[feature] support processing of (many) more media types (#3090)

* initial work replacing our media decoding / encoding pipeline with ffprobe + ffmpeg

* specify the video codec to use when generating static image from emoji

* update go-storage library (fixes incompatibility after updating go-iotools)

* maintain image aspect ratio when generating a thumbnail for it

* update readme to show go-ffmpreg

* fix a bunch of media tests, move filesize checking to callers of media manager for more flexibility

* remove extra debug from error message

* fix up incorrect function signatures

* update PutFile to just use regular file copy, as changes are file is on separate partition

* fix remaining tests, remove some unneeded tests now we're working with ffmpeg/ffprobe

* update more tests, add more code comments

* add utilities to generate processed emoji / media outputs

* fix remaining tests

* add test for opus media file, add license header to utility cmds

* limit the number of concurrently available ffmpeg / ffprobe instances

* reduce number of instances

* further reduce number of instances

* fix envparsing test with configuration variables

* update docs and configuration with new media-{local,remote}-max-size variables

1 files changed, 0 insertions, 101 deletions

diff --git a/vendor/github.com/golang/geo/s2/latlng.go b/vendor/github.com/golang/geo/s2/latlng.go
deleted file mode 100644
index a750304ab..000000000
--- a/vendor/github.com/golang/geo/s2/latlng.go
+++ /dev/null
@@ -1,101 +0,0 @@
-// Copyright 2014 Google Inc. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package s2
-
-import (
-	"fmt"
-	"math"
-
-	"github.com/golang/geo/r3"
-	"github.com/golang/geo/s1"
-)
-
-const (
-	northPoleLat = s1.Angle(math.Pi/2) * s1.Radian
-	southPoleLat = -northPoleLat
-)
-
-// LatLng represents a point on the unit sphere as a pair of angles.
-type LatLng struct {
-	Lat, Lng s1.Angle
-}
-
-// LatLngFromDegrees returns a LatLng for the coordinates given in degrees.
-func LatLngFromDegrees(lat, lng float64) LatLng {
-	return LatLng{s1.Angle(lat) * s1.Degree, s1.Angle(lng) * s1.Degree}
-}
-
-// IsValid returns true iff the LatLng is normalized, with Lat ∈ [-π/2,π/2] and Lng ∈ [-π,π].
-func (ll LatLng) IsValid() bool {
-	return math.Abs(ll.Lat.Radians()) <= math.Pi/2 && math.Abs(ll.Lng.Radians()) <= math.Pi
-}
-
-// Normalized returns the normalized version of the LatLng,
-// with Lat clamped to [-π/2,π/2] and Lng wrapped in [-π,π].
-func (ll LatLng) Normalized() LatLng {
-	lat := ll.Lat
-	if lat > northPoleLat {
-		lat = northPoleLat
-	} else if lat < southPoleLat {
-		lat = southPoleLat
-	}
-	lng := s1.Angle(math.Remainder(ll.Lng.Radians(), 2*math.Pi)) * s1.Radian
-	return LatLng{lat, lng}
-}
-
-func (ll LatLng) String() string { return fmt.Sprintf("[%v, %v]", ll.Lat, ll.Lng) }
-
-// Distance returns the angle between two LatLngs.
-func (ll LatLng) Distance(ll2 LatLng) s1.Angle {
-	// Haversine formula, as used in C++ S2LatLng::GetDistance.
-	lat1, lat2 := ll.Lat.Radians(), ll2.Lat.Radians()
-	lng1, lng2 := ll.Lng.Radians(), ll2.Lng.Radians()
-	dlat := math.Sin(0.5 * (lat2 - lat1))
-	dlng := math.Sin(0.5 * (lng2 - lng1))
-	x := dlat*dlat + dlng*dlng*math.Cos(lat1)*math.Cos(lat2)
-	return s1.Angle(2*math.Atan2(math.Sqrt(x), math.Sqrt(math.Max(0, 1-x)))) * s1.Radian
-}
-
-// NOTE(mikeperrow): The C++ implementation publicly exposes latitude/longitude
-// functions. Let's see if that's really necessary before exposing the same functionality.
-
-func latitude(p Point) s1.Angle {
-	return s1.Angle(math.Atan2(p.Z, math.Sqrt(p.X*p.X+p.Y*p.Y))) * s1.Radian
-}
-
-func longitude(p Point) s1.Angle {
-	return s1.Angle(math.Atan2(p.Y, p.X)) * s1.Radian
-}
-
-// PointFromLatLng returns an Point for the given LatLng.
-// The maximum error in the result is 1.5 * dblEpsilon. (This does not
-// include the error of converting degrees, E5, E6, or E7 into radians.)
-func PointFromLatLng(ll LatLng) Point {
-	phi := ll.Lat.Radians()
-	theta := ll.Lng.Radians()
-	cosphi := math.Cos(phi)
-	return Point{r3.Vector{math.Cos(theta) * cosphi, math.Sin(theta) * cosphi, math.Sin(phi)}}
-}
-
-// LatLngFromPoint returns an LatLng for a given Point.
-func LatLngFromPoint(p Point) LatLng {
-	return LatLng{latitude(p), longitude(p)}
-}
-
-// ApproxEqual reports whether the latitude and longitude of the two LatLngs
-// are the same up to a small tolerance.
-func (ll LatLng) ApproxEqual(other LatLng) bool {
-	return ll.Lat.ApproxEqual(other.Lat) && ll.Lng.ApproxEqual(other.Lng)
-}