diff --git a/amrwb/amrwb.go b/amrwb/amrwb.go
index 063b5a9..59445a7 100644
--- a/amrwb/amrwb.go
+++ b/amrwb/amrwb.go
@@ -31,6 +31,13 @@ const (
 	SampleRate     = 16000
 )
 
+type Format = amrwb.Format
+
+const (
+	Storage               = amrwb.Storage
+	RTPBandwidthEfficient = amrwb.RTPBandwidthEfficient
+)
+
 func init() {
 	media.RegisterCodec(media.NewAudioCodec(media.CodecInfo{
 		SDPName:     SDPNameAndRate,
@@ -39,7 +46,11 @@ func init() {
 		Priority:    -4,
 		FileExt:     "amrwb",
 		Disabled:    true,
-	}, Decode, Encode))
+	}, func(w media.PCM16Writer) media.WriteCloser[Sample] {
+		return Decode(w, RTPBandwidthEfficient)
+	}, func(w media.WriteCloser[Sample]) media.PCM16Writer {
+		return Encode(w, RTPBandwidthEfficient)
+	}))
 }
 
 type Sample []byte
@@ -58,13 +69,13 @@ func (s Sample) CopyTo(dst []byte) (int, error) {
 
 type Writer = media.WriteCloser[Sample]
 
-func Decode(w media.PCM16Writer) Writer {
+func Decode(w media.PCM16Writer, format amrwb.Format) Writer {
 	if w.SampleRate() != SampleRate {
 		w = media.ResampleWriter(w, SampleRate)
 	}
 	return &Decoder{
 		w: w,
-		d: amrwb.NewDecoder(),
+		d: amrwb.NewDecoder(format),
 	}
 }
 
@@ -108,13 +119,17 @@ func (d *Decoder) WriteSample(in Sample) error {
 	return blockErr
 }
 
-func Encode(w Writer) media.PCM16Writer {
+func Encode(w Writer, format amrwb.Format) media.PCM16Writer {
+	return EncodeWith(w, format, amrwb.Best)
+}
+
+func EncodeWith(w Writer, format amrwb.Format, mode amrwb.Mode) media.PCM16Writer {
 	if w.SampleRate() != SampleRate {
 		panic("unsupported sample rate")
 	}
 	return &Encoder{
 		w: w,
-		e: amrwb.NewEncoder(amrwb.Best),
+		e: amrwb.NewEncoder(format, mode),
 	}
 }
 
diff --git a/amrwb/amrwb_test.go b/amrwb/amrwb_test.go
index 505a32e..e2dfa08 100644
--- a/amrwb/amrwb_test.go
+++ b/amrwb/amrwb_test.go
@@ -4,9 +4,11 @@ import (
 	"bufio"
 	"crypto/sha1"
 	"encoding/hex"
+	"fmt"
 	"io"
 	"os"
 	"os/exec"
+	"slices"
 	"testing"
 
 	"github.com/livekit/amrwb-cgo"
@@ -15,14 +17,204 @@ import (
 	"github.com/livekit/media-sdk/res/testdata"
 )
 
+const rate = 16000
+
 func TestAMRWB(t *testing.T) {
-	const rate = 16000
-	frames := res.ReadOggAudioFile(testdata.TestAudioOgg16K, rate, 1)
+	frames := readOGG()
+
+	modes := [9]amrwb.Mode{
+		amrwb.Mode6Kb,
+		amrwb.Mode8Kb,
+		amrwb.Mode12Kb,
+		amrwb.Mode14Kb,
+		amrwb.Mode16Kb,
+		amrwb.Mode18Kb,
+		amrwb.Mode20Kb,
+		amrwb.Mode23Kb,
+		amrwb.Mode24Kb,
+	}
+
+	const selFrame = 41
+
+	pcmHash := [9][]string{
+		0: {
+			"3e1459dd8f153700478c28574d503c089af19057", // mac
+			"3127946be110e6ebc8d64ed18a3334415a61ac4a", // linux
+		},
+		1: {
+			"4d3e177ac9e6b71e0f74443aa137ffc4e4de15f9", // mac
+			"3d0f014fcdf88ad8e5e5ff7617470442db6d661c", // linux
+		},
+		2: {
+			"6565057924a517608b265b7dc4d1cdc1363c82a8", // mac
+			"9bb552a97849e1fd572d1df657ab0bb9998013e2", // linux
+		},
+		3: {
+			"47523e7b0defa53a6e631982e06bbbdf221c4ec6", // mac
+			"98d374a1c27b7d2a682df7d2c5b12abd330105f9", // linux
+		},
+		4: {
+			"1a8c286d32abc7695c34da729bcc6681407153d5", // mac
+			"ad82c55e9a5df28c7bf254c136a2d1bcc575ba87", // linux
+		},
+		5: {
+			"64172da7990f652ae993f70b2bcdb26753e16bfa", // mac
+			"8d7543be36a002b9de5fa035d5667545defd7bc0", // linux
+		},
+		6: {
+			"6880cd543b5d707b69fc73a46d23c1cd1ad8134e", // mac
+			"37692d0cff60b592f99b85bbb883469696785035", // linux
+		},
+		7: {
+			"251335ded3c16b58aaac409908e7dee0ff458333", // mac
+			"c67f2fbb32b3d9825a211cbc91ed39d88fc8dba4", // linux
+		},
+		8: {
+			"2315d3ac38e9b4523bd380c3719d1d8477c5fd00", // mac
+			"06f13780fe3b87a68c78ebe2e7f5d51c31adfc50", // linux
+		},
+	}
+
+	t.Run("storage", func(t *testing.T) {
+		const format = Storage
+		hashes := [9][]string{
+			0: {
+				"0236b84c931bcf121da1a0587420d30d1aac0301", // mac
+				"d9151ae183596869c845bb2e3bbfc6f05a7138ba", // linux
+			},
+			1: {
+				"dabd16afd6fcacefc26d221e3fa06a2bc6644076", // mac
+				"cdb173454b66f61bf3e783285d10d598f5686824", // linux
+			},
+			2: {
+				"61d20f4e120dd13e2fbaaf74dd3c08863ed5a557", // mac
+				"029223c3b4a263c7e472020954b9560b23d3b46f", // linux
+			},
+			3: {
+				"bece54885e71b89dfcd86c8cbe7ce9fd2fefb4f7", // mac
+				"4e43af5ec9e6de64828276d31b85d3f153b2e17a", // linux
+			},
+			4: {
+				"67fa8975e5757d3b83aba349a7cc1f4e5d06ff66", // mac
+				"a6cba7433d37e36718c8d4a31109e53a87ab699b", // linux
+			},
+			5: {
+				"6f9c014385c8e7dbde780ae2e4a89b03b5e03dcb", // mac
+				"484fb0173d291785a914876e9dab6c302117e635", // linux
+			},
+			6: {
+				"039be8ddd5d2de4bb148d166552e6d59eebb3e40", // mac
+				"39d075885e5cdfcff597e0ee64d599793446c9ab", // linux
+			},
+			7: {
+				"2d0346353617d23bb59a6519167707115be2245e", // mac
+				"f410a08e3ca0644663efbd92e047da64554abd3e", // linux
+			},
+			8: {
+				"266c17405ad9cb6057bfe1a3e0cf764c448a10a0", // mac
+				"b3d9349b01e93c523311e587d639142d0c79546b", // linux
+			},
+		}
+		for mi, mode := range modes {
+			t.Run(fmt.Sprintf("mode %d", mi), func(t *testing.T) {
+				hashes := hashes[mi]
+
+				blocks := encodeAMR(t, format, mode, frames)
+				t.Logf("block: %x", blocks[selFrame])
+
+				name := fmt.Sprintf("testdata_mode_%d", mode)
+
+				hashAMR := dumpAMR(t, name+".amrwb", blocks)
+				ffmpegAMRFileToOGG(t, name+".amrwb")
+				if !slices.Contains(hashes, hashAMR) {
+					t.Errorf("unexpected amrwb hash %s", hashAMR)
+				}
+
+				out := decodeAMR(t, format, blocks)
+
+				hashOut := dumpPCM(t, name+".s16le", out)
+				ffmpegPCMFileToOGG(t, name+".s16le")
+				if !slices.Contains(pcmHash[mi], hashOut) {
+					t.Errorf("unexpected output hash %s", hashOut)
+				}
+			})
+		}
+	})
+	t.Run("rtp", func(t *testing.T) {
+		const format = RTPBandwidthEfficient
+		hashes := [9][]string{
+			0: {
+				"a8e453a08c894e2c3d0f7bf62142d6eb63bfe5c8", // mac
+				"c202d8b71545a3886991712857e82948efbb8037", // linux
+			},
+			1: {
+				"270a13237d862e9e20e725a0a9484edddc3b4f00", // mac
+				"a4819af7e4a41ffd916671e632db55e85151995b", // linux
+			},
+			2: {
+				"607966a93720aaa1c8425e08b6471f58282c0884", // mac
+				"837c6def6dbd34aeb466bfc255c084cbc5af4ca9", // linux
+			},
+			3: {
+				"8a620e9c3ce1656ea07804be210befe5c878f3f3", // mac
+				"a64abd663ade6a5ebb2c9f6e539a669b935ca23f", // linux
+			},
+			4: {
+				"9121d8781a397f4784174f15309f6f48d86db338", // mac
+				"8b2ffe416d0a0f7e7d06baf44369f9ed4bb51388", // linux
+			},
+			5: {
+				"a6e005daf0e8040530157be090934376610beeb7", // mac
+				"d4aba015c82e362fe1582cba7ee94579abed9aa9", // linux
+			},
+			6: {
+				"4497873be7c5574468e68c0718a5e57d3c8ac099", // mac
+				"e4cc30e3a4e6e0f65a08d7764ba208ab432ab9aa", // linux
+			},
+			7: {
+				"b73f2049b96be4793f611339e4d3435ec19a8760", // mac
+				"31e80f7eb50f12a552e86b547eda421defa7bd16", // linux
+			},
+			8: {
+				"7aa1a489f7f951ab421f0e462abb18c7d4c00c68", // mac
+				"cbe884fc78d580078ccdb3ed7acec77928cffa52", // linux
+			},
+		}
+		for mi, mode := range modes {
+			t.Run(fmt.Sprintf("mode %d", mi), func(t *testing.T) {
+				hashes := hashes[mi]
+
+				blocks := encodeAMR(t, format, mode, frames)
+				t.Logf("block: %x", blocks[selFrame])
+
+				name := fmt.Sprintf("testdata_rtp_mode_%d", mode)
+
+				hashAMR := dumpAMR(t, name+".amrwb", blocks)
+				if !slices.Contains(hashes, hashAMR) {
+					t.Errorf("unexpected amrwb hash %s", hashAMR)
+				}
+
+				out := decodeAMR(t, format, blocks)
+
+				hashOut := dumpPCM(t, name+".s16le", out)
+				ffmpegPCMFileToOGG(t, name+".s16le")
+				if !slices.Contains(pcmHash[mi], hashOut) {
+					t.Errorf("unexpected output hash %s", hashOut)
+				}
+			})
+		}
+	})
+}
 
+func readOGG() []media.PCM16Sample {
+	return res.ReadOggAudioFile(testdata.TestAudioOgg16K, rate, 1)
+}
+
+func encodeAMR(t testing.TB, format amrwb.Format, mode amrwb.Mode, frames []media.PCM16Sample) []Sample {
 	blocks := make([]Sample, 0, len(frames))
 	fw := media.NewFrameWriter(&blocks, rate)
 
-	enc := Encode(fw)
+	enc := EncodeWith(fw, format, mode)
 	t.Cleanup(func() {
 		enc.Close()
 	})
@@ -32,33 +224,32 @@ func TestAMRWB(t *testing.T) {
 			t.Errorf("encoding frame %d/%d: %v", i+1, len(frames), err)
 		}
 	}
-	famr, err := os.Create("testdata.amrwb")
+	return blocks
+}
+
+func dumpAMR(t testing.TB, name string, blocks []Sample) string {
+	f, err := os.Create(name)
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer famr.Close()
-
-	hamr := sha1.New()
+	defer f.Close()
 
-	wbamr := bufio.NewWriter(io.MultiWriter(famr, hamr))
-	wbamr.WriteString(amrwb.Magic)
+	h := sha1.New()
+	bw := bufio.NewWriter(io.MultiWriter(f, h))
+	bw.WriteString(amrwb.Magic)
 	for _, block := range blocks {
-		wbamr.Write(block)
-	}
-	wbamr.Flush()
-
-	hashAMR := hex.EncodeToString(hamr.Sum(nil))
-	switch hashAMR {
-	default:
-		t.Errorf("unexpected amrwb hash %s", hashAMR)
-	case "266c17405ad9cb6057bfe1a3e0cf764c448a10a0",
-		"b3d9349b01e93c523311e587d639142d0c79546b":
+		bw.Write(block)
 	}
+	bw.Flush()
+
+	return hex.EncodeToString(h.Sum(nil))
+}
 
+func decodeAMR(t testing.TB, format amrwb.Format, blocks []Sample) []media.PCM16Sample {
 	var out []media.PCM16Sample
 	pw := media.NewPCM16FrameWriter(&out, rate)
 
-	dec := Decode(pw)
+	dec := Decode(pw, format)
 	t.Cleanup(func() {
 		dec.Close()
 	})
@@ -68,8 +259,15 @@ func TestAMRWB(t *testing.T) {
 			t.Error(err)
 		}
 	}
+	return out
+}
+
+type nopCloser struct{}
+
+func (nopCloser) Close() error { return nil }
 
-	f, err := os.Create("testdata.s16le")
+func dumpPCM(t testing.TB, name string, data []media.PCM16Sample) string {
+	f, err := os.Create(name)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -77,35 +275,48 @@ func TestAMRWB(t *testing.T) {
 
 	h := sha1.New()
 	bw := bufio.NewWriter(io.MultiWriter(f, h))
-	err = media.DumpFramesPCM16(f, rate, out)
+	err = media.DumpFramesPCM16(struct {
+		io.Writer
+		io.Closer
+	}{
+		Writer: bw,
+		Closer: nopCloser{},
+	}, rate, data)
 	if err != nil {
 		t.Fatal(err)
 	}
 	bw.Flush()
 
-	hashOut := hex.EncodeToString(h.Sum(nil))
-	if hashOut != "da39a3ee5e6b4b0d3255bfef95601890afd80709" {
-		t.Errorf("unexpected output hash %s", hashOut)
-	}
+	return hex.EncodeToString(h.Sum(nil))
+}
 
+func ffmpegAMRFileToOGG(t testing.TB, name string) {
 	if _, err := exec.LookPath("ffmpeg"); err != nil {
 		t.Log("ffmpeg not found in $PATH")
 		return
 	}
-
-	err = exec.Command("ffmpeg",
-		"-i", "testdata.amrwb",
-		"testdata.amrwb.ogg",
+	err := exec.Command("ffmpeg",
+		"-i", name, name+".ogg",
 	).Run()
 	if err != nil {
 		t.Error(err)
+	} else {
+		os.Remove(name)
+	}
+}
+
+func ffmpegPCMFileToOGG(t testing.TB, name string) {
+	if _, err := exec.LookPath("ffmpeg"); err != nil {
+		t.Log("ffmpeg not found in $PATH")
+		return
 	}
-	err = exec.Command("ffmpeg",
+	err := exec.Command("ffmpeg",
 		"-f", "s16le", "-ar", "16000", "-ac", "1",
-		"-i", "testdata.s16le",
-		"testdata.s16le.ogg",
+		"-i", name, name+".ogg",
 	).Run()
 	if err != nil {
 		t.Error(err)
+	} else {
+		os.Remove(name)
 	}
 }
diff --git a/go.mod b/go.mod
index dc7bfba..ed465d1 100644
--- a/go.mod
+++ b/go.mod
@@ -10,7 +10,7 @@ require (
 	github.com/go-logr/logr v1.4.3
 	github.com/gotranspile/g722 v0.0.0-20240123003956-384a1bb16a19
 	github.com/jfreymuth/oggvorbis v1.0.5
-	github.com/livekit/amrwb-cgo v0.0.0-20260527094629-96c39974d532
+	github.com/livekit/amrwb-cgo v0.0.0-20260612153743-6d4b69dc1470
 	github.com/livekit/protocol v1.46.7-0.20260605212020-c0615a2f6f84
 	github.com/pion/interceptor v0.1.45
 	github.com/pion/rtp v1.10.2
diff --git a/go.sum b/go.sum
index e701119..2b89d7d 100644
--- a/go.sum
+++ b/go.sum
@@ -44,8 +44,8 @@ github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
-github.com/livekit/amrwb-cgo v0.0.0-20260527094629-96c39974d532 h1:q0Gj2RmsBLAcsDJ6u9GWfXGKAhU88r66AOT//DCQ/XU=
-github.com/livekit/amrwb-cgo v0.0.0-20260527094629-96c39974d532/go.mod h1:nGBFrVVLyO0RlyM2pWnP/VKaZO6W3rzecL/YlkTPkW8=
+github.com/livekit/amrwb-cgo v0.0.0-20260612153743-6d4b69dc1470 h1:pYml12Ue55jDhrjJoQg+w8W+0PY9wlNsTo6INGwzOfU=
+github.com/livekit/amrwb-cgo v0.0.0-20260612153743-6d4b69dc1470/go.mod h1:nGBFrVVLyO0RlyM2pWnP/VKaZO6W3rzecL/YlkTPkW8=
 github.com/livekit/mageutil v0.0.0-20250511045019-0f1ff63f7731 h1:9x+U2HGLrSw5ATTo469PQPkqzdoU7be46ryiCDO3boc=
 github.com/livekit/mageutil v0.0.0-20250511045019-0f1ff63f7731/go.mod h1:Rs3MhFwutWhGwmY1VQsygw28z5bWcnEYmS1OG9OxjOQ=
 github.com/livekit/protocol v1.46.7-0.20260605212020-c0615a2f6f84 h1:dkHHthyor9dwxxdBmbeG1ZUI4bPHpTEk9DjYJSSSIl4=