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Could I Run a TV Station on Linux?
JesusQuintana asks: "I'm working with a low-power television station to update their playback system. Currently they're using tape and I've been tasked to move them to computerized playback (MPEG-2, etc.) There are proprietary solutions (very expensive) and there are companies that bundle software with Windows and standard x86 hardware. Overall, they are generally unimpressive and won't sell the software without bundling it with their own hardware. (They won't let us buy our own storage.) We have the expertise to build our own infrastructure (NAS, redundancy, etc.), but really just need the equivalent of iTunes for high quality video. There are lots of other pieces needed to complete the work-flow (such as encoding the media), which could be accomplished on Mac or Windows or even Linux. But what about playback? We need something that will play back these files at their scheduled times (perhaps scheduling cron jobs to change playlists) to broadcast quality hardware (SDI or YUV video). Could we run a TV station on Linux?"
Yes, this can be implemented on a linux box very easily.
Long story short I implemented this in 2002 at the University at Albany, SUNY with a friend.
It requires a dedicated server and a dedicated encoder.
What will make the process easier is going all digital on your content development.
It currently has a barebones site: Albany Student Television
You can use any number of devices to keep the content automated and going from cron to java scripts to shell scripts and what have you. The challenge is figuring out what you want to do and how you want it managed?
Since 2002 there is a lot more technology out there. Our solution at the time was to use windows explorer with embedded media playing. Two draw backs were an occasional refresh logo in the top, and IE's tendency to be unstable.
...it appears to me that BBC America is probably run by two people and an automated system. My reasoning for this? The glitches I see from time to time. Sometimes the schedule on their web site will say they are showing a certain program, when they are showing something else. Sometimes I've even seen things like a program go to commercial break and when the break is over, you're in the middle of a different program. I suspect these are automation glitches. My second reason for saying this is that I have a series of BBC America station IDs I've edited out of the regular program streams and I have an automated playlist system that can simulate a live BBC America feed just with the programs I've recorded and commercials I've produced myself. So the answer is: yes you can. The real question is, how much of your time do you want to dedicate to doing it and are you up to the challenge. I did it purely for the fun of running a virtual TV station. Would I trust it to work for a low-power TV station? Sure. But I think you'd definitely want better hardware than what I've got. Just make sure it's supported in Linux, or else it's a show stopper. (No pun intended)
-"...bad old ideas look confusingly fresh when they are packaged as technology" - Jaron Lanier (Digital Maoism on Edge.o
Just to backup what Yonder Way said, Yes. I worked on a project for a little while that was to provide scheduled playback for Internet audio and optional video streaming. It used a MySQL database for tracking artists, program schedules, playlists for the programs, supported e-Commerce, traked where the actual audio and video streams were, etc. For playback, there are many different applications (free) that can do the job depending upon the format you wish to provide. The hardest part (not including the time for development, which is not hard, just time consuming) is selecting the various components from all the choices available.
For the inventive and those that need a solution that doesn't exist, the various video formats and protocols are published and applications can be written to provide the solution needed (which is something I had to do in part for Akamai when I worked there).
As a final note, a Linux based solution would work far better and be far more reliable than a Windows based solution (it would also provide a far better ROI and a lower TCO).
PGA
Speaking of VLC, I know a guy at the cable co where I used to work who uses VLC running on $800 Dell servers with capture cards to digitize analog channels to a format that the digital boxes can read. He saved the company $9000/channel for each of the channels they didn't have already piped to them in digital format (the lowest cost purpose built digitizer was $10,000)
I designed something similar to this for their CNN Headline news division in Atlanta. The long and short of it is yes you can do it, but rollout approach is very important. For HL, the issue was the shear amount of requirment responsabilities. Everything from "if a plane crashes, do not show American Airlines commercials", to "In this special case, do this" type of thing.... It performs flawlessly, but you really need a good senior developer to pull it off...
Seriously, I've thought about what I'd do with a MythTV box. I've wanted it set it up to play my DVD collection according to a schedule, inserting promos for other upcoming shows between chapters and trailers for the next episode (some DVDs like The X-Files put the 10 and 30 second ads all on the last disk). Then some lower-third overlays for inserting severe weather information, caller-ID, and signaling of when someone's at the door. If I had a family, I'd get the kids involved with a camera to produce periodic news updates.
Basically turning it into what TiVo had once advertised: controlling my own TV network.
Unfortunately I've been happily employed on other coding tasks and haven't had the time even to put together a system for basic recording tasks let alone learn the source tree of MythTV to gauge how feasible it would be to adapt it for 24-hour scripted network control.
Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
This is utterly rubbish. Many modern broadcast systems have very sophisticated and very easy to manage front ends for handling staggering numbers of encoders/muxes/routing/modulating equipment. Of course the expense comes from redundancy, so that the broadcaster has minimal off-air time if a mux or encoder fails by having software managed backups (IE spare muxes and encoders). Advertisers will get very upset if their content isn't aired correctly. So in modern systems, switching from failed equipment can be detected and done so quickly that the consumer in most cases will not notice that the switch and associated re-routing has occurred. Equipment which can do this cleanly does not come cheap.
:)
Anyway, back to the original question. It's not stated whether the output is analog or digital. If digital, then the transport mux and program tables and all the other DVB mandatory content has to be correctly generated. Encoding high quality complient MPEG-2 on the fly requires some pretty serious hardware support in the professional encoders, so there is no way this could be done with a PC - sure you can encode crappy quality MPEG at low resolutions, but trying to produce professional quality video that makes the most out of your bitrate really isn't going to happen (good motion compensation is non-trivial, in a "You may think it's a long way down the road to the chemist, but that's just peanuts to quality motion compensation!" kind of way).
Of course, you can encode offline and store the transport streams on disk, but then when you mux the output with all the other DVB content, you've got to have consistent GOP structures, PCRs (Program Clock References), presentation time stamps, time codes etc, which is immensely difficult to achieve, especially if you're planning on splicing in adverts and other content (hint - this is one reason why satellite and cable broadcasters encode live from SDI inputs).
If you're trying to replace a tape archive (rather than "Run a TV Station on Linux" - which is a whole lot more, as discussed above), then perhaps you can MPEG encode the videos offline with a good quality software encoder and play it back raw (SDI/YUV) to the head-end bits that do the final encoding/modulating, but even then, getting it all synchronised correctly is likely to be non-trivial (you can't just produce your SDI frames willy-nilly you know - it's got to be synced to the rest of the station, just like the original tape system must have been - possibly off a "black and burst" generator).
Really, I think you're in for a very tough time trying to do this with Linux and OSS, unless you're willing to accept very low quality results that might not integrate with a professional broadcast system.
But, good luck nonetheless.
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