Update ffmpeg pkg for reading files and parsing ffmpeg version

internal/ffmpeg/ffmpeg.go

@@ -49,7 +49,7 @@ var defaults = map[string]string{
 	"global": "-hide_banner",
 
 	// inputs
-	"file": "-re -readrate_initial_burst 0.001 -i {input}",
+	"file": "-re -i {input}",
 	"http": "-fflags nobuffer -flags low_delay -i {input}",
 	"rtsp": "-fflags nobuffer -flags low_delay -timeout 5000000 -user_agent go2rtc/ffmpeg -rtsp_flags prefer_tcp -i {input}",
 
@@ -151,9 +151,10 @@ func inputTemplate(name, s string, query url.Values) string {
 func parseArgs(s string) *ffmpeg.Args {
 	// init FFmpeg arguments
 	args := &ffmpeg.Args{
-		Bin:    defaults["bin"],
-		Global: defaults["global"],
-		Output: defaults["output"],
+		Bin:     defaults["bin"],
+		Global:  defaults["global"],
+		Output:  defaults["output"],
+		Version: verAV,
 	}
 
 	var query url.Values

internal/ffmpeg/ffmpeg_test.go

@@ -3,6 +3,7 @@ package ffmpeg
 import (
 	"testing"
 
+	"github.com/AlexxIT/go2rtc/pkg/ffmpeg"
 	"github.com/stretchr/testify/require"
 )
 
@@ -292,3 +293,23 @@ func TestDrawText(t *testing.T) {
 		})
 	}
 }
+
+func TestVersion(t *testing.T) {
+	verAV = ffmpeg.Version61
+	tests := []struct {
+		name   string
+		source string
+		expect string
+	}{
+		{
+			source: "/media/bbb.mp4",
+			expect: `ffmpeg -hide_banner -readrate_initial_burst 0.001 -re -i /media/bbb.mp4 -c copy -user_agent ffmpeg/go2rtc -rtsp_transport tcp -f rtsp {output}`,
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			args := parseArgs(test.source)
+			require.Equal(t, test.expect, args.String())
+		})
+	}
+}

internal/ffmpeg/version.go

@@ -1,68 +1,47 @@
 package ffmpeg
 
 import (
-	"bytes"
 	"errors"
 	"os/exec"
-	"strings"
 	"sync"
 
+	"github.com/AlexxIT/go2rtc/pkg/ffmpeg"
 	"github.com/rs/zerolog/log"
 )
 
-var checkMu sync.Mutex
-var checkErr error
-var checkVer string
-
-const (
-	FFmpeg50 = "59. 16"
-	FFmpeg51 = "59. 27"
-	FFmpeg60 = "60.  3"
-	FFmpeg61 = "60. 16"
-	FFmpeg70 = "61.  1"
-)
+var verMu sync.Mutex
+var verErr error
+var verFF string
+var verAV string
 
 func Version() (string, error) {
-	checkMu.Lock()
-	defer checkMu.Unlock()
+	verMu.Lock()
+	defer verMu.Unlock()
 
-	if checkVer != "" {
-		return checkVer, checkErr
+	if verFF != "" {
+		return verFF, verErr
 	}
 
 	cmd := exec.Command(defaults["bin"], "-version")
 	b, err := cmd.Output()
 	if err != nil {
-		checkVer = "-"
-		checkErr = err
-		return checkVer, checkErr
+		verFF = "-"
+		verErr = err
+		return verFF, verErr
 	}
 
-	if len(b) < 100 {
-		checkVer = "?"
-		return checkVer, nil
+	verFF, verAV = ffmpeg.ParseVersion(b)
+
+	if verFF == "" {
+		verFF = "?"
 	}
 
-	// ffmpeg version n7.0-30-g8b0fe91754-20240520 Copyright (c) 2000-2024 the FFmpeg developers
-	b = b[15:]
-	if i := bytes.IndexByte(b, ' '); i > 0 {
-		checkVer = string(b[:i])
+	// better to compare libavformat, because nightly/master builds
+	if verAV != "" && verAV < ffmpeg.Version50 {
+		verErr = errors.New("ffmpeg: unsupported version: " + verFF)
 	}
 
-	// libavformat    60. 16.100 / 60. 16.100
-	if i := strings.Index(string(b), "libavformat"); i > 0 {
-		// better to compare libavformat, because nightly/master builds
-		libav := string(b[i+15 : i+25])
-		if libav < FFmpeg50 {
-			checkErr = errors.New("ffmpeg: unsupported version: " + checkVer)
-			return checkVer, checkErr
-		}
-		if libav < FFmpeg61 && strings.Contains(defaults["file"], "readrate_initial_burst") {
-			defaults["file"] = "-re -i {input}"
-		}
-	}
+	log.Debug().Str("version", verFF).Str("libavformat", verAV).Msgf("[ffmpeg] bin")
 
-	log.Debug().Str("version", checkVer).Msgf("[ffmpeg] bin")
-
-	return checkVer, nil
+	return verFF, verErr
 }

internal/ffmpeg/virtual/virtual.go

@@ -67,7 +67,7 @@ func GetInputTTS(src string) string {
 		return ""
 	}
 
-	input := `-re -readrate_initial_burst 0.001 -f lavfi -i "flite=text='` + query.Get("text") + `'`
+	input := `-re -f lavfi -i "flite=text='` + query.Get("text") + `'`
 
 	// ffmpeg -f lavfi -i flite=list_voices=1
 	// awb, kal, kal16, rms, slt

pkg/ffmpeg/ffmpeg.go

@@ -6,6 +6,15 @@ import (
 	"strings"
 )
 
+// correlation of libavformat versions with ffmpeg versions
+const (
+	Version50 = "59. 16"
+	Version51 = "59. 27"
+	Version60 = "60.  3"
+	Version61 = "60. 16"
+	Version70 = "61.  1"
+)
+
 type Args struct {
 	Bin     string   // ffmpeg
 	Global  string   // -hide_banner -v error
@@ -13,6 +22,7 @@ type Args struct {
 	Codecs  []string // -c:v libx264 -g:v 30 -preset:v ultrafast -tune:v zerolatency
 	Filters []string // scale=1920:1080
 	Output  string   // -f rtsp {output}
+	Version string   // libavformat version, it's more reliable than the ffmpeg version
 
 	Video, Audio int // count of Video and Audio params
 }
@@ -52,6 +62,11 @@ func (a *Args) String() string {
 	}
 
 	b.WriteByte(' ')
+	// starting from FFmpeg 6.1 readrate=1 has default initial bust 0.5 sec
+	// it might make us miss the first couple seconds of the file
+	if strings.HasPrefix(a.Input, "-re ") && a.Version >= Version61 {
+		b.WriteString("-readrate_initial_burst 0.001 ")
+	}
 	b.WriteString(a.Input)
 
 	multimode := a.Video > 1 || a.Audio > 1
@@ -91,3 +106,18 @@ func (a *Args) String() string {
 
 	return b.String()
 }
+
+func ParseVersion(b []byte) (ffmpeg string, libavformat string) {
+	if len(b) > 100 {
+		// ffmpeg version n7.0-30-g8b0fe91754-20240520 Copyright (c) 2000-2024 the FFmpeg developers
+		if i := bytes.IndexByte(b[15:], ' '); i > 0 {
+			ffmpeg = string(b[15 : 15+i])
+		}
+
+		// libavformat    60. 16.100 / 60. 16.100
+		if i := strings.Index(string(b), "libavformat"); i > 0 {
+			libavformat = string(b[i+15 : i+25])
+		}
+	}
+	return
+}