Media Key System Management (C/C++)

Using the MediaKeySystem class of the DRM module, you can manage MediaKeySystem instances, generate media key system requests, process responses to these requests, create media key sessions, manage offline media keys, and obtain DRM statistics and device configuration information.

How to Develop

Read DRM for the API reference.

  1. Import the NDK.

     #include "multimedia/drm_framework/interfaces/kits/c/drm_capi/common/native_drm_common.h"
 #include "multimedia/drm_framework/interfaces/kits/c/drm_capi/common/native_drm_err.h"
 #include "multimedia/drm_framework/interfaces/kits/c/drm_capi/include/native_mediakeysession.h"
 #include "multimedia/drm_framework/interfaces/kits/c/drm_capi/include/native_mediakeysystem.h"

  2. Link the DRM NDK dynamic library in the CMake script.

     target_link_libraries(PUBLIC libnative_drm.so)

  3. Call OH_MediaKeySystem_IsSupported in the MediaKeySystem class to check whether the device supports the media key system with a given name, MIME type, and content protection level.

     const char *uuid = "com.wiseplay.drm";
 const char *mimeType = "video/mp4";
 DRM_ContentProtectionLevel level = CONTENT_PROTECTION_LEVEL_SW_CRYPTO;
 ret = OH_MediaKeySystem_IsSupported(uuid);
 if (ret != true) {
     OH_LOG_ERROR(LOG_APP, "The device does not support the DRM scheme.");
 }
 ret = OH_MediaKeySystem_IsSupported2(uuid, mimeType);
 if (ret != true) {
     OH_LOG_ERROR(LOG_APP, "The device does not support the DRM scheme.");
 }
 ret = OH_MediaKeySystem_IsSupported3(uuid, mimeType, level);
 if (ret != true) {
     OH_LOG_ERROR(LOG_APP, "The device does not support the DRM scheme.");
 }

  4. Call OH_MediaKeySystem_GetMediaKeySystems in the MediaKeySystem class to obtain the names and UUIDs of the DRM plug-ins supported by the device.

     uint32_t count = 10;
 DRM_MediaKeySystemDescription infos[10];
 memset(infos, 0, sizeof(infos));
 Drm_ErrCode ret = OH_MediaKeySystem_GetMediaKeySystems(infos, &count);
 if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_GetMediaKeySystems failed.");
  return ret;
 }

  5. Call OH_MediaKeySystem_Create in the MediaKeySystem class to create a MediaKeySystem instance.

     MediaKeySystem *keySystem = NULL;
 const char *name = "com.wiseplay.drm";
 ret = OH_MediaKeySystem_Create(name, &keySystem);
 if (ret != DRM_OK) {
     OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Create failed.");
 }
 ret = OH_MediaKeySystem_Destroy(keySystem);
 if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Destroy failed.");
  return ret;
 }

  6. Call OH_MediaKeySystem_SetConfigurationString and OH_MediaKeySystem_GetConfigurationString in the MediaKeySystem class to set and obtain the device configuration information, respectively. The configuration information varies according to the DRM scheme and generally contains the following types: device attributes, session attributes, and output protection status attributes.

    The attribute names include "vendor", "version", "description", "algorithms", "maxSessionNum", "maxHDCPLevel", "currentHDCPLevel", "maxADCPLevel", and "currentADCPLevel".

     // Create a MediaKeySystem instance.
 MediaKeySystem *keySystem = NULL;
 const char *name = "com.wiseplay.drm";
 ret = OH_MediaKeySystem_Create(name, &keySystem);
 if (ret != DRM_OK) {
     OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Create failed.");
 }
 // Set a configuration item in the form of a string.
 ret = OH_MediaKeySystem_SetConfigurationString(keySystem, "version", "2.0");
 if (ret == DRM_OK) {
     OH_LOG_INFO(LOG_APP, "MediaKeySystem_SetConfigurationString success ");
 } else {
     OH_LOG_ERROR(LOG_APP, "MediaKeySystem_SetConfigurationString failed. %d ", ret);
 }
 char value[32];
 int32_t valueLen = 32;
  // Obtain the value of a configuration item in the form of a string.
 ret = OH_MediaKeySystem_GetConfigurationString(keySystem, "version", value, valueLen);
 if (ret == DRM_OK) {
     OH_LOG_INFO(LOG_APP, "OH_MediaKeySystem_GetConfigurationString success ");
 } else {
     OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_GetConfigurationString failed. %d ", ret);
 }
 // Set a configuration item in the form of a byte array.
 char description[5] = {1, 2, 3, 4, 5};
 ret = OH_MediaKeySystem_SetConfigurationByteArray(keySystem, "description", description, 5);
 if (ret == DRM_OK) {
     OH_LOG_INFO(LOG_APP, "OH_MediaKeySystem_SetConfigurationByteArray success ");
 } else {
     OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_SetConfigurationByteArray failed. %d ", ret);
 }
  // Obtain the value of a configuration item in the form of a byte array.
 unsigned char descriptionValue[32];
 uint32_t descriptionValueLen = 32;
 ret = OH_MediaKeySystem_GetConfigurationByteArray(keySystem, "description", descriptionValue, &descriptionValueLen);
 if (ret == DRM_OK) {
     OH_LOG_INFO(LOG_APP, "OH_MediaKeySystem_GetConfigurationByteArray success ");
 } else {
     OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_GetConfigurationByteArray failed. %d ", ret);
 }
 ret = OH_MediaKeySystem_Destroy(keySystem);
 if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Destroy failed.");
  return ret;
 }

  7. Call OH_MediaKeySystem_GetMaxContentProtectionLevel in the MediaKeySystem class to obtain the maximum content protection level.

     MediaKeySystem *keySystem = NULL;
 const char *name = "com.wiseplay.drm";
 ret = OH_MediaKeySystem_Create(name, &keySystem);
 if (ret != DRM_OK) {
     OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Create failed.");
 }
 DRM_ContentProtectionLevel contentProtectionLevel = CONTENT_PROTECTION_LEVEL_UNKNOWN;
 ret = OH_MediaKeySystem_GetMaxContentProtectionLevel(keySystem, &contentProtectionLevel);
 if (ret != DRM_OK) {
     OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_GetMaxContentProtectionLevel failed.");
 }
 ret = OH_MediaKeySystem_Destroy(keySystem);
 if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Destroy failed.");
  return ret;
 }

  8. Call OH_MediaKeySystem_SetMediaKeySystemCallback in the MediaKeySystem class to set a callback to listen for the media key system status.

     DRM_ErrCode TestSystemCallBack(DRM_EventType eventType, uint8_t *info,
     int32_t infoLen, char *extra)
 {
     OH_LOG_INFO(LOG_APP, "TestSystemCallBack");
 }
 DRM_ErrCode MediaKeySystem_SetMediaKeySystemCallback()
 {
 MediaKeySystem *keySystem = NULL;
 const char *name = "com.wiseplay.drm";
 ret = OH_MediaKeySystem_Create(name, &keySystem);
 if (ret != DRM_OK) {
     OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Create failed.");
 }
 ret = OH_MediaKeySystem_SetMediaKeySystemCallback(keySystem,
     TestSystemCallBack);
 if (ret != DRM_OK) {
     OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_SetMediaKeySystemCallback failed.");
 }
 ret = OH_MediaKeySystem_Destroy(keySystem);
 if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Destroy failed.");
  return ret;
 }
 return ret;
}

  9. Call OH_MediaKeySystem_CreateMediaKeySession in the MediaKeySystem class to create a MediaKeySession instance.

     MediaKeySystem *keySystem = NULL;
 const char *name = "com.wiseplay.drm";
 ret = OH_MediaKeySystem_Create(name, &keySystem);
 if (ret != DRM_OK) {
     OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Create failed.");
 }
 DRM_ContentProtectionLevel level = CONTENT_PROTECTION_LEVEL_HW_CRYPTO;
 MediaKeySession *keySession = NULL;
 ret = OH_MediaKeySystem_CreateMediaKeySession(keySystem, &level, &keySession);
 if (ret != DRM_OK) {
     OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_CreateMediaKeySession failed.");
 }
 ret = OH_MediaKeySession_Destroy(keySession);
 if (ret != DRM_OK) {
   OH_LOG_ERROR(LOG_APP, "OH_MediaKeySession_Destroy failed.");
   return ret;
 }
 ret = OH_MediaKeySystem_Destroy(keySystem);
 if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Destroy failed.");
  return ret;
 }

  10. Call OH_MediaKeySystem_GenerateKeySystemRequest in the MediaKeySystem class to generate a media key system request, and call OH_MediaKeySystem_ProcessKeySystemResponse in the MediaKeySystem class to process a response to the request.

    DRM_ErrCode MediaKeySystem_SetAndProcessMediaKeySystem()
{
 unsigned char *request = NULL;
 int32_t requestLen;
 char defaultUrl[MAX_DEFAULT_URL_LEN];
 MediaKeySystem *keySystem = NULL;
 const char *name = "com.wiseplay.drm";
 ret = OH_MediaKeySystem_Create(name, &keySystem);
 if (ret != DRM_OK) {
   OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Create failed.");
   return ret;
 }

 ret = OH_MediaKeySystem_GenerateKeySystemRequest(keySystem, &request,
  &requestLen, &defaultUrl, MAX_DEFAULT_URL_LEN);
 if (ret != DRM_OK) {
   OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_GenerateKeySystemRequest failed.");
   return ret;
 }
 unsigned char keySystemResponse[50] = {0};
 size_t keySystemResponseLen = sizeof(keySystemResponse);
 ret = OH_MediaKeySystem_ProcessKeySystemResponse(keySystem, keySystemResponse, keySystemResponseLen);
 if (ret != DRM_OK) {
   OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_GenerateKeySystemRequest failed.");
   return ret;
 }
 ret = OH_MediaKeySystem_Destroy(keySystem);
 if (ret != DRM_OK) {
   OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Destroy failed.");
   return ret;
 }
 return ret;
}

  11. Call OH_MediaKeySystem_GetOfflineMediaKeyIds in the MediaKeySystem class to obtain the IDs of offline media keys.

    MediaKeySystem *keySystem = NULL;
const char *name = "com.wiseplay.drm";
ret = OH_MediaKeySystem_Create(name, &keySystem);
if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Create failed.");
  return ret;
}
DRM_OfflineMediakeyIdArray offlineMediaKeyIds;
ret = OH_MediaKeySystem_GetOfflineMediaKeyIds(keySystem, &offlineMediaKeyIds);
ret = OH_MediaKeySystem_Destroy(keySystem);
if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Destroy failed.");
  return ret;
}

  12. Call OH_MediaKeySystem_GetOfflineMediaKeyStatus in the MediaKeySystem class to obtain the status of the offline media keys.

    MediaKeySystem *keySystem = NULL;
const char *name = "com.wiseplay.drm";
ret = OH_MediaKeySystem_Create(name, &keySystem);
if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Create failed.");
  return ret;
}
DRM_OfflineMediaKeyStatus OfflineMediaKeyStatus = OFFLINE_MEDIA_KEY_STATUS_UNKNOWN;
uint8_t offlineMediaKeyId[16] = "mediaKeyIdTest01";
ret = OH_MediaKeySystem_GetOfflineMediaKeyStatus(keySystem, offlineMediaKeyId, sizeof(offlineMediaKeyId)/sizeof(uint8_t), &OfflineMediaKeyStatus);
if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_GetOfflineMediaKeyStatus failed.");
  return ret;
}
ret = OH_MediaKeySystem_Destroy(keySystem);
if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Destroy failed.");
  return ret;
}

  13. Call OH_MediaKeySystem_ClearOfflineMediaKeys in the MediaKeySystem class to clear the offline media keys.

    MediaKeySystem *keySystem = NULL;
const char *name = "com.wiseplay.drm";
ret = OH_MediaKeySystem_Create(name, &keySystem);
if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Create failed.");
  return ret;
}
uint8_t meidaKeyId[8] = {1, 2, 3, 4, 5, 6, 7, 8};
ret = OH_MediaKeySystem_ClearOfflineMediaKeys(keySystem,
    meidaKeyId, sizeof(meidaKeyId)/sizeof(uint8_t));
if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_ClearOfflineMediaKeys failed.");
  return ret;
}
ret = OH_MediaKeySystem_Destroy(keySystem);
if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Destroy failed.");
  return ret;
}

  14. Call OH_MediaKeySystem_GetCertificateStatus in the MediaKeySystem class to obtain the device certificate status.

    MediaKeySystem *keySystem = NULL;
const char *name = "com.wiseplay.drm";
ret = OH_MediaKeySystem_Create(name, &keySystem);
if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Create failed.");
  return ret;
}
DRM_CertificateStatus certStatus = CERT_STATUS_INVALID;
ret = OH_MediaKeySystem_GetCertificateStatus(mediaKeySystem,
    &certStatus);
if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_GetCertificateStatus failed.");
  return ret;
}
ret = OH_MediaKeySystem_Destroy(keySystem);
if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Destroy failed.");
  return ret;
}

  15. Call OH_MediaKeySystem_Destroy in the MediaKeySystem class to destroy this MediaKeySystem instance.

    MediaKeySystem *keySystem = NULL;
const char *name = "com.wiseplay.drm";
ret = OH_MediaKeySystem_Create(name, &keySystem);
if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Create failed.");
  return ret;
}
ret = OH_MediaKeySystem_Destroy(keySystem);
if (ret != DRM_OK) {
  OH_LOG_ERROR(LOG_APP, "OH_MediaKeySystem_Destroy failed.");
  return ret;
}