Make console-output functions redirectable; add operator<< for Fraction, Point, Coordinate; new KeyFrame::PrintPoints & PrintValues with unit tests

[ferdnyc]

Redirectable output functions

To enable unit-testing of functions like ReaderBase::DisplayInfo() and Keyframe::PrintPoints() (which normally dump information to std::cout), each such function has been updated to have a signature like this:

/// Display effect information in the standard output stream (stdout)
void DisplayInfo(std::ostream* out=&std::cout);

The function now takes a pointer to the output stream to use, with std::cout being only the overridable default for that stream. In the output function, *out is streamed to instead of the hardcoded std::cout:

void WriterBase::DisplayInfo(std::ostream* out) {
	*out << std::fixed << std::setprecision(2) << std::boolalpha;
	*out << "----------------------------" << std::endl;
	*out << "----- File Information -----" << std::endl;
	*out << "----------------------------" << std::endl;
	*out << "--> Has Video: " << info.has_video << std::endl;
	*out << "--> Has Audio: " << info.has_audio << std::endl;

This makes it possible to unit test the functions by passing an alternate stream, then examining the captured output:

std::string expected(R"(----------------------------
----- File Information -----
----------------------------
--> Has Video: true
--> Has Audio: true
--> Has Single Image: false
--> Duration: 51.95 Seconds
--> File Size: 7.26 MB
----------------------------
----- Video Attributes -----
----------------------------
--> Width: 1280
--> Height: 720)");

// Store the DisplayInfo() text in 'output'
std::stringstream output;
r.DisplayInfo(&output);

// Compare a [0, expected.size()) substring of output to expected
auto compare_value = output.str().compare(0, expected.size(), expected);
CHECK(compare_value == 0);

Unit tests for ReaderBase::DisplayInfo() (via FFmpegReader), WriterBase::DisplayInfo() (via FFmpegWriter), and FrameMapper::PrintMapping() are included in the PR.

Output-stream compatible formatting for Coordinate, Point, Fraction

Also, the operator<< overloads taking openshot::Coordinate, openshot::Point, and openshot::Fraction which I'd written for another PR that ended up on hold are included here, along with their unit tests.

Updated Keyframe::PrintPoints() and Keyframe::PrintValues()

The new operator<<(openshot::Fraction) is used as part of a new KeyFrame::PrintValues() implementation; KeyFrame::PrintPoints() is also updated. Both have new unit tests. Sample output:

>>> import openshot
>>> k = openshot.Keyframe([
...     openshot.Point(1, 10), openshot.Point(5, 20), openshot.Point(6, -4), openshot.Point(10, 1)
... ])
>>> k.PrintPoints()
     1       10.0000
     5       20.0000
     6       -4.0000
    10        1.0000
>>> k.PrintValues()
│Frame# (X) │     Y Value │ Delta Y │ Increasing? │ Repeat Fraction    │
├───────────┼─────────────┼─────────┼─────────────┼────────────────────┤
│       1 * │     10.0000 │     +10 │        true │ Fraction(1, 1)     │
│       2   │     11.0702 │      +1 │        true │ Fraction(1, 1)     │
│       3   │     15.0000 │      +4 │        true │ Fraction(1, 1)     │
│       4   │     18.9298 │      +4 │        true │ Fraction(1, 1)     │
│       5 * │     20.0000 │      +1 │       false │ Fraction(1, 1)     │
│       6 * │     -4.0000 │     -24 │        true │ Fraction(1, 1)     │
│       7   │     -3.4649 │      +1 │        true │ Fraction(1, 1)     │
│       8   │     -1.5000 │      +1 │        true │ Fraction(1, 1)     │
│       9   │      0.4649 │      +2 │        true │ Fraction(1, 1)     │
│      10 * │      1.0000 │      +1 │        true │ Fraction(1, 1)     │
 * = Keyframe point (non-interpolated)

(Ick! Way to screw up the formatting, Github! Well, it looks right on my screen:)

[ferdnyc]

A unit test for ReaderBase::DisplayInfo() is included in the PR, the others are left as an exercise for the reader.

LOL. Which, of course, leads to CodeCov spanking me for not having sufficient coverage of the lines changed in the PR. Typical.

[codecov]

Codecov Report

Merging #661 (e5d70a8) into develop (7e419b9) will increase coverage by 1.06%.
The diff coverage is 95.42%.

@@             Coverage Diff             @@
##           develop     #661      +/-   ##
===========================================
+ Coverage    46.24%   47.31%   +1.06%     
===========================================
  Files          182      185       +3     
  Lines        16701    16839     +138     
===========================================
+ Hits          7724     7968     +244     
+ Misses        8977     8871     -106     

Impacted Files	Coverage Δ
src/AudioReaderSource.cpp	0.86% <0.00%> (-0.01%)	⬇️
src/Color.cpp	88.88% <ø> (ø)
src/EffectBase.cpp	20.58% <0.00%> (ø)
src/EffectBase.h	50.00% <ø> (ø)
src/FrameMapper.h	100.00% <ø> (ø)
src/KeyFrame.h	100.00% <ø> (ø)
src/ReaderBase.h	100.00% <ø> (ø)
src/WriterBase.h	100.00% <ø> (ø)
src/ClipBase.h	75.00% <100.00%> (-5.77%)	⬇️
src/Coordinate.cpp	100.00% <100.00%> (ø)
... and 22 more

---

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[github-actions]

Merge conflicts have been detected on this PR, please resolve.

[github-actions]

Merge conflicts have been detected on this PR, please resolve.

[ferdnyc]

Well, having heard nothing on this after many months, I'm going to merge it. 😞