I am developing an application which listens live streams and fingerprints them concurrently in order to be identified by a mobile phone.
I will use gracenote's sdk for fingerprinting process. Since I need to fingerprint live streams instantaneously and get rid of them after a few minute,I need to design my own server and database (I also do not know whether you have such server in your sdk or not.).
Now I would like to ask a question about your fingerprint, I can get fingerprints successfully with gnsdk_musicid_query_get_fp_data function in base64 format.
First question: What is the length of coded strings, which are base64, in seconds.
Second question: After decode base64 codes, How should I do the comparison, in binary wise(after concatenation of bytes) or in integer wise, if integer wise how many bits to align (1,2,4 or 8 bytes?) .
Could you give some hints about comparison?
The GracenoteSDK only has the ability to create fingerprints. The only implementation that can compare fingerprints is the Gracenote Service. So you won't be able to make a service of your own that will do fingerprint recognition, but you can certainly build an application that uses Gracenote to do this.
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I need some help.
What is the best way to set up LIVE STREAMING over the web from my WEBCAM to the server and back to multiple users?
Essentially I'm trying to create a group video chat application that can support many users.
I don't want it to be peer to peer webRTC.
I actually managed to make it work with getUserMedia() -> mediaRecorder -> ondataavailable -> pass blob chunks to node.js via SOCKET.IO -> socket.io sends back blob chunks to other connected users -> append those chunks to a sourceBuffer that's connected to a mediaSource that's set as the source URL on a
And it actually worked! BUT it's so slow and laggy and resource intensive. As these chunks get passed like 20 per second and it's slowing the page a lot. I don't think you're supposed to pass that many blobs to the sourceBuffer so quickly. Just for a test I tried saving mediaRecordings every 3 seconds (so it's not that resource intensive) and passing those webm blobs to the sourceBuffer but for some reason only the first webm loads, and the other ones don't get added or start playing.
It just can't work for a production app this way.
What's the "RIGHT" way to do this?
How to pass a video stream from webcam to a Node.js server properly?
And how to stream this live stream back to the web from the Node.js server so that we can have a group video chat?
I'm a bit lost. Please help.
Do I use HLS? RecordRTC?
Do I stream from Node.js via http or via socket.io?
There are services that already let you do that easily like vonage video api tokbox but those seem to be very expensive?
I want to run the video streaming through my own Node.js server that I control.
What's the best way to do this?
Please help.
Thank you
Essentially I'm trying to create a group video chat application that can support many users.
I don't want it to be peer to peer webRTC.
Video chat requires low latency, and therefore requires usage of WebRTC. Remember that one of the "peers" can actually be a server.
And it actually worked! BUT it's so slow and laggy and resource intensive.
Video encoding/decoding is resource intensive no matter how you do it. If by "slow" and "laggy" you mean high latency, then yes, recording chunks, sending chunks, decoding chunks, will have higher latency by its very nature. Additionally, what you're describing won't drop frames or dynamically adjust the encoding, so if a connection can't keep up, it's just going to buffer until it can. This is a different sort of tradeoff than what you want.
Again, for a video chat, realtime-ness is more important than quality and reliability. If that means discarding frames, resampling audio stupid-fast to catch up, encoding at low bitrates, even temporarily dropping streams entirely for a few seconds, that's what needs to happen. This is what the entire WebRTC stack does.
As these chunks get passed like 20 per second and it's slowing the page a lot. I don't think you're supposed to pass that many blobs to the sourceBuffer so quickly.
No, this is unlikely your problem. The receiving end probably just can't keep up with decoding all these streams.
Do I use HLS?
Not for anyone actively participating in the chat... people who require low latency. For everyone else, yes you can utilize HLS and DASH to give you a more affordable way to distribute your stream over existing CDNs. See this answer: https://stackoverflow.com/a/37475943/362536 Basically, scrutinize your requirements and determine if everyone is actually participating. If they aren't, move them to a cheaper streaming method than WebRTC.
RecordRTC?
No, this is irrelevant to your project and frankly I don't know why people keep using this library for anything. Maybe they have some specific use case for it I don't know about, but browsers have had built-in MediaRecorder for years.
There are services that already let you do that easily like vonage video api tokbox but those seem to be very expensive?
This is an expensive thing to do. I think you'll find that using an existing service that already has the infrastructure ready to go is going to be cheaper than doing it yourself in most cases.
I have a mini microservice project using NodeJS as backend and MQTT as the media for communicating between services. and I have a service that suppose to send an excel file to another service. Is there any way for MQTT to publish a file?
So far I only managed to send it as binary-data but had no idea what to do with that, or is there any way to recreate a file from binary-data in NodeJS?
This stackoverflow thread talks about MQTT byte limits.
The length of the actual topic string is at most 65536 bytes. This is a limit imposed by the mqtt spec, you can't change it. It is also worth noting that the topic is encoded with utf-8, so you may have less than 65536 characters available. The payload of the message is limited to 268,435,456 bytes. Again, this is defined by the spec.
If you exceed these limits, you need to break your file in chunks and use Base64 algorithm to encode them to ASCII. Make sure you send a hash of the whole file to check and guarantee that your file is consistent in the other side of the wire, after restoration.
This article does something similar using Python, in case you want to see some code. Hope it helps!
A file is just binary data and MQTT payloads are just binary data.
If you want to include meta data, e.g. a file name then you are going to have to come up with a data format to encode the filename along with the files content. That can be done any number of ways, be it in the topic you publish or by creating a data structure that includes the filename and the contents of the file.
since mqtt payload has limit, as #Fabio Manzano cited above, and it is impossible to publish binary data from even a small-sized file, i think i've managed to make this work by breaking it down into chunks (the binary data) and publish them separately. then merge them all back again when it finishes sending the last chunk.
and then do like what this thread suggests:
Writing image to local server
i've tried it and it succeed. thank you for the responses.
I am working on a project where an Arduino will send measurements and receive commands through an Ethernet interface and a REST API to open and lock a door. For all means, we can consider that the devices are protected, but that the Ethernet network may be accessed. Therefore, a Man-in-the-middle attack is plausible.
The commands to open/lock the door will be part of the reply of an HTTP GET request. In order to prevent a MITM attack where the response is faked to open the lock, I want to use some kind of encrypted response. Now, Arduinos lack the power to use HTTPS, and I want it to be Arduinos because of costs and ease of development.
I have come up with the following scheme:
Both the Arduino and the server have an identical set of index-value registers. The value will be used as a code to encrypt using AES-128.
When the Arduino sends its GET request, it also sends a randomly selected index, indicating to the server which value to use to encrypt the open/lock command.
The server sends a clear text response (JSON) where the command field is an encrypted text.
The Arduino will decode it and apply the required action.
The Arduino will also send some sensor data from time to time. In this case, it will send the index of the code it used to encrypt the data and the encrypted data.
The set of index-value keys is large, so repetitions are rare (but may occur from time to time).
My question is, is this scheme secure? Am I missing something? Is there any other more tested alternative for securing these interactions that doesn't involve using a more advanced platform?
Thanks in advance!
Use an ESP2866 based Arduino. It does not cost significantly more, it uses the same tools but you can use SSL instead of rolling your own solution. I have used the Wemos D1 boards and they work as a drop in Arduino replacement.
So I want to transfer sound bytes over a websocket from a phone to a server. However according to http://crossbar.io/docs/Features crossbar seems to only implement json and msgpack. Can I stil transfer binary messages over crossbar using some other way?
Also multiple crossbar clients (for eg )seems to only provide json and webpack as de/serialization formats. Am I missing something?
WAMP is primarily intended for transmission of messages, not large (binary) payloads. For small chunks you can encode the audio so that it can be part of a regular WAMP payload. For an example of this for a webcam image, see the Tessel camera example - https://github.com/crossbario/crossbarexamples/tree/master/iotcookbook/device/tessel/camera. This works fine in principle, though there is, of course, the encoding/decoding overhead.
I have just started using node.js, I'm running a node server with sockets.io and i need to send a buffer of bytes to the client.
I understand that this can be done by first translating the byte buffer to base64 and sending that, then translating it back on the client side. but i was wondering if there is a more elegant way of getting the byte stream to the client.
Socket.IO 1.0 Now supports Binary data transfer. Please have a look here . You can use Blob, ArrayBuffer and File.
https://github.com/binaryjs/binaryjs can be a solution. base 64 have ~30% of overhead size, so if you need to transfer large amount of data it will become inefficient.
There is also socket.io-stream https://github.com/nkzawa/socket.io-stream
It is little difficult to use binaryjs with socket.io.
Try deliveryjs
https://github.com/liamks/Delivery.js
which provides the means of communication between clients and server via socket.io.
However this module also uses the base64 conversion, which is a drawback.