I want to show image frames generated from OpenCV on react, I am using Django as server-side. I get a single frame from each request when I send requests from react to Django, so it constitutes a large number of requests at a time.
For now, I am just sending a request to API again and again which I think is not a proper way. I need resources like a tutorial , articles to learn the best way to achieve this thing.
I have seen like WebSockets will be good but I researched a lot but can't found a proper resource.
Can someone suggest to me or can share a good resource to learn?
I don't have much knowledge of react. But if I were to do the same task on a webpage then I would read images/frames from webcam using javascript.
Here is an example of it:
Read image from webcam using javascript.
After retrieving the image, you could send frames from js to Django and perform the OpenCV task there.
Related
Imagine I am given any video format, what is the most optimal way to convert the video to a format that can be posted on Instagram?
The video format must conform to this
Instagram Video Specifications
I'm looking at FFMPeg but I just felt I should ask first for probably existing solutions in the NodeJS community before re-inventing the wheel.
My tech stack is NodeJS.
Please note that I have attempted to search for solutions with no results.
Any ideas on this would be truly appreciated.
TLDR; Yes, FFMPEG command-line would be my preferred option. But, run it as a background worker.
This is what I would do:
For each video required, post the source URL to a queue (Azure Service Bus, RabbitMQ, etc...)
Create a background worker process (Docker container?) to pop each message off
Run the file through FFMPEG
Upload the result to Instagram
If there are no messages, just wait patiently in the background worker.
Generally it's a good idea to separate front-end API's from back-end workers so they can scale independently.
I have a django application that I use to visualize data. The data itself is in an Amazon S3 bucket, and the plotting of the data is done using bokeh. One of the applications however, uses d3 instead. And while I managed to configure the bokeh apps to work properly, I don't know how to do that with the d3 app. It has to read data either directly from S3 or locally (If I download it within django views before rendering the web page) and plot it. But whatever I try I get a 404 Not Found error.
I'm learning as I go, so I don't know what I'm doing wrong. Going through SO, I found this question which gives an example of downloading a file from S3 using Node.js, but I am already running a django server so I don't know if that works. I should also mention that the files to be read are quite large (several megabytes). So, to summarize, my question is:
Is using Node.js my only solution here and can it be done without having both Nodejs and django running at the same time? I'm worried that this might be too complex for me to set up. Or better yet, what would be a recommended solution in my case? I am almost done with the whole project but, unfortunately, I've gotten stuck pretty bad here.
Thank you to anyone willing to help or offer advice.
I am very new to webrtc, I am slightly confused about it.
I am able to do one-to-one video/audio call using node.js, but still confused is it possible to check how long two people had talked?
If yes, please guide me.
If not then what is the best way to monitor call length? (I don't want to record audio or video, just the length).
Thanks in Advance.
Are you using nodejs as your socket server, or as the actual endpoints? Last I checked webrtc didn't have a native nodejs interface but you could use one of the available NPM modules.
It's always possible to track from the app side. Get the time at the start, get the time at the end and report that to your server. The WebRTC api for iOS, Android, and JS has a GetStats api you can call during or after a session to get this information as well. AppRTC has examples on how to do that.
I need to write own video hosting with player on client side.
My required approaches:
The user can upload video to hosting
The user can watch any video from hosting
I don't ask to write me solution, I am asking for help where should I start from to lean about it? Which technologies or frameworks should I learn for my task to realize it using python?
P.S. Each detail will be very useful, especially some links to articles because I couldn't find by myself not knowing accurately what do I need to search.
Added
Now, I think to store videos in the file system directly and use postgresql to store additional information about videos and users. Of course, large services use Hadoop, BigTable and etc but for my task so solution will be enough I think.
When the user uploaded a new video, my server saves it into a temporary directory and puts in the processing queue. Small programs takes new videos one by one, generates thumbnails and decrease a quality of videos and moves it to the base storage. Is it a good idea?
But I still can't get how make a video streaming
Ok So I dont want to encourage the behavior of people thinking SO is a codewriting service, But this is a truly legitimate answer. So first of all, you want to choose a language. Currently I'd recommend the use of javascript and Node.js (Java needs to die). However, IDK Node as well as I know Python. Python is an all purpose language yadda yadda yadda blah blah blah. Whats important in this case is your framework of choice (or library). The libraries that allow you to make websites in python (or make it easier to do so) are very interesting. There are several but my favorite is Python Flask. Python flask is actually very similar to Node.js + Express.js. Use this link to get started. Take a few days to learn the insides of this framework. VERY MODULAR, VERY POWERFUL. Using basing logic and database knowledge, one can easily accomplish a simple file upload and authentication-using, web service. However I Know of 2 really good guides that will help you with the streaming of the videos. I mean yes, You don't really need to know this. You could potentially load the requested video using a <video> tag, but streaming is a much MUCH
more favorable solution. Take some time to learn about video streaming and compression, and after you think about it, check out these links: AUDIO STREAMING GIST and MIGUEL GRINBERG FLASK VIDEO STREAMING BLOG POST
Good luck with flask and
Pro tip: learn about http(s) and the get and post methods
You would never imagine how many times I struggled with a bad request error or a method not allowed because I didn't do my research
I am planning a project CCTV system using Node.js and openCV, WebGL.
Would you please take a look at my plan and find flaw or give me advice?
My plan is: Entire system consists of 3 types of host, CCTV-server-watchmen. Numbers of each host may be (more than 10)-1-3? CCTV take a video and send it to the server. The server identifies persons in the video, and analyzes who this person is and where he or she is(using OpenCV). Finally, watchmen can seize entire status of field he or she manages(map drawn by webGL helps it). I will use node.js as network method.
I have a few issues about my plan.
Is it efficient to use Node.js as video data transmitter?
Basic concept of Node.js is single-thread, so maybe large data like video does not fit to it. But, count of CCTV and watchmen is limited and fixed(It is system for closed intranet)
Is there any method can replace Node.js?
I will not replace openCV and WebGL. But Node.js could matters. At the beginning of planning, I was finding other means for networking between C/C++ program and web-browser. Honestly, I got failed at school-project last year. One of problems that I can't find solution was "How to send/receive data between C program installed at Raspberry Pi and web Browser". I chose Node.js as method this project, but also heard other means of Qt, DB, CGI. Is there a better way?
Thank you for reading it.