933449 - mozCaptureUntilEnded blocks video outputs

Status: VERIFIED FIXED

(Core :: WebRTC: Audio/Video, defect)

Description

[Suhas]

Attachment: audio_mozcapture.html

I am trying to pass in the MediaStream obtained from mozCaptureStreamUntilEnded() from audio or video element to another audio/video element.

In the audio case, neither the audio elements play sound.
In the video case, the source video plays only video tracks, but there is no audio on the source video element and no audio/video on the destination video element.

I have attached the html pages used for these two tests for reference.

Comment 1

[Suhas]

Attachment: video_mozcapture.html

Comment 2

[Suhas]

just an update , there are these lines through out

 Media graph 134c1e320 computing blocking for time 28.203515
579342336[12002d680]: MediaStream 1253ab8c0 is blocked due to explicit blocker
579342336[12002d680]: Media graph 134c1e320 computed blocking for interval 28.203515 to 28.215125


Also, when i tried to check count of AudioTracks, it always returns zero

Comment 3

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Nothing springs to mind.

Comment 4

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Suhas, are you trying this on a Web server or with local files? Local files won't work due to same-origin restrictions. If you're trying it on a Web server, can you point me to a link to your testcase?

Comment 5

[Suhas]

Hi Roc,
  I am serving these files from my  node.js WebServer on the localhost. Is there a place that I can upload to help you in this.
Please let me know

Comment 6

[Suhas]

I noticed that mAudioStreamCaptured is set to true @ http://hg.mozilla.org/mozilla-central/file/030e365d7c26/content/html/content/src/HTMLMediaElement.cpp#l1776 in the logic for mozCaptureStreamUntilEnded(). This in turn causes the decoder not to start the audio thread. This explains why the audio never gets played on the first audio element but not the second audio element to which we create a MediaInputPort to. 

I am assuming this is the expected behavior.

Comment 7

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Here's my version of your test:
http://people.mozilla.org/~roc/audio_mozcapture.html
It seems to work.

Comment 8

[Suhas]

Hi Roc
  Thanks for the test. Randell and I on debugging figured out that Origin not being the same was the reason for my test to bail out of decode loop. On re-working my server piece of the code, I was able to run a similar test of yours successfully.
Thanks again for your inputs.

Comment 9

[Suhas]

Attachment: video_mozcapture.html

Hello Roc

  When i attempt to setup a simple test for <video>, i see the following behavior (as in the video_mozcapture.html attachment)
   
     
  1. Audio seems to be properly getting rendered to the second <video> element
  2. Video gets played only on the first <video> element.

 I see "Decoder skipping writing video frame" logged for almost all the video frames.

Comment 10

[Suhas]

Attachment: MediaDecoder&MSG Log

Comment 11

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Can you please put a working testcase on a server?

Comment 12

[Suhas]

Hi Roc, 

  I have uploaded the video test file here: http://suhashere.github.io/try-webrtc/video_mozcapture.html
  Please let me know if you can access this.

Thanks

Comment 13

[Robert O'Callahan (:roc) (email my personal email if necessary)]

That test seems to work for me. The patches I just landed on inbound for bug 938022 may have helped. Please try again in the next nightly :-)

Comment 14

[Suhas]

Hi Roc ,
 
  The above examples works pretty well on the latest nightly .. Thanks for the info

Comment 15

[Petruta Horea [:phorea], Desktop QA]

Trying to reproduce the initial issue on Nightly 28.0a1 2013-22-23 under Mac OSX 10.7.5 I noticed that the first video from http://suhashere.github.io/try-webrtc/video_mozcapture.html is not played until the second one (who plays fine) is paused. After refreshing the page (Cmd+R), I have the same behavior as described in comment 9.

On Firefox 28 beta 4, both videos plays, but the first one plays a little jerky and it doesn't have audio. 

Any thoughts / suggestions on this? Thank you

Comment 16

[Robert O'Callahan (:roc) (email my personal email if necessary)]

(In reply to Petruta Rasa [QA] [:petruta] from comment #15)
> Trying to reproduce the initial issue on Nightly 28.0a1 2013-22-23 under Mac
> OSX 10.7.5 I noticed that the first video from
> http://suhashere.github.io/try-webrtc/video_mozcapture.html is not played
> until the second one (who plays fine) is paused. After refreshing the page
> (Cmd+R), I have the same behavior as described in comment 9.
> 
> On Firefox 28 beta 4, both videos plays, but the first one plays a little
> jerky and it doesn't have audio. 
> 
> Any thoughts / suggestions on this? Thank you

That sounds OK to me. The first video isn't supposed to play audio.

Comment 17

[Petruta Horea [:phorea], Desktop QA]

Thanks, marking as Verified.