Error message doesn't show up on Chrome 59

[foliovision]

I found this issue when playing http://mydoctor.kpnvly.org/rehabilitation/wp-content/uploads/sites/4/2016/01/2.0_-_2.1_Pre_Surgery_Exercise_Intro.m4v

Here is ffprobe output for that file:

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'http://mydoctor.kpnvly.org/rehabilitation/wp-content/uploads/sites/4/2016/01/2.0_-_2.1_Pre_Surgery_Exercise_Intro.m4v':

Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
creation_time : 2015-11-17T08:00:00.000000Z
encoder : Lavf53.18.0
Duration: 00:01:16.79, start: 0.000000, bitrate: 226 kb/s

Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 864x484, 103 kb/s, 23.98 fps, 23.98 tbr, 2997 tbn, 47.95 tbc (default)
Metadata:
  creation_time   : 2015-11-17T08:00:00.000000Z
  handler_name    : VideoHandler

Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 117 kb/s (default)
Metadata:
  creation_time   : 2015-11-17T08:00:00.000000Z
  handler_name    : SoundHandler

Here is the error which I got when using Chrome 59.0.3071.125 on Adroind 4.4.4 (Samsung X-Cover - SM-G388F):

Uncaught TypeError: Cannot assign to read only property 'message' of object '#'
at flowplayer-7.0.4.js:3273
at HTMLDivElement.internalHandler (flowplayer-7.0.4.js:1609)
at Object.obj.trigger (flowplayer-7.0.4.js:1672)
at triggerEvent (flowplayer-7.0.4.js:1040)
at HTMLDivElement.l (flowplayer-7.0.4.js:1153)

Uncaught (in promise) DOMException: Failed to load because no supported source was found.

I see it's caused by this line:

error.message = conf.errors[error.code];

I'm attaching a pull request where I put a simple try-catch around that line in the error event handler. That way there is no JavaScript error and the error message provided by Google Chrome which actually reads "DECODER_ERROR_NOT_SUPPORTED video decoder initialization fialed" appears properly.

The video plays fine on Android 5.1.1 (Asus) or Android 6.0 (Lenovo) though.

Thanks,
Martin

[foliovision]

Now I'm getting the same behavior on Chrome 59. When I put in some video file that doesn't exist there should be some error message about it but there isn't, it just shows that error on console.

So I believe Chrome 59 made the message property of the error read only and that's it.

But is it important to put your custom message into error.message at all? I updated my fix with something simpler - it just puts in the Flowplayer error message up and doesn't alter error.message.

[foliovision]

I also noticed that for Chrome's DECODER_ERROR_NOT_SUPPORTED error the error code is set to 4 = "Video file not found", but it should be 3 = "Video not properly encoded", so I added some code for that.

[phloxic]

From a practical point of view:
The question is whether this is a 'transient' Chrome issue, it would not be the first.
While there are shifting timestamp issues with that video - you'll notice when you run ffprobe -v debug on it - it may well be that it works again with the next upgrade.

Also DECODER_ERROR_NOT_SUPPORTED is not standard, it probably means exactly what it says: This Chrome's decoder cannot deal with this video.

@foliovision - arguably the 'custom' message assigned to error.code is a user facing convenience, but the interpretation of error.code for other purposes - whether to recover or not for example - depends on some consistency in those codes anyway, see below.

@nnarhinen - what should be revisited imho is:

1. The asignment of error symptoms to their code, according to https://html.spec.whatwg.org/multipage/media.html#error-codes (which is also what the reference in the source http://www.whatwg.org/specs/web-apps/current-work/multipage/the-video-element.html#error-codes redirects to) 4 is MEDIA_ERR_SRC_NOT_SUPPORTED (not custom Flowplayer 5 code), and may be 2 MEDIA_ERR_NETWORK should include (or set to) 'Video file not found' - compare with https://flowplayer.com/docs/api.html#error-codes
2. otoh the question is how strict clients adhere to the standard

[foliovision]

@blacktrash I was getting the same issue even in Chrome 60.0.3112.78.

I can also see that error on console here: http://demos.flowplayer.org/scripting/recover.html

And on http://demos.flowplayer.org/basics/bad-url.html it shows no error for the first video because of the same reason.

[phloxic]

@nnarhinen - I can confirm this. At least regarding the symptoms. So http://demos.flowplayer.org/basics/bad-url.html shows error 4 in the console - "code: 4, message: MEDIA_ELEMENT_ERROR: Format error", however api.error is undefined, and no error message is shown.

http://demos.flowplayer.org/scripting/recover.html recovers because the player reacts to error 4. Presumably at least. Unless the broken play() promise does something, but I doubt it because the play() promise scenario is not covered in core.