delete guess expected size feature

it it doing some really bad guesses for opus files

iout/copy_range.go

@@ -1,23 +0,0 @@
-package iout
-
-import (
-	"errors"
-	"fmt"
-	"io"
-)
-
-func CopyRange(w io.Writer, r io.Reader, start, length int64) error {
-	if _, err := io.CopyN(io.Discard, r, start); err != nil && !errors.Is(err, io.EOF) {
-		return fmt.Errorf("discard %d: %w", start, err)
-	}
-	if length == 0 {
-		if _, err := io.Copy(w, r); err != nil && !errors.Is(err, io.EOF) {
-			return fmt.Errorf("direct copy: %w", err)
-		}
-		return nil
-	}
-	if _, err := io.CopyN(w, io.MultiReader(r, NewNullReader()), length); err != nil && !errors.Is(err, io.EOF) {
-		return fmt.Errorf("copy %d: %w", length, err)
-	}
-	return nil
-}

iout/copy_range_test.go

@@ -1,42 +0,0 @@
-package iout_test
-
-import (
-	"bytes"
-	"testing"
-
-	"github.com/matryer/is"
-	"go.senan.xyz/gonic/iout"
-)
-
-func TestCopyRange(t *testing.T) {
-	t.Parallel()
-	is := is.New(t)
-
-	realLength := 50
-	cr := func(start, length int64) []byte {
-		is.Helper()
-		var data []byte
-		for i := 0; i < realLength; i++ {
-			data = append(data, byte(i%10))
-		}
-		var buff bytes.Buffer
-		is.NoErr(iout.CopyRange(&buff, bytes.NewReader(data), start, length))
-		return buff.Bytes()
-	}
-
-	// range
-	is.Equal(len(cr(0, 50)), 50)
-	is.Equal(len(cr(10, 10)), 10)
-	is.Equal(cr(10, 10)[0], byte(0))
-	is.Equal(cr(10, 10)[5], byte(5))
-	is.Equal(cr(25, 35)[0], byte(5))
-	is.Equal(cr(25, 35)[5], byte(0))
-
-	// 0 padding
-	is.Equal(len(cr(0, 5000)), 5000)
-	is.Equal(cr(0, 5000)[50:], make([]byte, 5000-50))
-
-	// no bound
-	is.Equal(len(cr(0, 0)), 50)
-	is.Equal(len(cr(50, 0)), 0)
-}

iout/countrw.go

@@ -1,46 +0,0 @@
-package iout
-
-import (
-	"io"
-	"sync/atomic"
-)
-
-type CountReader struct {
-	r io.Reader
-	c *uint64
-}
-
-func NewCountReader(r io.Reader) *CountReader {
-	return &CountReader{r: r, c: new(uint64)}
-}
-
-func (c *CountReader) Reset()        { atomic.StoreUint64(c.c, 0) }
-func (c *CountReader) Count() uint64 { return atomic.LoadUint64(c.c) }
-
-func (c *CountReader) Read(p []byte) (int, error) {
-	n, err := c.r.Read(p)
-	atomic.AddUint64(c.c, uint64(n))
-	return n, err
-}
-
-var _ io.Reader = (*CountReader)(nil)
-
-type CountWriter struct {
-	r io.Writer
-	c *uint64
-}
-
-func NewCountWriter(r io.Writer) *CountWriter {
-	return &CountWriter{r: r, c: new(uint64)}
-}
-
-func (c *CountWriter) Reset()        { atomic.StoreUint64(c.c, 0) }
-func (c *CountWriter) Count() uint64 { return atomic.LoadUint64(c.c) }
-
-func (c *CountWriter) Write(p []byte) (int, error) {
-	n, err := c.r.Write(p)
-	atomic.AddUint64(c.c, uint64(n))
-	return n, err
-}
-
-var _ io.Writer = (*CountWriter)(nil)

iout/null_reader.go

@@ -1,18 +0,0 @@
-package iout
-
-import "io"
-
-type nullReader struct{}
-
-func NewNullReader() io.Reader {
-	return &nullReader{}
-}
-
-func (*nullReader) Read(p []byte) (n int, err error) {
-	for b := range p {
-		p[b] = 0
-	}
-	return len(p), nil
-}
-
-var _ io.Reader = (*nullReader)(nil)

iout/tee_closer.go

@@ -1,28 +0,0 @@
-package iout
-
-import "io"
-
-type teeCloser struct {
-	r io.ReadCloser
-	w io.WriteCloser
-}
-
-func NewTeeCloser(r io.ReadCloser, w io.WriteCloser) io.ReadCloser {
-	return &teeCloser{r, w}
-}
-
-func (t *teeCloser) Read(p []byte) (int, error) {
-	n, err := t.r.Read(p)
-	if n > 0 {
-		if n, err := t.w.Write(p[:n]); err != nil {
-			return n, err
-		}
-	}
-	return n, err
-}
-
-func (t *teeCloser) Close() error {
-	t.r.Close()
-	t.w.Close()
-	return nil
-}

server/ctrlsubsonic/ctrl_test.go

@@ -1,3 +1,4 @@
+//nolint:deadcode
 package ctrlsubsonic
 
 import (
@@ -16,10 +17,10 @@ import (
 
 	jd "github.com/josephburnett/jd/lib"
 
-	"go.senan.xyz/gonic/server/ctrlbase"
-	"go.senan.xyz/gonic/server/ctrlsubsonic/params"
 	"go.senan.xyz/gonic/db"
 	"go.senan.xyz/gonic/mockfs"
+	"go.senan.xyz/gonic/server/ctrlbase"
+	"go.senan.xyz/gonic/server/ctrlsubsonic/params"
 	"go.senan.xyz/gonic/transcode"
 )
 

server/ctrlsubsonic/handlers_raw.go

@@ -12,12 +12,10 @@ import (
 	"github.com/disintegration/imaging"
 	"github.com/jinzhu/gorm"
 
-	"go.senan.xyz/gonic/iout"
+	"go.senan.xyz/gonic/db"
-	"go.senan.xyz/gonic/server/ctrlsubsonic/httprange"
 	"go.senan.xyz/gonic/server/ctrlsubsonic/params"
 	"go.senan.xyz/gonic/server/ctrlsubsonic/spec"
 	"go.senan.xyz/gonic/server/ctrlsubsonic/specid"
-	"go.senan.xyz/gonic/db"
 	"go.senan.xyz/gonic/transcode"
 )
 
@@ -296,30 +294,11 @@ func (c *Controller) ServeStream(w http.ResponseWriter, r *http.Request) *spec.R
 
 	log.Printf("trancoding to %q with max bitrate %dk", profile.MIME(), profile.BitRate())
 
-	transcodeReader, err := c.Transcoder.Transcode(r.Context(), profile, audioPath)
+	w.Header().Set("Content-Type", profile.MIME())
-	if err != nil {
+	if err := c.Transcoder.Transcode(r.Context(), profile, audioPath, w); err != nil {
 		return spec.NewError(0, "error transcoding: %v", err)
 	}
-	defer transcodeReader.Close()
 
-	length := transcode.GuessExpectedSize(profile, time.Duration(file.AudioLength())*time.Second) // TODO: if there's no duration?
-	rreq, err := httprange.Parse(r.Header.Get("Range"), length)
-	if err != nil {
-		return spec.NewError(0, "error parsing range: %v", err)
-	}
-
-	w.Header().Set("Content-Type", profile.MIME())
-	w.Header().Set("Content-Length", fmt.Sprintf("%d", rreq.Length))
-	w.Header().Set("Accept-Ranges", string(httprange.UnitBytes))
-
-	if rreq.Partial {
-		w.WriteHeader(http.StatusPartialContent)
-		w.Header().Set("Content-Range", fmt.Sprintf("%s %d-%d/%d", httprange.UnitBytes, rreq.Start, rreq.End, length))
-	}
-
-	if err := iout.CopyRange(w, transcodeReader, int64(rreq.Start), int64(rreq.Length)); err != nil {
-		log.Printf("error writing transcoded data: %v", err)
-	}
 	if f, ok := w.(http.Flusher); ok {
 		f.Flush()
 	}

server/ctrlsubsonic/handlers_raw_test.go

@@ -1,152 +0,0 @@
-package ctrlsubsonic
-
-import (
-	"fmt"
-	"io/fs"
-	"net/http"
-	"net/url"
-	"os"
-	"os/exec"
-	"strconv"
-	"testing"
-	"time"
-
-	"github.com/matryer/is"
-	"go.senan.xyz/gonic/db"
-	"go.senan.xyz/gonic/transcode"
-)
-
-func TestServeStreamRaw(t *testing.T) {
-	t.Parallel()
-	if _, err := exec.LookPath("ffmpeg"); err != nil {
-		t.Skipf("no ffmpeg in $PATH")
-	}
-
-	is := is.New(t)
-	contr := makeControllerAudio(t)
-
-	statFlac := stat(t, audioPath10s)
-
-	rr, req := makeHTTPMock(url.Values{"id": {"tr-1"}})
-	serveRaw(t, contr, contr.ServeStream, rr, req)
-
-	is.Equal(rr.Code, http.StatusOK)
-	is.Equal(rr.Header().Get("content-type"), "audio/flac")
-	is.Equal(atoi(t, rr.Header().Get("content-length")), int(statFlac.Size()))
-	is.Equal(atoi(t, rr.Header().Get("content-length")), rr.Body.Len())
-}
-
-func TestServeStreamOpus(t *testing.T) {
-	t.Parallel()
-	if _, err := exec.LookPath("ffmpeg"); err != nil {
-		t.Skipf("no ffmpeg in $PATH")
-	}
-
-	is := is.New(t)
-	contr := makeControllerAudio(t)
-
-	var user db.User
-	is.NoErr(contr.DB.Where("name=?", mockUsername).Find(&user).Error)
-	is.NoErr(contr.DB.Create(&db.TranscodePreference{UserID: user.ID, Client: mockClientName, Profile: "opus"}).Error)
-
-	rr, req := makeHTTPMock(url.Values{"id": {"tr-1"}})
-	serveRaw(t, contr, contr.ServeStream, rr, req)
-
-	is.Equal(rr.Code, http.StatusOK)
-	is.Equal(rr.Header().Get("content-type"), "audio/ogg")
-	is.Equal(atoi(t, rr.Header().Get("content-length")), transcode.GuessExpectedSize(transcode.Opus, 10*time.Second))
-	is.Equal(atoi(t, rr.Header().Get("content-length")), rr.Body.Len())
-}
-
-func TestServeStreamOpusMaxBitrate(t *testing.T) {
-	t.Parallel()
-	if _, err := exec.LookPath("ffmpeg"); err != nil {
-		t.Skipf("no ffmpeg in $PATH")
-	}
-
-	is := is.New(t)
-	contr := makeControllerAudio(t)
-
-	var user db.User
-	is.NoErr(contr.DB.Where("name=?", mockUsername).Find(&user).Error)
-	is.NoErr(contr.DB.Create(&db.TranscodePreference{UserID: user.ID, Client: mockClientName, Profile: "opus"}).Error)
-
-	const bitrate = 5
-
-	rr, req := makeHTTPMock(url.Values{"id": {"tr-1"}, "maxBitRate": {strconv.Itoa(bitrate)}})
-	serveRaw(t, contr, contr.ServeStream, rr, req)
-
-	profile := transcode.WithBitrate(transcode.Opus, transcode.BitRate(bitrate))
-	expectedLength := transcode.GuessExpectedSize(profile, 10*time.Second)
-
-	is.Equal(rr.Code, http.StatusOK)
-	is.Equal(rr.Header().Get("content-type"), "audio/ogg")
-	is.Equal(atoi(t, rr.Header().Get("content-length")), expectedLength)
-	is.Equal(atoi(t, rr.Header().Get("content-length")), rr.Body.Len())
-}
-
-func TestServeStreamMP3Range(t *testing.T) {
-	t.Parallel()
-	if _, err := exec.LookPath("ffmpeg"); err != nil {
-		t.Skipf("no ffmpeg in $PATH")
-	}
-
-	is := is.New(t)
-	contr := makeControllerAudio(t)
-
-	var user db.User
-	is.NoErr(contr.DB.Where("name=?", mockUsername).Find(&user).Error)
-	is.NoErr(contr.DB.Create(&db.TranscodePreference{UserID: user.ID, Client: mockClientName, Profile: "mp3"}).Error)
-
-	var totalBytes []byte
-	{
-		rr, req := makeHTTPMock(url.Values{"id": {"tr-1"}})
-		serveRaw(t, contr, contr.ServeStream, rr, req)
-		is.Equal(rr.Code, http.StatusOK)
-		is.Equal(rr.Header().Get("content-type"), "audio/mpeg")
-		totalBytes = rr.Body.Bytes()
-	}
-
-	const chunkSize = 2 << 16
-
-	var bytes []byte
-	for i := 0; i < len(totalBytes); i += chunkSize {
-		rr, req := makeHTTPMock(url.Values{"id": {"tr-1"}})
-		req.Header.Set("range", fmt.Sprintf("bytes=%d-%d", i, min(i+chunkSize, len(totalBytes))-1))
-		t.Log(req.Header.Get("range"))
-		serveRaw(t, contr, contr.ServeStream, rr, req)
-		is.Equal(rr.Code, http.StatusPartialContent)
-		is.Equal(rr.Header().Get("content-type"), "audio/mpeg")
-		is.True(atoi(t, rr.Header().Get("content-length")) == chunkSize || atoi(t, rr.Header().Get("content-length")) == len(totalBytes)%chunkSize)
-		is.Equal(atoi(t, rr.Header().Get("content-length")), rr.Body.Len())
-		bytes = append(bytes, rr.Body.Bytes()...)
-	}
-
-	is.Equal(len(totalBytes), len(bytes))
-	is.Equal(totalBytes, bytes)
-}
-
-func stat(t *testing.T, path string) fs.FileInfo {
-	t.Helper()
-	info, err := os.Stat(path)
-	if err != nil {
-		t.Fatalf("stat %q: %v", path, err)
-	}
-	return info
-}
-
-func atoi(t *testing.T, in string) int {
-	t.Helper()
-	i, err := strconv.Atoi(in)
-	if err != nil {
-		t.Fatalf("atoi %q: %v", in, err)
-	}
-	return i
-}
-
-func min(a, b int) int {
-	if a < b {
-		return a
-	}
-	return b
-}

server/ctrlsubsonic/httprange/httprange.go

@@ -1,59 +0,0 @@
-package httprange
-
-import (
-	"fmt"
-	"regexp"
-	"strconv"
-)
-
-type Unit string
-
-const (
-	UnitBytes Unit = "bytes"
-)
-
-//nolint:gochecknoglobals
-var (
-	reg   = regexp.MustCompile(`^(?P<unit>\w+)=(?P<start>(?:\d+)?)\s*-\s*(?P<end>(?:\d+)?)$`)
-	unit  = reg.SubexpIndex("unit")
-	start = reg.SubexpIndex("start")
-	end   = reg.SubexpIndex("end")
-)
-
-var (
-	ErrInvalidRange = fmt.Errorf("invalid range")
-	ErrUnknownUnit  = fmt.Errorf("unknown range")
-)
-
-type Range struct {
-	Start, End, Length int // bytes
-	Partial            bool
-}
-
-func Parse(in string, fullLength int) (Range, error) {
-	parts := reg.FindStringSubmatch(in)
-	if len(parts)-1 != reg.NumSubexp() {
-		return Range{0, fullLength - 1, fullLength, false}, nil
-	}
-
-	switch unit := parts[unit]; Unit(unit) {
-	case UnitBytes:
-	default:
-		return Range{}, fmt.Errorf("%q: %w", unit, ErrUnknownUnit)
-	}
-
-	start, _ := strconv.Atoi(parts[start])
-	end, _ := strconv.Atoi(parts[end])
-	length := fullLength
-	partial := false
-
-	switch {
-	case end > 0 && end < length:
-		length = end - start + 1
-		partial = true
-	case end == 0 && length > 0:
-		end = length - 1
-	}
-
-	return Range{start, end, length, partial}, nil
-}

server/ctrlsubsonic/httprange/httprange_test.go

@@ -1,30 +0,0 @@
-package httprange_test
-
-import (
-	"testing"
-
-	"github.com/matryer/is"
-	"go.senan.xyz/gonic/server/ctrlsubsonic/httprange"
-)
-
-func TestParse(t *testing.T) {
-	is := is.New(t)
-
-	full := func(start, end, length int) httprange.Range {
-		return httprange.Range{Start: start, End: end, Length: length}
-	}
-	partial := func(start, end, length int) httprange.Range {
-		return httprange.Range{Start: start, End: end, Length: length, Partial: true}
-	}
-	parse := func(in string, length int) httprange.Range {
-		is.Helper()
-		rrange, err := httprange.Parse(in, length)
-		is.NoErr(err)
-		return rrange
-	}
-
-	is.Equal(parse("bytes=0-0", 0), full(0, 0, 0))
-	is.Equal(parse("bytes=0-", 10), full(0, 9, 10))
-	is.Equal(parse("bytes=0-49", 50), partial(0, 49, 50))
-	is.Equal(parse("bytes=50-99", 100), partial(50, 99, 50))
-}

transcode/testdata/fuzz/FuzzGuessExpectedSize/1e10ee326324ee7e1f371585414e7e41d5c802b4db45ebc79abe0397fb915a0c

@@ -1,3 +0,0 @@
-go test fuzz v1
-byte('Y')
-byte('\x05')

transcode/testdata/fuzz/FuzzGuessExpectedSize/3eaed9c9c8a57078033cea3337a79e1e6bfebf7e5eb7421878c911df2d78d1ac

@@ -1,3 +0,0 @@
-go test fuzz v1
-byte('\x15')
-byte('}')

transcode/testdata/fuzz/FuzzGuessExpectedSize/ce5db7c5c16dcb48567255c77772cacc3ca86d524cbb2d3a769248625bc3edc8

@@ -1,3 +0,0 @@
-go test fuzz v1
-byte('\a')
-byte('\x02')

transcode/transcode.go

@@ -15,7 +15,7 @@ import (
 )
 
 type Transcoder interface {
-	Transcode(ctx context.Context, profile Profile, in string) (io.ReadCloser, error)
+	Transcode(ctx context.Context, profile Profile, in string, out io.Writer) error
 }
 
 var UserProfiles = map[string]Profile{
@@ -106,24 +106,3 @@ func parseProfile(profile Profile, in string) (string, []string, error) {
 
 	return name, args, nil
 }
-
-// GuessExpectedSize guesses how big the transcoded file will be in bytes.
-// Handy if we want to send a Content-Length header to the client before
-// the transcode has finished. This way, clients like DSub can render their
-// scrub bar and duration as the track is streaming.
-//
-// The estimate should overshoot a bit (2s in this case) otherwise some HTTP
-// clients will shit their trousers given some unexpected bytes.
-func GuessExpectedSize(profile Profile, length time.Duration) int {
-	if length == 0 {
-		return 0
-	}
-
-	bytesPerSec := int(profile.BitRate() * 1000 / 8)
-
-	var guess int
-	guess += bytesPerSec * int(length.Seconds()-profile.seek.Seconds())
-	guess += bytesPerSec * 2 // 2s pading
-	guess += 10000           // 10kb byte padding
-	return guess
-}

transcode/transcode_test.go

@@ -1,47 +0,0 @@
-//go:build go1.18
-// +build go1.18
-
-package transcode_test
-
-import (
-	"context"
-	"io"
-	"testing"
-	"time"
-
-	"github.com/matryer/is"
-	"go.senan.xyz/gonic/transcode"
-)
-
-// FuzzGuessExpectedSize makes sure all of our profile's estimated transcode
-// file sizes are slightly bigger than the real thing.
-func FuzzGuessExpectedSize(f *testing.F) {
-	var profiles []transcode.Profile
-	for _, v := range transcode.UserProfiles {
-		profiles = append(profiles, v)
-	}
-
-	type track struct {
-		path   string
-		length time.Duration
-	}
-	var tracks []track
-	tracks = append(tracks, track{"testdata/5s.mp3", 5 * time.Second})
-	tracks = append(tracks, track{"testdata/10s.mp3", 10 * time.Second})
-
-	tr := transcode.NewFFmpegTranscoder()
-	f.Fuzz(func(t *testing.T, pseed uint8, tseed uint8) {
-		is := is.New(t)
-		profile := profiles[int(pseed)%len(profiles)]
-		track := tracks[int(tseed)%len(tracks)]
-
-		sizeGuess := transcode.GuessExpectedSize(profile, track.length)
-
-		reader, err := tr.Transcode(context.Background(), profile, track.path)
-		is.NoErr(err)
-
-		actual, err := io.ReadAll(reader)
-		is.NoErr(err)
-		is.True(sizeGuess > len(actual))
-	})
-}

transcode/transcoder_caching.go

@@ -7,8 +7,6 @@ import (
 	"io"
 	"os"
 	"path/filepath"
-
-	"go.senan.xyz/gonic/iout"
 )
 
 const perm = 0644
@@ -24,14 +22,14 @@ func NewCachingTranscoder(t Transcoder, cachePath string) *CachingTranscoder {
 	return &CachingTranscoder{transcoder: t, cachePath: cachePath}
 }
 
-func (t *CachingTranscoder) Transcode(ctx context.Context, profile Profile, in string) (io.ReadCloser, error) {
+func (t *CachingTranscoder) Transcode(ctx context.Context, profile Profile, in string, out io.Writer) error {
 	if err := os.MkdirAll(t.cachePath, perm^0111); err != nil {
-		return nil, fmt.Errorf("make cache path: %w", err)
+		return fmt.Errorf("make cache path: %w", err)
 	}
 
 	name, args, err := parseProfile(profile, in)
 	if err != nil {
-		return nil, fmt.Errorf("split command: %w", err)
+		return fmt.Errorf("split command: %w", err)
 	}
 
 	key := cacheKey(name, args)
@@ -39,18 +37,21 @@ func (t *CachingTranscoder) Transcode(ctx context.Context, profile Profile, in s
 
 	cf, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE, 0644)
 	if err != nil {
-		return nil, fmt.Errorf("open cache file: %w", err)
+		return fmt.Errorf("open cache file: %w", err)
 	}
+	defer cf.Close()
+
 	if i, err := cf.Stat(); err == nil && i.Size() > 0 {
-		return cf, nil
+		_, _ = io.Copy(out, cf)
+		return nil
 	}
 
-	out, err := t.transcoder.Transcode(ctx, profile, in)
+	if err := t.transcoder.Transcode(ctx, profile, in, io.MultiWriter(out, cf)); err != nil {
-	if err != nil {
+		os.Remove(path)
-		return nil, fmt.Errorf("internal transcode: %w", err)
+		return fmt.Errorf("internal transcode: %w", err)
 	}
 
-	return iout.NewTeeCloser(out, cf), nil
+	return nil
 }
 
 func cacheKey(cmd string, args []string) string {

transcode/transcoder_ffmpeg.go

@@ -2,6 +2,7 @@ package transcode
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"os/exec"
@@ -17,23 +18,25 @@ func NewFFmpegTranscoder() *FFmpegTranscoder {
 
 var ErrFFmpegExit = fmt.Errorf("ffmpeg exited with non 0 status code")
 
-func (*FFmpegTranscoder) Transcode(ctx context.Context, profile Profile, in string) (io.ReadCloser, error) {
+func (*FFmpegTranscoder) Transcode(ctx context.Context, profile Profile, in string, out io.Writer) error {
 	name, args, err := parseProfile(profile, in)
 	if err != nil {
-		return nil, fmt.Errorf("split command: %w", err)
+		return fmt.Errorf("split command: %w", err)
 	}
 
-	preader, pwriter := io.Pipe()
-
 	cmd := exec.CommandContext(ctx, name, args...)
-	cmd.Stdout = pwriter
+	cmd.Stdout = out
+
 	if err := cmd.Start(); err != nil {
-		return nil, fmt.Errorf("starting cmd: %w", err)
+		return fmt.Errorf("starting cmd: %w", err)
 	}
 
-	go func() {
+	var exitErr *exec.ExitError
-		_ = pwriter.CloseWithError(cmd.Wait())
+	if err := cmd.Wait(); err != nil && !errors.As(err, &exitErr) {
-	}()
+		return fmt.Errorf("waiting cmd: %w", err)
-
+	}
-	return preader, nil
+	if code := cmd.ProcessState.ExitCode(); code > 1 {
+		return fmt.Errorf("%w: %d", ErrFFmpegExit, code)
+	}
+	return nil
 }

transcode/transcoder_none.go

@@ -2,6 +2,7 @@ package transcode
 
 import (
 	"context"
+	"fmt"
 	"io"
 	"os"
 )
@@ -14,6 +15,14 @@ func NewNoneTranscoder() *NoneTranscoder {
 	return &NoneTranscoder{}
 }
 
-func (*NoneTranscoder) Transcode(ctx context.Context, _ Profile, in string) (io.ReadCloser, error) {
+func (*NoneTranscoder) Transcode(ctx context.Context, _ Profile, in string, out io.Writer) error {
-	return os.Open(in)
+	file, err := os.Open(in)
+	if err != nil {
+		return fmt.Errorf("open file: %w", err)
+	}
+	defer file.Close()
+	if _, err := io.Copy(out, file); err != nil {
+		return fmt.Errorf("copy file: %w", err)
+	}
+	return nil
 }