feat: FFmpeg GUI desktop application

Wails v2 + Vue3 + Go project with:
- Encode/Remux/Subtitle burn with hardware acceleration
- Real-time progress with ffmpeg stderr parsing (\r delimiter handling)
- Task queue with cancel support
- Per-task log viewer with color-coded output
- Custom frameless window with resize support
- Dark/light theme toggle
- Hardware encoder detection (NVENC/QSV/AMF)

frontend/src/views/EncodePage.vue

@@ -0,0 +1,297 @@
+<template>
+  <div class="encode-page">
+    <h2>重新转码</h2>
+    <p class="page-desc">重新编码视频和音频流，可调整编码器、质量、分辨率等参数</p>
+
+    <!-- Input File Card -->
+    <div class="card">
+      <div class="card-header"><h3>输入文件</h3></div>
+      <div class="input-row">
+        <input :value="inputFile" readonly placeholder="选择要转码的视频文件..." @click="browseInput" />
+        <button class="btn-secondary" @click="browseInput">选择文件</button>
+      </div>
+      <div v-if="mediaInfo" class="stream-tags">
+        <span v-for="s in mediaInfo.streams" :key="s.index" class="stream-tag">
+          <span class="stream-type">{{ typeLabel(s.codec_type) }}</span>
+          {{ codecLabel(s) }}
+        </span>
+        <span v-if="mediaInfo.format.duration" class="stream-tag dur">
+          {{ formatDuration(mediaInfo.format.duration) }}
+        </span>
+      </div>
+    </div>
+
+    <!-- Hardware + Encoder Card -->
+    <div class="card">
+      <div class="card-header"><h3>编码硬件与编码器</h3></div>
+      <div class="fields-row">
+        <div class="field">
+          <label class="field-label">硬件加速</label>
+          <select v-model="hwAccel">
+            <option value="">CPU 软件编码</option>
+            <option value="cuda">NVIDIA CUDA</option>
+            <option value="d3d11va">Direct3D 11 (DXVA)</option>
+            <option value="dxva2">DirectX VA2</option>
+            <option value="qsv">Intel Quick Sync</option>
+          </select>
+        </div>
+        <div class="field">
+          <label class="field-label">视频编码器</label>
+          <select v-model="encodeSettings.videoCodec">
+            <optgroup label="软件编码">
+              <option value="libx264">H.264 / AVC (libx264)</option>
+              <option value="libx265">H.265 / HEVC (libx265)</option>
+              <option value="libsvtav1">AV1 (libsvtav1)</option>
+            </optgroup>
+            <optgroup label="NVIDIA NVENC">
+              <option value="h264_nvenc">H.264 NVENC</option>
+              <option value="hevc_nvenc">HEVC NVENC</option>
+              <option value="av1_nvenc">AV1 NVENC</option>
+            </optgroup>
+            <optgroup label="Intel QSV">
+              <option value="h264_qsv">H.264 QSV</option>
+              <option value="hevc_qsv">HEVC QSV</option>
+              <option value="av1_qsv">AV1 QSV</option>
+            </optgroup>
+            <optgroup label="AMD AMF">
+              <option value="h264_amf">H.264 AMF</option>
+              <option value="hevc_amf">HEVC AMF</option>
+              <option value="av1_amf">AV1 AMF</option>
+            </optgroup>
+          </select>
+        </div>
+      </div>
+      <div class="fields-row">
+        <div class="field">
+          <label class="field-label">音频编码器</label>
+          <select v-model="encodeSettings.audioCodec">
+            <option value="aac">AAC</option>
+            <option value="opus">Opus</option>
+            <option value="mp3">MP3</option>
+            <option value="copy">复制（不重新编码）</option>
+          </select>
+        </div>
+        <div class="field">
+          <label class="field-label">Preset</label>
+          <select v-model="encodeSettings.preset">
+            <template v-if="isHardwareCodec">
+              <option value="p1">P1 — 最快（低画质）</option>
+              <option value="p2">P2</option>
+              <option value="p3">P3</option>
+              <option value="p4">P4 — 中等</option>
+              <option value="p5">P5</option>
+              <option value="p6">P6</option>
+              <option value="p7">P7 — 最慢（高画质）</option>
+            </template>
+            <template v-else>
+              <option value="ultrafast">ultrafast — 最快</option>
+              <option value="veryfast">veryfast</option>
+              <option value="faster">faster</option>
+              <option value="fast">fast</option>
+              <option value="medium">medium — 中等</option>
+              <option value="slow">slow</option>
+              <option value="slower">slower</option>
+            </template>
+          </select>
+        </div>
+      </div>
+    </div>
+
+    <!-- Encoding Settings Card -->
+    <div class="card">
+      <div class="card-header"><h3>编码参数</h3></div>
+      <div class="fields-row">
+        <div class="field">
+          <label class="field-label">码率控制</label>
+          <select v-model="rateControl">
+            <option value="crf">CRF / CQ (质量优先)</option>
+            <option value="bitrate">固定码率</option>
+          </select>
+        </div>
+        <div class="field" v-if="rateControl === 'crf'">
+          <label class="field-label">CRF / CQ (越小质量越高)</label>
+          <div class="crf-group">
+            <input type="range" min="14" max="35" v-model.number="encodeSettings.crf"
+                   style="height:auto;padding:0;box-shadow:none;flex:1" />
+            <span class="crf-value">{{ encodeSettings.crf || 23 }}</span>
+          </div>
+          <div class="range-hint"><span>高质量</span><span>低质量</span></div>
+        </div>
+        <div class="field" v-else>
+          <label class="field-label">视频码率</label>
+          <input v-model="encodeSettings.videoBitrate" placeholder="5M / 8000k" />
+        </div>
+      </div>
+      <div class="fields-row">
+        <div class="field">
+          <label class="field-label">音频码率</label>
+          <select v-model="encodeSettings.audioBitrate">
+            <option value="128k">128 kbps</option>
+            <option value="192k">192 kbps</option>
+            <option value="256k">256 kbps</option>
+            <option value="320k">320 kbps</option>
+          </select>
+        </div>
+        <div class="field">
+          <label class="field-label">宽度 (0=保持原尺寸)</label>
+          <input type="number" v-model.number="encodeSettings.width" placeholder="1920" />
+        </div>
+        <div class="field">
+          <label class="field-label">高度 (0=保持原尺寸)</label>
+          <input type="number" v-model.number="encodeSettings.height" placeholder="1080" />
+        </div>
+      </div>
+      <div class="fields-row">
+        <div class="field">
+          <label class="field-label">帧率 (0=保持原始)</label>
+          <select v-model.number="encodeSettings.fps">
+            <option :value="0">保持原始</option>
+            <option :value="23.976">23.976</option>
+            <option :value="24">24</option>
+            <option :value="25">25</option>
+            <option :value="30">30</option>
+            <option :value="60">60</option>
+          </select>
+        </div>
+        <div class="field"></div>
+        <div class="field"></div>
+      </div>
+    </div>
+
+    <!-- Output Card -->
+    <div class="card">
+      <div class="card-header"><h3>输出位置</h3></div>
+      <div class="input-row">
+        <input :value="outputFile" readonly placeholder="选择输出文件的保存路径..." @click="browseOutput" />
+        <button class="btn-secondary" @click="browseOutput">浏览</button>
+      </div>
+    </div>
+
+    <!-- Start Button -->
+    <div class="submit-area">
+      <span v-if="!canSubmit" class="field-hint submit-hint">请先选择输入和输出文件</span>
+      <button class="btn-primary btn-lg" @click="addTask" :disabled="!canSubmit">
+        开始任务
+      </button>
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { ref, computed } from 'vue'
+import { api } from '../api/wails'
+import type { MediaInfo, StreamInfo, EncodeSettings } from '../types'
+
+const emit = defineEmits<{ taskAdded: [] }>()
+
+const inputFile = ref('')
+const outputFile = ref('')
+const mediaInfo = ref<MediaInfo | null>(null)
+const hwAccel = ref('')
+const rateControl = ref<'crf' | 'bitrate'>('crf')
+
+const encodeSettings = ref<EncodeSettings>({
+  videoCodec: 'libx264', audioCodec: 'aac', hwEncoder: '',
+  width: 0, height: 0, fps: 0,
+  videoBitrate: '', audioBitrate: '192k', crf: 23, preset: 'medium', pixelFormat: '',
+})
+
+const isHardwareCodec = computed(() => {
+  const c = encodeSettings.value.videoCodec
+  return c.includes('nvenc') || c.includes('qsv') || c.includes('amf')
+})
+
+const canSubmit = computed(() => inputFile.value && outputFile.value)
+
+async function browseInput() {
+  try { const p = await api.selectInputFile(); if (p) { inputFile.value = p; await analyzeMedia() } } catch {}
+}
+async function browseOutput() {
+  try { const p = await api.selectOutputFile('output.mp4'); if (p) outputFile.value = p } catch {}
+}
+
+async function analyzeMedia() {
+  if (!inputFile.value) return
+  try {
+    mediaInfo.value = await api.getMediaInfo(inputFile.value)
+    outputFile.value ||= inputFile.value.replace(/\.[^.]+$/, '_encoded.mp4')
+  } catch { mediaInfo.value = null }
+}
+
+async function addTask() {
+  if (!canSubmit.value) return
+  try {
+    const taskId = await api.addTask({
+      id: '', type: 'encode', inputFile: inputFile.value, outputFile: outputFile.value,
+      status: 'pending', progress: {} as any,
+      encode: { ...encodeSettings.value },
+      remux: {} as any, subtitle: {} as any,
+      createdAt: new Date().toISOString(),
+    })
+    await api.setHWAccel(hwAccel.value)
+    await api.startTask(taskId)
+    emit('taskAdded')
+    resetForm()
+  } catch (e: any) { alert('添加失败: ' + (e?.message || e)) }
+}
+
+function resetForm() {
+  inputFile.value = ''
+  outputFile.value = ''
+  mediaInfo.value = null
+  hwAccel.value = ''
+  rateControl.value = 'crf'
+  encodeSettings.value = {
+    videoCodec: 'libx264', audioCodec: 'aac', hwEncoder: '',
+    width: 0, height: 0, fps: 0,
+    videoBitrate: '', audioBitrate: '192k', crf: 23, preset: 'medium', pixelFormat: '',
+  }
+}
+
+function typeLabel(t: string) {
+  if (t === 'video') return 'V'
+  if (t === 'audio') return 'A'
+  if (t === 'subtitle') return 'S'
+  return t[0]?.toUpperCase() || ''
+}
+function codecLabel(s: StreamInfo) {
+  let label = s.codec_name
+  if (s.codec_type === 'video' && s.width) label += ` ${s.width}x${s.height}`
+  if (s['tags>language']) label += ` [${s['tags>language']}]`
+  return label
+}
+function formatDuration(d?: string) {
+  if (!d) return ''; const s = parseFloat(d); if (isNaN(s)) return d
+  return `${Math.floor(s/60)}:${Math.floor(s%60).toString().padStart(2,'0')}`
+}
+</script>
+
+<style scoped>
+.encode-page { display: flex; flex-direction: column; gap: 16px; }
+.encode-page > h2 { margin-bottom: 0; }
+.page-desc { font-size: 13px; color: var(--text-dim); margin-top: -8px; }
+
+.input-row { display: flex; gap: 8px; }
+.input-row input { flex: 1; }
+
+.stream-tags { display: flex; flex-wrap: wrap; gap: 6px; padding-top: 8px; }
+.stream-tag {
+  font-size: 12px; padding: 3px 8px; line-height: 1.5;
+  border-radius: 4px; background: var(--bg-input); color: var(--text-secondary);
+  display: flex; align-items: center; gap: 4px;
+}
+.stream-type {
+  font-size: 10px; font-weight: 700; padding: 0 4px;
+  border-radius: 2px; background: var(--accent); color: white;
+  min-width: 16px; text-align: center; line-height: 16px;
+}
+.stream-tag.dur { font-weight: 500; }
+
+.crf-group { display: flex; align-items: center; gap: 10px; }
+.crf-value { font-size: 16px; font-weight: 700; color: var(--accent); min-width: 28px; }
+.range-hint { display: flex; justify-content: space-between; font-size: 11px; color: var(--text-dim); }
+input[type="range"] { accent-color: var(--accent); }
+
+.submit-area { display: flex; align-items: center; justify-content: flex-end; gap: 16px; padding-top: 4px; }
+.submit-hint { margin-right: auto; }
+</style>