I cannot find a clear answer to this question. From what I understand, RTSP is a protocol for live streams only. Is this correct? Does RTSP support commands to play footage that has been already recorded, say, days or weeks ago?
RTSP does support playbacks.
Here is an example of Hikvision format for a real time and a playback url.
Real time: rtsp://{device.Username}:{device.Password}#{device.Host}/ISAPI/Streaming/channels/{channel}
playback: rtsp://{device.Username}:{device.Password}#{device.Host}/Streaming/tracks/{trackId}/?starttime={startTime_str}&endtime={endTime_str}
Related
I want to play RTSP stream from ip video cameras (MP4, H264) on my intranet web page, I use React. I have 12 cameras and NVR.
I did not find a way to do this without an intermediate server (Webrtc is not suitable), that spends resources on transcoding h264 stream to the mjpeg.
If I set a high resolution and quality of the stream, then a lot of resources are spent on transcoding, and most importantly, the streaming of mjpeg images takes a lot of traffic.
Is there a way or solution to stream from the ip camera directly to the web page so that the decoding is on the user's webbrowser side.
This will free the intermediate server from a heavy load for big streams.
It is necessary that the playback work on mobile phones.
Thanks for the answer.
There is no way to stream RTSP camera's H264 video directly to web browser.
But cameras support outputting still jpeg images - you can create a webpage that will display such an image from a camera every 200ms or so.
If you are not happy with the above solution, you must use a media server in between, which will pull RTSP stream from the camera and will convert it to some protocol that browser understands. You are mistaken in one thing: no video transcoding is involved. I don't know why WebRTC is not an option for you, but most media servers will offer 4 types of output:
Low latency:
WebRTC
Websockets to MSE
High latency:
HLS
MPEG-Dash
All these methods do NOT require transcoding of your original H264 video, encoded by RTSP camera/NVR. Some media servers you can use: Unreal Media Server, Wowza, Janus.
Live demo: http://www.umediaserver.net/umediaserver/demos.html
No browser has native RTSP support, so if you want decoding to happen on the end user side, then you'll have to write your own custom web player.
You can start by looking at the open-source solution like this one:
git://github.com/Streamedian/html5_rtsp_player.git
It works on PC and Android, but didn't work with iPhone for me (but you can try it for yourself https://streamedian.com/demonstration/ maybe it's just my issue), but maybe you can find better alternative or fork it and make it work on all devices.
It still requires a middle-man proxy server though because it uses a websocket tech to work, but since it doesn't do any video converting or decoding, it don't suppose to take any resources at all.
I need to get live video from a device. I have to play the video on the browser. live video can be received as RTP or UDP.
Since there is no support for VLC, I published the video by getting it via RTP with FFMPEG and creating a web server with Nginx.
But later I realized that it is recording video tracks to disk. This is a situation I don't want.
Is there any other way to do this?
Not with RTP or UDP, no, there is no way. You must use WebRTC, or an HTTP based method like HLS or DASH.
I am trying to build a website and mobile app (iOS, Android) for the internet radio station.
Website users broadcast their music or radio and mobile users will just listen radio stations and chat with other listeners.
I searched a week and make a prototype with Wowza engine (using HLS and RTMP) and SHOUTcast server on Amazon EC2.
Using HLS has a delay with 5 seconds, but RTMP and SHOUTcast has 2 second delay.
With this result I think I should choose RTMP or SHOUTcast.
But I am not sure RTMP and SHOUTcast are the best protocol. :(
What protocol should I choose?
Do I need to provide a various protocol to cover all platform?
This is a very broad question. Let's start with the distribution protocol.
Streaming Protocol
HLS has the advantage of allowing users to get the stream in the bitrate that is best for their connection. Clients can scale up/down seamlessly without stopping playback. This is particularly important for video, but for audio even mobile clients are capable of playing 128kbit streams in most areas. If you intend to have a variety of bitrates available and want to change quality mid-stream, then HLS is a good protocol for you.
The downside of HLS is compatibility. iOS supports it, but that's about it. Android has HLS support but it is still buggy. (Maybe in another year or two once all the Android 3.0 folks are gone, this won't be as much of an issue.) JWPlayer has some hacks to make HLS work in Flash for desktop users.
I wouldn't bother with RTMP unless you're only concerned with Flash users.
Pure progressive streaming with HTTP is the route I almost always choose to go. Everything can play it. (Even my Palm Pilot's default media player from 12 years ago.) It's simple to implement and well understood.
SHOUTcast is effectively HTTP, but a poorly implemented version that has compatibility issues, particularly on mobile devices. It has a non-standard status line in its response which breaks a lot of clients. Icecast is a good alternative, and is what I would recommend for production use today. As another option, I have created my own streaming service called AudioPump which is HTTP as well, and has been specifically built to fix compatibility with oddball mobile clients, such as native Android players on old hardware. It isn't generally available yet, but you can contact me at brad#audiopump.co if you want to try it.
Latency
You mentioned a latency of 2 seconds being desirable. If you're getting 2-second latency with SHOUTcast, something is wrong. You don't want latency that low, particularly if you're streaming to mobile clients. I usually start with a 20-second buffer at a minimum, which is flushed to the client as fast as it can receive it. This enables immediate starting of the stream playback (as it fills up the client-side buffer so it can begin decoding) while providing some protection against buffer underruns due to network conditions. It's not uncommon for mobile users to walk around the corner of a building and lose their nice signal quality. You want your stream to survive that as best as possible, so if you have already sent the data to cover the drop out, the user doesn't have to know or care that their connection became mediocre for a short period of time.
If you do require low latency, you're looking at the wrong technology entirely. For low latency, check out WebRTC.
You certainly can tweak your traditional internet radio setup to reduce latency, but rarely is that a good idea.
Codec
Codec choice is what will dictate your compatibility more than anything else. MP3 is easily the most compatible, and AAC isn't far behind. If you go with AAC, you get better quality audio for a given bitrate. Most folks use this to reduce their bandwidth bill.
There are licensing fees with MP3, and there may be with AAC depending on what you're using for a codec. Check with a lawyer. I am not one, and the licensing is extremely complicated.
Other codecs include Vorbis and Opus. If you can use Opus, do so as the licensing is wide open and you get good quality for the bandwidth. Client compatibility here though is the killer of Opus. (Maybe in a few years it will be better.) Vorbis is a mediocre codec, but is free and clear.
On the extreme end, I have some stations doing their streaming in FLAC. This is lossless audio quality, but you're paying for 8x the bandwidth as you would with a medium quality MP3 station. FLAC over HTTP streaming compatibility is not code at the moment, but it works alright in VLC.
It is very common to support multiple codecs for your streams. Depending on your budget, if you can't do that, you're best off with MP3.
Finally on encoding, don't go from a lossy codec to another lossy codec if you can help it. Try to get the output stream as close to the input as possible. If you re-encode audio, you lose quality every time.
Recording from Browser
You mentioned users streaming from a browser. I built something like this a couple years ago with the Web Audio API where the audio is captured and then encoded and sent off to Icecast/SHOUTcast servers. Check it out here: http://demo.audiopump.co:3000/ A brief explanation of how it works is here: https://stackoverflow.com/a/20850467/362536
Anyway, I hope this helps you get started.
Streaming straight audio/mpeg (mp3 packets) has worked everywhere I've tried.
If you are developing an APP then go with AAC, if you are simply playing via web browser then you need a HTML5 Implimentation which is MP3. All custom protocols like RTMP or SHOUTcast requires additional UI to be built. There are some third party players available in open source world. You can either use them or stick to HTML5 MP3/OGG as most people now days are using chrome browser or other HTML5 complaint browsers.
I am working on a RTSP RTP-over-TCP H264 streaming application from a live HW-based encoder.
I am sure , there is somewhere a example code, please any reference, web.
Most of the hardware appliances I have had to deal with (mostly IP cameras) use Live555. It is quite straightforward - you set up the needed tracks and then provide NAL units and the framework takes care of all the rest. They have a nice set of test programs that describe the API - at least I was able to make a RTSP server for a Texas Instruments Pandaboard SoC, and there are lots of info on Live555 on Stackoverflow.
Is it possible to see the live stream of an IP camera using RTSP ?
Example URL: rtsp://public ip:554/1363e66e.mp4
The encoding is mp4 h.264 baseline profile at 320 x 240 resolution.
I followed the Wiki link here.
But I get the error: Prefetch error -2
When I try to play using real player on the nokia e72, I get the error: 'General: System Error'.
Please let me know what I can do about this.
There are no video players on Ovi store that can play the stream either but I am able to play the stream on VLC on the desktop.
You can stream it using ReaPlayer if you don't have VLC player in Ovi store. See the port address range supported by your IP camera. Try the range of 1024 - 2000. RTSP supports VLC, Quicktime and Real player. Using any of these objects you can stream it.
So I think here is the case,
There are a few different mp4 containers. Standard one wont allow you to wrap a real time data into a mp4 container because mp4 needs to have a field/atom in its header called
MDAT and it has information about the file and its size as well.(which is written after the file is completely encoded. )
So unless you wake that you can not stream live stuff in mp4 UNLESS it is fragmented mp4.
Media Foundation will allow you to do this when windows 8 is out( i got the intel from the msdn forum so I dont know how true it is).
I dont know what ffmpeg/Gstreamer is capable of. Again if this is a commercial product you are working on you might run into some licensing issues with ffmpeg.
Look at webrtc.
I am guessing best bet it to use webm or ogg/theora but I am not sure if theora can do what you want, This is something I am also working on.
Please share your findings
Thanks.