优

internal/service/transcoder.go

@@ -272,6 +272,9 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 	input.Quality = quality
 	t.maybeFillDuration(ctx, m, input)
 	settings := ffmpegArgSettingsFromConfig(cfg, quality)
+	// 「原画」档位遇到浏览器可解的 H.264 源时只换封装，避免慢机器上重编码
+	// 追不上播放（两核软件编码实测 0.1～0.2 倍速）。其它档位要改分辨率，仍重编码。
+	input.CopyVideo = t.remuxEligible(ctx, m, quality, subtitleStream)
 	jobEncoder := settings.encoder
 	if settings.noScale || subtitleStream >= 0 {
 		jobEncoder = ""
@@ -312,6 +315,9 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 	if subtitleStream >= 0 {
 		jobEncoder = "software (subtitle burn-in)"
 	}
+	if input.CopyVideo {
+		jobEncoder = remuxEncoderLabel
+	}
 	job := &hlsJob{
 		jobKey:         jobKey,
 		mediaID:        mediaID,

internal/service/transcoder_ffmpeg_args.go

@@ -16,6 +16,9 @@ type transcodeInput struct {
 	StartSec       float64
 	SubtitleStream *int
 	Quality        *LocalHLSQuality
+	// CopyVideo 为 true 时视频流只换封装（-c:v copy），不重编码。
+	// 仅当源视频是浏览器可解的老三样（H.264/8bit/4:2:0）且不需要缩放时启用。
+	CopyVideo bool
 }
 
 type ffmpegArgSettings struct {
@@ -52,6 +55,7 @@ func buildFFmpegArgsForInput(cfg *config.Config, input transcodeInput, playlist,
 		// 原画档位不做硬件缩放的兼容处理，直接走软件编码，保持源分辨率。
 		settings.encoder = ""
 	}
+	copyVideo := input.CopyVideo && input.SubtitleStream == nil
 	video := ffmpegVideoPlanForSettings(settings)
 	if input.SubtitleStream != nil {
 		// Bitmap subtitles must be composited in software. Keeping CUDA/QSV/
@@ -60,13 +64,17 @@ func buildFFmpegArgsForInput(cfg *config.Config, input transcodeInput, playlist,
 		settings.encoder = ""
 		video = ffmpegVideoPlanForSettings(settings)
 	}
+	if copyVideo {
+		// 直通：不做缩放、不挂滤镜、不选编码器，整条视频流原样塞进 TS。
+		video = ffmpegVideoPlan{codec: "copy"}
+	}
 
 	// Mid-file restarts must not use -re: output -ss would otherwise crawl to the
 	// seek point at 1x wall-clock before emitting the first HLS segment.
 	realtime := settings.realtime && input.StartSec <= 0.05
 	args := baseFFmpegArgs(video.preInput, realtime)
-	args = appendInputAndVideoArgs(args, input, settings, video)
+	args = appendInputAndVideoArgs(args, input, settings, video, copyVideo)
-	args = appendOutputHLSArgs(args, settings, segments, playlist)
+	args = appendOutputHLSArgs(args, settings, segments, playlist, copyVideo)
 	return args
 }
 
@@ -161,7 +169,7 @@ func baseFFmpegArgs(preInput string, realtime bool) []string {
 	return args
 }
 
-func appendInputAndVideoArgs(args []string, input transcodeInput, settings ffmpegArgSettings, video ffmpegVideoPlan) []string {
+func appendInputAndVideoArgs(args []string, input transcodeInput, settings ffmpegArgSettings, video ffmpegVideoPlan, copyVideo bool) []string {
 	args = append(args, ffmpegHTTPInputArgs(input)...)
 	ss := ""
 	if input.StartSec > 0.05 {
@@ -172,6 +180,11 @@ func appendInputAndVideoArgs(args []string, input transcodeInput, settings ffmpe
 	// scrubbing; CDNs with Range support jump via demuxer seek instead.
 	if ss != "" {
 		args = append(args, "-ss", ss)
+		if copyVideo {
+			// 复制视频流时 ffmpeg 不能解码，精确 seek 会把关键帧之前的分组丢掉，
+			// 输出从 P 帧开始（花屏）。退到前一个关键帧，最多提前一两秒。
+			args = append(args, "-noaccurate_seek")
+		}
 	}
 	args = append(args, "-i", input.Source)
 	if input.SubtitleStream != nil {
@@ -197,7 +210,23 @@ func appendInputAndVideoArgs(args []string, input transcodeInput, settings ffmpe
 	return args
 }
 
-func appendOutputHLSArgs(args []string, settings ffmpegArgSettings, segments, playlist string) []string {
+func appendOutputHLSArgs(args []string, settings ffmpegArgSettings, segments, playlist string, copyVideo bool) []string {
+	if copyVideo {
+		// 视频是复制进来的，编码参数一律不适用；只保留音频转 AAC 与切片参数。
+		// -avoid_negative_ts 让带 B 帧的源在 -ss 之后不会出现负时间戳。
+		return append(args,
+			"-avoid_negative_ts", "make_zero",
+			"-c:a", "aac",
+			"-ar", "48000",
+			"-b:a", "128k",
+			"-ac", "2",
+			"-f", "hls",
+			"-hls_time", fmt.Sprintf("%d", settings.segmentSeconds),
+			"-hls_list_size", "0",
+			"-hls_segment_filename", segments,
+			playlist,
+		)
+	}
 	return append(args,
 		"-pix_fmt", "yuv420p",
 		"-b:v", settings.bitrate,

internal/service/transcoder_remux.go

@@ -0,0 +1,102 @@
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"strings"
+
+	"github.com/truewhile/MeBox/internal/model"
+)
+
+// 蓝光原盘（m2ts，40 Mbps 级别）在两核小机器上重编码只有 0.1～0.2 倍速，HLS
+// 永远追不上播放，播放器等不到切片就报「转码失败」。当源视频本身就是浏览器
+// 能解的 H.264 / 8bit / 4:2:0，且用户选的是「原画」档位（不改分辨率）时，
+// 这里改走只换封装（-c:v copy）的直通路径：视频不重编码，音频转 AAC，
+// CPU 占用接近于零，起播时间从几十秒降到几秒。
+//
+// 直通只对「原画」生效。1080P/720P/480P 档位意味着要改分辨率，必须重新编码；
+// 那类请求仍然按原来的 libx264 路径处理（慢，但码率可控）。
+
+// remuxEncoderLabel 是直通任务在日志与任务面板里的标签。
+const remuxEncoderLabel = "remux"
+
+// remuxEligible 判断这次请求能否复制视频流而不是重编码。
+func (t *TranscoderService) remuxEligible(ctx context.Context, m *model.Media, quality *LocalHLSQuality, subtitleStream int) bool {
+	if t == nil || t.repo == nil || m == nil {
+		return false
+	}
+	// 烧录图形字幕要把字幕叠加进画面，必须解码+重编码。
+	if subtitleStream >= 0 {
+		return false
+	}
+	if !remuxAppliesToQuality(quality) {
+		return false
+	}
+	probe, err := t.repo.MediaProbe.Get(ctx, m.ID)
+	if err != nil || probe == nil {
+		// 没有探测缓存就无法确认档次/像素格式，保守走重编码。
+		return false
+	}
+	return remuxCopyableHeight(probe) > 0
+}
+
+// remuxAppliesToQuality 只放行「原画」档位（Height 为 0，即不缩放）。
+// quality 为 nil 表示调用方没有指定档位（走全局 max_height），同样不直通，
+// 否则会绕过配置的分辨率上限给出一个远超预期的码流。
+func remuxAppliesToQuality(quality *LocalHLSQuality) bool {
+	return quality != nil && quality.Height <= 0
+}
+
+// remuxCopyableHeight 在源视频可直接复制进 HLS 时返回它的高度，否则返回 0。
+func remuxCopyableHeight(probe *model.MediaProbe) int {
+	if probe == nil || probe.Height <= 0 {
+		return 0
+	}
+	if !strings.EqualFold(strings.TrimSpace(probe.VideoCodec), "h264") {
+		return 0
+	}
+	if !browserSafeH264Payload(probe.Payload) {
+		return 0
+	}
+	return probe.Height
+}
+
+// probePayloadStreams 只解析落库 payload 里与直通判断有关的字段。
+type probePayloadStreams struct {
+	Streams []struct {
+		Type    string `json:"type"`
+		Profile string `json:"profile"`
+		PixFmt  string `json:"pix_fmt"`
+	} `json:"streams"`
+}
+
+// browserSafeH264Payload 只放行 8bit 4:2:0 的 Baseline/Main/High。
+// Hi10P（High 10）和 4:2:2 母带浏览器解不出来，复制过去只会黑屏或无声。
+func browserSafeH264Payload(payload string) bool {
+	payload = strings.TrimSpace(payload)
+	if payload == "" {
+		// 老数据没有 payload：已经有 codec + 分辨率，按 8bit 常规情况处理。
+		return true
+	}
+	var parsed probePayloadStreams
+	if err := json.Unmarshal([]byte(payload), &parsed); err != nil {
+		return false
+	}
+	for _, stream := range parsed.Streams {
+		if !strings.EqualFold(strings.TrimSpace(stream.Type), "video") {
+			continue
+		}
+		switch strings.ToLower(strings.TrimSpace(stream.Profile)) {
+		case "", "constrained baseline", "baseline", "main", "high":
+		default:
+			return false
+		}
+		switch strings.ToLower(strings.TrimSpace(stream.PixFmt)) {
+		case "", "yuv420p", "yuvj420p":
+		default:
+			return false
+		}
+		return true
+	}
+	return true
+}

internal/service/transcoder_remux_test.go

@@ -0,0 +1,170 @@
+package service
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/model"
+)
+
+// 直通档位必须真的把视频流复制过去：一旦又带上 libx264 / -vf / 码率参数，
+// 慢机器上的「原画」就还是几十秒起播。
+func TestBuildFFmpegArgsRemuxCopiesVideoStream(t *testing.T) {
+	cfg := &config.Config{}
+	cfg.Transcoder.SegmentSeconds = 4
+	cfg.Transcoder.Realtime = true
+	cfg.Transcoder.Threads = 2
+	cfg.Transcoder.MaxHeight = 720
+
+	quality, ok := LocalHLSQualityByID("source")
+	if !ok {
+		t.Fatal("source quality missing")
+	}
+	args := buildFFmpegArgsForInput(cfg, transcodeInput{
+		Source:    "https://cdn.example/x.m2ts",
+		Headers:   map[string]string{"User-Agent": "MeBox-115-GoClient/1.0"},
+		StartSec:  52.4,
+		Quality:   &quality,
+		CopyVideo: true,
+	}, "/cache/hls/k/run-1/index.m3u8", "/cache/hls/k/run-1/seg_%05d.ts")
+	joined := strings.Join(args, " ")
+
+	for _, want := range []string{
+		"-c:v copy",
+		"-c:a aac",
+		"-ar 48000",
+		"-b:a 128k",
+		"-ac 2",
+		"-avoid_negative_ts make_zero",
+		"-ss 52.400",
+		"-noaccurate_seek",
+		"-hls_time 4",
+		"-hls_segment_filename /cache/hls/k/run-1/seg_%05d.ts",
+	} {
+		if !strings.Contains(joined, want) {
+			t.Errorf("remux args missing %q: %s", want, joined)
+		}
+	}
+	for _, unwanted := range []string{
+		"libx264",
+		"-vf ",
+		"-b:v",
+		"-maxrate",
+		"-bufsize",
+		"-force_key_frames",
+		"-preset",
+		"-threads",
+		"-pix_fmt",
+	} {
+		if strings.Contains(joined, unwanted) {
+			t.Errorf("remux args must not contain %q: %s", unwanted, joined)
+		}
+	}
+	// 中途起播不能加 -re，否则会先按 1 倍速爬到目标位置才出第一个切片。
+	if strings.Contains(joined, " -re ") {
+		t.Errorf("mid-file remux must not use -re: %s", joined)
+	}
+}
+
+// 烧录图形字幕要把字幕叠进画面，必须解码重编码，不能被直通标志绕过。
+func TestBuildFFmpegArgsRemuxIgnoredForSubtitleBurnIn(t *testing.T) {
+	cfg := &config.Config{}
+	cfg.Transcoder.MaxHeight = 720
+	cfg.Transcoder.SegmentSeconds = 4
+
+	quality, _ := LocalHLSQualityByID("source")
+	subtitle := 4
+	args := buildFFmpegArgsForInput(cfg, transcodeInput{
+		Source:         "/media/ep.mkv",
+		Quality:        &quality,
+		CopyVideo:      true,
+		SubtitleStream: &subtitle,
+	}, "/o/x.m3u8", "/o/seg_%05d.ts")
+	joined := strings.Join(args, " ")
+
+	if strings.Contains(joined, "-c:v copy") {
+		t.Fatalf("subtitle burn-in must not copy the video stream: %s", joined)
+	}
+	if !strings.Contains(joined, "libx264") || !strings.Contains(joined, "-filter_complex") {
+		t.Fatalf("subtitle burn-in should re-encode: %s", joined)
+	}
+	if strings.Contains(joined, "-noaccurate_seek") {
+		t.Fatalf("encoded path should keep accurate seek: %s", joined)
+	}
+}
+
+// 只有「原画」档位（不缩放）可以直通；其它档位要改分辨率。
+func TestRemuxAppliesToQuality(t *testing.T) {
+	if remuxAppliesToQuality(nil) {
+		t.Fatal("nil quality must not remux: it falls back to the configured max height")
+	}
+	source, _ := LocalHLSQualityByID("source")
+	if !remuxAppliesToQuality(&source) {
+		t.Fatal("source quality should remux")
+	}
+	for _, id := range []string{"1080", "720", "480"} {
+		quality, ok := LocalHLSQualityByID(id)
+		if !ok {
+			t.Fatalf("quality %s missing", id)
+		}
+		if remuxAppliesToQuality(&quality) {
+			t.Fatalf("quality %s must re-encode", id)
+		}
+	}
+}
+
+// 只有 8bit 4:2:0 的 H.264 能安全复制；Hi10P / 4:2:2 / HEVC 复制过去浏览器黑屏。
+func TestRemuxCopyableHeight(t *testing.T) {
+	const blurayPayload = `{"container":"mpegts","duration_sec":1451,"bit_rate":42609934,"streams":[{"index":0,"type":"video","codec":"h264","profile":"High","width":1920,"height":1080,"pix_fmt":"yuv420p","frame_rate":"23.976"},{"index":1,"type":"audio","codec":"pcm_bluray","channels":2}]}`
+
+	cases := []struct {
+		name  string
+		probe *model.MediaProbe
+		want  int
+	}{
+		{
+			name:  "bluray h264 8bit 420",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 1080, Payload: blurayPayload},
+			want:  1080,
+		},
+		{
+			name:  "no payload falls back to codec and height",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 720},
+			want:  720,
+		},
+		{
+			name:  "hevc cannot be copied into browser hls",
+			probe: &model.MediaProbe{VideoCodec: "hevc", Height: 1080, Payload: `{"streams":[{"type":"video","profile":"Main 10","pix_fmt":"yuv420p10le"}]}`},
+			want:  0,
+		},
+		{
+			name:  "hi10p h264 is unplayable in browsers",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 1080, Payload: `{"streams":[{"type":"video","profile":"High 10","pix_fmt":"yuv420p10le"}]}`},
+			want:  0,
+		},
+		{
+			name:  "4:2:2 h264 is unplayable in browsers",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 1080, Payload: `{"streams":[{"type":"video","profile":"High 4:2:2","pix_fmt":"yuv422p"}]}`},
+			want:  0,
+		},
+		{
+			name:  "missing probe",
+			probe: nil,
+			want:  0,
+		},
+		{
+			name:  "unknown height",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 0, Payload: blurayPayload},
+			want:  0,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := remuxCopyableHeight(tc.probe); got != tc.want {
+				t.Fatalf("remuxCopyableHeight() = %d, want %d", got, tc.want)
+			}
+		})
+	}
+}