采用ffmpeg和ffserver实现音视频直播和点播
一、嵌入式开发板采集音视频(远程)
音频采集程序：./audioc -i 222.222.222.222 -p 8888;
视频采集程序：./videoc -i 222.222.222.222 -p 9999;
音频采集程序利用alsa库，采集原始音频帧，发送至服务器进程(222.222.222.222, 8888);
视频采集程序利用v4l2库，采集原始视频帧，h.264硬编码后，发送至服务器进程(222.222.222.222, 9999);
二、Linux服务器接收音视频
音频接收程序：./audios -rp 8888 -sp 8899 -i 239.255.1.2;
视频接收程序：./videos -rp 9999 -sp 9988 -i 239.255.1.2;
音频接收程序，接收原始音频帧，并发送至组播(239.255.1.2, 8899);
视频接收程序，接收264视频帧，并发送至组播(239.255.1.2, 9988);
三、ffserver流媒体服务器搭建
1. ffserver的配置文件：ffserver.conf
配置文件如：
#################################################################### # Port on which the server is listening. You must select a different # port from your standard HTTP web server if it is running on the same # computer. HTTPPort 8090 # Address on which the server is bound. Only useful if you have # several network interfaces. HTTPBindAddress 0.0.0.0 # Number of simultaneous HTTP connections that can be handled. It has # to be defined *before* the MaxClients parameter, since it defines the # MaxClients maximum limit. MaxHTTPConnections 2000 # Number of simultaneous requests that can be handled. Since FFServer # is very fast, it is more likely that you will want to leave this high # and use MaxBandwidth, below. MaxClients 1000 # This the maximum amount of kbit/sec that you are prepared to # consume when streaming to clients. MaxBandwidth 1000 # Access log file (uses standard Apache log file format) # '-' is the standard output. CustomLog - ###################################################################### ###################################################################### # Definition of the live feeds. Each live feed contains one video # and/or audio sequence coming from an ffmpeg encoder or another # ffserver. This sequence may be encoded simultaneously with several # codecs at several resolutions. <Feed feed1.ffm> # You must use 'ffmpeg' to send a live feed to ffserver. In this # example, you can type: # # ffmpeg http://localhost:8090/feed1.ffm # ffserver can also do time shifting. It means that it can stream any # previously recorded live stream. The request should contain: # "http://xxxx?date=[YYYY-MM-DDT][[HH:]MM:]SS[.m...]".You must specify # a path where the feed is stored on disk. You also specify the # maximum size of the feed, where zero means unlimited. Default: # File=/tmp/feed_name.ffm FileMaxSize=5M File feed1.ffm FileMaxSize 5M # You could specify # ReadOnlyFile /saved/specialvideo.ffm # This marks the file as readonly and it will not be deleted or updated. # Specify launch in order to start ffmpeg automatically. # First ffmpeg must be defined with an appropriate path if needed, # after that options can follow, but avoid adding the http:// field #Launch ffmpeg # Only allow connections from localhost to the feed. ACL allow 127.0.0.1 </Feed> <Feed feed2.ffm> File feed2.ffm FileMaxSize 5M ACL allow 127.0.0.1 </Feed> ######################################################################### ######################################################################### # live streams # flv video + audio stream <Stream demo.flv> #Stream：每一个广播（转换后的视频流）的转码设置项目 Format flv #视频流格式 Feed feed1.ffm #视频流的种子来源 VideoFrameRate 25 #视频帧频 VideoBitRate 200 #视频比特率 VideoGopSize 28 VideoSize 480x272 #视频帧大小 AVOptionVideo flags +global_header AudioBitRate 64 AudioChannels 2 AudioSampleRate 44100 AVOptionAudio flags +global_header StartSendOnKey </Stream> # mp3 audio stream <Stream demoAudio.mp3> Format mp3 Feed feed2.ffm AudioBitRate 64 AudioChannels 2 AudioSampleRate 44100 AVOptionAudio flags +global_header NoVideo </Stream> # swf video stream # <Stream demoVideo.swf> #Stream：每一个广播（转换后的视频流）的转码设置项目 # Format swf #视频流格式 # Feed feed3.ffm #视频流的种子来源 # VideoFrameRate 25 #视频帧频 # VideoBitRate 200 #视频比特率 # VideoGopSize 28 # VideoSize 480x272 #视频帧大小 # AVOptionVideo flags +global_header # NoAudio #</Stream> # webm video + audio stream # <Stream demoSystem.webm> #Stream：每一个广播（转换后的视频流）的转码设置项目 # Format webm #视频流格式 # Feed feed1.ffm #视频流的种子来源 # AudioCodec vorbis # AudioBitRate 64 # VideoCodec libvpx # VideoFrameRate 25 #视频帧频 # VideoBitRate 200 #视频比特率 # VideoGopSize 28 # VideoSize 480x272 #视频帧大小 # AVOptionVideo flags +global_header # AVOptionVideo cpu-used 0 # AVOptionVideo qmin 10 # AVOptionVideo qmax 42 # AVOptionAudio flags +global_header # PreRoll 15 # StartSendOnKey # </Stream> # Ogg Vorbis audio # <Stream test.ogg> # Format ogg # Feed feed2.ffm # Metadata title "Stream title" # AudioBitRate 64 # AudioChannels 2 # AudioSampleRate 44100 # NoVideo # </Stream> ######################################################################## ######################################################################## # local streams <Stream dengZiQi> File "dengZiQi.flv" Format flv </Stream> <Stream Maroon5_Sugar> File "Sugar.flv" Format flv </Stream> ######################################################################### ######################################################################### # Server status <Stream stat.html> Format status # Only allow local people to get the status ACL allow 127.0.0.1 ACL allow 192.168.0.0 192.168.255.255 #FaviconURL http://pond1.gladstonefamily.net:8080/favicon.ico </Stream> ######################################################################### ######################################################################### # Redirect index.html to the appropriate site <Redirect index.html> URL http://www.ffmpeg.org/ </Redirect> #########################################################################
其中，<Stream demo.flv>是音视频直播流，从feed1.ffm中获取数据， <Stream demoAudio.mp3>为单独的音频流，从
feed2.ffm中获取数据。<Stream demoVideo.swf>为单独的视频流，由于ffserver在出现音频流后不能再出现单独的视频流，所以
此处注释掉了<Stream demoVideo.swf>。
local streams下的都是本地文件，ffserver支持本地文件的点播。
关于播放，swf是flash支持的格式，几乎所有的浏览器都支持播放此格式视频；flv是最为流行的网络视频格式，但一般情况
下，浏览器不支持该格式视频直接播放，需安装插件，这里采用vlc插件：http://www.videolan.org/；webm是最新的html5支持的
视频格式，此格式视频可以在chrome浏览器和firefox浏览器中直接播放；mp3、wav等音频格式可以在浏览器中直接播放。
2. ffserver启动命令：
#! /bin/sh ./ffserver -f ./ffserver.conf
四、ffserver实现视频点播
在ffserver.conf中加入如下命令：
<Stream dengZiQi> File "dengZiQi.flv" Format flv </Stream>
五、向ffserver接入音视频流，实现视频直播
1. 从组播中接入实时音视频流并转码封装
./ffmpeg -f s16le -ar 44100 -ac 1 -i udp://239.255.1.2:8899 -i udp://239.255.1.2:9988 http://222.222.222.222:8090/feed1.ffm
前面udp流是音频流(udp地址为上述组播地址)；中间udp流是视频流(udp地址为上述组播地址)；后面http流是根据ffserver.conf
进行转码并封装后的特定格式音视频流(http地址为远程ffserver服务器地址)，它存储在ffserver的feed1.ffm缓冲文件中。这里，由于
接收的是原始音频流，所以采用pcm_s16le压缩编码，采样率为44.1k，单声道；而视频流本身已经采用H.264压缩编码了，不再采
用其他压缩编码。
2. 从组播中接入实时音频流
./ffmpeg -f s16le -ar 44100 -ac 1 -i udp://239.255.1.2:8899 http://222.222.222.222:8090/feed2.ffm
3. 从组播中接入实时视频流
./ffmpeg -i udp://239.255.1.2:9988 http://222.222.222.222:8090/feed3.ffm
4. 从本地文件中接入音视频流
./ffmpeg -i video.mp4 -i audio.mp3 http://222.222.222.222:8090/feed4.ffm
5. 录制屏幕接入音视频流
./ffmpeg -f x11grab -r 25 -s 640x512 -i :0.0 -f alsa -i pulse http://222.222.222.222:8090/feed5.ffm
6. 从摄像头获取视频麦克风获取音频接入音视频流
./ffmpeg -f video4linux2 -s 640x480 -r 25 -i /dev/video0 -f alsa -i pulse http://222.222.222.222:8090/feed6.ffm
命令如：
#! /bin/sh exec ./audios -rp 8888 -sp 8899 -i 239.255.1.2 1>/dev/null 2>&1 & exec ./videos -rp 9999 -sp 9988 -i 239.255.1.2 1>/dev/null 2>&1 & exec ./ffmpeg -f s16le -ar 44100 -ac 1 -i udp://239.255.1.2:8899 -i udp://239.255.1.2:9988 http://222.222.222.222:8090/feed1.ffm 1>/dev/null 2>&1 & exec ./ffmpeg -f s16le -ar 44100 -ac 1 -i udp://239.255.1.2:8899 http://222.222.222.222:8090/feed2.ffm 1>/dev/null 2>&1 & exec ./ffmpeg -i udp://239.255.1.2:9988 http://222.222.222.222:8090/feed3.ffm 1>/dev/null 2>&1 &