1323012 - Recording video with playbackRate = 0.5 should generate video with double duration (using mozCaptureStream())

Status: RESOLVED DUPLICATE of bug 1517199

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

Description

[Soledad Penades [:sole] [:spenades]]

When you try to record the output of a video which uses playbackRate != 1, using mozCaptureStream (in lieu of having the non prefixed version implemented), you expect the captured video to reflect the actual rate that was used to play the media.

For example this test cases plays a video with playbackRate = 0.5 which if captured should generate a stream that lasts double. Since the original video is 9 seconds long, the captured (via MediaRecorder) video should be 18 seconds. But it is reported to be 8.999 seconds, which is even less!

(Thanks to Joshua for finding this bug - his original gist is here https://twitter.com/BlurSpline/status/808332434940903425 :-))

Comment 1

[Paul Adenot (:padenot)]

Thanks Sole, duping accordingly (this is caused by a higher level issue), as we're tracking this together with `volume` not working as well.