I need to synchronize a video in diferrent devices with windows phone. So i get the hour from a ntp server and then convert it to miliseconds. Now i think i need to make a internal clock to count the time to launch the video. I have some difficultes to understand this. I don't see examples in the internet. Can anyone help me? I need to know how to do that.
Your question is vey vague and missing lots of information relevant to what you're actually trying to achieve. However, by piecing together information from what I assume are your related other questions, here goes.
The simplest way of having a video play at the same time on multiple devices is to have it streamed in real time from a central server.
If it's not playing directly from a central server then there is a question about where the video file is downloaded from and how you define when the video should be started from. There is also a question about why/if it really needs to be played in sync.
Assuming that you have a central server to determine what to play when:
An NTP server only seems relevant to this scenario if the video content is shipped with the app or is fully downloaded. You can then use the NTP server to determine the difference between the devices time and that returned from the central server. (Note that you can't set the devices time via the available APIs.) You should then query the central server to find out where the video should be played from. I'd suggest having the server respond with a response that indicates the point to start playing back in a couple of seconds. i.e. the equivalent of "Play video X, skipping the first Y seconds/milliseconds/ticks and starting in Z seconds time.
If you don't have a central server to determine when to play what then, the only assumption I can make about how this scenario would work is if all devices have the content (or first download it before trying to play) and details about when that content should be played. A simple example of this would be a 1 hour video which is played on a loop. The NTP server could be used to find out what the actual current time is (subject to the difference allowed for the NTP request) and then start playing the track at the same position through at the time it is past the hour.
In the above scenarios when I state that content must be downlaoded before trying to play, this is to ensure that there aren't issues with the download being slower than playback as the time taken to buffer would get playback out of sync.
Hope this helps.
Related
I am using Streamlink to help some of my technically challenged older friends watch streams from selected sites that webcast LIVE two or thee times a week and are ingested into Youtube. In between webcasts, it would nice to show the User when the next one will begin via the apps Status page.
The platform is Raspberry Pi 3 B+. I have modified the Youtube plugin to allow/prohibit non-live streams. If '--youtube-live-required' is in the command line, then only LIVE streams will play. This prevents the LIVE webcast from re-starting after it has ended, and also prevents videos that Youtube randomly selects, from playing. I have also applied a 'soon to be released' patch that fixes a breaking-change that Youtube made recently. I mention these so you know that I have at least a minimal understanding of the Streamlink code, and am not looking for a totally free ride. But for some reason, I cannot get my head around how to add a feature to get the 'scheduledStartTime' value from the Youtube.py plugin. I am hoping someone with a deep understanding of the Streamlink code can toss me a clue or two.
Once the 'scheduledStartTime' value is obtained (it is in epoch notation), a custom module will send that value to the onboard Python server, via socketio, which can then massage the data and push it to the Status page of connected clients.
Within an infinite loop, Popen starts Streamlink. The output of Popen is PIPEd and observed in order to learn what is happening, and then sends that info to the Server, again using socketio. It is within this loop that the 'scheduledStartTime' data would be gleaned (I think).
How do I solve the problem?
I have a solution to this problem that I am not very proud of, but it solves the problem and I can close this project, finally. Also, it turns out that this solution did not have to utilize the streamlink youtube.py plugin, but since it fetches the contents of the URL of interest anyways, I decided to hack the plugin and keep all of this business in one place.
In a nutshell, a simple regex gets the value of scheduledStartTime IF it is present in the fetched URL contents. The Hack: That value is printed out as a string 'SCHEDULE START TIME:epoch time value', which surfaces through streamlink via Popen PIPE which is polled for such information, in a custom module. Socket.io then sends the info to the on-board server, that sends a massaged version of the info to the app's Status Page (Ionic framework, typescript, etc). Works. Simple. Ugly. Done.
I am using a shared hosting plan at Bluehost to host a golf tournament live scoring mobile web app. I am caching everything I can on Cloudflare, and spent quite some time on overall optimization of the initial download & rendering times. There might be more I could do, but without question my single biggest issue is the initial call to my website: www.spanishpointscup.org. Sometimes this seems to be related to DNS lookup and other times related to Waiting(TTFB).
Below are 2 screen shot images of the network calls that show variations in accessing my index.html. Sometimes this initial file load can be even longer. Very rarely are any of the other files downloaded creating a long delay time, so my only focus now is the initial file load. I think that even if I had server side rendering, I would still have this issue.
Does anyone have specific recommendations that they are confident will help me? Switch to VPS or other host? Thank you.
This is typical when you use a shared server.
The DNS has nothing to do with the issue. DNS has to do with the request not the response. It is the Browser that must resolve the the domain name to an ip address.
The delay you are seeing is due to the server being busy and your page is sitting in a queue waiting behind other processes. Possibly you have a CPU grabbing neighbor on your shared server. Or Bluehost has some performance issues.
You will likely notice some image files take an excessively long time to transmit. Which image is slow will appear to be random with each fresh (not in cache) page load.
UPDATE
After further review I noticed the "wait" times are excessive. Wait time is in green on your waterfall. Notice how the transmit time (blue) is short. This is the time it takes the server to retrieve the page from the disk and put it into the transmit buffer. 300-400 millisecond is excessive.
Find a new service provider.
In my application I get rss feed from a website and than compare it with previously saved feed in isolated storage and show the updated feed. I want to update live tile with the updated feed items count, even when the app is not running. Kindly gave me guidelines for this.
You can use a background agent scheduler task. Depending on how resource intensive your call is, you can opt to use a Periodic tasks.
see periodic tasks here
See an example of how to implement it here
you have to note that the earliest a periodic task would run in wp7 is every 30 minutes. it is also subject to available resources on the device, hence it might not always run when you want it too.
I am planning to write WP7 app, which needs to send to server phones GPS position every 5 minutes. Data must be sent to server even if app is not running. One way to do that is to use Background agents (I am using 7.5 Mango), but in that case app will send data only every 30 minutes, which is not acceptable in my case.
Is there any other solution?
Thanks in advice.
No, this is not a supported usecase for WP7 apps on Mango. Also, it's important to mention that the location you'll get for GeoCoordinateWatcher on a background agent is a cached geolocation from approximately the last 15 minutes and not the real-time geolocation.
What exactly are you trying to build if you don't mind me asking? This sounds oddly close to spyware. Even if it's innocuous and meant for a good purpose, I'd be careful walking in any direction that constantly shares GeoLoc with a remote server.
Your only choices are sending the data every 5 minutes while application is running (even when the phone is locked) and/or send the data once every 30 minutes by registering a PeriodicTask.
Having said that, I agree with Justin in that what you are describing sounds nefarious.
I guys:)
I am doing an windows phone application that presents videos, but presents when syncronized with an ntp server. I already have a variable with the time but i don´t know now what to do. I try search in google but i dont find anything.. I want to make an application to present the same video at the same time in different phones..
Any help? Examples?
The simplest way to get multiple devices doing something in sync is to define a time at which they should all start (do this on a central server) and then have each device request the amount of time to wait until the start. Each device should then start playback when that period has elapsed.
If you need to have different devices join in at specific ppoints when some are already playing the video your central point will need to send the point to start playing as well as the amount of time to wait until playback shoudl begin.
Due to the latency of the network communication you won't be able to get perfect sync though.