MediaCapabilities codecTransitionsSupported Example

// SITE OBJECTIVE
// This site has a variety of codecs. It will prefer hw-secure CDM, but it's main
// priority is being able to transition between codecs. Not sure if this is realistic,
// but it helps exercise all the code.


function allTransitionSupported(info_list) {
  return info_list.every((info) => info.codec_transitions_supported);
}

(async _ => {

  // First try to setup hw-secure with transitions

  let hw_secure_configs = [ VP9_OPUS_HW_SECURE, H264_AAC_HW_SECURE ];
  let hw_secure_infos = await Promise.all(hw_secure_configs.map(config => decodingInfo(config)));
  let hw_secure_supported = allSupported(hw_secure_infos);
  if (hw_secure_supported && allTransitionsSupported(hw_secure_infos)) {
    setupPlayback(hw_secure_infos);
    return;
  }

  // HW-secure either wasn't supported, or couldn't transition. Let's see about sw-secure.

  let sw_secure_configs = [ VP9_OPUS_SW_SECURE, H264_AAC_SW_SECURE ];
  let sw_secure_infos = await Promise.all(sw_secure_configs.map(config => decodingInfo(config)));
  let sw_secure_supported = allSupported(sw_secure_infos);
  if (sw_secure_supported && allTransitionsSupported(sw_secure_infos)) {
      setupPlayback(sw_secure_infos);
      return;
    }
  }

  // Didn't get transitions with either. Fall back to h264+aac using the highest security available

  if (hw_secure_supported) {
    setupPlayback(hw_secure_infos.slice(1));
  } else if (sw_secure_supported) {
    setupPlayback(sw_secure_infos.slice(1));
  } else {
    alert('no supported configurations');
  }

})(); // End async wrapper