update

core/media_streamer.go

@@ -0,0 +1,227 @@
+package core
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"mime"
+	"os"
+	"sync"
+	"time"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core/ffmpeg"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/utils/cache"
+)
+
+type MediaStreamer interface {
+	NewStream(ctx context.Context, id string, reqFormat string, reqBitRate int, offset int) (*Stream, error)
+	DoStream(ctx context.Context, mf *model.MediaFile, reqFormat string, reqBitRate int, reqOffset int) (*Stream, error)
+}
+
+type TranscodingCache cache.FileCache
+
+func NewMediaStreamer(ds model.DataStore, t ffmpeg.FFmpeg, cache TranscodingCache) MediaStreamer {
+	return &mediaStreamer{ds: ds, transcoder: t, cache: cache}
+}
+
+type mediaStreamer struct {
+	ds         model.DataStore
+	transcoder ffmpeg.FFmpeg
+	cache      cache.FileCache
+}
+
+type streamJob struct {
+	ms       *mediaStreamer
+	mf       *model.MediaFile
+	filePath string
+	format   string
+	bitRate  int
+	offset   int
+}
+
+func (j *streamJob) Key() string {
+	return fmt.Sprintf("%s.%s.%d.%s.%d", j.mf.ID, j.mf.UpdatedAt.Format(time.RFC3339Nano), j.bitRate, j.format, j.offset)
+}
+
+func (ms *mediaStreamer) NewStream(ctx context.Context, id string, reqFormat string, reqBitRate int, reqOffset int) (*Stream, error) {
+	mf, err := ms.ds.MediaFile(ctx).Get(id)
+	if err != nil {
+		return nil, err
+	}
+
+	return ms.DoStream(ctx, mf, reqFormat, reqBitRate, reqOffset)
+}
+
+func (ms *mediaStreamer) DoStream(ctx context.Context, mf *model.MediaFile, reqFormat string, reqBitRate int, reqOffset int) (*Stream, error) {
+	var format string
+	var bitRate int
+	var cached bool
+	defer func() {
+		log.Info(ctx, "Streaming file", "title", mf.Title, "artist", mf.Artist, "format", format, "cached", cached,
+			"bitRate", bitRate, "user", userName(ctx), "transcoding", format != "raw",
+			"originalFormat", mf.Suffix, "originalBitRate", mf.BitRate)
+	}()
+
+	format, bitRate = selectTranscodingOptions(ctx, ms.ds, mf, reqFormat, reqBitRate)
+	s := &Stream{ctx: ctx, mf: mf, format: format, bitRate: bitRate}
+	filePath := mf.AbsolutePath()
+
+	if format == "raw" {
+		log.Debug(ctx, "Streaming RAW file", "id", mf.ID, "path", filePath,
+			"requestBitrate", reqBitRate, "requestFormat", reqFormat, "requestOffset", reqOffset,
+			"originalBitrate", mf.BitRate, "originalFormat", mf.Suffix,
+			"selectedBitrate", bitRate, "selectedFormat", format)
+		f, err := os.Open(filePath)
+		if err != nil {
+			return nil, err
+		}
+		s.ReadCloser = f
+		s.Seeker = f
+		s.format = mf.Suffix
+		return s, nil
+	}
+
+	job := &streamJob{
+		ms:       ms,
+		mf:       mf,
+		filePath: filePath,
+		format:   format,
+		bitRate:  bitRate,
+		offset:   reqOffset,
+	}
+	r, err := ms.cache.Get(ctx, job)
+	if err != nil {
+		log.Error(ctx, "Error accessing transcoding cache", "id", mf.ID, err)
+		return nil, err
+	}
+	cached = r.Cached
+
+	s.ReadCloser = r
+	s.Seeker = r.Seeker
+
+	log.Debug(ctx, "Streaming TRANSCODED file", "id", mf.ID, "path", filePath,
+		"requestBitrate", reqBitRate, "requestFormat", reqFormat, "requestOffset", reqOffset,
+		"originalBitrate", mf.BitRate, "originalFormat", mf.Suffix,
+		"selectedBitrate", bitRate, "selectedFormat", format, "cached", cached, "seekable", s.Seekable())
+
+	return s, nil
+}
+
+type Stream struct {
+	ctx     context.Context
+	mf      *model.MediaFile
+	bitRate int
+	format  string
+	io.ReadCloser
+	io.Seeker
+}
+
+func (s *Stream) Seekable() bool      { return s.Seeker != nil }
+func (s *Stream) Duration() float32   { return s.mf.Duration }
+func (s *Stream) ContentType() string { return mime.TypeByExtension("." + s.format) }
+func (s *Stream) Name() string        { return s.mf.Title + "." + s.format }
+func (s *Stream) ModTime() time.Time  { return s.mf.UpdatedAt }
+func (s *Stream) EstimatedContentLength() int {
+	return int(s.mf.Duration * float32(s.bitRate) / 8 * 1024)
+}
+
+// TODO This function deserves some love (refactoring)
+func selectTranscodingOptions(ctx context.Context, ds model.DataStore, mf *model.MediaFile, reqFormat string, reqBitRate int) (format string, bitRate int) {
+	format = "raw"
+	if reqFormat == "raw" {
+		return format, 0
+	}
+	if reqFormat == mf.Suffix && reqBitRate == 0 {
+		bitRate = mf.BitRate
+		return format, bitRate
+	}
+	trc, hasDefault := request.TranscodingFrom(ctx)
+	var cFormat string
+	var cBitRate int
+	if reqFormat != "" {
+		cFormat = reqFormat
+	} else {
+		if hasDefault {
+			cFormat = trc.TargetFormat
+			cBitRate = trc.DefaultBitRate
+			if p, ok := request.PlayerFrom(ctx); ok {
+				cBitRate = p.MaxBitRate
+			}
+		} else if reqBitRate > 0 && reqBitRate < mf.BitRate && conf.Server.DefaultDownsamplingFormat != "" {
+			// If no format is specified and no transcoding associated to the player, but a bitrate is specified,
+			// and there is no transcoding set for the player, we use the default downsampling format.
+			// But only if the requested bitRate is lower than the original bitRate.
+			log.Debug("Default Downsampling", "Using default downsampling format", conf.Server.DefaultDownsamplingFormat)
+			cFormat = conf.Server.DefaultDownsamplingFormat
+		}
+	}
+	if reqBitRate > 0 {
+		cBitRate = reqBitRate
+	}
+	if cBitRate == 0 && cFormat == "" {
+		return format, bitRate
+	}
+	t, err := ds.Transcoding(ctx).FindByFormat(cFormat)
+	if err == nil {
+		format = t.TargetFormat
+		if cBitRate != 0 {
+			bitRate = cBitRate
+		} else {
+			bitRate = t.DefaultBitRate
+		}
+	}
+	if format == mf.Suffix && bitRate >= mf.BitRate {
+		format = "raw"
+		bitRate = 0
+	}
+	return format, bitRate
+}
+
+var (
+	onceTranscodingCache     sync.Once
+	instanceTranscodingCache TranscodingCache
+)
+
+func GetTranscodingCache() TranscodingCache {
+	onceTranscodingCache.Do(func() {
+		instanceTranscodingCache = NewTranscodingCache()
+	})
+	return instanceTranscodingCache
+}
+
+func NewTranscodingCache() TranscodingCache {
+	return cache.NewFileCache("Transcoding", conf.Server.TranscodingCacheSize,
+		consts.TranscodingCacheDir, consts.DefaultTranscodingCacheMaxItems,
+		func(ctx context.Context, arg cache.Item) (io.Reader, error) {
+			job := arg.(*streamJob)
+			t, err := job.ms.ds.Transcoding(ctx).FindByFormat(job.format)
+			if err != nil {
+				log.Error(ctx, "Error loading transcoding command", "format", job.format, err)
+				return nil, os.ErrInvalid
+			}
+
+			// Choose the appropriate context based on EnableTranscodingCancellation configuration.
+			// This is where we decide whether transcoding processes should be cancellable or not.
+			var transcodingCtx context.Context
+			if conf.Server.EnableTranscodingCancellation {
+				// Use the request context directly, allowing cancellation when client disconnects
+				transcodingCtx = ctx
+			} else {
+				// Use background context with request values preserved.
+				// This prevents cancellation but maintains request metadata (user, client, etc.)
+				transcodingCtx = request.AddValues(context.Background(), ctx)
+			}
+
+			out, err := job.ms.transcoder.Transcode(transcodingCtx, t.Command, job.filePath, job.bitRate, job.offset)
+			if err != nil {
+				log.Error(ctx, "Error starting transcoder", "id", job.mf.ID, err)
+				return nil, os.ErrInvalid
+			}
+			return out, nil
+		})
+}