[技术分享]Android平台实时音视频录像模块设计之道

实现布景

录像有什么难的？无非就是数据过来，编码保存mp4罢了，这可能是很多开发者在做录像模块的时分的考虑输出。是的，确实不难，但是做好，或许和其他模块有非常好的逻辑合作，确实不容易。

很多开发者期望聊聊录像模块，实际上录像这块，需求层面的东西大家都清楚，无非就是规划的时分，做的更智能，逻辑清楚罢了。

规划思路

以大牛直播SDK的录像模块的技能实现为例，咱们在规划的时分，确保录像模块和RTMP推送、内置轻量级RTSP服务、转发模块、GB28181设备接入模块彻底阻隔，可以组合运用，也可以分初步用。

录像数据源，这块很好了解，无非就是编码前的yuv、nv12、nv21、rgb、pcm等（ 比如Android camera、camera2，或许otg收集到的数据等），编码成H.264/H.265/AAC，或外部接口直接投递的编码后的264、h265、aac等。

录像模块的功用层面，比较好了解，比如需求支撑随时录像，设置单个录像文件大小、录像途径等，并支撑纯音频、纯视频、音视频录制形式，此外，最好支撑录像过程中，暂停录像、恢复录像。
从初步录像，到录像完毕，需求规划event callback，告知上层逻辑，什么时分初步录像了，什么时分生成了个录像文件，途径是什么。

• 文件格局：MP4；
• 涉及相关库：libSmartPublisher.so
• 头文件：SmartPublisherJniV2.java
• Jar：smartavengine.jar

接口概述

调用示例

录像装备

    void ConfigRecorderParam() {
        if (libPublisher != null && publisherHandle != 0) {
            if (recDir != null && !recDir.isEmpty()) {
                int ret = libPublisher.SmartPublisherCreateFileDirectory(recDir);
                if (0 == ret) {
                    if (0 != libPublisher.SmartPublisherSetRecorderDirectory(publisherHandle, recDir)) {
                        Log.e(TAG, "Set record dir failed , path:" + recDir);
                        return;
                    }
                    // 更细粒度操控录像的, 一般状况无需调用
                    //libPublisher.SmartPublisherSetRecorderAudio(publisherHandle, 0);
                    //libPublisher.SmartPublisherSetRecorderVideo(publisherHandle, 0);
                    if (0 != libPublisher.SmartPublisherSetRecorderFileMaxSize(publisherHandle, 200)) {
                        Log.e(TAG, "SmartPublisherSetRecorderFileMaxSize failed.");
                        return;
                    }
                } else {
                    Log.e(TAG, "Create record dir failed, path:" + recDir);
                }
            }
        }
    }

初步、间断录像

    class ButtonStartRecorderListener implements View.OnClickListener {
        public void onClick(View v) {
            if (isRecording) {
                stopRecorder();
                if (!isPushingRtmp && !isRTSPPublisherRunning && !isGB28181StreamRunning) {
                    ConfigControlEnable(true);
                }
                btnStartRecorder.setText("实时录像");
                btnPauseRecorder.setText("暂停录像");
                btnPauseRecorder.setEnabled(false);
                isPauseRecording = true;
                return;
            }
            Log.i(TAG, "onClick start recorder..");
            if (libPublisher == null)
                return;
            if (!isPushingRtmp && !isRTSPPublisherRunning&& !isGB28181StreamRunning) {
                InitAndSetConfig();
            }
            ConfigRecorderParam();
            int startRet = libPublisher.SmartPublisherStartRecorder(publisherHandle);
            if (startRet != 0) {
                if (!isPushingRtmp && !isRTSPPublisherRunning && !isGB28181StreamRunning) {
                    if (publisherHandle != 0) {
                        long handle = publisherHandle;
                        publisherHandle = 0;
                        libPublisher.SmartPublisherClose(handle);
                    }
                }
                Log.e(TAG, "Failed to start recorder.");
                return;
            }
            if (!isPushingRtmp && !isRTSPPublisherRunning && !isGB28181StreamRunning) {
                CheckInitAudioRecorder();
                ConfigControlEnable(false);
            }
            startLayerPostThread();
            btnStartRecorder.setText("间断录像");
            isRecording = true;
            btnPauseRecorder.setEnabled(true);
            isPauseRecording = true;
        }
    }

间断录像封装

    //间断录像
    private void stopRecorder() {
        if(!isRecording)
            return;
        isRecording = false;
        if (!isPushingRtmp && !isRTSPPublisherRunning && !isGB28181StreamRunning)
            stopLayerPostThread();
        if (!isPushingRtmp && !isRTSPPublisherRunning && !isGB28181StreamRunning) {
            if (audioRecord_ != null) {
                Log.i(TAG, "stopRecorder, call audioRecord_.StopRecording..");
                audioRecord_.Stop();
                if (audioRecordCallback_ != null) {
                    audioRecord_.RemoveCallback(audioRecordCallback_);
                    audioRecordCallback_ = null;
                }
                audioRecord_ = null;
            }
        }
        if (null == libPublisher || 0 == publisherHandle)
            return;
        libPublisher.SmartPublisherStopRecorder(publisherHandle);
        if (!isPushingRtmp && !isRTSPPublisherRunning && !isGB28181StreamRunning) {
            releasePublisherHandle();
        }
    }

暂停/恢复录像

    class ButtonPauseRecorderListener implements View.OnClickListener {
        public void onClick(View v) {
            if (isRecording) {
                if(isPauseRecording)
                {
                    int ret = libPublisher.SmartPublisherPauseRecorder(publisherHandle, 1);
                    if (ret == 0)
                    {
                        isPauseRecording = false;
                        btnPauseRecorder.setText("恢复录像");
                    }
                    else if(ret == 3)
                    {
                        Log.e(TAG, "Pause recorder failed, please re-try again..");
                    }
                    else
                    {
                        Log.e(TAG, "Pause recorder failed..");
                    }
                }
                else
                {
                    int ret = libPublisher.SmartPublisherPauseRecorder(publisherHandle, 0);
                    if (ret == 0)
                    {
                        isPauseRecording = true;
                        btnPauseRecorder.setText("暂停录像");
                    }
                    else if(ret == 3)
                    {
                        Log.e(TAG, "Resume recorder failed, please re-try again..");
                    }
                    else
                    {
                        Log.e(TAG, "Resume recorder failed..");
                    }
                }
            }
        }
    }

event回调

case NTSmartEventID.EVENT_DANIULIVE_ERC_PUBLISHER_RECORDER_START_NEW_FILE:
     publisher_event = "初步一个新的录像文件 : " + param3;
     break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PUBLISHER_ONE_RECORDER_FILE_FINISHED:
     publisher_event = "已生成一个录像文件 : " + param3;
     break;

技能总结

录像模块，单纯地实现不难，如果是需求和GB28181设备接入模块、RTMP推送、轻量级RTSP服务模块一起运用的时分，需求考虑的就多了，感兴趣的开发者，可以酌情参阅。