SRS学习-配置DVR

介绍

硬盘录像机（Digital Video Recorder，简称DVR），即数字视频录像机，相对于传统的模拟视频录像机，采用硬盘录像，故常常被称为硬盘录像机，也被称为DVR。

它是一套进行图像存储处理的计算机系统，具有对图像/语音进行长时间录像、录音、远程监视和控制的功能。DVR采用的是数字记录技术，在图像处理、图像储存、检索、备份、以及网络传递、远程控制等方面也远远优于模拟监控设备，DVR代表了电视监控系统的发展方向，是市面上电视监控系统的首选产品。

之前介绍了如何配置SRS服务，现在需要将摄像头数据存储到硬盘中，作为历史数据方便后续查看。

SRS服务中已经集成了DVR功能，我们可以进行简单的配置来开启服务。

配置DVR

SRS-DVR官方文档

DVR的配置文件：

vhost your_vhost {
    # DVR RTMP stream to file,
    # start to record to file when encoder publish,
    # reap flv/mp4 according by specified dvr_plan.
    dvr {
        # whether enabled dvr features
        # default: off
        enabled         on;
        # the filter for dvr to apply to.
        #       all, dvr all streams of all apps.
        #       <app>/<stream>, apply to specified stream of app.
        # for example, to dvr the following two streams:
        #       live/stream1 live/stream2
        # default: all
        dvr_apply       all;
        # the dvr plan. canbe:
        #       session reap flv/mp4 when session end(unpublish).
        #       segment reap flv/mp4 when flv duration exceed the specified dvr_duration.
        # @remark The plan append is removed in SRS3+, for it's no use.
        # default: session
        dvr_plan        session;
        # the dvr output path, *.flv or *.mp4.
        # we supports some variables to generate the filename.
        #       [vhost], the vhost of stream.
        #       [app], the app of stream.
        #       [stream], the stream name of stream.
        #       [2006], replace this const to current year.
        #       [01], replace this const to current month.
        #       [02], replace this const to current date.
        #       [15], replace this const to current hour.
        #       [04], replace this const to current minute.
        #       [05], replace this const to current second.
        #       [999], replace this const to current millisecond.
        #       [timestamp],replace this const to current UNIX timestamp in ms.
        # @remark we use golang time format "2006-01-02 15:04:05.999" as "[2006]-[01]-[02]_[15].[04].[05]_[999]"
        # for example, for url rtmp://ossrs.net/live/livestream and time 2015-01-03 10:57:30.776
        # 1. No variables, the rule of SRS1.0(auto add [stream].[timestamp].flv as filename):
        #       dvr_path ./objs/nginx/html;
        #       =>
        #       dvr_path ./objs/nginx/html/live/livestream.1420254068776.flv;
        # 2. Use stream and date as dir name, time as filename:
        #       dvr_path /data/[vhost]/[app]/[stream]/[2006]/[01]/[02]/[15].[04].[05].[999].flv;
        #       =>
        #       dvr_path /data/ossrs.net/live/livestream/2015/01/03/10.57.30.776.flv;
        # 3. Use stream and year/month as dir name, date and time as filename:
        #       dvr_path /data/[vhost]/[app]/[stream]/[2006]/[01]/[02]-[15].[04].[05].[999].flv;
        #       =>
        #       dvr_path /data/ossrs.net/live/livestream/2015/01/03-10.57.30.776.flv;
        # 4. Use vhost/app and year/month as dir name, stream/date/time as filename:
        #       dvr_path /data/[vhost]/[app]/[2006]/[01]/[stream]-[02]-[15].[04].[05].[999].flv;
        #       =>
        #       dvr_path /data/ossrs.net/live/2015/01/livestream-03-10.57.30.776.flv;
        # 5. DVR to mp4:
        #       dvr_path ./objs/nginx/html/[app]/[stream].[timestamp].mp4;
        #       =>
        #       dvr_path ./objs/nginx/html/live/livestream.1420254068776.mp4;
        # @see https://github.com/ossrs/srs/wiki/v4_CN_DVR#custom-path
        # @see https://github.com/ossrs/srs/wiki/v4_CN_DVR#custom-path
        #       segment,session apply it.
        # default: ./objs/nginx/html/[app]/[stream].[timestamp].flv
        dvr_path        ./objs/nginx/html/[app]/[stream].[timestamp].flv;
        # the duration for dvr file, reap if exceed, in seconds.
        #       segment apply it.
        #       session,append ignore.
        # default: 30
        dvr_duration    30;
        # whether wait keyframe to reap segment,
        # if off, reap segment when duration exceed the dvr_duration,
        # if on, reap segment when duration exceed and got keyframe.
        #       segment apply it.
        #       session,append ignore.
        # default: on
        dvr_wait_keyframe       on;
        # about the stream monotonically increasing:
        #   1. video timestamp is monotonically increasing,
        #   2. audio timestamp is monotonically increasing,
        #   3. video and audio timestamp is interleaved monotonically increasing.
        # it's specified by RTMP specification, @see 3. Byte Order, Alignment, and Time Format
        # however, some encoder cannot provides this feature, please set this to off to ignore time jitter.
        # the time jitter algorithm:
        #   1. full, to ensure stream start at zero, and ensure stream monotonically increasing.
        #   2. zero, only ensure stream start at zero, ignore timestamp jitter.
        #   3. off, disable the time jitter algorithm, like atc.
        # apply for all dvr plan.
        # default: full
        time_jitter             full;

        # on_dvr, never config in here, should config in http_hooks.
        # for the dvr http callback, @see http_hooks.on_dvr of vhost hooks.callback.srs.com
        # @read https://github.com/ossrs/srs/wiki/v4_CN_DVR#http-callback
        # @read https://github.com/ossrs/srs/wiki/v4_CN_DVR#http-callback
    }
}

DVR的计划即决定什么时候关闭flv文件，打开新的flv文件，主要的录制计划包括：

• session：按照session来关闭flv文件，即编码器停止推流时关闭flv，整个session录制为一个flv。
• segment：按照时间分段录制，flv文件时长配置为dvr_duration和dvr_wait_keyframe。注意：若不按关键帧切flv（即dvr_wait_keyframe配置为off），所以会导致后面的flv启动时会花屏。
• time_jitter: 时间戳抖动算法。full使用完全的时间戳矫正；zero只是保证从0开始；off不矫正时间戳。
• dvr_path: 录制的路径

示例

vhost __defaultVhost__ {
    rtc {
        enabled     on;
        bframe      discard;
    }

  dvr {
        enabled             on;
        dvr_path            /home/srs/[app]/[stream]/[2006]/[01]/[02]/[15].[04].[05].[999].flv;
        dvr_plan            segment;
        dvr_duration        600;
        dvr_wait_keyframe   on;
    }

    http_remux {
        enabled     on;
        mount       [vhost]/[app]/[stream].flv;
    }
}

我这里设置的是10分钟记录一次

记录效果如下所示（tmp是临时文件）

保存成功后的文件为flv格式视频

总结

• SRS配置DVR后默认会对所有的视频流进行记录（后面看看能不能指定流进行记录）
• 如果文件存储的太多，可以设置一个定时清理的方法（只保留一个月的视频）