diff --git a/README.md b/README.md
index 5e50878..fa5e83a 100644
--- a/README.md
+++ b/README.md
@@ -54,6 +54,12 @@ cd backend/
 sqlc generate
 ```
 
+Mocks require [mockery](https://github.com/vektra/mockery) to be installed, and can be regenerated with:
+
+```
+go generate
+```
+
 ### Migrations
 
 Database migrations require [golang-migrate](https://github.com/golang-migrate/migrate).
diff --git a/backend/generated/mocks/S3Client.go b/backend/generated/mocks/S3Client.go
new file mode 100644
index 0000000..7bcf177
--- /dev/null
+++ b/backend/generated/mocks/S3Client.go
@@ -0,0 +1,166 @@
+// Code generated by mockery v2.9.4. DO NOT EDIT.
+
+package mocks
+
+import (
+	context "context"
+
+	mock "github.com/stretchr/testify/mock"
+
+	s3 "github.com/aws/aws-sdk-go-v2/service/s3"
+)
+
+// S3Client is an autogenerated mock type for the S3Client type
+type S3Client struct {
+	mock.Mock
+}
+
+// AbortMultipartUpload provides a mock function with given fields: _a0, _a1, _a2
+func (_m *S3Client) AbortMultipartUpload(_a0 context.Context, _a1 *s3.AbortMultipartUploadInput, _a2 ...func(*s3.Options)) (*s3.AbortMultipartUploadOutput, error) {
+	_va := make([]interface{}, len(_a2))
+	for _i := range _a2 {
+		_va[_i] = _a2[_i]
+	}
+	var _ca []interface{}
+	_ca = append(_ca, _a0, _a1)
+	_ca = append(_ca, _va...)
+	ret := _m.Called(_ca...)
+
+	var r0 *s3.AbortMultipartUploadOutput
+	if rf, ok := ret.Get(0).(func(context.Context, *s3.AbortMultipartUploadInput, ...func(*s3.Options)) *s3.AbortMultipartUploadOutput); ok {
+		r0 = rf(_a0, _a1, _a2...)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*s3.AbortMultipartUploadOutput)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, *s3.AbortMultipartUploadInput, ...func(*s3.Options)) error); ok {
+		r1 = rf(_a0, _a1, _a2...)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// CompleteMultipartUpload provides a mock function with given fields: _a0, _a1, _a2
+func (_m *S3Client) CompleteMultipartUpload(_a0 context.Context, _a1 *s3.CompleteMultipartUploadInput, _a2 ...func(*s3.Options)) (*s3.CompleteMultipartUploadOutput, error) {
+	_va := make([]interface{}, len(_a2))
+	for _i := range _a2 {
+		_va[_i] = _a2[_i]
+	}
+	var _ca []interface{}
+	_ca = append(_ca, _a0, _a1)
+	_ca = append(_ca, _va...)
+	ret := _m.Called(_ca...)
+
+	var r0 *s3.CompleteMultipartUploadOutput
+	if rf, ok := ret.Get(0).(func(context.Context, *s3.CompleteMultipartUploadInput, ...func(*s3.Options)) *s3.CompleteMultipartUploadOutput); ok {
+		r0 = rf(_a0, _a1, _a2...)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*s3.CompleteMultipartUploadOutput)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, *s3.CompleteMultipartUploadInput, ...func(*s3.Options)) error); ok {
+		r1 = rf(_a0, _a1, _a2...)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// CreateMultipartUpload provides a mock function with given fields: _a0, _a1, _a2
+func (_m *S3Client) CreateMultipartUpload(_a0 context.Context, _a1 *s3.CreateMultipartUploadInput, _a2 ...func(*s3.Options)) (*s3.CreateMultipartUploadOutput, error) {
+	_va := make([]interface{}, len(_a2))
+	for _i := range _a2 {
+		_va[_i] = _a2[_i]
+	}
+	var _ca []interface{}
+	_ca = append(_ca, _a0, _a1)
+	_ca = append(_ca, _va...)
+	ret := _m.Called(_ca...)
+
+	var r0 *s3.CreateMultipartUploadOutput
+	if rf, ok := ret.Get(0).(func(context.Context, *s3.CreateMultipartUploadInput, ...func(*s3.Options)) *s3.CreateMultipartUploadOutput); ok {
+		r0 = rf(_a0, _a1, _a2...)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*s3.CreateMultipartUploadOutput)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, *s3.CreateMultipartUploadInput, ...func(*s3.Options)) error); ok {
+		r1 = rf(_a0, _a1, _a2...)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// GetObject provides a mock function with given fields: _a0, _a1, _a2
+func (_m *S3Client) GetObject(_a0 context.Context, _a1 *s3.GetObjectInput, _a2 ...func(*s3.Options)) (*s3.GetObjectOutput, error) {
+	_va := make([]interface{}, len(_a2))
+	for _i := range _a2 {
+		_va[_i] = _a2[_i]
+	}
+	var _ca []interface{}
+	_ca = append(_ca, _a0, _a1)
+	_ca = append(_ca, _va...)
+	ret := _m.Called(_ca...)
+
+	var r0 *s3.GetObjectOutput
+	if rf, ok := ret.Get(0).(func(context.Context, *s3.GetObjectInput, ...func(*s3.Options)) *s3.GetObjectOutput); ok {
+		r0 = rf(_a0, _a1, _a2...)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*s3.GetObjectOutput)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, *s3.GetObjectInput, ...func(*s3.Options)) error); ok {
+		r1 = rf(_a0, _a1, _a2...)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// UploadPart provides a mock function with given fields: _a0, _a1, _a2
+func (_m *S3Client) UploadPart(_a0 context.Context, _a1 *s3.UploadPartInput, _a2 ...func(*s3.Options)) (*s3.UploadPartOutput, error) {
+	_va := make([]interface{}, len(_a2))
+	for _i := range _a2 {
+		_va[_i] = _a2[_i]
+	}
+	var _ca []interface{}
+	_ca = append(_ca, _a0, _a1)
+	_ca = append(_ca, _va...)
+	ret := _m.Called(_ca...)
+
+	var r0 *s3.UploadPartOutput
+	if rf, ok := ret.Get(0).(func(context.Context, *s3.UploadPartInput, ...func(*s3.Options)) *s3.UploadPartOutput); ok {
+		r0 = rf(_a0, _a1, _a2...)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*s3.UploadPartOutput)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, *s3.UploadPartInput, ...func(*s3.Options)) error); ok {
+		r1 = rf(_a0, _a1, _a2...)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
diff --git a/backend/generated/mocks/S3PresignClient.go b/backend/generated/mocks/S3PresignClient.go
new file mode 100644
index 0000000..2a35f49
--- /dev/null
+++ b/backend/generated/mocks/S3PresignClient.go
@@ -0,0 +1,48 @@
+// Code generated by mockery v2.9.4. DO NOT EDIT.
+
+package mocks
+
+import (
+	context "context"
+
+	mock "github.com/stretchr/testify/mock"
+
+	s3 "github.com/aws/aws-sdk-go-v2/service/s3"
+
+	v4 "github.com/aws/aws-sdk-go-v2/aws/signer/v4"
+)
+
+// S3PresignClient is an autogenerated mock type for the S3PresignClient type
+type S3PresignClient struct {
+	mock.Mock
+}
+
+// PresignGetObject provides a mock function with given fields: _a0, _a1, _a2
+func (_m *S3PresignClient) PresignGetObject(_a0 context.Context, _a1 *s3.GetObjectInput, _a2 ...func(*s3.PresignOptions)) (*v4.PresignedHTTPRequest, error) {
+	_va := make([]interface{}, len(_a2))
+	for _i := range _a2 {
+		_va[_i] = _a2[_i]
+	}
+	var _ca []interface{}
+	_ca = append(_ca, _a0, _a1)
+	_ca = append(_ca, _va...)
+	ret := _m.Called(_ca...)
+
+	var r0 *v4.PresignedHTTPRequest
+	if rf, ok := ret.Get(0).(func(context.Context, *s3.GetObjectInput, ...func(*s3.PresignOptions)) *v4.PresignedHTTPRequest); ok {
+		r0 = rf(_a0, _a1, _a2...)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*v4.PresignedHTTPRequest)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, *s3.GetObjectInput, ...func(*s3.PresignOptions)) error); ok {
+		r1 = rf(_a0, _a1, _a2...)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
diff --git a/backend/generated/mocks/Store.go b/backend/generated/mocks/Store.go
new file mode 100644
index 0000000..3ab992d
--- /dev/null
+++ b/backend/generated/mocks/Store.go
@@ -0,0 +1,165 @@
+// Code generated by mockery v2.9.4. DO NOT EDIT.
+
+package mocks
+
+import (
+	context "context"
+
+	mock "github.com/stretchr/testify/mock"
+
+	store "git.netflux.io/rob/clipper/generated/store"
+
+	uuid "github.com/google/uuid"
+)
+
+// Store is an autogenerated mock type for the Store type
+type Store struct {
+	mock.Mock
+}
+
+// CreateMediaSet provides a mock function with given fields: _a0, _a1
+func (_m *Store) CreateMediaSet(_a0 context.Context, _a1 store.CreateMediaSetParams) (store.MediaSet, error) {
+	ret := _m.Called(_a0, _a1)
+
+	var r0 store.MediaSet
+	if rf, ok := ret.Get(0).(func(context.Context, store.CreateMediaSetParams) store.MediaSet); ok {
+		r0 = rf(_a0, _a1)
+	} else {
+		r0 = ret.Get(0).(store.MediaSet)
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, store.CreateMediaSetParams) error); ok {
+		r1 = rf(_a0, _a1)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// GetMediaSet provides a mock function with given fields: _a0, _a1
+func (_m *Store) GetMediaSet(_a0 context.Context, _a1 uuid.UUID) (store.MediaSet, error) {
+	ret := _m.Called(_a0, _a1)
+
+	var r0 store.MediaSet
+	if rf, ok := ret.Get(0).(func(context.Context, uuid.UUID) store.MediaSet); ok {
+		r0 = rf(_a0, _a1)
+	} else {
+		r0 = ret.Get(0).(store.MediaSet)
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, uuid.UUID) error); ok {
+		r1 = rf(_a0, _a1)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// GetMediaSetByYoutubeID provides a mock function with given fields: _a0, _a1
+func (_m *Store) GetMediaSetByYoutubeID(_a0 context.Context, _a1 string) (store.MediaSet, error) {
+	ret := _m.Called(_a0, _a1)
+
+	var r0 store.MediaSet
+	if rf, ok := ret.Get(0).(func(context.Context, string) store.MediaSet); ok {
+		r0 = rf(_a0, _a1)
+	} else {
+		r0 = ret.Get(0).(store.MediaSet)
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, string) error); ok {
+		r1 = rf(_a0, _a1)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// SetEncodedAudioUploaded provides a mock function with given fields: _a0, _a1
+func (_m *Store) SetEncodedAudioUploaded(_a0 context.Context, _a1 store.SetEncodedAudioUploadedParams) (store.MediaSet, error) {
+	ret := _m.Called(_a0, _a1)
+
+	var r0 store.MediaSet
+	if rf, ok := ret.Get(0).(func(context.Context, store.SetEncodedAudioUploadedParams) store.MediaSet); ok {
+		r0 = rf(_a0, _a1)
+	} else {
+		r0 = ret.Get(0).(store.MediaSet)
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, store.SetEncodedAudioUploadedParams) error); ok {
+		r1 = rf(_a0, _a1)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// SetRawAudioUploaded provides a mock function with given fields: _a0, _a1
+func (_m *Store) SetRawAudioUploaded(_a0 context.Context, _a1 store.SetRawAudioUploadedParams) (store.MediaSet, error) {
+	ret := _m.Called(_a0, _a1)
+
+	var r0 store.MediaSet
+	if rf, ok := ret.Get(0).(func(context.Context, store.SetRawAudioUploadedParams) store.MediaSet); ok {
+		r0 = rf(_a0, _a1)
+	} else {
+		r0 = ret.Get(0).(store.MediaSet)
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, store.SetRawAudioUploadedParams) error); ok {
+		r1 = rf(_a0, _a1)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// SetVideoThumbnailUploaded provides a mock function with given fields: _a0, _a1
+func (_m *Store) SetVideoThumbnailUploaded(_a0 context.Context, _a1 store.SetVideoThumbnailUploadedParams) (store.MediaSet, error) {
+	ret := _m.Called(_a0, _a1)
+
+	var r0 store.MediaSet
+	if rf, ok := ret.Get(0).(func(context.Context, store.SetVideoThumbnailUploadedParams) store.MediaSet); ok {
+		r0 = rf(_a0, _a1)
+	} else {
+		r0 = ret.Get(0).(store.MediaSet)
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, store.SetVideoThumbnailUploadedParams) error); ok {
+		r1 = rf(_a0, _a1)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// SetVideoUploaded provides a mock function with given fields: _a0, _a1
+func (_m *Store) SetVideoUploaded(_a0 context.Context, _a1 store.SetVideoUploadedParams) (store.MediaSet, error) {
+	ret := _m.Called(_a0, _a1)
+
+	var r0 store.MediaSet
+	if rf, ok := ret.Get(0).(func(context.Context, store.SetVideoUploadedParams) store.MediaSet); ok {
+		r0 = rf(_a0, _a1)
+	} else {
+		r0 = ret.Get(0).(store.MediaSet)
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, store.SetVideoUploadedParams) error); ok {
+		r1 = rf(_a0, _a1)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
diff --git a/backend/generated/mocks/YoutubeClient.go b/backend/generated/mocks/YoutubeClient.go
new file mode 100644
index 0000000..bb93805
--- /dev/null
+++ b/backend/generated/mocks/YoutubeClient.go
@@ -0,0 +1,70 @@
+// Code generated by mockery v2.9.4. DO NOT EDIT.
+
+package mocks
+
+import (
+	context "context"
+	io "io"
+
+	mock "github.com/stretchr/testify/mock"
+
+	youtube "github.com/kkdai/youtube/v2"
+)
+
+// YoutubeClient is an autogenerated mock type for the YoutubeClient type
+type YoutubeClient struct {
+	mock.Mock
+}
+
+// GetStreamContext provides a mock function with given fields: _a0, _a1, _a2
+func (_m *YoutubeClient) GetStreamContext(_a0 context.Context, _a1 *youtube.Video, _a2 *youtube.Format) (io.ReadCloser, int64, error) {
+	ret := _m.Called(_a0, _a1, _a2)
+
+	var r0 io.ReadCloser
+	if rf, ok := ret.Get(0).(func(context.Context, *youtube.Video, *youtube.Format) io.ReadCloser); ok {
+		r0 = rf(_a0, _a1, _a2)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(io.ReadCloser)
+		}
+	}
+
+	var r1 int64
+	if rf, ok := ret.Get(1).(func(context.Context, *youtube.Video, *youtube.Format) int64); ok {
+		r1 = rf(_a0, _a1, _a2)
+	} else {
+		r1 = ret.Get(1).(int64)
+	}
+
+	var r2 error
+	if rf, ok := ret.Get(2).(func(context.Context, *youtube.Video, *youtube.Format) error); ok {
+		r2 = rf(_a0, _a1, _a2)
+	} else {
+		r2 = ret.Error(2)
+	}
+
+	return r0, r1, r2
+}
+
+// GetVideoContext provides a mock function with given fields: _a0, _a1
+func (_m *YoutubeClient) GetVideoContext(_a0 context.Context, _a1 string) (*youtube.Video, error) {
+	ret := _m.Called(_a0, _a1)
+
+	var r0 *youtube.Video
+	if rf, ok := ret.Get(0).(func(context.Context, string) *youtube.Video); ok {
+		r0 = rf(_a0, _a1)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*youtube.Video)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(context.Context, string) error); ok {
+		r1 = rf(_a0, _a1)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
diff --git a/backend/go.mod b/backend/go.mod
index 651c167..b30bab8 100644
--- a/backend/go.mod
+++ b/backend/go.mod
@@ -48,6 +48,7 @@ require (
 	github.com/mattn/go-isatty v0.0.14 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/rs/cors v1.8.0 // indirect
+	github.com/stretchr/objx v0.2.0 // indirect
 	go.uber.org/atomic v1.9.0 // indirect
 	go.uber.org/multierr v1.7.0 // indirect
 	golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97 // indirect
diff --git a/backend/go.sum b/backend/go.sum
index a8aba53..037cdf3 100644
--- a/backend/go.sum
+++ b/backend/go.sum
@@ -584,6 +584,7 @@ github.com/streadway/amqp v0.0.0-20190827072141-edfb9018d271/go.mod h1:AZpEONHx3
 github.com/streadway/handy v0.0.0-20190108123426-d5acb3125c2a/go.mod h1:qNTQ5P5JnDBl6z3cMAg/SywNDC5ABu5ApDIw6lUbRmI=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.2.0 h1:Hbg2NidpLE8veEBkEZTL3CvlkUIVzuU9jDplZO54c48=
 github.com/stretchr/objx v0.2.0/go.mod h1:qt09Ya8vawLte6SNmTgCsAVtYtaKzEcn8ATUoHMkEqE=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
diff --git a/backend/media/service_test.go b/backend/media/service_test.go
index 1296c8a..d6f6d53 100644
--- a/backend/media/service_test.go
+++ b/backend/media/service_test.go
@@ -1,13 +1,125 @@
 package media_test
 
 import (
+	"context"
+	"fmt"
 	"io"
+	"os"
 	"testing"
 
+	"git.netflux.io/rob/clipper/config"
+	"git.netflux.io/rob/clipper/generated/mocks"
+	"git.netflux.io/rob/clipper/generated/store"
 	"git.netflux.io/rob/clipper/media"
+	"github.com/aws/aws-sdk-go-v2/service/s3"
+	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/zap"
 )
 
+func TestGetAudioSegment(t *testing.T) {
+	testCases := []struct {
+		name                 string
+		fixturePath          string
+		fixtureLen           int64
+		startFrame, endFrame int64
+		channels             int32
+		numBins              int
+		wantPeaks            []int16
+		wantErr              string
+	}{
+		{
+			name:        "entire fixture, stereo, 1 bin",
+			fixturePath: "testdata/tone-44100-stereo-int16.raw",
+			fixtureLen:  176400,
+			startFrame:  0,
+			endFrame:    44100,
+			channels:    2,
+			numBins:     1,
+			wantPeaks:   []int16{32747, 32747},
+		},
+		{
+			name:        "entire fixture, stereo, 4 bins",
+			fixturePath: "testdata/tone-44100-stereo-int16.raw",
+			fixtureLen:  176400,
+			startFrame:  0,
+			endFrame:    44100,
+			channels:    2,
+			numBins:     4,
+			wantPeaks:   []int16{8173, 8177, 16366, 16370, 24557, 24555, 32747, 32747},
+		},
+		{
+			name:        "entire fixture, stereo, 16 bins",
+			fixturePath: "testdata/tone-44100-stereo-int16.raw",
+			fixtureLen:  176400,
+			startFrame:  0,
+			endFrame:    44100,
+			channels:    2,
+			numBins:     16,
+			wantPeaks:   []int16{2029, 2029, 4075, 4076, 6124, 6125, 8173, 8177, 10222, 10221, 12267, 12265, 14314, 14313, 16366, 16370, 18413, 18411, 20453, 20454, 22505, 22508, 24557, 24555, 26604, 26605, 28644, 28643, 30698, 30694, 32747, 32747},
+		},
+		{
+			name:        "entire fixture, mono, 1 bin",
+			fixturePath: "testdata/tone-44100-mono-int16.raw",
+			fixtureLen:  88200,
+			startFrame:  0,
+			endFrame:    44100,
+			channels:    1,
+			numBins:     1,
+			wantPeaks:   []int16{32748},
+		},
+		{
+			name:        "entire fixture, mono, 32 bins",
+			fixturePath: "testdata/tone-44100-mono-int16.raw",
+			fixtureLen:  88200,
+			startFrame:  0,
+			endFrame:    44100,
+			channels:    1,
+			numBins:     32,
+			wantPeaks:   []int16{1026, 2030, 3071, 4075, 5122, 6126, 7167, 8172, 9213, 10217, 11259, 12264, 13311, 14315, 15360, 16364, 17405, 18412, 19450, 20453, 21497, 22504, 23549, 24554, 25599, 26607, 27641, 28642, 29688, 30738, 31746, 32748},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			expectedBytes := (tc.endFrame - tc.startFrame) * int64(tc.channels) * media.SizeOfInt16
+
+			audioFile, err := os.Open(tc.fixturePath)
+			require.NoError(t, err)
+			defer audioFile.Close()
+			audioData := io.NopCloser(io.LimitReader(audioFile, int64(expectedBytes)))
+
+			mediaSetID := uuid.New()
+			mediaSet := store.MediaSet{ID: mediaSetID, AudioChannels: tc.channels}
+
+			// store is passed the mediaSetID and returns a mediaSet
+			store := &mocks.Store{}
+			store.On("GetMediaSet", mock.Anything, mediaSetID).Return(mediaSet, nil)
+			defer store.AssertExpectations(t)
+
+			// S3 is passed the expected byte range, and returns an io.Reader
+			s3Client := &mocks.S3Client{}
+			s3Client.On("GetObject", mock.Anything, mock.MatchedBy(func(input *s3.GetObjectInput) bool {
+				return *input.Range == fmt.Sprintf("bytes=0-%d", expectedBytes)
+			})).Return(&s3.GetObjectOutput{Body: audioData, ContentLength: tc.fixtureLen}, nil)
+			defer s3Client.AssertExpectations(t)
+			s3API := media.S3API{S3Client: s3Client, S3PresignClient: &mocks.S3PresignClient{}}
+
+			service := media.NewMediaSetService(store, nil, s3API, config.Config{}, zap.NewNop())
+			peaks, err := service.GetAudioSegment(context.Background(), mediaSetID, tc.startFrame, tc.endFrame, tc.numBins)
+
+			if tc.wantErr == "" {
+				assert.NoError(t, err)
+				assert.Equal(t, tc.wantPeaks, peaks)
+			} else {
+				assert.EqualError(t, err, tc.wantErr)
+			}
+		})
+	}
+}
+
 type testReader struct {
 	count int
 	data  [][]byte
diff --git a/backend/media/testdata/tone-44100-mono-int16.raw b/backend/media/testdata/tone-44100-mono-int16.raw
new file mode 100644
index 0000000..723e43f
Binary files /dev/null and b/backend/media/testdata/tone-44100-mono-int16.raw differ
diff --git a/backend/media/testdata/tone-44100-stereo-int16.raw b/backend/media/testdata/tone-44100-stereo-int16.raw
new file mode 100644
index 0000000..ff07d35
Binary files /dev/null and b/backend/media/testdata/tone-44100-stereo-int16.raw differ
diff --git a/backend/media/types.go b/backend/media/types.go
index 7a24da6..9839eca 100644
--- a/backend/media/types.go
+++ b/backend/media/types.go
@@ -1,5 +1,9 @@
 package media
 
+//go:generate mockery --recursive --name S3* --output ../generated/mocks
+//go:generate mockery --recursive --name Store --output ../generated/mocks
+//go:generate mockery --recursive --name YoutubeClient --output ../generated/mocks
+
 import (
 	"context"
 	"io"