ios wx.compressVideo压缩前后大小不变问题

安卓手机使用wx.compressVideo压缩没有问题就是慢了点。。iOS使用wx.compressVideo压缩视频的大小基本没有变化

wx.compressVideo({
            bitrate: 720,
            fps: 60,
            quality: 'medium',
            resolution: 1,
            src: videoList[0].tempFilePath,
            success(comRes) {
              console.log("comRes=-==", comRes)
              if (comRes.size / 1024 > 45) {
                that.setUpload(2)
              } else {
                console.log("压缩完成", new Date())
                videoList[0] = comRes;
                that.uploading(imgList, videoList, data)
              }
            },
            fail(comErr) {
              that.setUpload(2)
              console.log("comErr=-==", comErr)
            }
          })