On Sun, Sep 7, 2014 at 12:33 AM, Keith Johnson <ke...@xentrik.tv> wrote: > Hi Everybody - > > I'm a complete newbie to MLT, having arrived here in my quest for a solution > to a new project I'm involved in. We have the requirement to shoot a series > of speakers at a conference using two cameras (MS and wide, probably HDV). > There will be full-day sessions with each person speaking for about 5 or 10 > minutes. We shall have to record both cameras simultaneously, with the > ability to monitor/log in live or near-live time. Ultimately we need to clip > up each individual speaker, cutting between the two cameras as required, so > need to maintain sync between streams. > > Ideally we could be doing the clipping up while the event is going on, so > I've considered the option of capturing the HDV streams to one server for > security and simultaneously copying them (or creating smaller proxies) to a > machine where they can be scrubbed back and forth, marked up, then later > conforming and transcoding the original streams as required. > > I'm hoping someone here can give me a few pointers to how I should go about > implementing this with MLT, which might make it less of an uphill struggle - > especially as we have to have this working by November! > > I'm sure MLT can do all this, but it's just a question of knowing where to > start. If I can get a roadmap in my mind I'm keen to do all the work to get > it together. Some links to any relevant working examples which can be > compilied, tested and tinkered with would be very useful. > > All suggestions and ideas gratefully received. And I look forward to sharing > the results of this project with others using MLT. >
Keith, I am not quite sure how to answer this. I do not really understand what you need and are asking for. It does not sound like there are many MLT applications that are close to what you need. With Shotcut or melt, you can record (capture and encode) from HDMI, SDI, and V4L. If you use FireWire cams, MLT can receive the stream through libavdevice as long as there is no stream discontinuity, but it can only then decode it and then do something else with it like view or encode to file. In other words, it does not provide direct capture to file of FireWire data streams like dvgrab does. MLT can switch between sources and clips. Shotcut shows this can be done by letting you add live sources to a playlist alongside clips. However, there is no MLT app I know of that shows more than one device source in a multiview while simultaneously capturing let alone switching between them. Developing something for this will take a lot of time if you do not already know MLT. With that said, here is a python script that comes with MLT that provides a very simple web service that switches between two sources, outputting to a third: https://github.com/mltframework/mlt/blob/master/src/swig/python/switcher.py You can execute this to see what it does without DeckLink devices: ./switcher.py color:blue noise: sdl Then "curl localhost:8888/switch" to trigger it. It does not actually do a simple switch; rather, a friend needed it to reduce input 1 size by 20% revealing input 2 in the background along the left and bottom edges, and then to return input 1 to full size on the next switch. I am afraid I will not be able to help you much with the project as this is just a part time hobby, and I am already so busy with Shotcut. Do you know about DVswitch? http://dvswitch.alioth.debian.org/wiki/ Alas, that appears to be a SD only solution. Also, from this list: http://www.opensourcebroadcast.com/category/directory/video-post-production Snowmix and Open Playout are 2 gstreamer-based projects worth considering. -- +-DRD-+ ------------------------------------------------------------------------------ Want excitement? Manually upgrade your production database. When you want reliability, choose Perforce. Perforce version control. Predictably reliable. http://pubads.g.doubleclick.net/gampad/clk?id=157508191&iu=/4140/ostg.clktrk _______________________________________________ Mlt-devel mailing list Mlt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mlt-devel
