diff --git a/pkg/encoder_options.go b/pkg/encoder_options.go
index 16e0843..a925ff7 100644
--- a/pkg/encoder_options.go
+++ b/pkg/encoder_options.go
@@ -2,6 +2,7 @@ package transcode
 
 import (
 	"reflect"
+	"strings"
 
 	buffer "github.com/harshabose/tools/buffer/pkg"
 
@@ -16,37 +17,80 @@ type codecSettings interface {
 	ForEach(func(string, string) error) error
 }
 
-type X264Settings struct {
-	Preset        string `x264:"preset"`
-	Tune          string `x264:"tune"`
-	Refs          string `x264:"refs"`
-	Profile       string `x264:"profile"`
-	Level         string `x264:"level"`
-	Qmin          string `x264:"qmin"`
-	Qmax          string `x264:"qmax"`
-	BFrames       string `x264:"bframes"`
-	BAdapt        string `x264:"b-adapt"`
-	NGOP          string `x264:"keyint"`
-	NGOPMin       string `x264:"min-keyint"`
-	Scenecut      string `x264:"scenecut"`
-	InfraRefresh  string `x264:"intra-refresh"`
-	LookAhead     string `x264:"rc-lookahead"`
-	SlicedThreads string `x264:"sliced-threads"`
-	SyncLookAhead string `x264:"sync-lookahead"`
-	ForceIDR      string `x264:"force-idr"`
-	AQMode        string `x264:"aq-mode"`
-	AQStrength    string `x264:"aq-strength"`
-	MBTree        string `x264:"mbtree"`
-	Bitrate       string `x264:"bitrate"`
-	VBVMaxBitrate string `x264:"vbv-maxrate"`
-	VBVBuffer     string `x264:"vbv-bufsize"`
-	RateTol       string `x264:"ratetol"`
-	Threads       string `x264:"threads"`
-	AnnexB        string `x264:"annexb"`
-	Aud           string `x264:"aud"`
+type X264Opts struct {
+	// RateControl   string `x264-opts:"rate-control"`
+	Bitrate       string `x264-opts:"bitrate"`
+	VBVMaxBitrate string `x264-opts:"vbv-maxrate"`
+	VBVBuffer     string `x264-opts:"vbv-bufsize"`
+	RateTol       string `x264-opts:"ratetol"`
+	SyncLookAhead string `x264-opts:"sync-lookahead"`
+	AnnexB        string `x264-opts:"annexb"`
 }
 
-func (s X264Settings) ForEach(fn func(key, value string) error) error {
+func (x264 X264Opts) ForEach(fn func(string, string) error) error {
+	t := reflect.TypeOf(x264)
+	v := reflect.ValueOf(x264)
+
+	// Build a single x264opts string
+	var optParts []string
+
+	for i := 0; i < t.NumField(); i++ {
+		field := t.Field(i)
+		tag := field.Tag.Get("x264-opts")
+		if tag != "" && v.Field(i).String() != "" {
+			optParts = append(optParts, tag+"="+v.Field(i).String())
+		}
+	}
+
+	// Join all options with colons
+	if len(optParts) > 0 {
+		x264optsValue := strings.Join(optParts, ":")
+		// Set as a single parameter
+		if err := fn("x264opts", x264optsValue); err != nil {
+			return err
+		}
+	}
+
+	// Also apply any regular x264 parameters
+	for i := 0; i < t.NumField(); i++ {
+		field := t.Field(i)
+		tag := field.Tag.Get("x264")
+		if tag != "" {
+			if err := fn(tag, v.Field(i).String()); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+type X264OpenSettings struct {
+	X264Opts
+	Preset        string `x264:"preset"`        // exists
+	Tune          string `x264:"tune"`          // exists
+	Refs          string `x264:"refs"`          // exists
+	Profile       string `x264:"profile"`       // exists
+	Level         string `x264:"level"`         // exists
+	Qmin          string `x264:"qmin"`          // exists
+	Qmax          string `x264:"qmax"`          // exists
+	BFrames       string `x264:"bf"`            // exists
+	BAdapt        string `x264:"b_strategy"`    // exists
+	NGOP          string `x264:"g"`             // exists
+	NGOPMin       string `x264:"keyint_min"`    // exists
+	Scenecut      string `x264:"sc_threshold"`  // exists
+	InfraRefresh  string `x264:"intra-refresh"` // exists
+	LookAhead     string `x264:"rc-lookahead"`  // exists
+	SlicedThreads string `x264:"slice"`         // exists
+	ForceIDR      string `x264:"force-idr"`     // exists
+	AQMode        string `x264:"aq-mode"`       // exists
+	AQStrength    string `x264:"aq-strength"`   // exists
+	MBTree        string `x264:"mbtree"`        // exists
+	Threads       string `x264:"threads"`       // exists
+	Aud           string `x264:"aud"`           // exists
+}
+
+func (s X264OpenSettings) ForEach(fn func(key, value string) error) error {
 	t := reflect.TypeOf(s)
 	v := reflect.ValueOf(s)
 
@@ -59,10 +103,20 @@ func (s X264Settings) ForEach(fn func(key, value string) error) error {
 			}
 		}
 	}
-	return nil
+
+	return s.X264Opts.ForEach(fn)
 }
 
-var DefaultX264Settings = X264Settings{
+var DefaultX264Settings = X264OpenSettings{
+	X264Opts: X264Opts{
+		// RateControl:   "abr",
+		Bitrate:       "4000",
+		VBVMaxBitrate: "5000",
+		VBVBuffer:     "8000",
+		RateTol:       "1",
+		SyncLookAhead: "1",
+		AnnexB:        "1",
+	},
 	Preset:        "medium",
 	Tune:          "film",
 	Refs:          "6",
@@ -78,21 +132,24 @@ var DefaultX264Settings = X264Settings{
 	InfraRefresh:  "0",
 	LookAhead:     "40",
 	SlicedThreads: "0",
-	SyncLookAhead: "1",
 	ForceIDR:      "0",
 	AQMode:        "1",
 	AQStrength:    "1.0",
 	MBTree:        "1",
-	Bitrate:       "4000",
-	VBVMaxBitrate: "5000",
-	VBVBuffer:     "8000",
-	RateTol:       "1",
 	Threads:       "0",
-	AnnexB:        "1",
 	Aud:           "0",
 }
 
-var LowBandwidthX264Settings = X264Settings{
+var LowBandwidthX264Settings = X264OpenSettings{
+	X264Opts: X264Opts{
+		// RateControl:   "abr",
+		Bitrate:       "1500",
+		VBVMaxBitrate: "1800",
+		VBVBuffer:     "3000",
+		RateTol:       "0.25",
+		SyncLookAhead: "0",
+		AnnexB:        "1",
+	},
 	Preset:        "veryfast",
 	Tune:          "fastdecode",
 	Refs:          "2",
@@ -108,21 +165,24 @@ var LowBandwidthX264Settings = X264Settings{
 	InfraRefresh:  "0",
 	LookAhead:     "20",
 	SlicedThreads: "1",
-	SyncLookAhead: "0",
 	ForceIDR:      "0",
 	AQMode:        "0",
 	AQStrength:    "1.2",
 	MBTree:        "0",
-	Bitrate:       "1500",
-	VBVMaxBitrate: "1800",
-	VBVBuffer:     "3000",
-	RateTol:       "0.25",
 	Threads:       "0",
-	AnnexB:        "1",
 	Aud:           "0",
 }
 
-var LowLatencyX264Settings = X264Settings{
+var LowLatencyX264Settings = X264OpenSettings{
+	X264Opts: X264Opts{
+		// RateControl:   "abr",
+		Bitrate:       "5000",
+		VBVMaxBitrate: "12000",
+		VBVBuffer:     "20000",
+		RateTol:       "0.5",
+		SyncLookAhead: "0",
+		AnnexB:        "1",
+	},
 	Preset:        "ultrafast",
 	Tune:          "zerolatency",
 	Refs:          "1",
@@ -138,21 +198,25 @@ var LowLatencyX264Settings = X264Settings{
 	InfraRefresh:  "1",
 	LookAhead:     "10",
 	SlicedThreads: "1",
-	SyncLookAhead: "0",
 	ForceIDR:      "1",
 	AQMode:        "0",
 	AQStrength:    "0",
 	MBTree:        "0",
-	Bitrate:       "2500",
-	VBVMaxBitrate: "3000",
-	VBVBuffer:     "5000",
-	RateTol:       "0.5",
-	Threads:       "0",
-	AnnexB:        "1",
-	Aud:           "1",
+
+	Threads: "0",
+	Aud:     "1",
 }
 
-var HighQualityX264Settings = X264Settings{
+var HighQualityX264Settings = X264OpenSettings{
+	X264Opts: X264Opts{
+		// RateControl:   "abr",
+		Bitrate:       "15000",
+		VBVMaxBitrate: "20000",
+		VBVBuffer:     "30000",
+		RateTol:       "2.0",
+		SyncLookAhead: "1",
+		AnnexB:        "1",
+	},
 	Preset:        "slow",
 	Tune:          "film",
 	Refs:          "8",
@@ -168,18 +232,13 @@ var HighQualityX264Settings = X264Settings{
 	InfraRefresh:  "0",
 	LookAhead:     "60",
 	SlicedThreads: "0",
-	SyncLookAhead: "1",
 	ForceIDR:      "0",
 	AQMode:        "0",
 	AQStrength:    "1.3",
 	MBTree:        "1",
-	Bitrate:       "15000",
-	VBVMaxBitrate: "20000",
-	VBVBuffer:     "30000",
-	RateTol:       "2.0",
-	Threads:       "0",
-	AnnexB:        "1",
-	Aud:           "0",
+
+	Threads: "0",
+	Aud:     "0",
 }
 
 func WithX264DefaultOptions(encoder *Encoder) error {