feat(canvas): 视频节点截取重生成 - 支持多段/时间线导入并调用视频模型批量重生成 (#197)

* feat(canvas): 视频节点截取重生成 - 支持多段/时间线导入并调用视频模型批量重生成

* test(canvas): 视频节点时间线导入 - 修正旧数据标题回退测试

* style(canvas): 视频节点截取重生成 - 格式化新增文件并修正测试

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Co-authored-by: sikongyue <3155157671@qq.com>

web/src/lib/canvas/canvas-video-segment.ts

@@ -0,0 +1,104 @@
+import { fetchFile } from "@ffmpeg/util";
+
+import { getMediaBlob } from "@/services/file-storage";
+import { loadFFmpeg } from "./canvas-video-merge";
+
+export type VideoSegmentRange = {
+    startMs: number;
+    endMs: number;
+};
+
+export type VideoSegmentSource = {
+    url?: string;
+    storageKey?: string;
+};
+
+export type VideoSegmentProgress = {
+    phase: "loading" | "reading" | "encoding";
+    progress: number;
+};
+
+const INPUT_NAME = "segment-input.mp4";
+const OUTPUT_NAME = "segment-output.mp4";
+
+function assertValidRange(range: VideoSegmentRange, durationMs?: number) {
+    const startMs = Math.max(0, Math.round(range.startMs));
+    const endMs = Math.round(range.endMs);
+    if (endMs <= startMs) throw new Error("片段结束时间必须晚于开始时间");
+    if (durationMs !== undefined && endMs > Math.round(durationMs)) throw new Error("片段结束时间超过视频时长");
+}
+
+async function readVideoSourceBlob(source: VideoSegmentSource) {
+    if (source.storageKey) {
+        const stored = await getMediaBlob(source.storageKey);
+        if (stored) return stored;
+    }
+    if (source.url) {
+        const response = await fetch(source.url);
+        if (!response.ok) throw new Error(`视频资源请求失败（${response.status}）`);
+        return response.blob();
+    }
+    throw new Error("找不到视频素材，请重新上传后再操作");
+}
+
+async function runSegmentJob(
+    source: VideoSegmentSource,
+    range: VideoSegmentRange,
+    durationMs: number | undefined,
+    buildArgs: (startSec: string, durationSec: string) => string[],
+    onProgress?: (progress: VideoSegmentProgress) => void,
+    outputType = "video/mp4",
+) {
+    assertValidRange(range, durationMs);
+    const ffmpeg = await loadFFmpeg(({ phase, progress }) => onProgress?.({ phase: phase === "loading" ? "loading" : "reading", progress }));
+    const blob = await readVideoSourceBlob(source);
+    onProgress?.({ phase: "reading", progress: 45 });
+    await ffmpeg.writeFile(INPUT_NAME, await fetchFile(blob));
+    const startSec = String(range.startMs / 1000);
+    const durationSec = String((range.endMs - range.startMs) / 1000);
+    onProgress?.({ phase: "encoding", progress: 55 });
+    try {
+        const exitCode = await ffmpeg.exec(["-y", ...buildArgs(startSec, durationSec)]);
+        if (exitCode !== 0) throw new Error("媒体处理失败，请确认视频编码格式兼容");
+        const output = await ffmpeg.readFile(OUTPUT_NAME);
+        onProgress?.({ phase: "encoding", progress: 100 });
+        return new Blob([output as BlobPart], { type: outputType });
+    } finally {
+        await Promise.all([INPUT_NAME, OUTPUT_NAME].map((file) => ffmpeg.deleteFile(file).catch(() => undefined)));
+    }
+}
+
+/** 按片段范围截取视频，输出统一编码 MP4（复用时间线 trim 的参数模板）。 */
+export async function trimVideoSegment(source: VideoSegmentSource, range: VideoSegmentRange, durationMs?: number, onProgress?: (progress: VideoSegmentProgress) => void) {
+    return runSegmentJob(
+        source,
+        range,
+        durationMs,
+        (startSec, durationSec) => ["-ss", startSec, "-i", INPUT_NAME, "-t", durationSec, "-c:v", "libx264", "-preset", "veryfast", "-crf", "20", "-c:a", "aac", "-movflags", "+faststart", OUTPUT_NAME],
+        onProgress,
+        "video/mp4",
+    );
+}
+
+/** 从视频片段提取声音为 MP3；优先 libmp3lame，内核不支持时回退默认 mp3 编码器。 */
+export async function extractVideoAudio(source: VideoSegmentSource, range: VideoSegmentRange, durationMs?: number, onProgress?: (progress: VideoSegmentProgress) => void) {
+    const ffmpeg = await loadFFmpeg(({ phase, progress }) => onProgress?.({ phase: phase === "loading" ? "loading" : "reading", progress }));
+    const blob = await readVideoSourceBlob(source);
+    onProgress?.({ phase: "reading", progress: 45 });
+    await ffmpeg.writeFile(INPUT_NAME, await fetchFile(blob));
+    assertValidRange(range, durationMs);
+    const startSec = String(range.startMs / 1000);
+    const durationSec = String((range.endMs - range.startMs) / 1000);
+    onProgress?.({ phase: "encoding", progress: 55 });
+    try {
+        const args = (audioCodec: string) => ["-ss", startSec, "-i", INPUT_NAME, "-t", durationSec, "-vn", "-c:a", audioCodec, "-q:a", "2", OUTPUT_NAME];
+        let exitCode = await ffmpeg.exec(["-y", ...args("libmp3lame")]);
+        if (exitCode !== 0) exitCode = await ffmpeg.exec(["-y", ...args("mp3")]);
+        if (exitCode !== 0) throw new Error("音频提取失败：当前 FFmpeg 内核不支持 MP3 编码");
+        const output = await ffmpeg.readFile(OUTPUT_NAME);
+        onProgress?.({ phase: "encoding", progress: 100 });
+        return new Blob([output as BlobPart], { type: "audio/mpeg" });
+    } finally {
+        await Promise.all([INPUT_NAME, OUTPUT_NAME].map((file) => ffmpeg.deleteFile(file).catch(() => undefined)));
+    }
+}