I'd like to get real-time video from the iPhone to another device (either desktop browser or another iPhone, e.g. point-to-point).
NOTE: It's not one-to-many, just one-to-one at the moment. Audio can be part of stream or via telephone call on iphone.
There are four ways I can think of...
Capture frames on iPhone, send
frames to mediaserver, have
mediaserver publish realtime video
using host webserver.
Capture frames on iPhone, convert to
images, send to httpserver, have
javascript/AJAX in browser reload
images from server as fast as
possible.
Run httpServer on iPhone, Capture 1 second duration movies on
iPhone, create M3U8 files on iPhone, have the other
user connect directly to httpServer on iPhone for
liveStreaming.
Capture 1 second duration movies on
iPhone, create M3U8 files on iPhone,
send to httpServer, have the other
user connected to the httpServer
for liveStreaming. This is a good answer, has anyone gotten it to work?
Is there a better, more efficient option?
What's the fastest way to get data off the iPhone? Is it ASIHTTPRequest?
Thanks, everyone.
Sending raw frames or individual images will never work well enough for you (because of the amount of data and number of frames). Nor can you reasonably serve anything from the phone (WWAN networks have all sorts of firewalls). You'll need to encode the video, and stream it to a server, most likely over a standard streaming format (RTSP, RTMP). There is an H.264 encoder chip on the iPhone >= 3GS. The problem is that it is not stream oriented. That is, it outputs the metadata required to parse the video last. This leaves you with a few options.
Get the raw data and use FFmpeg to encode on the phone (will use a ton of CPU and battery).
Write your own parser for the H.264/AAC output (very hard)
Record and process in chunks (will add latency equal to the length of the chunks, and drop around 1/4 second of video between each chunk as you start and stop the sessions).
"Record and process in chunks (will add latency equal to the length of the chunks, and drop around 1/4 second of video between each chunk as you start and stop the sessions)."
I have just wrote such a code, but it is quite possible to eliminate such a gap by overlapping two AVAssetWriters. Since it uses the hardware encoder, I strongly recommend this approach.
We have similar needs; to be more specific, we want to implement streaming video & audio between an iOS device and a web UI. The goal is to enable high-quality video discussions between participants using these platforms. We did some research on how to implement this:
We decided to use OpenTok and managed to pretty quickly implement a proof-of-concept style video chat between an iPad and a website using the OpenTok getting started guide. There's also a PhoneGap plugin for OpenTok, which is handy for us as we are not doing native iOS.
Liblinphone also seemed to be a potential solution, but we didn't investigate further.
iDoubs also came up, but again, we felt OpenTok was the most promising one for our needs and thus didn't look at iDoubs in more detail.
Related
I don't know if this is the right place to ask, but I have a question..
I am working on a students project where we want to stream a video from one server to multiple devices. But the video should only play on one display at a time. The other displays should be black. But if you switch to another display, the video should continue seamlessly. (Please ask if you need clarification)
The video outputs can be plain displays or with additional servers so a wide range of protocols can be implemented. Wifi connection is possible. Web solutions for running the video in a browser is also possible.
I thought of a lot of alternatives like DLNA, RTP or Chromecast. But I don't know where to start and which is the right solution. It is important that the video that is streamed from the server can be continued on any display seamlessly.
If would mean much to me if you'd give me a hint.
I'd like to stream video from the camera on an iOS device to a receiver via wifi, in effect turning the device into a wireless webcam. Is there a way to build a small app that captures video input on an iOS app and sends it via an RTSP stream or similar?
As this is an ad hoc experiment, I'm not concerned about App Store guidelines and can jailbreak if necessary.
If I interpret your question correctly you more or less need to solve four problems:
Get the camera feed.
Convert/encode this to the right format.
Stream the data.
Prevent the phone from locking itself and going into deep sleep.
The first one is fairly simple and Apple has as always provided good documentation and examples -> API link. Make sure you check out their example in the end as you will get a CMSampleBufferRef data object back.
For the second and third part, you should check out the CFNetwork framework and specially CFFTPStream for streaming using FTP.
If your are only building this for yourself then you can always turn off the Auto-Lock feature in the settings. If you on the other hand would like to distribute this to other users you could use a trick to play a mute sound every 10 seconds. This is more or less how all the alarm clocks work in the App Store. Here's a tutorial. =)
I hope I helped a little bit at least.
Good luck and best regards!
I'm 70% of the way to doing the same thing. Here's how I did it:
Capture content from video input
Chop video into files for use in HTML Live Streaming.
Spin up a web server on the iPhone and make the video files available.
Connect to the IP address of the phone and viola! you've got live streaming video.
Last time I touched the code I was trying to debug my Live Streaming not working. I'll try and get my source code posted on github this weekend, if you'd like to take a look.
I want to be able to (live) stream the frames/video FROM the iPhone camera to the internet. I've seen in a Thread (streaming video FROM an iPhone) that it's possible using AVCaptureSession's beginConfiguration and commitConfiguration. But I don't know how to start designing this task. There are already a lot of tutorials about how to stream video TO the iPhone, and it is not actually what I am searching for.
Could you guys give me any ideas which could help me further?
That's a tricky one. You should be able to do it, but it won't be easy.
One way that wouldn't be live (not answering your need, but worth mentioning) is to capture from the camera and save it to a video file. see the AV Foundation Guide on how to do that. Once saved you can then use the HTTP Live Streaming segmenter to generate the proper segments. Apple has applications for Mac OSX, but there's an open source version as well that you could adapt for iOS. On top of that, you'd also have to run an http server to serve those segments. Lots of http servers out there you could adapt.
But to do it live, first as you have already found, you need to collect frames from the camera. Once you have those you want to convert them to h.264. For that you want ffmpeg. Basically you shove the images to ffmpeg's AVPicture, making a stream. Then you'd need to manage that stream so that the live streaming segmenter recognized it as a live streaming h.264 device. I'm not sure how to do that, and it sounds like some serious work. Once you've done that, then you need to have an http server, serving that stream.
What might actually be easier would be to use an RTP/RTSP based stream instead. That approach is covered by open source versions of RTP and ffmpeg supports that fully. It's not http live streaming, but it will work well enough.
Using FFMPEG, Live555, JSON
Not sure how it works but if you look at the source files at http://github.com/dropcam/dropcam_for_iphone you can see that they are using a combination of open source projects like FFMPEG, Live555, JSON etc. Using Wireshark to sniff the packets sent from one of the public cameras that's available to view with the free "Dropcam For Iphone App" at the App Store, I was able to confirm that the iphone was receiving H264 video via RTP/RTSP/RTCP and even RTMPT which looks like maybe some of the stream is tunneled?
Maybe someone could take a look at the open source files and explain how they got RTSP to work on the iphone.
Thanks for the info TinC0ils. After digging a little deeper I'v read that they have modified the Axis camera with custom firmware to limit the streaming to just a single 320x240 H264 feed, to better provide a consistent quality video over different networks and, as you point out, be less of a draw on the phone's hardware etc. My interest was driven by a desire to use my iphone to view live video and audio from a couple of IP cameras that I own without the jerkiness of MJPEG or the inherent latency that is involved with "http live streaming". I think Dropcam have done an excellent job with their hardware/software combo, I just don't need any new hardware at the moment.
Oh yeah, I almost forgot the reason of this post RTSP PROTOCOL DOES WORK ON THE IPHONE!
They are using open source projects to receive the frames and decoding in software instead of using hardware decoders. This will work, however, this runs counter to Apple's requirement that you use their HTTP Streaming. It will also require greater CPU resources such that it doesn't decode video at the desired fps/resolution on older devices and/or decrease battery life compared to HTTP streaming.
I'm wondering if there are any examples atomic examples out there for streaming audio FROM the iPhone to a server. I'm not interested in telephony or SIP style solutions, just a simple socket stream to send an audio clip, in .wav format, as it is being recorded. I haven't had much luck with the google or other obvious avenues, although there seem to be many examples of doing this the other way around.
i cant figure out how to register the unregistered account i initially posted with.
anyway, I'm not really interested in the audio format at present, just the streaming aspect. i want to take the microphone input, and stream it from the iphone to a server. i dont presently care about the transfer rate as ill initially just test from a wifi connection, not the 3g setup. the reason i cant cache it is because im interested in trying out some open source speech recognition stuffs for my undergraduate thesis. caching and then sending the recording is possible but then it takes considerably longer to get the voice data to the server. if i can start sending the data as soon as i start recording, then the response time is considerably improved because most of the data will have already reached the server by the time i let go of the record button. furthermore, if i can get this streaming functionality to work from the iphone then on the server side of things i can also start the speech recognizer as soon as the first bit of audio comes through. again this should considerably speech up the final amount of time that the transaction takes from the user perspective.
colin barrett mentions the phones and phone networks, but these are actually a pretty suboptimal solution for asr, mainly because they provide no good way to recover from errors - doing so over a voip dialogue is a horrible experience. however, the iphone and in particular the touch screen provide a great way to do that, through use of an ime or nbest lists for the other recognition candidates.
if i can figure out the basic architecture for streaming the audio, then i can start thinking about doing flac encoding or something to reduce the required transfer rate. maybe even feature extraction, although that limits the later ability to retrain the system with the recordings.