Add config example to use VMAF phone model

.golangci.yaml

@@ -46,6 +46,7 @@ linters:
     - typecheck
     - unused
     # Additional
+    - copyloopvar
     - dupl
     - errname
     - misspell
@@ -54,7 +55,7 @@ linters:
     - goimports
     - goheader
     - gosec
-    - exportloopref
     - ireturn
     - prealloc
     - reassign
+    - usestdlibvars

bitrate.go

@@ -147,8 +147,8 @@ func run(videoFile, plotFile, ffprobePath string) error {
 	}
 
 	canvases := plot.Align(plots, t, dc)
-	for j := 0; j < rows; j++ {
-		for i := 0; i < cols; i++ {
+	for j := range rows {
+		for i := range cols {
 			if plots[j][i] != nil {
 				plots[j][i].Draw(canvases[j][i])
 			}

example/README.md

@@ -0,0 +1,6 @@
+# Examples in this direcotry
+
+- [ease_conf_phone_model.json](./ease_conf_phone_model.json) is a sample configuration file to use in case one needs to predirct VMAF scores using "phone model" [1].
+
+
+[1]: https://github.com/Netflix/vmaf/blob/master/resource/doc/models.md#predict-quality-on-a-cellular-phone-screen 

example/ease_conf_phone_model.json

@@ -0,0 +1,3 @@
+{
+  "ffmpeg_vmaf_template": "-hide_banner -i {{.CompressedFile}} -i {{.SourceFile}} -lavfi libvmaf=n_subsample=1:log_path={{.ResultFile}}:feature=name=psnr:log_fmt=json:model=version=vmaf_v0.6.1\\\\\\\\:enable_transform=true:n_threads={{.NThreads}} -f null -"
+}

internal/vqm/vqm.go

@@ -45,11 +45,7 @@ func NewFfmpegVMAF(cfg *FfmpegVMAFConfig, compressedFile, sourceFile string) (*F
 
 	// Too much CPU threads are also bad. This was an issue on 128 threaded AMD
 	// EPYC, ffmpeg was deadlocking at some point during VMAF calculations.
-	nThreads := 32
-
-	if runtime.NumCPU() < nThreads {
-		nThreads = runtime.NumCPU()
-	}
+	nThreads := min(runtime.NumCPU(), 32)
 
 	// Template requires a struct with exported fields.
 	tplContext := struct {