.log(dp.plugins.dash); // Dash 实例
</script>

video: {
        url: 'dplayer.mp4',
        pic: 'dplayer.png',
        thumbnails: 'thumbnails.jpg',
        type: 'auto',
    }

import gc
from utime import ticks_ms, ticks_diff
import machine
import os

def pi(places=100):
    # 3 + 3*(1/24) + 3*(1/24)*(9/80) + 3*(1/24)*(9/80)*(25/168)
    # The numerators 1, 9, 25, ... are given by (2x + 1) ^ 2
    # The denominators 24, 80, 168 are given by (16x^2 -24x + 8)
    extra = 8
    one = 10 ** (places+extra)
    t, c, n, na, d, da = 3*one, 3*one, 1, 0, 0, 24

    while t > 1:
        n, na, d, da = n+na, na+8, d+da, da+32
        t = t * n // d
        c += t
    return c // (10 ** extra)

def pi_t(n=1000):
    gc.collect()
    t1 = ticks_ms()
    pi(n)
    t2 = ticks_ms()
    print('  ', ticks_diff(t2, t1), 'ms')


r = os.uname()
print('\n\n')
print('Pi calculation performance test')
print('===============================')
print('chip:', r.sysname)
print('ver: ', r.version)
try:
    print('Freq:', machine.freq())
except:
    print('Freq: unknow')
print('Ram: ', gc.mem_free() + gc.mem_alloc())
for i in (100, 500, 1000, 2000, 5000, 10000, 100000):
    try:
        print('\nCalc {} bits pi'.format(i))
        pi_t(i)
    except:
        print('Calc error!')
        
        
        

RP2350	150	486848	1.24	11	82	279	1071	8782	42860
RP2350	250	486848	1.24	7	49	167	643	5270	25717
RP2350	300	486848	1.24	5	41	139	536	4391	21430
RP2350（不稳定）	320	486848	1.24	5	38	131	503	4116	20091