Video: Add config option for FFmpeg num_capture_buffers #703

internal/config/flags.go

@@ -321,6 +321,12 @@ var GlobalFlags = []cli.Flag{
 		Value:  "libx264",
 		EnvVar: "PHOTOPRISM_FFMPEG_CODEC",
 	},
+	cli.IntFlag{
+		Name:   "ffmpeg-buffers",
+		Usage:  "FFmpeg capture buffers",
+		Value:  32,
+		EnvVar: "PHOTOPRISM_FFMPEG_BUFFERS",
+	},
 	cli.StringFlag{
 		Name:   "exiftool-bin",
 		Usage:  "ExifTool `COMMAND` for enhanced metadata extraction",

internal/config/fs.go

@@ -264,6 +264,19 @@ func (c *Config) FFmpegCodec() string {
 	return c.options.FFmpegCodec
 }
 
+// FFmpegBuffers returns the number of ffmpeg capture buffers.
+func (c *Config) FFmpegBuffers() int {
+	if c.options.FFmpegBuffers <= 8 {
+		return 8
+	}
+
+	if c.options.FFmpegBuffers >= 2048 {
+		return 2048
+	}
+
+	return c.options.FFmpegBuffers
+}
+
 // TempPath returns a temporary directory name for uploads and downloads.
 func (c *Config) TempPath() string {
 	if c.options.TempPath == "" {

internal/config/options.go

@@ -91,7 +91,8 @@ type Options struct {
 	DarktablePresets  bool   `yaml:"DarktablePresets" json:"DarktablePresets" flag:"darktable-presets"`
 	HeifConvertBin    string `yaml:"HeifConvertBin" json:"-" flag:"heifconvert-bin"`
 	FFmpegBin         string `yaml:"FFmpegBin" json:"-" flag:"ffmpeg-bin"`
-	FFmpegCodec       string `yaml:"FFmpegCodec" json:"-" flag:"ffmpeg-codec"`
+	FFmpegCodec       string `yaml:"FFmpegCodec" json:"FFmpegCodec" flag:"ffmpeg-codec"`
+	FFmpegBuffers     int    `yaml:"FFmpegBuffers" json:"FFmpegBuffers" flag:"ffmpeg-buffers"`
 	ExifToolBin       string `yaml:"ExifToolBin" json:"-" flag:"exiftool-bin"`
 	DetachServer      bool   `yaml:"DetachServer" json:"-" flag:"detach-server"`
 	DownloadToken     string `yaml:"DownloadToken" json:"-" flag:"download-token"`

internal/photoprism/convert.go

@@ -339,8 +339,8 @@ func (c *Convert) AvcConvertCommand(f *MediaFile, avcName, codecName string) (re
 			"-c:v", codecName,
 			"-c:a", "copy",
 			"-vf", format,
-			"-num_output_buffers", "32",
-			"-num_capture_buffers", "32",
+			"-num_output_buffers", strconv.Itoa(c.conf.FFmpegBuffers()+8),
+			"-num_capture_buffers", strconv.Itoa(c.conf.FFmpegBuffers()),
 			"-crf", "23",
 			"-b:v", c.AvcBitrate(f),
 			"-f", "mp4",