I'm guessing this happens because in the default case
generateMediaConstraints() returns {video:true,audio:true} but when you're
fiddling with resolution and frame rate you're omitting the audio property.*Andreas Pehrson *--- Software Engineer (+47) 959 60 374 | [email protected] | www.telenordigital.com On Tue, Jun 16, 2015 at 3:00 PM, <[email protected]> wrote: > Hi, > > I'm an intern of a well-known telecommunication french operator. > The subject of my intership is evaluating the WebRTC technology's > performances through google Chrome and Mozilla Firefox. > First I studied how work this technology with Firefox Hello, to understand > what is WebRTC, how it works, how media-stream are exchanged etc. > > Then I started to work with the website https://apprtc.appspot.com/ On > chrome and Firefox, to compare the behavior of every brower through the > same webRTC app. Till now everything was good except the fact that I didn't > master content injection (video resolution), the A/V bitrate and A/V > encoders. 'caus as you know it, the video bitrate is blocked around > 2Mb/sec. And we would like to see if it's possible to unleash the video > bitrate to have a better quality and by using another less greedy encoder > (VP8 ? H.264?) > > A formation was given to my colleagues to develop their own WebRTC app > using javascript language. It allows us to manage all parameters of a > WebRTC communication (media constraints etc.). So now I can inject 1080p > content into the communication, unleash the bitrate, manage the displayed > resolution. Just to specify, I used Chrome first. > Anytime I modify the content of the SDP packet to manage de max bitrate : > > localSDP.sdp = localSDP.sdp.replace( /a=mid:video\r\n/g , > 'a=mid:video\r\nb=AS:4000\r\n'); > > So I could therefore make my own tests without any problems on Chrome. But > I have to compare my results with another A/V encoder for subjectives tests. > On Mozilla Firefox, the H.264 encoder works, even if it's not selected by > default into a WebRTC communication (using Firefox Hello or apprtc). So I > modify the content of the SDP packet to force the choice of the A/V encoder > (replacing VP8 with H.264): > > localSDP.sdp = localSDP.sdp.replace( / 120 126 /g,' 126 '); > > I can do the same thing to replace the opus encoder with the G.722 encoder. > If forcing A/V encoders works without problems, the media-stream parts are > giving me headaches. In fact, if I inject 1080p content (with Firefox > obviously) during a WebRTC app, the resolution in return has been > downscaled to 640x480. And it doesn't depends on the resolution injected, > even if the source resolution is smaller than 640x480, what I see in output > is 640x480. But if I modify the displayed resolution, it's good in output > but I lose the audio stream. As a matter of fact, till i try to modify the > resolution, when the communication begin, the browser doesn't ask me to > share the microphone. > > To explain a bit more how work the app I use, i give you some sourcecode > (not all because i didn't develop it, so I can't share all the code) : > > var mediaConstraints = {video:true,audio:true}; > [...] > mediaConstraints = generateMediaConstraints(); > [...] > function generateMediaConstraints(){ > if (replaceResolution == true && replaceFPS == true && > replaceRatio == true){ > return { > video: { > mandatory: { > maxWidth: userMaxWidht.value, > maxHeight: userMaxHeight.value, > minWidth: userMinWidht.value, > minHeight: userMinHeight.value, > > maxAspectRatio: userRatio.value, > > minAspectRatio: userRatio.value, > > minFrameRate: userFPS.value, > > maxFrameRate: userFPS.value > } > } > }; > } > else if(replaceResolution == true && replaceFPS == true && > replaceRatio == false){ > return { > video: { > mandatory: { > maxWidth: userMaxWidht.value, > maxHeight: userMaxHeight.value, > minWidth: userMinWidht.value, > minHeight: userMinHeight.value, > > minFrameRate: userFPS.value, > > maxFrameRate: userFPS.value > } > } > }; > } > else if(replaceResolution == true && replaceFPS == false && > replaceRatio == true){ > return { > video: { > mandatory: { > maxWidth: userMaxWidht.value, > maxHeight: userMaxHeight.value, > minWidth: userMinWidht.value, > minHeight: userMinHeight.value, > > maxAspectRatio: userRatio.value, > > minAspectRatio: userRatio.value > } > } > }; > } > else if(replaceResolution == true && replaceFPS == false && > replaceRatio == false){ > return { > video: { > mandatory: { > maxWidth: userMaxWidht.value, > maxHeight: userMaxHeight.value, > minWidth: userMinWidht.value, > minHeight: userMinHeight.value > } > } > }; > } > else if(replaceResolution == false && replaceFPS == true && > replaceRatio == true){ > return { > video: { > mandatory: { > > maxAspectRatio: userRatio.value, > > minAspectRatio: userRatio.value, > > minFrameRate: userFPS.value, > > maxFrameRate: userFPS.value > } > } > }; > } > else if(replaceResolution == false && replaceFPS == true && > replaceRatio == false){ > return { > video: { > mandatory: { > > minFrameRate: userFPS.value, > > maxFrameRate: userFPS.value > } > } > }; > } > else if(replaceResolution == false && replaceFPS == false && > replaceRatio == true){ > return { > video: { > mandatory: { > > maxAspectRatio: userRatio.value, > > minAspectRatio: userRatio.value > } > } > }; > } > else{ > return {video:true,audio:true} > } > } > > I tried to put the audio variable into one of the subconditions' function, > ie : > else if(replaceResolution == true && replaceFPS == false && replaceRatio > == false){...} > > It works because the audio stream work, but I can't manage the resolution > anymore. I don't underderstand why and how. > Colleagues who développed this app left the compagny. I'm a really ban > developper (well, I'm not a dev). I'm blocked on this f****** since one > week. I don't see what to do. > Could you please help me to fix that ? maybe give me the solution I dunno. > > Thanks in advance. > _______________________________________________ > dev-media mailing list > [email protected] > https://lists.mozilla.org/listinfo/dev-media > _______________________________________________ dev-media mailing list [email protected] https://lists.mozilla.org/listinfo/dev-media
