HarmonyOS鸿蒙Next中应用侧特定区域的视频录制
HarmonyOS鸿蒙Next中应用侧特定区域的视频录制 【问题描述】：想实现应用侧特定区域的视频录制，我们场景是uvc摄像头进行红外测温，上面的水印和icon等都是应用侧处理的，视频流是uvc底层渲染的。现在我们要有个录像功能，基于红框区域对整个视频画面和水印等进行录像
【问题现象】：看官方的这块文档写的很简陋，而且好像只能从native层实现，有没有可以参考的相关demo啊，参照文档：屏幕录制支持矩形区域录制-录制-媒体开发指导(C/C++)-Media Kit（媒体服务）-媒体 - 华为HarmonyOS开发者
【版本信息】：未涉及
【复现代码】：未涉及
【尝试解决方案】：未涉及
更多关于HarmonyOS鸿蒙Next中应用侧特定区域的视频录制的实战教程也可以访问 https://www.itying.com/category-93-b0.html
3 回复
【背景知识】
- 屏幕录制支持开发者获取屏幕数据，可用于屏幕录制、会议共享、直播等场景。根据不同的场景需求HarmonyOS提供了三种方案实现屏幕录制，包括面向ArkTS侧的AVScreenCaptureRecorder和面向C++的AVScreenCapture模块，详情可参考基于AVScreenCapture实现屏幕录制。
- AVScreenCaptureRecorder录屏写文件(ArkTS)：开发者可以调用录屏（AVScreenCaptureRecorder)模块的ArkTS接口，完成屏幕录制，采集设备内、麦克风等的音视频源数据。可以调用录屏模块获取音视频文件，然后通过文件的形式流转到其他模块进行播放或处理，达成文件形式分享屏幕内容的场景。
【解决方案】
参考基于AVScreenCapture实现屏幕录制，提供了native进行屏幕录制的Demo
src/main/cpp/CAVScreenCaptureToFile/CAVScreenCaptureToFile.cpp中调用OH_AVScreenCapture_SetCaptureArea()接口传入希望录制的矩形区，可以完成矩形区的录制
/*
* Copyright (c) 2025 Huawei Device Co., Ltd.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "CAVScreenCaptureToFile.h"
#include "hilog/log.h"
#include <js_native_api.h>
#include <multimedia/player_framework/native_avscreen_capture.h>
#include <multimedia/player_framework/native_avscreen_capture_errors.h>
#include <node_api.h>
#include <thread>
#undef LOG_DOMAIN
#undef LOG_TAG
#define LOG_DOMAIN 0x3200
#define LOG_TAG "MY_CAVSCREENCAPTURE"
bool m_IsRunning = false;
OH_AVScreenCapture *g_avCapture_;
napi_threadsafe_function tsFn;
void CAVScreenCaptureToFile::StopScreenCaptureRecording(struct OH_AVScreenCapture *capture) {
if (m_IsRunning && capture != nullptr) {
OH_AVScreenCapture_StopScreenRecording(capture);
m_IsRunning = false;
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile ScreenCapture StopScreenCapture");
}
}
/*
* Screen recording Error callback
*/
void CAVScreenCaptureToFile::OnErrorSaveFile(OH_AVScreenCapture *capture, int32_t errorCode, void *userData) {
(void)capture;
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile ScreenCapture OnError errorCode is %{public}d", errorCode);
(void)userData;
}
void CAVScreenCaptureToFile::ReleaseSCWorker(struct OH_AVScreenCapture *capture) {
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile ScreenCapture ReleaseSCInstanceWorker S");
OH_AVScreenCapture_Release(capture);
m_IsRunning = false;
g_avCapture_ = nullptr;
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile ScreenCapture ReleaseSCInstanceWorker E");
}
/*
* Screen recording state change callback
*/
void CAVScreenCaptureToFile::OnStateChangeSaveFile(struct OH_AVScreenCapture *capture,
OH_AVScreenCaptureStateCode stateCode, void *userData) {
(void)capture;
switch (stateCode) {
case OH_SCREEN_CAPTURE_STATE_STARTED: {
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile ScreenCapture OnStateChange OH_SCREEN_CAPTURE_STATE_STARTED");
break;
}
case OH_SCREEN_CAPTURE_STATE_CANCELED: {
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile ScreenCapture OnStateChange OH_SCREEN_CAPTURE_STATE_CANCELED ");
StopScreenCaptureRecording(capture);
break;
}
case OH_SCREEN_CAPTURE_STATE_STOPPED_BY_CALL: {
OH_LOG_INFO(LOG_APP,
"CAVScreenCaptureToFile ScreenCapture OnStateChange OH_SCREEN_CAPTURE_STATE_STOPPED_BY_CALL");
break;
}
case OH_SCREEN_CAPTURE_STATE_MIC_UNAVAILABLE: {
OH_LOG_INFO(LOG_APP,
"CAVScreenCaptureToFile ScreenCapture OnStateChange OH_SCREEN_CAPTURE_STATE_MIC_UNAVAILABLE");
break;
}
case OH_SCREEN_CAPTURE_STATE_INTERRUPTED_BY_OTHER: {
OH_LOG_INFO(LOG_APP,
"CAVScreenCaptureToFile ScreenCapture OnStateChange OH_SCREEN_CAPTURE_STATE_INTERRUPTED_BY_OTHER");
break;
}
case OH_SCREEN_CAPTURE_STATE_MIC_MUTED_BY_USER: {
OH_LOG_INFO(LOG_APP,
"CAVScreenCaptureToFile ScreenCapture OnStateChange OH_SCREEN_CAPTURE_STATE_MIC_MUTED_BY_USER");
break;
}
case OH_SCREEN_CAPTURE_STATE_MIC_UNMUTED_BY_USER: {
OH_LOG_INFO(LOG_APP,
"CAVScreenCaptureToFile ScreenCapture OnStateChange OH_SCREEN_CAPTURE_STATE_MIC_MUTED_BY_USER");
break;
}
case OH_SCREEN_CAPTURE_STATE_ENTER_PRIVATE_SCENE: {
OH_LOG_INFO(LOG_APP,
"CAVScreenCaptureToFile ScreenCapture OnStateChange OH_SCREEN_CAPTURE_STATE_ENTER_PRIVATE_SCENE");
std::thread releaseSCInstanceThread(ReleaseSCWorker, capture);
releaseSCInstanceThread.detach();
break;
}
case OH_SCREEN_CAPTURE_STATE_EXIT_PRIVATE_SCENE: {
OH_LOG_INFO(LOG_APP,
"CAVScreenCaptureToFile ScreenCapture OnStateChange OH_SCREEN_CAPTURE_STATE_EXIT_PRIVATE_SCENE");
break;
}
case OH_SCREEN_CAPTURE_STATE_STOPPED_BY_USER: {
napi_acquire_threadsafe_function(tsFn);
napi_call_threadsafe_function(tsFn, nullptr, napi_tsfn_nonblocking);
napi_release_threadsafe_function(tsFn, napi_tsfn_release);
tsFn = nullptr;
OH_LOG_INFO(LOG_APP,
"CAVScreenCaptureToFile ScreenCapture OnStateChange OH_SCREEN_CAPTURE_STATE_STOPPED_BY_USER");
std::thread releaseSCInstanceThread(ReleaseSCWorker, capture);
releaseSCInstanceThread.detach();
break;
}
default:
break;
}
(void)userData;
}
/*
* Configuration parameters
*/
void CAVScreenCaptureToFile::SetConfigAsFile(OH_AVScreenCaptureConfig &config, int32_t videoWidth,
int32_t videoHeight) {
OH_AudioCaptureInfo micCapInfo = {.audioSampleRate = 48000, .audioChannels = 2, .audioSource = OH_SOURCE_DEFAULT};
OH_AudioCaptureInfo innerCapInfo = {.audioSampleRate = 48000, .audioChannels = 2, .audioSource = OH_ALL_PLAYBACK};
OH_AudioEncInfo audioEncInfo = {.audioBitrate = 96000, .audioCodecformat = OH_AudioCodecFormat::OH_AAC_LC};
OH_AudioInfo audioInfo = {.micCapInfo = micCapInfo, .innerCapInfo = innerCapInfo, .audioEncInfo = audioEncInfo};
OH_VideoCaptureInfo videoCapInfo = {
.videoFrameWidth = videoWidth, .videoFrameHeight = videoHeight, .videoSource = OH_VIDEO_SOURCE_SURFACE_RGBA};
OH_VideoEncInfo videoEncInfo = {
.videoCodec = OH_VideoCodecFormat::OH_H264, .videoBitrate = 10000000, .videoFrameRate = 30};
OH_VideoInfo videoInfo = {.videoCapInfo = videoCapInfo, .videoEncInfo = videoEncInfo};
config = {
.captureMode = OH_CAPTURE_HOME_SCREEN,
.dataType = OH_ORIGINAL_STREAM,
.audioInfo = audioInfo,
.videoInfo = videoInfo,
.recorderInfo = {},
};
//
////// 初始化录屏，传入配置信息OH_AVScreenRecorderConfig。
//OH_AVScreenCapture_Init(g_avCapture_, config);
//// 1. 可选，可以根据需要设置区域坐标和大小，设置想要捕获的区域，如下方创建了一个从（0, 0）为起点的长100，宽100的矩形区域。
//OH_Rect* region = new OH_Rect;
//region->x = 0;
//region->y = 0;
//region->width = 400;
//region->height = 400;
//// 2. 传入矩形区域所在的屏幕Id。
//uint64_t regionDisplayId = 0;
//OH_AVScreenCapture_SetCaptureArea(g_avCapture_, regionDisplayId, region);
}
napi_value CAVScreenCaptureToFile::StopScreenCaptureToFile(napi_env env, napi_callback_info info) {
(void)info;
OH_AVSCREEN_CAPTURE_ErrCode result = AV_SCREEN_CAPTURE_ERR_OPERATE_NOT_PERMIT;
napi_value res;
if (m_IsRunning && g_avCapture_ != nullptr) {
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile ScreenCapture File Stop");
result = OH_AVScreenCapture_StopScreenRecording(g_avCapture_);
if (result != AV_SCREEN_CAPTURE_ERR_BASE) {
OH_LOG_ERROR(
LOG_APP,
"CAVScreenCaptureToFile StopScreenCapture OH_AVScreenCapture_StopScreenRecording Result: %{public}d",
result);
} else {
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile StopScreenCapture OH_AVScreenCapture_StopScreenRecording");
}
result = OH_AVScreenCapture_Release(g_avCapture_);
if (result != AV_SCREEN_CAPTURE_ERR_BASE) {
OH_LOG_ERROR(LOG_APP, "CAVScreenCaptureToFile StopScreenCapture OH_AVScreenCapture_Release: %{public}d",
result);
} else {
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile OH_AVScreenCapture_Release success");
}
m_IsRunning = false;
g_avCapture_ = nullptr;
}
napi_create_int32(env, result, &res);
return res;
}
napi_value CAVScreenCaptureToFile::StartScreenCaptureToFile(napi_env env, napi_callback_info info) {
size_t argc = 3;
napi_value args[3] = {nullptr};
napi_get_cb_info(env, info, &argc, args, nullptr, nullptr);
int32_t outputFd, videoWidth, videoHeight;
napi_get_value_int32(env, args[0], &outputFd);
napi_get_value_int32(env, args[1], &videoWidth);
napi_get_value_int32(env, args[2], &videoHeight);
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile FD %{public}d", outputFd);
if (outputFd <= 0) {
OH_LOG_ERROR(LOG_APP, "CAVScreenCaptureToFile FD ERROR %{public}d", outputFd);
napi_value res;
napi_create_int32(env, -1, &res);
return res;
}
if (g_avCapture_ != nullptr) {
StopScreenCaptureRecording(g_avCapture_);
OH_AVScreenCapture_Release(g_avCapture_);
}
g_avCapture_ = OH_AVScreenCapture_Create();
if (g_avCapture_ == nullptr) {
OH_LOG_ERROR(LOG_APP, "CAVScreenCaptureToFile create screen capture failed");
}
OH_AVScreenCaptureConfig config_;
OH_RecorderInfo recorderInfo;
std::string fileUrl = "fd://" + std::to_string(outputFd);
recorderInfo.url = const_cast<char *>(fileUrl.c_str());
recorderInfo.fileFormat = OH_ContainerFormatType::CFT_MPEG_4;
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile ScreenCapture fileUrl %{public}s", fileUrl.c_str());
SetConfigAsFile(config_, videoWidth, videoHeight);
config_.captureMode = OH_CAPTURE_HOME_SCREEN;
config_.dataType = OH_CAPTURE_FILE;
config_.recorderInfo = recorderInfo;
bool isMicrophone = true;
OH_AVScreenCapture_SetMicrophoneEnabled(g_avCapture_, isMicrophone);
OH_AVScreenCapture_SetErrorCallback(g_avCapture_, OnErrorSaveFile, nullptr);
OH_AVScreenCapture_SetStateCallback(g_avCapture_, OnStateChangeSaveFile, nullptr);
OH_AVScreenCapture_SetCanvasRotation(g_avCapture_, true);
OH_AVSCREEN_CAPTURE_ErrCode result = OH_AVScreenCapture_Init(g_avCapture_, config_);
if (result != AV_SCREEN_CAPTURE_ERR_OK) {
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile ScreenCapture OH_AVScreenCapture_Init failed %{public}d", result);
}
OH_LOG_INFO(LOG_APP, "CAVScreenCapt ureToFile ScreenCapture OH_AVScreenCapture_Init succ %{public}d", result);
// 1. 可选，可以根据需要设置区域坐标和大小，设置想要捕获的区域，如下方创建了一个从（0, 0）为起点的长100，宽100的矩形区域。
OH_Rect* region = new OH_Rect;
region->x = 0;
region->y = 0;
region->width = 400;
region->height = 400;
// 2. 传入矩形区域所在的屏幕Id。
uint64_t regionDisplayId = 0;
OH_AVScreenCapture_SetCaptureArea(g_avCapture_, regionDisplayId, region);
result = OH_AVScreenCapture_StartScreenRecording(g_avCapture_);
if (result != AV_SCREEN_CAPTURE_ERR_OK) {
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile ScreenCapture Started failed %{public}d", result);
OH_AVScreenCapture_Release(g_avCapture_);
}
OH_LOG_INFO(LOG_APP, "CAVScreenCaptureToFile ScreenCapture Started succ %{public}d", result);
m_IsRunning = true;
napi_value res;
napi_create_int32(env, result, &res);
return res;
}
void CAVScreenCaptureToFile::SetStopFlag(napi_env env, napi_value jsCb, void *context, void *data) {
if (env == nullptr) {
return;
}
napi_value res;
napi_call_function(env, nullptr, jsCb, 0, nullptr, &res);
}
/*
* Set the callback function after stopping
*/
napi_value CAVScreenCaptureToFile::SetStopCallbackToFile(napi_env env, napi_callback_info info) {
size_t argc = 1;
napi_value args[1] = {nullptr};
napi_get_cb_info(env, info, &argc, args, nullptr, nullptr);
napi_value resourceName = nullptr;
napi_create_string_utf8(env, "ThreadSafeSetStopFlag", NAPI_AUTO_LENGTH, &resourceName);
napi_create_threadsafe_function(env, args[0], nullptr, resourceName, 0, 1, nullptr, nullptr, nullptr, SetStopFlag,
&tsFn);
return nullptr;
}
更多关于HarmonyOS鸿蒙Next中应用侧特定区域的视频录制的实战系列教程也可以访问 https://www.itying.com/category-93-b0.html
HarmonyOS Next中应用侧特定区域视频录制通过AVRecorder API实现。开发者需配置录制参数，包括视频源类型、输出格式、编码规格及帧率。使用SurfaceProvider创建指定区域的绘制表面，绑定到AVRecorder进行画面捕获。录制过程支持实时预览，可控制开始、暂停、恢复和停止操作。最终视频文件保存至应用沙箱路径，支持后续处理或分享。
针对您提出的在HarmonyOS Next中实现应用侧特定区域视频录制的需求，结合您提到的UVC摄像头红外测温场景，核心思路是捕获并合成应用层UI与摄像头视频流。官方文档侧重于Native层基础能力，要实现您的需求，关键在于在应用层进行画面合成与录制。
以下是具体的技术路径和要点：
-
核心方案：离屏渲染与画面合成 您需要将两个画面源进行合成：
- 摄像头视频流：通过
UVC或CameraKit获取原始视频帧（PixelMap或ArrayBuffer）。 - 应用层UI（水印、图标、红框）：在
Canvas或CustomNode上绘制。
推荐使用
XComponent或OffscreenCanvas创建一个离屏渲染区域。在此区域中，首先绘制摄像头视频帧作为背景，然后在对应坐标上叠加绘制您的UI元素（水印、红框等）。这个合成后的画面，才是您需要录制的最终画面。 - 摄像头视频流：通过
-
录制实现：使用MediaRecorder 将上述合成后的画面帧，通过
MediaRecorderAPI进行编码和录制。关键步骤包括：- 配置视频源：创建
VideoRecorderConfig时，视频源应设置为来自您合成画面的数据流。您需要将离屏画布中合成好的每一帧图像数据，转换为MediaRecorder可接受的格式（如Image或ArrayBuffer），并通过回调或Surface提供给录制器。 - 设置录制区域：您提到的“红框区域”是整个合成画面的一部分。可以在合成时直接以红框区域为边界进行绘制和裁剪，确保离屏画布的输出尺寸就是红框区域的大小。这样，
MediaRecorder录制的就是已经裁剪好的目标区域内容，无需在录制器层面再做复杂的区域设置。
- 配置视频源：创建
-
性能与参考
- 性能考虑：画面合成与帧数据转换是CPU/GPU密集型操作，建议在
Worker线程中进行，避免阻塞UI。同时，注意控制录制分辨率与帧率，以平衡画质和性能。 - 参考方向：目前公开Demo可能不直接匹配。建议重点参考
MediaRecorder开发指南和XComponent/Canvas的离屏渲染示例。您的实现本质上是自定义视频源的录制，即由应用生成每一帧画面，而非直接录制系统屏幕或单个摄像头视图。
- 性能考虑：画面合成与帧数据转换是CPU/GPU密集型操作，建议在
总结，您需要构建一个自定义的合成渲染管线，将UVC视频流与应用UI在指定区域合成，并将结果帧输送给MediaRecorder。这完全可以在应用层（ArkTS）实现，无需深入Native层处理复杂的屏幕捕获逻辑。
