here is my question:
I use Android Apis "MediaMuxer" to combine h264 stream and aac stream to mp4 file,when I want to stop record,so I call this:mMediaMuxer.stop(),and the mp4 file can play well.
but sometimes,there is an unexpected happen,like kill power or power is gone suddendly,so there is no time to call "mMediaMuxer.stop()",finally this file can not play anyway....
Is anybody know now to fix this problem? I want to play this video event didn't call "mMediaMuxer.stop()" this method... or there is other Apis or sdk can combine h264+aac stream well?
I'm trying to get the raw audio in getUserMedia() success callback and post it to the server.
The success callback receives the LocalMediaStream object.
var onSuccess = function(s) {
var m=s.getAudioTracks(s);
//m[0] contains MediaStreamTrack object for audio
//get the raw audio and do the stuff
}
But there is no attribute or method to get the raw audio from channels in MediaStreamTrack.
How can we access the raw audio into this callback which is called on success of getUserMedia()?
I found the Recorder.js library-- https://github.com/mattdiamond/Recorderjs
But it is recording blank audio in Chrome: Version 26.0.1410.64 m.
It works fine on Chrome: Version 29.0.1507.2 canary SyzyASan.
I think there is issue of Web Audio API used by recorder.js
I'm looking for the solution without Web Audio API, that should work at least on chrome's official build.
Check out the MediaStreamAudioSourceNode. You can create one of those (via the AudioContext's createMediaStreamSource method) and then connect the output to RecorderJS or a plain old ScriptProcessorNode (which is what RecorderJS is built on).
Edit: Just realized you're asking if you can access the raw audio samples without the Web Audio API. As far as I know, I don't think that's possible.
Is it possible for a Chrome extension to listen for streaming audio from any of the browser's tabs? I would like to capture the streaming audio data and then analyse it.
Thanks
You could try 3 ways, neither one does provide 100% guarantee to meet your needs.
Before going into more detailed descriptions, I must note that Chrome extensions do not provide convenient tools for working on per connection level - sufficiently low level, required for stream capturing. This is by design. This is why the 1-st way is:
To look at other browsers, for example Firefox, which provides low-level APIs for connections. They are already known to be used by similar extensions. You may have a look at MediaStealer. If you do not have a specific requirement to build your system on Chrome, you should possibly move to Firefox.
You can develop a Chrome extension, which intercepts HTTP-requests by means of webRequest API, analyses their headers and extracts media urls (such as containing audio/mpeg MIME-type, for example, in HTTP-headers). Just for a quick example of code you make look at the following SO question - How to change response header in Chrome. Having the url you may force appropriate media download as a file. It will land in default downloads folder and may have unfriendly name. (I made such an extension, but I do not have requirements for further processing). If you need to further process such files, it can be a challenge to monitor them in the folder, and run additional analysis in a separate program.
You may have a look at NPAPI plugins in general, and their streaming APIs in particular. I can imagine that you create a plugin registered for, again, audio/mpeg MIME-type, and receives the data via NPP_NewStream, NPP_WriteReady and NPP_Write methods. The plugin can be wrapped into a Chrome extension. Though I made NPAPI plugins, I never used this API, and I'm not sure it will work as expected. Nethertheless, I'm mentioning this possibility here for completenees. This method requires some coding other than web-coding, meaning C/C++. NB. NPAPI plugins are deprecated and not supported in Chrome since September 2015.
Taking into account that you have some external (to the extension) "fingerprinting service" in mind, which sounds like an intelligent data processing, you may be interested in building all the system out of a browser. For example, you could, possibly, involve a HTTP-proxy, saving media from passing traffic.
If you're writing a Chrome extension, you can use the Chrome tabCapture API to record audio.
chrome.tabCapture.capture({audio: true}, function(stream) {
var recorder = new MediaRecorder(stream);
[...]
});
The rest is left as an exercise to the reader; MDN has more documentation on how to use MediaRecorder.
When this question was asked in 2013, neither chrome.tabCapture nor MediaRecorder existed.
Mac OSX solution using soundflower: http://rogueamoeba.com/freebies/soundflower/
After installing soundflower it should appear as a separate audio device in the sound preferences (apple > system preferences > sound). Divert the computer's audio to the 2ch option (stereo, 16ch is surround), then inside a DAW, such as 'audacity', set the audio input as soundflower. Now the sound should be channeled to your DAW ready for recording.
Note: having diverted the audio from the internal speakers to soundflower you will only be able to hear the audio if the 'soundflowerbed' app is actually open. You know it's open if there's a 8 legged blob in the top right task bar. Clicking this icon gives you the sound flower options.
My privoxy has the following log:
2013-08-28 18:25:27.953 00002f44 Request: api.audioaddict.com/v1/di/listener_sessions.jsonp?_method=POST&callback=_AudioAddict_WP_ListenerSession_create&listener_session%5Bid%5D=null&listener_session%5Bis_premium%5D=false&listener_session%5Bmember_id%5D=null&listener_session%5Bdevice_id%5D=6&listener_session%5Bchannel_id%5D=178&listener_session%5Bstream_set_key%5D=webplayer&_=1377699927926
2013-08-28 18:25:27.969 0000268c Request: api.audioaddict.com/v1/ping.jsonp?callback=_AudioAddict_WP_Ping__ping&_=1377699927928
2013-08-28 18:25:27.985 00002d48 Request: api.audioaddict.com/v1/di/track_history/channel/178.jsonp?callback=_AudioAddict_TrackHistory_Channel&_=1377699927942
2013-08-28 18:25:54.080 00003360 Request: pub7.di.fm/di_progressivepsy_aac?type=.flv
So I got the stream url and record it:
D:\Profiles\user\temp>wget pub7.di.fm/di_progressivepsy_aac?type=.flv
--18:26:32-- http://pub7.di.fm/di_progressivepsy_aac?type=.flv
=> `di_progressivepsy_aac#type=.flv'
Resolving pub7.di.fm... done.
Connecting to pub7.di.fm[67.221.255.50]:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [video/x-flv]
[ <=> ] 1,234,151 8.96K/s
I got the file that can be reproduced in any multimedia pleer.
I've been playing around with node and websockets and built a small test app that streams audio using websockets. The server breaks apart the mp3 using createReadStream, throttles the stream using node-throttle and sens the binary data using the "ws" module.
On the client side I pick up the chunks on the websocket and use decodeAudioData (http://www.html5rocks.com/en/tutorials/webaudio/intro/) to decode and play the chunk. It all works relatively ok.
What I was curious to do next was to stream video in the same manner to the HTML5 video tag. But I can't really find any reference material on the web to achieve this in the same manner as my audio test above.
Is there a video equivalent for "decodeAudioData"?
Can I feed chunks of data into a video tag?
I've got a similar sample running that I picked up from...
https://gist.github.com/paolorossi/1993068
But this isn't really what I am looking for. First of all it doesn't really seem to be streaming to me. The client buffers it all before playing it.
Also, similar to my audio test I want the stream to be throttled on the server side so that when a new client connects they join the video at whatever point it is currently at. i.e. 30 minutes in or whatever.
Thanks
OK,
I found a solution to this after much searching.
The MediaSource API is what I was looking for...
var mediaSource = new MediaSource();
var sourceBuffer = mediaSource.addSourceBuffer('video/webm; codecs="vorbis,vp8"');
sourceBuffer.append(new Uint8Array(data));
This link provided the solution...
http://html5-demos.appspot.com/static/media-source.html
I have a back end sound.php which can return .m4a sound file from web server and I can make a web request with id to the sound.php to return specify .m4a file. i.e. sound.php?id=1234
I am now trying to use org.osmf.media.MediaPlayer and AudioElement and URLResource
var mediaPlayer:MediaPlayer = new MediaPlayer();
var ae:AudioElement = new AudioElement(new URLResource("http://xxx.com/sound.php?id=12"));
mediaPlayer.media = ae;
mediaPlayer.play();
and it throw error of The specified capability is not currently supported .I have tested the link via browser which is return a .m4a file sucessfully .
I dont understand if it is claiming the requesting method or the returned file , would somebody has any idea? Thanks
Try setting the MediaPlayer.autoPlay to true or you should wait until the media is loaded, which is signaled through the mediaPlayerStateChange event, with state READY.
[UPDATE]
As stated in the NetStream - Adobe ActionScript® 3 (AS3 ) API Reference page and also in the Supported codecs | Flash Player page:
Flash Player 9 Update 3 plays files derived from the standard MPEG-4
container format that contain H.264 video and/or HE-AAC audio, such as
F4V, MP4, M4A, MOV, MP4V, 3GP, and 3G2. One thing to note is that
protected MP4 files, such as those downloaded from iTunes or digitally
encrypted by FairPlay, are not supported.
It seems you will have to try the NetStream approach.