直播：三模式采集、Canvas 单轨与可拖动小窗；观众端单路视频

Made-with: Cursor

admin/src/utils/liveWebRTC.js

@@ -1,7 +1,9 @@
 /**
- * 管理后台 WebRTC 开播（/api/web/live/ws?role=publish&token=）
- * 画质：官网 /live 写入 localStorage（yh_live_capture_quality）
- * 支持：仅摄像头 / 屏幕共享 + 摄像头小窗；信令断线自动重连（复用 MediaStream）
+ * 管理后台 WebRTC 开播（观众端始终单路视频）
+ * - camera：仅摄像头
+ * - screen_only：仅共享屏幕 + 麦克风
+ * - screen_pip：屏幕与摄像头 Canvas 合成；小窗位置由 getPipRect() 归一化矩形 (nx,ny,nw,nh) 决定，与预览拖动一致
+ * - 直播中可 switchMode 切换，无需结束直播
  */
 const apiBase = (import.meta.env.VITE_API_BASE || '').replace(/\/$/, '')
 
@@ -59,6 +61,9 @@ const defaultIce = [{ urls: 'stun:stun.l.google.com:19302' }]
 
 const MAX_SIGNAL_RECONNECT = 15
 
+const CANVAS_W = 1280
+const CANVAS_H = 720
+
 function healthCheckUrl() {
   if (apiBase) return `${apiBase}/api/health`
   if (typeof window !== 'undefined') return `${window.location.origin}/api/health`
@@ -80,6 +85,22 @@ function buildCameraConstraints(publishKey, videoDeviceId) {
   }
 }
 
+function clamp(v, lo, hi) {
+  return Math.min(hi, Math.max(lo, v))
+}
+
+/** @param {() => { nx?: number, ny?: number, nw?: number, nh?: number } | null | undefined} getPipRect */
+function readPipRect(getPipRect) {
+  const d = typeof getPipRect === 'function' ? getPipRect() : null
+  const nw = clamp(Number(d?.nw) || 0.24, 0.08, 0.55)
+  const nh = clamp(Number(d?.nh) || 0.24, 0.08, 0.55)
+  const defNx = 1 - nw - 10 / CANVAS_W
+  const defNy = 1 - nh - 10 / CANVAS_H
+  const nx = clamp(Number(d?.nx) || defNx, 0, 1 - nw)
+  const ny = clamp(Number(d?.ny) || defNy, 0, 1 - nh)
+  return { nx, ny, nw, nh }
+}
+
 function humanizeGetUserMediaError(err) {
   const name = err && err.name
   const raw = ((err && err.message) || '').toLowerCase()
@@ -106,31 +127,28 @@ function humanizeGetUserMediaError(err) {
   return (err && err.message) || '无法打开摄像头'
 }
 
-/**
- * @param {object} opts
- * @param {string} opts.token
- * @param {'camera'|'screen_pip'} [opts.captureMode]
- * @param {string} [opts.videoDeviceId] videoinput deviceId，空则默认设备
- * @param {(s: string) => void} [opts.onStatus]
- * @param {(p: { main: MediaStream, pip: MediaStream|null }) => void} [opts.onLocalStream]
- */
 export function startPublishing(opts = {}) {
   const {
     token = '',
-    captureMode = 'camera',
-    videoDeviceId = '',
+    captureMode: initialMode = 'camera',
+    videoDeviceId: initialDeviceId = '',
     onStatus = () => {},
-    onLocalStream = () => {}
+    onLocalStream = () => {},
+    onActiveModeChange = () => {},
+    getPipRect = null
   } = opts
 
   if (!token) {
     onStatus('未登录，无法开播')
-    return { stop: () => {} }
+    return { stop: () => {}, switchMode: async () => {} }
   }
 
   const publishKey = effectivePublishQualityKey()
   const wsUrl = liveWsURLPublish(token)
 
+  let activeMode = initialMode
+  let deviceIdState = initialDeviceId
+
   let closedByLocal = false
   let stream = null
   let ws = null
@@ -139,6 +157,42 @@ export function startPublishing(opts = {}) {
   let reconnectAttempt = 0
   let wsGen = 0
   let reconnectStopped = false
+  let switchBusy = false
+
+  let rafId = null
+  let vScreen = null
+  let vCam = null
+  let canvasEl = null
+  let screenShareTrack = null
+
+  function teardownComposite() {
+    if (rafId != null) {
+      cancelAnimationFrame(rafId)
+      rafId = null
+    }
+    if (vScreen) {
+      try {
+        const so = vScreen.srcObject
+        if (so) so.getTracks().forEach((t) => t.stop())
+      } catch (_) {}
+      try {
+        vScreen.srcObject = null
+      } catch (_) {}
+      vScreen = null
+    }
+    if (vCam) {
+      try {
+        const so = vCam.srcObject
+        if (so) so.getTracks().forEach((t) => t.stop())
+      } catch (_) {}
+      try {
+        vCam.srcObject = null
+      } catch (_) {}
+      vCam = null
+    }
+    canvasEl = null
+    screenShareTrack = null
+  }
 
   function clearReconnectTimer() {
     if (reconnectTimer) {
@@ -151,44 +205,121 @@ export function startPublishing(opts = {}) {
     if (ws && ws.readyState === WebSocket.OPEN) ws.send(JSON.stringify(o))
   }
 
-  async function acquireMedia() {
-    if (captureMode === 'screen_pip') {
+  async function acquireDisplayStream() {
     let display
     try {
-        display = await navigator.mediaDevices.getDisplayMedia({ video: true, audio: false })
+      display = await navigator.mediaDevices.getDisplayMedia({
+        video: true,
+        audio: false
+      })
     } catch (e) {
       const name = e && e.name
       throw new Error(name === 'NotAllowedError' ? '已取消或未允许屏幕共享' : (e && e.message) || '屏幕共享失败')
     }
-      const screenVideo = display.getVideoTracks()[0]
-      if (!screenVideo) {
+    const sTr = display.getVideoTracks()[0]
+    if (!sTr) {
       display.getTracks().forEach((t) => t.stop())
       throw new Error('未获得屏幕画面')
     }
-      screenVideo.addEventListener('ended', () => {
+    screenShareTrack = sTr
+    sTr.addEventListener('ended', () => {
       if (!closedByLocal) {
         onStatus('屏幕共享已结束')
         stop()
       }
     })
-      let cam
+    return display
+  }
+
+  async function buildPublishStream() {
+    teardownComposite()
+    if (activeMode === 'screen_only') {
+      const display = await acquireDisplayStream()
+      const sTr = display.getVideoTracks()[0]
+      let micStream
       try {
-        cam = await navigator.mediaDevices.getUserMedia(buildCameraConstraints(publishKey, videoDeviceId))
+        micStream = await navigator.mediaDevices.getUserMedia({ audio: true, video: false })
       } catch (e) {
-        screenVideo.stop()
+        sTr.stop()
         display.getTracks().forEach((t) => t.stop())
         throw e
       }
-      const camVideo = cam.getVideoTracks()[0]
+      const previewVid = new MediaStream([sTr])
+      onLocalStream({ layout: 'screen_only', main: previewVid })
+      return new MediaStream([sTr, ...micStream.getAudioTracks()])
+    }
+    if (activeMode === 'screen_pip') {
+      const display = await acquireDisplayStream()
+      const sTr = display.getVideoTracks()[0]
+      let cam
+      try {
+        cam = await navigator.mediaDevices.getUserMedia(buildCameraConstraints(publishKey, deviceIdState))
+      } catch (e) {
+        sTr.stop()
+        display.getTracks().forEach((t) => t.stop())
+        throw e
+      }
+      vScreen = document.createElement('video')
+      vCam = document.createElement('video')
+      vScreen.muted = true
+      vCam.muted = true
+      vScreen.playsInline = true
+      vCam.playsInline = true
+      vScreen.srcObject = display
+      vCam.srcObject = cam
+      await vScreen.play().catch(() => {})
+      await vCam.play().catch(() => {})
+
+      canvasEl = document.createElement('canvas')
+      canvasEl.width = CANVAS_W
+      canvasEl.height = CANVAS_H
+      const ctx = canvasEl.getContext('2d')
+
+      function tick() {
+        if (closedByLocal || !canvasEl) return
+        ctx.fillStyle = '#000'
+        ctx.fillRect(0, 0, CANVAS_W, CANVAS_H)
+        if (vScreen && vScreen.readyState >= 2) {
+          try {
+            ctx.drawImage(vScreen, 0, 0, CANVAS_W, CANVAS_H)
+          } catch (_) {}
+        }
+        if (vCam && vCam.readyState >= 2) {
+          const { nx, ny, nw, nh } = readPipRect(getPipRect)
+          const pw = Math.round(CANVAS_W * nw)
+          const ph = Math.round(CANVAS_H * nh)
+          const px = Math.round(CANVAS_W * nx)
+          const py = Math.round(CANVAS_H * ny)
+          ctx.strokeStyle = 'rgba(64,158,255,0.9)'
+          ctx.lineWidth = 3
+          ctx.strokeRect(px, py, pw, ph)
+          try {
+            ctx.drawImage(vCam, px, py, pw, ph)
+          } catch (_) {}
+        }
+        rafId = requestAnimationFrame(tick)
+      }
+      tick()
+
+      const cap = canvasEl.captureStream(30)
+      const outV = cap.getVideoTracks()[0]
+      if (!outV) {
+        teardownComposite()
+        sTr.stop()
+        cam.getTracks().forEach((t) => t.stop())
+        throw new Error('画布采集失败')
+      }
       const mic = cam.getAudioTracks()
-      const publish = new MediaStream([screenVideo, camVideo, ...mic])
-      const mainPrev = new MediaStream([screenVideo])
-      const pipPrev = new MediaStream([camVideo])
-      onLocalStream({ main: mainPrev, pip: pipPrev })
+      const publish = new MediaStream([outV, ...mic])
+      onLocalStream({
+        layout: 'screen_pip',
+        screen: display,
+        cam: new MediaStream([cam.getVideoTracks()[0]])
+      })
       return publish
     }
-    const s = await navigator.mediaDevices.getUserMedia(buildCameraConstraints(publishKey, videoDeviceId))
-    onLocalStream({ main: s, pip: null })
+    const s = await navigator.mediaDevices.getUserMedia(buildCameraConstraints(publishKey, deviceIdState))
+    onLocalStream({ layout: 'camera', main: s })
     return s
   }
 
@@ -203,8 +334,9 @@ export function startPublishing(opts = {}) {
           t.stop()
         } catch (_) {}
       })
+      teardownComposite()
       try {
-        stream = await acquireMedia()
+        stream = await buildPublishStream()
       } catch (e) {
         const msg =
           e && typeof e.message === 'string' && e.message
@@ -233,6 +365,62 @@ export function startPublishing(opts = {}) {
     onStatus('协商中…')
   }
 
+  async function switchMode(mode, camDeviceId) {
+    if (closedByLocal || switchBusy || !pc || pc.signalingState === 'closed') return
+    switchBusy = true
+    if (typeof camDeviceId === 'string') deviceIdState = camDeviceId
+    const switchingTo = mode
+    activeMode = mode
+    onStatus('切换画面中…')
+    try {
+      stream?.getTracks().forEach((t) => {
+        try {
+          t.stop()
+        } catch (_) {}
+      })
+      stream = null
+      teardownComposite()
+      try {
+        stream = await buildPublishStream()
+      } catch (e1) {
+        if (switchingTo === 'screen_pip' || switchingTo === 'screen_only') {
+          activeMode = 'camera'
+          try {
+            onActiveModeChange('camera')
+          } catch (_) {}
+          onStatus(
+            e1?.message ? `${e1.message}，已切回仅摄像头` : '屏幕共享未就绪，已切回仅摄像头'
+          )
+          stream = await buildPublishStream()
+        } else {
+          throw e1
+        }
+      }
+      const vT = stream.getVideoTracks()[0]
+      const aT = stream.getAudioTracks()[0]
+      const vSender = pc.getSenders().find((s) => s.track?.kind === 'video')
+      const aSender = pc.getSenders().find((s) => s.track?.kind === 'audio')
+      if (vSender && vT) {
+        await vSender.replaceTrack(vT)
+      } else if (vT) {
+        pc.addTrack(vT, stream)
+      }
+      if (aSender && aT) {
+        await aSender.replaceTrack(aT)
+      } else if (aT) {
+        pc.addTrack(aT, stream)
+      }
+      const offer = await pc.createOffer({ iceRestart: false })
+      await pc.setLocalDescription(offer)
+      send({ type: 'offer', sdp: offer.sdp })
+      onStatus('已切换，协商中…')
+    } catch (e) {
+      onStatus(e?.message || humanizeGetUserMediaError(e))
+    } finally {
+      switchBusy = false
+    }
+  }
+
   function onSocketMessage(ev) {
     let msg
     try {
@@ -269,7 +457,7 @@ export function startPublishing(opts = {}) {
     if (reconnectAttempt > MAX_SIGNAL_RECONNECT) {
       reconnectStopped = true
       onStatus(
-        `信令已重试 ${MAX_SIGNAL_RECONNECT} 次仍失败。多为 API 返回 502（进程未启动/崩溃）或 Nginx 未正确反代到 Go。请检查服务与 \`/api/web/live/ws\` 的 WebSocket 配置，修复后刷新本页再点「开始直播」。`
+        `信令已重试 ${MAX_SIGNAL_RECONNECT} 次仍失败。多为 API 502 或未启动。修复后刷新本页再开播。`
       )
       return
     }
@@ -281,10 +469,10 @@ export function startPublishing(opts = {}) {
       try {
         const r = await fetch(healthCheckUrl(), { method: 'GET', cache: 'no-store' })
         if (!r.ok) {
-          onStatus(`API 不可用（HTTP ${r.status}），多为网关 502，推迟重试…`)
+          onStatus(`API 不可用（HTTP ${r.status}）`)
         }
       } catch (_) {
-        onStatus('无法访问健康检查接口，请确认网络与域名。')
+        onStatus('无法访问健康检查接口')
       }
       if (closedByLocal || reconnectStopped) return
       openSignalingSocket()
@@ -349,6 +537,7 @@ export function startPublishing(opts = {}) {
     reconnectStopped = true
     wsGen += 1
     clearReconnectTimer()
+    teardownComposite()
     if (ws) {
       try {
         ws.close()
@@ -371,5 +560,8 @@ export function startPublishing(opts = {}) {
 
   openSignalingSocket()
 
-  return { stop }
+  return {
+    stop,
+    switchMode: (mode, camDeviceId) => switchMode(mode, camDeviceId)
+  }
 }

admin/src/views/sites/LiveBroadcast.vue

@@ -5,12 +5,13 @@
         <span>官网视频直播（WebRTC）</span>
       </template>
       <p class="status">{{ status }}</p>
-      <div v-if="!session" class="form-block">
+      <div class="form-block">
         <div class="field-row">
           <span class="field-label">画面来源</span>
-          <el-radio-group v-model="captureMode" :disabled="!token">
+          <el-radio-group v-model="captureMode" :disabled="!token || switchingCapture">
             <el-radio-button value="camera">仅摄像头</el-radio-button>
-            <el-radio-button value="screen_pip">屏幕 + 摄像头小窗</el-radio-button>
+            <el-radio-button value="screen_only">仅共享屏幕</el-radio-button>
+            <el-radio-button value="screen_pip">共享屏幕 + 摄像头</el-radio-button>
           </el-radio-group>
         </div>
         <div class="field-row">
@@ -21,7 +22,7 @@
             clearable
             filterable
             style="width: 100%; max-width: 360px"
-            :disabled="!token"
+            :disabled="!token || switchingCapture"
           >
             <el-option label="系统默认" value="" />
             <el-option
@@ -33,21 +34,54 @@
           </el-select>
           <el-button :disabled="!token" @click="refreshVideoDevices">刷新列表</el-button>
         </div>
+        <p v-if="session" class="hint-live">
+          直播中可切换三种模式；「屏幕+摄像头」下可拖动小窗，观众画面与预览一致（画布 16:9
+          铺满）。共享整屏时尽量勿把本管理页选进画面，以免套娃。
+        </p>
+        <div v-if="session" class="field-row">
+          <el-button
+            type="primary"
+            plain
+            :disabled="!token || switchingCapture"
+            :loading="switchingCapture"
+            @click="applyCaptureSwitch"
+          >
+            应用切换（不切断直播）
+          </el-button>
+        </div>
       </div>
       <div class="actions">
         <el-button v-if="!session" type="primary" :disabled="!token" @click="start">开始直播</el-button>
         <el-button v-else type="danger" @click="stop">结束直播</el-button>
       </div>
-      <div class="preview-wrap">
-        <video ref="previewMainRef" class="preview-main" playsinline muted autoplay></video>
+      <div ref="previewWrapRef" class="preview-wrap">
         <video
-          v-show="captureMode === 'screen_pip'"
-          ref="previewPipRef"
-          class="preview-pip"
+          v-show="previewLayout !== 'screen_pip'"
+          ref="previewMainRef"
+          class="preview-main"
           playsinline
           muted
           autoplay
         ></video>
+        <video
+          v-show="previewLayout === 'screen_pip'"
+          ref="previewScreenRef"
+          class="preview-main preview-main--fill"
+          playsinline
+          muted
+          autoplay
+        ></video>
+        <video
+          v-show="previewLayout === 'screen_pip'"
+          ref="previewCamRef"
+          class="preview-pip-drag"
+          :style="pipStyle"
+          playsinline
+          muted
+          autoplay
+          title="拖动调整小窗位置（观众端同步）"
+          @pointerdown.prevent="onPipPointerDown"
+        ></video>
       </div>
     </el-card>
   </div>
@@ -61,13 +95,80 @@ import { startPublishing } from '../../utils/liveWebRTC'
 
 const authStore = useAuthStore()
 const token = computed(() => authStore.getToken() || '')
+const previewWrapRef = ref(null)
 const previewMainRef = ref(null)
-const previewPipRef = ref(null)
+const previewScreenRef = ref(null)
+const previewCamRef = ref(null)
 const status = ref('就绪')
 const session = ref(null)
 const captureMode = ref('camera')
 const selectedCameraId = ref('')
 const videoInputs = ref([])
+const switchingCapture = ref(false)
+/** @type {import('vue').Ref<'camera'|'screen_only'|'screen_pip'>} */
+const previewLayout = ref('camera')
+
+/** 与推流画布 1280×720 一致的归一化小窗矩形（左上 + 宽高，0~1） */
+const pipNorm = ref(defaultPipNorm())
+
+function defaultPipNorm() {
+  const nw = 0.24
+  const nh = 0.24
+  return {
+    nx: 1 - nw - 10 / 1280,
+    ny: 1 - nh - 10 / 720,
+    nw,
+    nh
+  }
+}
+
+const pipStyle = computed(() => ({
+  left: `${pipNorm.value.nx * 100}%`,
+  top: `${pipNorm.value.ny * 100}%`,
+  width: `${pipNorm.value.nw * 100}%`,
+  height: `${pipNorm.value.nh * 100}%`
+}))
+
+let pipDragging = false
+let pipDragStart = { cx: 0, cy: 0, nx: 0, ny: 0 }
+
+function clamp01(v, lo, hi) {
+  return Math.min(hi, Math.max(lo, v))
+}
+
+function onPipPointerDown(e) {
+  if (previewLayout.value !== 'screen_pip') return
+  pipDragging = true
+  pipDragStart.cx = e.clientX
+  pipDragStart.cy = e.clientY
+  pipDragStart.nx = pipNorm.value.nx
+  pipDragStart.ny = pipNorm.value.ny
+  try {
+    e.target.setPointerCapture(e.pointerId)
+  } catch (_) {}
+  window.addEventListener('pointermove', onPipPointerMove)
+  window.addEventListener('pointerup', onPipPointerUp, { once: true })
+  window.addEventListener('pointercancel', onPipPointerUp, { once: true })
+}
+
+function onPipPointerMove(e) {
+  if (!pipDragging || !previewWrapRef.value) return
+  const rect = previewWrapRef.value.getBoundingClientRect()
+  if (rect.width < 1 || rect.height < 1) return
+  const dx = (e.clientX - pipDragStart.cx) / rect.width
+  const dy = (e.clientY - pipDragStart.cy) / rect.height
+  const { nw, nh } = pipNorm.value
+  pipNorm.value = {
+    ...pipNorm.value,
+    nx: clamp01(pipDragStart.nx + dx, 0, 1 - nw),
+    ny: clamp01(pipDragStart.ny + dy, 0, 1 - nh)
+  }
+}
+
+function onPipPointerUp() {
+  pipDragging = false
+  window.removeEventListener('pointermove', onPipPointerMove)
+}
 
 async function refreshVideoDevices() {
   try {
@@ -77,14 +178,36 @@ async function refreshVideoDevices() {
   } catch (_) {}
 }
 
-function applyPreview({ main, pip }) {
+function applyPreview(payload) {
+  const { layout, main, screen, cam } = payload || {}
+  previewLayout.value = layout || 'camera'
+  if (previewLayout.value === 'screen_pip') {
+    if (previewMainRef.value) previewMainRef.value.srcObject = null
+    if (previewScreenRef.value) previewScreenRef.value.srcObject = screen || null
+    if (previewCamRef.value) previewCamRef.value.srcObject = cam || null
+  } else {
+    if (previewScreenRef.value) previewScreenRef.value.srcObject = null
+    if (previewCamRef.value) previewCamRef.value.srcObject = null
     if (previewMainRef.value) previewMainRef.value.srcObject = main || null
-  if (previewPipRef.value) previewPipRef.value.srcObject = pip || null
+  }
 }
 
 function clearPreview() {
+  previewLayout.value = 'camera'
+  pipNorm.value = defaultPipNorm()
   if (previewMainRef.value) previewMainRef.value.srcObject = null
-  if (previewPipRef.value) previewPipRef.value.srcObject = null
+  if (previewScreenRef.value) previewScreenRef.value.srcObject = null
+  if (previewCamRef.value) previewCamRef.value.srcObject = null
+}
+
+async function applyCaptureSwitch() {
+  if (!session.value?.switchMode) return
+  switchingCapture.value = true
+  try {
+    await session.value.switchMode(captureMode.value, selectedCameraId.value || '')
+  } finally {
+    switchingCapture.value = false
+  }
 }
 
 function start() {
@@ -93,16 +216,20 @@ function start() {
     return
   }
   status.value = '正在连接…'
-  const { stop } = startPublishing({
+  const { stop, switchMode } = startPublishing({
     token: token.value,
     captureMode: captureMode.value,
     videoDeviceId: selectedCameraId.value || '',
     onStatus: (s) => {
       status.value = s
     },
-    onLocalStream: applyPreview
+    onLocalStream: applyPreview,
+    onActiveModeChange: (m) => {
+      captureMode.value = m
+    },
+    getPipRect: () => ({ ...pipNorm.value })
   })
-  session.value = { stop }
+  session.value = { stop, switchMode }
 }
 
 function stop() {
@@ -124,6 +251,7 @@ onMounted(() => {
 
 onUnmounted(() => {
   window.removeEventListener('beforeunload', onBeforeUnload)
+  window.removeEventListener('pointermove', onPipPointerMove)
 })
 
 onBeforeRouteLeave(() => {
@@ -155,6 +283,13 @@ onBeforeRouteLeave(() => {
   color: #606266;
   min-width: 72px;
 }
+.hint-live {
+  margin: 0 0 10px;
+  font-size: 13px;
+  line-height: 1.5;
+  color: #909399;
+  max-width: 720px;
+}
 .actions {
   margin-bottom: 16px;
 }
@@ -171,17 +306,24 @@ onBeforeRouteLeave(() => {
   border-radius: 8px;
   background: #000;
   object-fit: contain;
+  aspect-ratio: 16 / 9;
 }
-.preview-pip {
+.preview-main--fill {
+  object-fit: fill;
+}
+.preview-pip-drag {
   position: absolute;
-  right: 14px;
-  bottom: 14px;
-  width: min(32%, 280px);
-  aspect-ratio: 4 / 3;
+  box-sizing: border-box;
   border-radius: 8px;
-  border: 2px solid #409eff;
+  border: 3px solid #409eff;
   background: #000;
   object-fit: cover;
+  cursor: grab;
+  touch-action: none;
   box-shadow: 0 4px 16px rgba(0, 0, 0, 0.35);
+  z-index: 2;
+}
+.preview-pip-drag:active {
+  cursor: grabbing;
 }
 </style>

web/src/utils/liveWebRTC.js

@@ -42,23 +42,15 @@ export async function fetchLiveStatus() {
 const defaultIce = [{ urls: 'stun:stun.l.google.com:19302' }]
 
 /**
- * 观众端：轮询 live 后拉流；支持双路视频（第一路主画面、第二路摄像头小窗）
- * @param {HTMLVideoElement | null} videoEl 主画面
- * @param {{ pipVideoEl?: HTMLVideoElement | null, onStatus?: function, onLive?: function, onEnded?: function, pollMs?: number, muted?: boolean }} [opts]
+ * 观众端：轮询 live 后拉流；单路视频 + 音频（主播端 Canvas 合成）
+ * @param {HTMLVideoElement | null} videoEl
+ * @param {{ onStatus?: function, onLive?: function, onEnded?: function, pollMs?: number, muted?: boolean }} [opts]
  */
 export function startViewing(videoEl, opts = {}) {
-  const {
-    pipVideoEl = null,
-    onPipActive = () => {},
-    onStatus = () => {},
-    onLive = () => {},
-    onEnded = () => {},
-    pollMs = 1200,
-    muted = true
-  } = opts
+  const { onStatus = () => {}, onLive = () => {}, onEnded = () => {}, pollMs = 1200, muted = true } =
+    opts
 
   let mainRecv = new MediaStream()
-  let videoIdx = 0
 
   function syncMain() {
     if (!videoEl) return
@@ -67,15 +59,6 @@ export function startViewing(videoEl, opts = {}) {
     videoEl.play().catch(() => {})
   }
 
-  function clearPip() {
-    if (pipVideoEl) {
-      pipVideoEl.srcObject = null
-    }
-    try {
-      onPipActive(false)
-    } catch (_) {}
-  }
-
   function handleTrack(e) {
     if (e.track.kind === 'audio') {
       mainRecv.addTrack(e.track)
@@ -83,19 +66,13 @@ export function startViewing(videoEl, opts = {}) {
       return
     }
     if (e.track.kind === 'video') {
-      const i = videoIdx++
-      if (i === 0) {
+      mainRecv.getVideoTracks().forEach((t) => {
+        try {
+          mainRecv.removeTrack(t)
+        } catch (_) {}
+      })
       mainRecv.addTrack(e.track)
       syncMain()
-      } else if (pipVideoEl) {
-        const pipMs = new MediaStream([e.track])
-        pipVideoEl.srcObject = pipMs
-        pipVideoEl.muted = true
-        pipVideoEl.play().catch(() => {})
-        try {
-          onPipActive(true)
-        } catch (_) {}
-      }
     }
   }
 
@@ -155,8 +132,6 @@ export function startViewing(videoEl, opts = {}) {
       pc.close()
     } catch (_) {}
     mainRecv = new MediaStream()
-    videoIdx = 0
-    clearPip()
     pc = newPeer()
   }
 
@@ -164,7 +139,6 @@ export function startViewing(videoEl, opts = {}) {
     if (stopped) return
     clearBlackFrameTimer()
     if (videoEl) videoEl.srcObject = null
-    clearPip()
     if (tip) onStatus(tip)
     if (pollTimer) return
     rebuildPeer()
@@ -186,7 +160,6 @@ export function startViewing(videoEl, opts = {}) {
       else icePending.push(msg)
     }
     pc.addTransceiver('video', { direction: 'recvonly' })
-    pc.addTransceiver('video', { direction: 'recvonly' })
     pc.addTransceiver('audio', { direction: 'recvonly' })
     const offer = await pc.createOffer()
     await pc.setLocalDescription(offer)
@@ -297,7 +270,6 @@ export function startViewing(videoEl, opts = {}) {
     ws = null
     pc.close()
     if (videoEl) videoEl.srcObject = null
-    clearPip()
   }
 
   return { stop }

web/src/views/LiveRoom.vue

@@ -21,19 +21,10 @@
         <div class="live-video-wrap">
           <video
             ref="watchVideoRef"
-            class="live-room-video live-room-video--watch"
-            :class="{ 'live-room-video--contain': pipVisible }"
+            class="live-room-video live-room-video--watch live-room-video--contain"
             playsinline
             autoplay
           ></video>
-          <video
-            v-show="pipVisible"
-            ref="pipVideoRef"
-            class="live-room-pip-video"
-            playsinline
-            autoplay
-            muted
-          ></video>
           <div class="live-dm-layer" aria-hidden="true">
             <div
               v-for="d in dmItems"
@@ -88,8 +79,6 @@ import { LIVE_QUALITY_OPTIONS, LIVE_CAPTURE_QUALITY_STORAGE_KEY } from '../utils
 import { startViewing, liveDanmakuWsURL } from '../utils/liveWebRTC'
 
 const watchVideoRef = ref(null)
-const pipVideoRef = ref(null)
-const pipVisible = ref(false)
 const rawLiveUrl = ref('')
 const pageTitle = ref('视频直播')
 const watchStatus = ref('正在检测本站直播…')
@@ -163,11 +152,6 @@ function unmuteAndPlay() {
   if (!v) return
   v.muted = false
   v.play().catch(() => {})
-  const p = pipVideoRef.value
-  if (p) {
-    p.muted = true
-    p.play().catch(() => {})
-  }
 }
 
 function toggleVideoFullscreen() {
@@ -308,10 +292,6 @@ onMounted(async () => {
   await nextTick()
   connectDanmaku()
   viewSession = startViewing(watchVideoRef.value, {
-    pipVideoEl: pipVideoRef.value,
-    onPipActive: (on) => {
-      pipVisible.value = on
-    },
     muted: false,
     onStatus: (s) => {
       watchStatus.value = s
@@ -327,7 +307,6 @@ onUnmounted(() => {
     dmReconnectTimer = null
   }
   viewSession?.stop()
-  pipVisible.value = false
   try {
     dmWs?.close()
   } catch (_) {}
@@ -562,18 +541,4 @@ onUnmounted(() => {
   object-fit: contain;
   aspect-ratio: 16 / 9;
 }
-.live-room-pip-video {
-  position: absolute;
-  right: 10px;
-  bottom: 10px;
-  width: 30%;
-  max-width: 200px;
-  aspect-ratio: 4 / 3;
-  border-radius: 10px;
-  border: 2px solid rgba(0, 212, 255, 0.65);
-  background: #000;
-  object-fit: cover;
-  z-index: 4;
-  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.45);
-}
 </style>