奇怪的 chrome 视频解码问题

来源于 b 站的 banner 。

貌似 chrome 解码.webm格式的视频是软解，cpu 飙高风扇狂转，而解码.mp4却是硬件解码。二者视频 codec 一致，只是封装后缀不一样。。。

Input #0, matroska,webm, from 'a6f3f362-14c3-4dfd-8801-d69e8547a529.webm':
  Metadata:
    encoder         : libwebm-0.2.1.0
    creation_time   : 2024-09-25T18:16:52.000000Z
  Duration: 00:00:01.58, start: -0.007000, bitrate: 331 kb/s
  Stream #0:0(eng): Video: vp9 (Profile 0), yuv420p(tv), 3200x300, SAR 1:1 DAR 32:3, 12 fps, 12 tbr, 1k tbn (default)
      Metadata:
        alpha_mode      : 1
  Stream #0:1(eng): Audio: opus, 48000 Hz, stereo, fltp (default)

转下面.mp4硬解

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'a.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2mp41
    encoder         : Lavf61.3.100
  Duration: 00:00:01.60, start: 0.000000, bitrate: 227 kb/s
  Stream #0:0[0x1](eng): Video: vp9 (Profile 0) (vp09 / 0x39307076), yuv420p(tv), 3200x300, 220 kb/s, SAR 1:1 DAR 32:3, 12 fps, 12 tbr, 16k tbn (default)
      Metadata:
        handler_name    : VideoHandler
        vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](eng): Audio: opus (Opus / 0x7375704F), 48000 Hz, stereo, fltp, 1 kb/s (default)
      Metadata:
        handler_name    : SoundHandler
        vendor_id       : [0][0][0][0]