get_prpgress function of VideoReader can compatible with more video format

[Thatwho]

My actions before raising this issue

while extract from video with typical format, like mkv, it can't show precise progress. Like shown in the code:

    def get_progress(self, pos):
        container = self._get_av_container()
        # Not for all containers return real value
        stream = container.streams.video[0]
        return pos / stream.duration if stream.duration else None

VideoStream object may not have a real duration value.

Expected Behaviour

But we can find duration information from metadata of VideoStream object, then we can calculate precise progress instead of showing "Images are being compressed |/-\"

[azhavoro]

@Thatwho Hi, thanks for the suggestion, would you like to prepare a PR for this?

[Thatwho]

@Thatwho Hi, thanks for the suggestion, would you like to prepare a PR for this?

Of course! I had made a PR which is #3381. Please let me know the PR has any error.