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安装DVB驱动程序 使用VLS串流 使用VLC串流本文只针对GNU/Linux.
要从DVB卡串流的话，必须先安装驱动程序（译者注：这不是废话吗？）
如果是Linux 2.6.x 内核的话, 只需要在内核配置时选择恰当的模块.
如果是Linux 2.4.x 内核, 必须下载DVB卡的最新驱动（LinuxTV项目的DVB驱动下载页面）.
以下章节假定你已经安装好了2.6内核或者2.4内核的DVB驱动补丁. 如果安装出现问题的话，联系驱动开发者，谢谢.
VLS已经被遗弃，多年没有人维护了. 强烈建议安装VLC，它有着跟VLS同样甚至更多的功能. VLS唯一的优势在于支持dvbrc的语法和低一些的CPU占用率. 可是VLS已经不在支持和维护了.
在home目录下放置 .dvbrc 文件，在里面配置好卫星或者地面数字电视的频道 (有些可能在 libdvb 的tar包中已经配置好卫星的频道).
在命令行中运行 :
% vls -vv -d udp:192.168.0.42 dvb:"EUROSPORT" --ttl 12其中:
"EUROSPORT" 是你在 ~/.dvbrc 文件中配置的频道 ,
192.168.0.42 可以是以下几种选择 :
单播的目标主机地址;
单播的目标主机域名;
多播地址.
12 是你的IP包的生存周期TTL，也就是该IP包能通过的路由数为11.
VLC有着比VLS更多的功能. 第一，VLC提供了更多的串流时的高级选项，像转码和各种高级的输出支持. 第二，VLC能够使用一些DVB适配器的通用接口以提供一种或多种的服务. 现在最新版本的VLC只支持底层的API，所以一些DVB适配器可能不能协同工作. 一些CAM模块和DVB卡不兼容，详见它们的linux-dvb文档. 所谓的专业级的CAM模块能够解扰至多12路服务，而定制的模块只能解一到两路服务，除非特别指定.
编译VLC的时候必须指定 --enable-dvb 且系统中必须安装 linux-dvb 头文件. 下面是一个命令行启动DVB串流的例子 :
% vlc -vvv --color --ttl 12 --ts-es-id-pid --programs=8508,8505 dvb: / --dvb-frequency=11739000 --dvb-srate=27500000 --dvb-voltage=13 / --sout-standard-access=udp --sout-standard-mux=ts --sout / '#duplicate{dst=rtp{dst=address1,mux=ts},select="program=8508",dst=rtp{dst=address2,mux=ts},select="program=8505"}'上述例子是输出两路点播服务的最简单的配置. 下面是前端DVB的配置列表, 根据不同的DVB有所不同:
通用选项
dvb-adapter : 当你的系统拥有多个适配器的情况下，指定特定的适配器（默认是0号适配器）
dvb-device : 指定DVB设备的名称（并不需要标准的linux-dvb安装，这个意思要自己体会，我也不知道怎么表达）
dvb-srate : 指定符号率（单位符号每秒）
dvb-inversion : 指定信号是否倒相，默认是自动检测
dvb-budget-mode : 过滤需要的PID，因此VLC不再需要过滤
卫星接收卡 (QPSK)
dvb-frequency : specifies the frequency to tune to in kHz; according to the frequency range, VLC auto-detects the band to use: S (2.5-2.7 GHz), C-lower (3.4-4.2 GHz), C-higher (4.5-4.8 GHz), Ku (10.7-13.25 GHz) or direct BIS frequency (0.95-2.15 GHz); it is mandatory to supply the dvb-srate option to satellite frontends
dvb-voltage : specifies the voltage to apply on the IF; most LNBs behave differently when supplied with 13 V or 18 V; universal LNBs select vertical polarity with 13 V and horizontal with 18 V; you can also select 0 V if your LNB has another power supply (default is 13 V)
dvb-tone : specifies whether to send a 22 kHz pulse tone to the LNB; universal LNBs switch to high-band when this pulse is sent; by default VLC automatically adopts the correct behaviour if the frequency supplied is in the Ku band (other bands do not need this)
dvb-fec : specifies the code-rate to use for Forward Error Correction; type in the first number of the code-rate, for 2/3 use --dvb-rate=2, etc. (default is 9, meaning automatic detection)
dvb-high-voltage : enables a special mode of the DVB adapter to compensate for the voltage loss in very long cables (AFAIK it is present in the API, but no DVB adapter actually implements it)
dvb-lnb-lof1, dvb-lnb-lof2, dvb-lnb-slof : specifies the frequencies of the first and second local oscillators, and the frequency at which the 22 kHz pulse should be activated to enable the second oscillator; by default VLC uses the values for universal LNBs if the frequency supplied is in the Ku band (other bands do not need this)
有线接收卡 (QAM)
dvb-frequency : specifies the frequency to tune to in Hz; it is mandatory to supply thedvb-srate option to cable frontends
dvb-modulation : specifies the modulation of the analog signal; valid values are -1 (QPSK), 0 (automatic QAM, default), 16 (QAM16), 32 (QAM32), 64 (QAM64) 128 (QAM128), 256 (QAM256)
地面数字电视接收卡 (OFDM)
dvb-frequency : specifies the frequency to tune to in Hz; it is mandatory to supply thedvb-bandwidth option, all other parameters are optional
dvb-bandwidth : specifies the bandwidth of the OFDM channel (6, 7 or 8 MHz depending on the country)
dvb-hierarchy : specifies if the OFDM channel uses hierarchic information; allowed values are -1 (no hierarchy), 0 (automatic, default), 1, 2 and 4
dvb-code-rate-hp, dvb-code-rate-lp : specifies the code-rate to use for higher and lower hierarchies respectively (default auto, same syntax as dvb-fec)
dvb-guard : specifies the guard interval; valid values are 0 (automatic, default), 4 (1/4), 8 (1/8), 16 (1/16) and 32 (1/32)
dvb-transmission : specifies the transmission mode; valid values are 0 (automatic, default), 2 (2K) and 8 (8K)
另外，命令行中还有些不是DVB特定的选项应该解释一下:
ts-es-id-pid : 如果你使用了#duplicate 将复用的流过滤到几个输出，那么这个选项是必须的指定的; 如果流中只有一路节目，则没必要使用#duplicate 和 ts-es-id-pid 选项
programs, program, sout-all : there are several ways of specifying the services to select (and optionally descramble):
programs : used to specify one or serveral programs to select; VLC selects all known elementary streams of these programs; this is the currently recommended way
program : used to specify one program to select; it differs from using programs with only one program in that this option only select the first audio stream, and no subtitle stream; it should be used if you plan to switch programs and audio with a GUI
sout-all : tells VLC to select all programs; this is discouraged because of the extra CPU load needed to demultiplex unwanted programs, and because it is not compatible with CAM descrambling
其他选项是标准的串流选项，可以在本文的其他章节查阅。
