[wp-trac] [WordPress Trac] #43114: FLV video - NetworkError: Exception ProgressEvent error

[WordPress Trac]

#43114: FLV video - NetworkError: Exception ProgressEvent error
--------------------------+------------------------------
 Reporter:  Fred001       |       Owner:
     Type:  defect (bug)  |      Status:  new
 Priority:  normal        |   Milestone:  Awaiting Review
Component:  Media         |     Version:  4.9.2
 Severity:  normal        |  Resolution:
 Keywords:                |     Focuses:
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Comment (by iandunn):

 Hmmm, I've done a bunch of testing, but have only come up with more
 questions.

 I tested a local copy of the [http://famillemathy.fr/wp-
 content/uploads/2012/07/Taxi.flv Taxi.flv] video from comment:4 and
 [http://la2.indexcom.com/me/flv/guqin.flv guqin.flv] from MediaElement's
 demo. I used a Windows 7 VM, with IE 11 and the latest versions of Chrome
 and Firefox. All 3 had Flash installed.

 There are several variables at play here:
 * The WP 4.8.x -> 4.9.x upgrade replaced MediaElement 2.x with
 MediaElement 4.x
 * The WP 4.8.5 and 4.9.2 updates removed the SWF files from MediaElement
 2.x and 4.x
 * Browser support for FLVs, particular codecs, etc.
 * Maybe the FLV encoding or other characteristics.

 ||= File =||= Browser =||= WP Version =||= SWF used =||= Works =||
 || Taxi.flv || Firefox 57 || 4.8.4 || Yes || Yes ||
 || Taxi.flv || Chrome 63 || 4.8.4 || No || No ||
 || Taxi.flv || IE 11 || 4.8.4 || Yes || Yes ||
 || Taxi.flv || Firefox 57 || 4.8.5 || Yes || No ||
 || Taxi.flv || Chrome 63 || 4.8.5 || No || No ||
 || Taxi.flv || IE 11 || 4.8.5 || Yes || No ||
 || Taxi.flv || Firefox 57 || 4.9.1 || No || No ||
 || Taxi.flv || Chrome 63 || 4.9.1 || No || No ||
 || Taxi.flv || IE 11 || 4.9.1 || Yes || Yes ||
 || Taxi.flv || Firefox 57 || 4.9.2 || No || No ||
 || Taxi.flv || Chrome 63 || 4.9.2 || No || No ||
 || Taxi.flv || IE 11 || 4.9.2 || Yes || No ||
 || guqin.flv || Firefox 57 || 4.8.4 || Yes || Yes ||
 || guqin.flv || Chrome 63 || 4.8.4 || No || No ||
 || guqin.flv || IE 11 || 4.8.4 || Yes || Yes ||
 || guqin.flv || Firefox 57 || 4.8.5 || Yes || No ||
 || guqin.flv || Chrome 63 || 4.8.5 || No || No ||
 || guqin.flv || IE 11 || 4.8.5 || Yes || No ||
 || guqin.flv || Firefox 57 || 4.9.1 || No || No ||
 || guqin.flv || Chrome 63 || 4.9.1 || No || Yes ||
 || guqin.flv || IE 11 || 4.9.1 || Yes || Yes ||
 || guqin.flv || Firefox 57 || 4.9.2 || No || Yes ||
 || guqin.flv || Chrome 63 || 4.9.2 || No || Yes ||
 || guqin.flv || IE 11 || 4.9.2 || Yes || No ||

 These things stood out to me:

 * IE 11 needs the SWF fallbacks to play FLV videos. I think I missed that
 in researching the safety of removing the SWF files in the latest release.
 * Both IE and Firefox stopped working in the update from 4.8.4 to 4.8.5,
 because they were trying to use the SWF. Based on the above, that's
 expected for IE, but it shouldn't be necessary for Firefox, which has
 native support for FLVs. You can see that working in
 [http://www.mediaelementjs.com/ MediaElement's demo], even without Flash
 installed.
 * Chrome only worked with `guqin.flv` in WP 4.9.x. So, it only worked with
 MediaElement 4.x, but not in 2.x. It should work in both. It also has
 native support for FLVs (again, see the MEjs demo).
 * Chrome never worked with `Taxi.flv`, even with MediaElement 4.x. Maybe
 there's something about the way it's encoded that Chrome doesn't like?
 * `guqin.flv` works in Firefox with WP 4.9.2, but not with 4.9.1. That
 doesn't make any sense, based on the variables listed above. The WP 4.8.5
 and 4.9.2 updates [https://core.trac.wordpress.org/changeset/42462 did
 remove some MediaElement 4.x renderers for 3rd-party hosting platforms and
 language files], but that shouldn't affect anything.

 @Fred001, let me know if anything above gives you any clues as to what the
 problem is.

 It'd also be helpful to learn the specific WP version where your videos
 stopped working. You could try temporarily downgrading to 4.9.1, then test
 the video, then 4.8.5 and test, then 4.8.4 and test.

 Also, does [http://la2.indexcom.com/me/flv/guqin.flv guqin.flv] work on
 your site? It may be important to upload a copy to your site, rather than
 embedding the remote video, to test your web server's MIME type
 configuration.

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Ticket URL: <https://core.trac.wordpress.org/ticket/43114#comment:5>
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