User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:40.0) Gecko/20100101 Firefox/40.0 Build ID: 20150415030206 Steps to reproduce: 1) Open a short few seconds long video on Youtube, which has sound shortly before the end. 2) Make sure the HTML5 player is used 3) Play the video Example videos https://www.youtube.com/watch?v=rh8m2-q71qQ https://www.youtube.com/watch?v=7LlIKtQwIxI (you can see the mouth still moving while the sounds just disappears) Actual results: Video plays fine, but sounds disappears shortly before the end. Expected results: Sound should play all the way to the end. Which it does if Flash player is used instead of the HTML5 player.
Happens in Chrome too, so probably a youtube bug not a Firefox one.
Ok. Apparently Youtube now serves HTML5 to IE too. And surprisingly IE manages to not cut off the end. Well if IE can do it, why not Firefox. so reopening..?
The end of the audio in https://www.youtube.com/watch?v=rh8m2-q71qQ is cut off for me in IE Edge (and Firefox and Chrome). I get "A few" in all three. Same with the other video. Curiously, if I download the MP4 and WebM versions with youtube-dl, less of the audio is cut off. I get "A few moments later" (but it cuts mid-"r"), so the actual media is longer and plays fully in VLC, Firefox, and Chrome. Same with the other video. So this does look like a YouTube-side issue. What video and IE version were you seeing complete playback with?
https://www.youtube.com/watch?v=7LlIKtQwIxI Windows 7, IE 11, i can clearly hear all of "unbearable faggots" where as in Firefox all i hear is "unbearab"
Hitting refresh gives me different amounts of audio each time.
If I disable MSE by setting media.mediasource.enabled to false, I get consistent playback of all audio... could be a timing/buffer appending issue with the MSE player.
OK, i tried mozregression for **** and giggles, and the results are last good build build_date: 2014-03-16 build_txt_url: http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2014/03/2014-03-16-03-02-02-mozilla-central/firefox-30.0a1.en-US.win64-x86_64.txt build_type: nightly build_url: http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2014/03/2014-03-16-03-02-02-mozilla-central/firefox-30.0a1.en-US.win64-x86_64.zip changeset: e3b76b155ca4 pushlog_url: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=e3b76b155ca4&tochange=5d61fabc49a8 repo: mozilla-central repository: https://hg.mozilla.org/mozilla-central first bad build_date: 2014-03-17 build_txt_url: http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2014/03/2014-03-17-16-58-01-mozilla-central/firefox-31.0a1.en-US.win64-x86_64.txt build_type: nightly build_url: http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2014/03/2014-03-17-16-58-01-mozilla-central/firefox-31.0a1.en-US.win64-x86_64.zip changeset: 5d61fabc49a8 pushlog_url: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=82c90c17fc95&tochange=082761b7bc54 repo: mozilla-central repository: https://hg.mozilla.org/mozilla-central Note i had to force youtube to give me html5, because for older versions it automatically wants to revert to flash.
Well i just found out the "Magic options" addon causes this. Its "auto replay" option restarts the video before it reaches the end. If i disable it the problem goes away. Other addons which have this option might be affected too. Anyways, marking this as resolved because its not an Firefox bug.