网络电视、PC-TV互联

网络电视、PC-TV互联

(2013-12-22 22:51:46) 下一个

PC输出送电视显示，在PC出现后就开始了，当时的CGA与NTSC模拟电视频率相近，分辨率 640x200。现在的数码电视1920x1280居多，可以支持几种不同分辨率，PC的分辨率反而低些。但两者都可以微调屏幕尺寸，因此对接只要选两者 相近的分辨率，接口一致（通常是HDMI，或将HDMI转DVI)就可以了。

电视与PC的不同，在于前者功能单一，CPU速度不高需加硬件解码，固件变动不大支持的标准不多；后者多用Intel/AMD高速CPU软件解码，支持较 多的编码且升级频繁，用法繁复。介于两者之间的高清播放器应运而生，支持多种编码格式，内置硬件解码（有的内置硬盘或蓝光），高清播放机的代表是 roku，苹果的就是apple TV，google的stick叫Chromecast ，都是为了解码去电视看。这里稳定性最好的可能是苹果（封闭式设计支持的流媒体格式较少），其次是roku，google的stick看来处理能力有限。类似roku的高清播放机国内有几百种产品，大家都是在3-4个平台上开发的。

HDTV出台十几年了，ATSC/DVB都是MPEG2，目前流媒体即在网上传的媒体以H.264（MPEG4 part 10）和Divx（MPEG4)居多，H.265标准也已发布，也会先以PC软件的方式使用。

网络电视开始是指用网络传输电视的内容，泛指网上的时事新闻节目但也包括音乐电影等。目前的smart TV带有网络接口，浏览器的质量比2000年时有很大提高（微软webTV计划在2000年左右以失败告终）。而网络互连各类设备的一个重要的plug- and-play的标准就是DLNA。网络媒体要求网速高且稳定，媒体交换机（switch）的要点就是保证媒体传输延迟小。交换机可用带宽不超过标称 70%，因此交换机/路由器（router）的性能也很重要，目前无线是个趋势。苹果喜欢把标准冠以自己的名称：

AirPort	802.11b	11 Mbps	150 Feet	2.4 GHz
AirPort Extreme	802.11g	54 Mbps	50 Feet	2.4 GHz
AirPort Extreme	802.11a*	54 Mbps	50 Feet	5 GHz
AirPort Extreme	802.11n	300 Mbps 450 Mbps§	175 Feet	2.4/5 GHz

最新802.11ac的带宽约2-~4倍于802.11n。802.11n以普及有150n，300n，600n，900n几种,实际速率要看产品说明，比如ASUS 300n/900n的路由器是300/450Mbps。目前最好的产品有：http://reviews.cnet.com/best-wireless-routers/
亦即家用可选ASUS RT-N66U router，电脑没有802.11n的话用ASUS USB-N10 adapter。

家用的PC-TV互连方案有很多种：
1.AppleTV去TV HDMI，Ipad (mini)的WIFI与Apple TV处于同一局域网中，用苹果的Air play互连: http://support.apple.com/kb/HT4437?viewlocale=zh_TW&locale=zh_TW
不知能否播放ipad存储的节目？基本上apple的东西都是付费的。
2.roku和其他网络机顶盒，以及google Chromecast 与appleTV类似，一头联网一头去电视，互连多是DLNA。用SONY PS3也行，支持DLNA。都只要一般电视就行了，支持的媒体格式不是电视决定的。
3.smartTV带WIFI/网口，与PC联网用DLNA看PC上的节目。当然也如appleTV/roku一样支持netflex，youtube 等。smart TV如VISIO E241I-A1，据说浏览速度比samsung快。支持的媒体格式由smart TV决定。
4. PC上加iTune软件实现air play，也许air play就是apple版的DLNA？
5. PC上加USB-ATSC增加电视/收音调谐。别的方案都是用internet上的无线电台网台。
看来最简单的就是买smart TV，共享局域网的资源通过DLNA（windows 7以上直接支持，由电视机的media目录能显示访问PC媒体文件，XP则需加装第三方软件。（见本文附录）
6. PS3的DLNA：任何DLNA设备都可以连，例如电视、PC、手机：https://www.youtube.com/watch?v=dqu7BPqjo4s?  
操控PC的无线键盘也有许多种（略）。最后说一下硬盘。硬盘至少有消费级、企业级和视频盘三种。据说前两种是按5x8小时设计后者用7x24小时工作设计。但由用户反馈看企业级的或许还是好一些。硬盘早晚都会坏的，每年2-4%。WD质量是黑/红/普通盘。

PS3原带wireless游戏controller，按其上PS3图标待背部4灯同亮转为1灯即匹配好。我用的PowerA自带USB stick，先开PS3再插入USB并按其上Connect纽，此时USB快闪，再按controller上4灯纽，4灯纽闪烁变为稳定单灯就好了，其4象限代表4个频道之一，这样就匹配好了。主要键是四光标、X(Enter)和O(quit)。PS3 Bluetooth controller需要用wireless contoller进accesory选register BD再按屏幕提示设置来匹配。
附录： http://thebitplague.wordpress.com/2012/10/22/play-stream-video-from-pc-to-vizio-tv/

How to play movies from your PC on your Vizio Smart TV

Posted on 10/22/2012 by vaughnteegarden 60 Comments

If you were to thumb through the manual of your new Vizio Smart TV, you might come to the conclusion that you cannot play video files stored on your computer’s hard drive on your TV.  The only mention of playing external media involves plugging in a usb drive, and that is limited to photos and music.

After several searches of the internet, I was becoming convinced it couldn’t be done. I read discussions of potentially making a widget for Plex, a popular media server, but no one had written one yet.  My experiments with a couple of different media servers went nowhere.

What the manual doesn’t tell you, and what I now know,  is that your TV is capable of displaying media streamed from a DLNA-compliant media server. I stumbled across a post here suggesting that if a DLNA media server was present, it would show under the “Media” menu (which was only mentioned in the manual with regards to playing music off a usb drive).

I looked up the wikipedia entry for DLNA media servers, and noticed the PS3 Media Server was listed. I had read a recommendation of this server as being one that “just works”, and so I downloaded and ran it.

PS3 Media Server – Main Screen

Once the server was running, I checked the Media app on the TV, and sure enough my computer was listed. Clicking on the computer name, you have the choice of Photo, Music, or Video… I chose video.

By default it was sharing my entire PC, at the “My Computer” level. That was no good, so on the “Navigation/Share Settings” tab I added my video directory as a shared folder. I pressed Save at the top of the screen, and restarted the server. It now correctly restricted sharing to only the one folder.

PS3 Media Server – Specify Shared Folder

From then on, it “just worked”. Clicking on a video file played the movie almost immediately, and the play, pause, fast forward and rewind buttons on my Vizio remote all worked. Video and Audio quality were both excellent, given the source file.

Some notes about this tip…

• I use Windows XP at home because I’m a cheap bastard, and I don’t see  a point in upgrading until I upgrade my hardware as well.  I understand some or all Windows 7 systems have a media server built in. If you have Windows 7, fire up your computer, and check the Media item in your TV. You may not need PS3 Media Server at all.
• I believe that for a DLNA media server to work, you must have your PC and TV connected through a DLNA compliant router. I have the excellent Asus RT-N66U, and I can’t recommend it enough. It’s worth the money for the speed, range, and extra features.
• As always, your mileage may vary.

I hope this post helps others searching for a way to play video files from their PC on their Vizio TV.

PS3 Media Server homepage

Optoma HD33 其实这个投影机最大的亮点就是不用买进口的发射器和3D眼镜，国产创维的大家都知道的，相当好用。型号是RD04SA和RD06SA，发射器网址奉上  http://item.taobao.com/item.htm?spm=a230r.1.10.64.AjFeY9&id=18875988291

WIFI smart TV: Philips 32PFL4909/F7 720P $280(Target sale $230), 40PFL4909/F7 1080P $435 802.11g/n
http://www.walmart.com/ip/Philips-32PFL4909-32-720p-LED-LCD-TV-16-9-HDTV/39364375
http://download.p4c.philips.com/files/3/32pfl4908_f7/32pfl4908_f7_pss_aenus.pdf室内天线： RCA 1650R，平躺最好，也可直立。
上述smartTV太厚了准备退掉。薄的1080P有Samsung 5999=1.5",5500=1.9",ViZIO M322i=2.08"，不然Ruko或Chromecast好了。