Support creating thumbnails using the avif command

Makefile

@@ -1,4 +1,4 @@
-# Should contain src/github.com/Kagami/go-avif
+# Should contain src/github.com/kagami/go-avif
 export GOPATH = $(PWD)/../../../..
 
 all: build

README.md

@@ -1,8 +1,8 @@
-# go-avif [![Build Status](https://travis-ci.org/Kagami/go-avif.svg?branch=master)](https://travis-ci.org/Kagami/go-avif) [![GoDoc](https://godoc.org/github.com/Kagami/go-avif?status.svg)](https://godoc.org/github.com/Kagami/go-avif)
+# go-avif [![Build Status](https://travis-ci.org/kagami/go-avif.svg?branch=master)](https://travis-ci.org/kagami/go-avif) [![GoDoc](https://godoc.org/github.com/kagami/go-avif?status.svg)](https://godoc.org/github.com/kagami/go-avif)
 
 go-avif implements
 AVIF ([AV1 Still Image File Format](https://aomediacodec.github.io/av1-avif/))
-encoder for Go using libaom, the [high quality](https://github.com/Kagami/av1-bench)
+encoder for Go using libaom, the [high quality](https://github.com/kagami/av1-bench)
 AV1 codec.
 
 ## Requirements
@@ -18,16 +18,16 @@ sudo apt-get install libaom-dev
 To use go-avif in your Go code:
 
 ```go
-import "github.com/Kagami/go-avif"
+import "github.com/kagami/go-avif"
 ```
 
 To install go-avif in your $GOPATH:
 
 ```bash
-go get github.com/Kagami/go-avif
+go get github.com/kagami/go-avif
 ```
 
-For further details see [GoDoc documentation](https://godoc.org/github.com/Kagami/go-avif).
+For further details see [GoDoc documentation](https://godoc.org/github.com/kagami/go-avif).
 
 ## Example
 
@@ -40,7 +40,7 @@ import (
 	"log"
 	"os"
 
-	"github.com/Kagami/go-avif"
+	"github.com/kagami/go-avif"
 )
 
 func main() {
@@ -81,7 +81,7 @@ PNG files to AVIF:
 
 ```bash
 # Compile and put avif binary to $GOPATH/bin
-go get github.com/Kagami/go-avif/...
+go get github.com/kagami/go-avif/...
 
 # Encode JPEG to AVIF with default settings
 avif -e cat.jpg -o kitty.avif
@@ -92,12 +92,15 @@ avif -e dog.png -o doggy.avif --best -q 15
 # Lossless encoding
 avif -e pig.png -o piggy.avif --lossless
 
+# Create thumbnail
+avif -e horse.png -o horsey.avif --thumb=640:480
+
 # Show help
 avif -h
 ```
 
 Static 64-bit builds for Windows, macOS and Linux are available at
-[releases page](https://github.com/Kagami/go-avif/releases). They include
+[releases page](https://github.com/kagami/go-avif/releases). They include
 latest libaom from git at the moment of build.
 
 ## Display

avif.go

@@ -55,6 +55,7 @@ func (e OptionsError) Error() string {
 // An EncoderError reports that the encoder error has occured.
 type EncoderError int
 
+// ToString returns the string representation of an EncoderError.
 func (e EncoderError) ToString() string {
 	switch e {
 	case C.AVIF_ERROR_GENERAL:

cmd/avif/main.go

@@ -1,19 +1,23 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"image"
 	_ "image/jpeg"
 	_ "image/png"
 	"io"
 	"os"
+	"strconv"
+	"strings"
 
-	"github.com/Kagami/go-avif"
 	"github.com/docopt/docopt-go"
+	"github.com/kagami/go-avif"
+	"github.com/nfnt/resize"
 )
 
-const VERSION = "0.0.0"
+const version = "0.0.0"
-const USAGE = `
+const usage = `
 Usage: avif [options] -e src_filename -o dst_filename
 
 AVIF encoder
@@ -23,6 +27,7 @@ Options:
   -V, --version             Display version number
   -e <src>, --encode=<src>  Source filename
   -o <dst>, --output=<dst>  Destination filename
+  -b <w:h>, --thumb=<w:h>   Maximum image dimensions
   -q <qp>, --quality=<qp>   Compression level (0..63), [default: 25]
   -s <spd>, --speed=<spd>   Compression speed (0..8), [default: 4]
   -t <td>, --threads=<td>   Number of threads (0..64, 0 for all available cores), [default: 0]
@@ -34,6 +39,7 @@ Options:
 type config struct {
 	Encode   string
 	Output   string
+	Thumb    string
 	Quality  int
 	Speed    int
 	Threads  int
@@ -58,7 +64,7 @@ func check(cond bool, errStr string) {
 
 func main() {
 	var conf config
-	opts, err := docopt.ParseArgs(USAGE, nil, VERSION)
+	opts, err := docopt.ParseArgs(usage, nil, version)
 	checkErr(err)
 	err = opts.Bind(&conf)
 	checkErr(err)
@@ -103,6 +109,19 @@ func main() {
 	img, _, err := image.Decode(src)
 	checkErr(err)
 
+	if conf.Thumb != "" {
+		split := strings.Split(conf.Thumb, ":")
+		if len(split) != 2 {
+			checkErr(errors.New("failed to create thumbnail: invalid dimensions, must be in w:h format"))
+		}
+		w, err := strconv.Atoi(split[0])
+		checkErr(err)
+		h, err := strconv.Atoi(split[1])
+		checkErr(err)
+
+		img = resize.Thumbnail(uint(w), uint(h), img, resize.Lanczos3)
+	}
+
 	err = avif.Encode(dst, img, &avifOpts)
 	checkErr(err)
 }

example_test.go

@@ -6,7 +6,7 @@ import (
 	"log"
 	"os"
 
-	"github.com/Kagami/go-avif"
+	"github.com/kagami/go-avif"
 )
 
 const usageHelp = "Usage: %s src.jpg dst.avif"

go.mod

@@ -0,0 +1,8 @@
+module github.com/kagami/go-avif
+
+go 1.16
+
+require (
+	github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815
+	github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646
+)

go.sum

@@ -0,0 +1,4 @@
+github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815 h1:bWDMxwH3px2JBh6AyO7hdCn/PkvCZXii8TGj7sbtEbQ=
+github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815/go.mod h1:WwZ+bS3ebgob9U8Nd0kOddGdZWjyMGR8Wziv+TBNwSE=
+github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646 h1:zYyBkD/k9seD2A7fsi6Oo2LfFZAehjjQMERAvZLEDnQ=
+github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646/go.mod h1:jpp1/29i3P1S/RLdc7JQKbRpFeM1dOBd8T9ki5s+AY8=

mp4.go

@@ -41,9 +41,8 @@ func ulen(s string) uint32 {
 func bflag(b bool, pos uint8) uint8 {
 	if b {
 		return 1 << (pos - 1)
-	} else {
-		return 0
 	}
+	return 0
 }
 
 func writeAll(w io.Writer, writers ...io.WriterTo) (err error) {
@@ -744,7 +743,7 @@ func muxFrame(w io.Writer, m image.Image, subsampling image.YCbCrSubsampleRatio,
 			lengthSize:     4,
 			baseOffsetSize: 4,
 			items: []boxILOCItem{
-				boxILOCItem{
+				{
 					itemID:  1,
 					extents: []boxILOCItemExtent{{}},
 				},
@@ -752,7 +751,7 @@ func muxFrame(w io.Writer, m image.Image, subsampling image.YCbCrSubsampleRatio,
 		},
 		itemInfos: boxIINF{
 			itemInfos: []boxINFEv2{
-				boxINFEv2{
+				{
 					itemID:   1,
 					itemType: itemTypeAV01,
 					itemName: "Image",
@@ -776,7 +775,7 @@ func muxFrame(w io.Writer, m image.Image, subsampling image.YCbCrSubsampleRatio,
 			},
 			association: boxIPMA{
 				entries: []boxIPMAAssociation{
-					boxIPMAAssociation{
+					{
 						itemID: 1,
 						props: []boxIPMAAssociationProperty{
 							{false, 1}, // non-essential width/height