Freeswitch单路带录制的视频通话CPU持续高到15%问题解决

呱牛笔记

发布于 2023-05-02 15:47:29

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发布于 2023-05-02 15:47:29

现象是视频通话，给FS配置录制到rtsp服务器，单路通话Freeswitch占用CPU高：

?PID?USER??????PR??NI????VIRT????RES????SHR?S??%CPU??%MEM?????TIME+?
COMMAND?696684?root??????-2?-10??848068?144700??24264?S??15.0???3.6??23:25.80?freeswitch

录制配置：

//录本端
<action?application=\"set\"?data=\"execute_on_answer=record_session?rtsp://192.168.16.83/live/"?.?$this->account_id?.?"_".?$destination_number."\"/>"

CPU高主要发生在几个方面：

a_leg -> FS收包

? ? ? ? ? ? ? 配置了录制bug通达后，FS收包先会进行H264解码，然后在发送给对方前，再H264编码发给b_leg

? ? ? ? ? ? ? ? ->? ?FS将解码的img 通过record_callback 方法，调用switch_core_file_write写到rtsp流，这里使用的是avformat.c的实现；

FS要转流到rtsp服务器，需要修改avformat.c, 配置rtsp，修改av_file_open方法：

		//if?((handle->stream_name?&&?(!strcasecmp(handle->stream_name,?"rtmp")?||?!strcasecmp(handle->stream_name,?"rtmps"))))?{
		if?((handle->stream_name?&&?(!strcasecmp(handle->stream_name,?"rtmp")?||?!strcasecmp(handle->stream_name,?"rtmps")?||?!strcasecmp(handle->stream_name,?"rtsp"))))?{
			if?(fmt->video_codec?!=?AV_CODEC_ID_H264?)?{
				fmt->video_codec?=?AV_CODEC_ID_H264;?//?force?H264
			}

			fmt->audio_codec?=?AV_CODEC_ID_AAC;
			handle->samplerate?=?44100;
			handle->mm.samplerate?=?44100;
			handle->mm.ab?=?128;
			handle->mm.cbr?=?1;
			handle->mm.vencspd?=?SWITCH_VIDEO_ENCODE_SPEED_FAST;
			handle->mm.vprofile?=?SWITCH_VIDEO_PROFILE_BASELINE;

			if?(!handle->mm.vb?&&?handle->mm.vw?&&?handle->mm.vh)?{
				switch(handle->mm.vh)?{
				case?240:
					handle->mm.vb?=?400;
					break;
				case?360:
					handle->mm.vb?=?750;
					break;
				case?480:
					handle->mm.vb?=?1000;
					break;
				case?720:
					handle->mm.vb?=?2500;
					break;
				case?1080:
					handle->mm.vb?=?4500;
					break;
				default:
					handle->mm.vb?=?switch_calc_bitrate(handle->mm.vw,?handle->mm.vh,?1,?handle->mm.fps);
					break;
				}
			}

			if?(handle->mm.fps?>?0.0f)?{
				handle->mm.keyint?=?(int)?2.0f?*?handle->mm.fps;
			}
		}

		desc?=?avcodec_descriptor_get(fmt->video_codec);

		switch_log_printf(SWITCH_CHANNEL_LOG,?SWITCH_LOG_DEBUG,?"use?video?codec:?[%d]?%s?(%s)\n",?fmt->video_codec,?desc->name,?desc->long_name);
	}

?在av_file_write_video方法中，img会进行再次编码后发送出去；

所以一共有一次解码、两次编码，所以单路视频通话配置record_session后,CPU一直高的原因在这里；

怎么修改，首先H264转发前的编码可以不用做，因为两端都支持H264的情况下，不需要FS做中间的转码；

修改switch_core_media.c中的switch_core_session_write_video_frame方法：

#if?1//modify?for?no?need?encode?h264
??????{
?????????const?char?*s;
?????????if?((s?=?switch_channel_get_variable(session->channel,?"v_codec_match"))?&&?switch_true(s))?{
		switch_status_t?vstatus;

????????????//direct?proxy?packet.
		switch_set_flag((frame),?SFF_PROXY_PACKET);
		//switch_set_flag(frame,?SWITCH_RTP_FLAG_RAW_WRITE);//
	
		//switch_set_flag(frame,?SFF_RAW_RTP_PARSE_FRAME?|?SWITCH_RTP_FLAG_RAW_WRITE);
?
		//switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session),?SWITCH_LOG_INFO,?"%s?is?same?codec?no?need?encode.\n",?switch_channel_get_name(session->channel));
		vstatus?=?switch_core_session_write_encoded_video_frame(session,?frame,?flags,?stream_id);
		switch_goto_status(vstatus,?done);
?????????}else{
???????
????????	if?(!img)?{
????????		switch_status_t?vstatus;

????????		vstatus?=?switch_core_session_write_encoded_video_frame(session,?frame,?flags,?stream_id);
????????		switch_goto_status(vstatus,?done);
????????	}
?????????}
??????}
#else
???????
	if?(!img)?{
		switch_status_t?vstatus;

		vstatus?=?switch_core_session_write_encoded_video_frame(session,?frame,?flags,?stream_id);
		switch_goto_status(vstatus,?done);
	}

#endif

?在video_bridge_thread记录两端video的codec是否一致：

static?void?video_bridge_thread(switch_core_session_t?*session,?void?*obj)
????????????????#if?1
				if?(a_codec->implementation->impl_id?==?b_codec->implementation->impl_id){????????????????????????????
?????????????????????????????????switch_channel_set_variable(channel,?"v_codec_match",?"true");??????????????????????????
?????????????????????????????????switch_channel_set_variable(b_channel,?"v_codec_match",?"true");
				}else{?????????????
?????????????????????????????????switch_channel_set_variable(channel,?"v_codec_match",?"false");??????????????????????????
?????????????????????????????????switch_channel_set_variable(b_channel,?"v_codec_match",?"false");
???????????????????????????}
????????????????#endif//lyz?add?for?codec

结果，单路带录制的视频通话CPU降到了10%左右：

?PID?USER??????PR??NI????VIRT????RES????SHR?S??%CPU??%MEM?????TIME+?
COMMAND?696684?root??????-2?-10??848068?144700??24264?S??10.0???3.6??23:25.80?freeswitch

下一步计划是去掉record的视频编码动作，一并去掉收包的解码动作！