技术背景
我们在对接GB28181设备接入侧的时候，除了常规实时音视频按需上传外，还有个重要的功能，就是本地实时录像，录像后的数据，在执法记录仪等前端设备留底，然后，到工作站拷贝到专门的平台。
本文探讨的是，基于GB28181设备接入更进一步的处理：录像查询和录像下载，本文以我们Android平台开发的GB28181设备接入为例，做个简单的分析。
本地录像存储
GB28181设备接入侧，非常重要的功能属性就是实时录像，我们在做实时录像的时候，设计如下：
先说录像参数设置：
/** * SmartPublisherJniV2.java * Author: daniusdk.com * Created on 2015/09/20. */ /** * 音频录制开关, 目的是为了更细粒度的去控制录像, 一般不需要调用这个接口, 这个接口使用场景比如同时推送音视频，但只想录制视频，可以调用这个接口关闭音频录制 * * @param is_recoder: 0: do not recorder; 1: recorder; sdk默认是1 * * @return {0} if successful */ public native int SmartPublisherSetRecorderAudio(long handle, int is_recoder); /** * 视频录制开关, 目的是为了更细粒度的去控制录像, 一般不需要调用这个接口, 这个接口使用场景比如同时推送音视频，但只想录制音频，可以调用这个接口关闭视频录制 * * @param is_recoder: 0: do not recorder; 1: recorder; sdk默认是1 * * @return {0} if successful */ public native int SmartPublisherSetRecorderVideo(long handle, int is_recoder); /** * Create file directory(创建录像存放目录) * * @param path, E.g: /sdcard/daniulive/rec * * <pre> The interface is only used for recording the stream data to local side. </pre> * * @return {0} if successful */ public native int SmartPublisherCreateFileDirectory(String path); /** * Set recorder directory(设置录像存放目录) * * @param path: the directory of recorder file. * * <pre> NOTE: make sure the path should be existed, or else the setting failed. </pre> * * @return {0} if successful */ public native int SmartPublisherSetRecorderDirectory(long handle, String path); /** * Set the size of every recorded file(设置单个录像文件大小，如超过最大文件大小，自动切换到下个文件录制) * * @param size: (MB), (5M~500M), if not in this range, set default size with 200MB. * * @return {0} if successful */ public native int SmartPublisherSetRecorderFileMaxSize(long handle, int size);
录像控制：
/** * Start recorder(开始录像) * * @return {0} if successful */ public native int SmartPublisherStartRecorder(long handle); /** * Pause recorder(暂停/恢复录像) * * is_pause: 1表示暂停, 0表示恢复录像, 输入其他值将调用失败 * * @return {0} if successful */ public native int SmartPublisherPauseRecorder(long handle, int is_pause); /** * Stop recorder(停止录像) * * @return {0} if successful */ public native int SmartPublisherStopRecorder(long handle);
录像状态回调
private static class EventHandlerPublisherV2 implements NTSmartEventCallbackV2 { @Override public void onNTSmartEventCallbackV2(long handle, int id, long param1, long param2, String param3, String param4, Object param5) { Log.i(TAG, "EventHandeV2: handle=" + handle + " id:" + id); String publisher_event = ""; switch (id) { case NTSmartEventID.EVENT_DANIULIVE_ERC_PUBLISHER_STARTED: publisher_event = "开始.."; break; case NTSmartEventID.EVENT_DANIULIVE_ERC_PUBLISHER_CONNECTING: publisher_event = "连接中.."; break; case NTSmartEventID.EVENT_DANIULIVE_ERC_PUBLISHER_CONNECTION_FAILED: publisher_event = "连接失败.."; break; case NTSmartEventID.EVENT_DANIULIVE_ERC_PUBLISHER_CONNECTED: publisher_event = "连接成功.."; break; case NTSmartEventID.EVENT_DANIULIVE_ERC_PUBLISHER_DISCONNECTED: publisher_event = "连接断开.."; break; case NTSmartEventID.EVENT_DANIULIVE_ERC_PUBLISHER_STOP: publisher_event = "关闭.."; break; case NTSmartEventID.EVENT_DANIULIVE_ERC_PUBLISHER_RECORDER_START_NEW_FILE: publisher_event = "开始一个新的录像文件 : " + param3; break; case NTSmartEventID.EVENT_DANIULIVE_ERC_PUBLISHER_ONE_RECORDER_FILE_FINISHED: if (record_executor_ != null) { RecordExecutorService executor = record_executor_.get(); if (executor != null) executor.execute(new RecordFileFinishedHandler().set(handle, param3, param1)); } publisher_event = "已生成一个录像文件 : " + param3; break; case NTSmartEventID.EVENT_DANIULIVE_ERC_PUBLISHER_SEND_DELAY: publisher_event = "发送时延: " + param1 + " 帧数:" + param2; break; case NTSmartEventID.EVENT_DANIULIVE_ERC_PUBLISHER_CAPTURE_IMAGE: publisher_event = "快照: " + param1 + " 路径：" + param3; if (param1 == 0) { publisher_event = publisher_event + "截取快照成功.."; } else { publisher_event = publisher_event + "截取快照失败.."; } break; case NTSmartEventID.EVENT_DANIULIVE_ERC_PUBLISHER_RTSP_URL: publisher_event = "RTSP服务URL: " + param3; break; case NTSmartEventID.EVENT_DANIULIVE_ERC_PUSH_RTSP_SERVER_RESPONSE_STATUS_CODE: publisher_event ="RTSP status code received, codeID: " + param1 + ", RTSP URL: " + param3; break; case NTSmartEventID.EVENT_DANIULIVE_ERC_PUSH_RTSP_SERVER_NOT_SUPPORT: publisher_event ="服务器不支持RTSP推送, 推送的RTSP URL: " + param3; break; } String str = "当前回调状态：" + publisher_event; Log.i(TAG, str); if (handler_ != null) { android.os.Handler handler = handler_.get(); if (handler != null) { Message message = new Message(); message.what = PUBLISHER_EVENT_MSG; message.obj = publisher_event; handler.sendMessage(message); } } } public NTSmartEventCallbackV2 set(android.os.Handler handler, RecordExecutorService record_executor) { this.handler_ = new WeakReference<>(handler); this.record_executor_ = new WeakReference<>(record_executor); return this; } private WeakReference<android.os.Handler> handler_; private WeakReference<RecordExecutorService> record_executor_; }
为适配GB28181的录像查询和处理，我们会把录像的文件，文件名做一定的处理，比如加上开始、结束时间还有duration和file size。
录像调用逻辑如下：
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; } // 更细粒度控制录像的, 一般情况无需调用 //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); } } } } 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("停止录像"); isRecording = true; btnPauseRecorder.setEnabled(true); isPauseRecording = true; } } 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.."); } } } } }
总结
如果需要实现GB28181平台的录像查询和录像下载，实时录像的处理必不可少。下一章节，我们将根据GB28181规范探讨录像查询和录像下载。
