Possible integer overflow in StreamInfo::set_duration()

[sylt]

System info

Operating System: Ubuntu 14.04 trusty
Shaka Packager Version: c223bc9-release

Issue and steps to reproduce the problem

When I tried to segment a WebM file with a long duration, I got a mediaPresentationDuration attribute in my MPD manifest that was about int64_t(-1), but written as floating point (it was something like 1.844e+13).

According to libwebm (using the mkvparser_sample program), my WebM stream header looks like this:

	 libwebm version: 1.0.0.30
		    EBML Header
	EBML Version		: 1
	EBML MaxIDLength	: 4
	EBML MaxSizeLength	: 8
	Doc Type		: webm
	Pos			: 43

		   Segment Info
	TimeCodeScale		: 1000000 
	Duration		: 4096000000000
	Duration(secs)		: 4096.000
	Track Name		: NULL
	Muxing App		: Lavf57.41.100
	Writing App		: Lavf57.41.100
	Position(Segment)	: 55
	Size(Segment)		: 51598901

This duration will be (correctly) parsed by the WebM parser in the shaka-packager, but in WebMMediaParser::ParseInfoAndTracks(), where we should set the parsed duration to our AudioStreamInfo or VideoStreamInfo using StreamInfo::set_duration(), there will in this case be an integer overflow.

The reason is that the duration accepted by StreamInfo::set_duration() is int, as opposed to int64_t or uint64_t (which by the way is the internal representation for the duration in the StreamInfo class). Once I exchanged that to uint64_t, my mediaPresentationDuration was alright again.

Thank you for having a look! :)

[kqyang]

That is definitely a bug. Thanks for catching it! Since you have a fix already, would you like to submit a pull request to fix the issue? See https://github.com/google/shaka-packager/blob/master/CONTRIBUTING.md on how to contribute.

[kqyang]

@sylt Thanks for fixing the bug!