OCR

resources/js/component/ocr_canvas.js

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+/**
+ * 视频右侧栏 OCR 结果 canvas 复刻绘制。
+ * 数据源：CDN 上的分P全量 JSON（{space:[w,h], recs:[[ts,[[x1,y1,x2,y2,text],...]],...]}）
+ * 或服务器注入的单帧快照（{ts, lines:[[x1,y1,x2,y2,text],...]}）。
+ */
+(function () {
+    // 按框坐标 1:1 复刻：黑底、黄框、白字，字号按框高自适应
+    function drawFrame(canvas, space, lines) {
+        const sw = space[0], sh = space[1];
+        const cssWidth = canvas.clientWidth || 200;
+        const scale = cssWidth / sw;
+        const cssHeight = Math.max(1, Math.round(sh * scale));
+        const dpr = window.devicePixelRatio || 1;
+        canvas.width = Math.round(cssWidth * dpr);
+        canvas.height = Math.round(cssHeight * dpr);
+        canvas.style.height = cssHeight + "px";
+        const ctx = canvas.getContext("2d");
+        ctx.setTransform(dpr * scale, 0, 0, dpr * scale, 0, 0);
+        ctx.fillStyle = "#000000";
+        ctx.fillRect(0, 0, sw, sh);
+        ctx.strokeStyle = "#eab308";
+        ctx.fillStyle = "#ffffff";
+        ctx.textBaseline = "middle";
+        lines.forEach(function (line) {
+            const x1 = line[0], y1 = line[1], x2 = line[2], y2 = line[3], text = line[4];
+            ctx.lineWidth = 2 / scale;
+            ctx.strokeRect(x1, y1, x2 - x1, y2 - y1);
+            if (text) {
+                ctx.font = Math.max(4, (y2 - y1) * 0.75) + "px sans-serif";
+                ctx.fillText(text, x1 + 2 / scale, (y1 + y2) / 2, x2 - x1 - 4 / scale);
+            }
+        });
+    }
+
+    function formatHms(seconds) {
+        seconds = Math.max(0, Math.floor(seconds));
+        const h = Math.floor(seconds / 3600);
+        const m = Math.floor((seconds % 3600) / 60);
+        const s = seconds % 60;
+        const pad = (n) => String(n).padStart(2, "0");
+        return h + ":" + pad(m) + ":" + pad(s);
+    }
+
+    // 单帧 space：按本帧最大框坐标向上取整到 16 的倍数（与导出端一致）
+    function frameSpace(lines) {
+        let maxX = 0, maxY = 0;
+        lines.forEach(function (line) {
+            maxX = Math.max(maxX, line[2]);
+            maxY = Math.max(maxY, line[3]);
+        });
+        return [Math.max(16, Math.ceil(maxX / 16) * 16), Math.max(16, Math.ceil(maxY / 16) * 16)];
+    }
+
+    // 稿件详情页：CDN 全量 + 进度条联动（展示 ts<=t 最近一条）
+    function initPlayer(panel) {
+        const urls = JSON.parse(panel.dataset.urls || "{}");
+        const canvas = panel.querySelector("canvas");
+        const slider = panel.querySelector("input[type=range]");
+        const timeLabel = panel.querySelector("[data-ocr-time]");
+        const status = panel.querySelector("[data-ocr-status]");
+        const tabs = panel.querySelectorAll("[data-ocr-part]");
+        let data = null;
+        let loadSeq = 0;
+
+        function showStatus(text) {
+            if (status) {
+                status.textContent = text;
+                status.style.display = text ? "" : "none";
+            }
+        }
+
+        function currentIndex(t) {
+            // 二分：ts<=t 的最后一条；t 早于首条时展示首条
+            const recs = data.recs;
+            let lo = 0, hi = recs.length - 1, ans = 0;
+            while (lo <= hi) {
+                const mid = (lo + hi) >> 1;
+                if (recs[mid][0] <= t) { ans = mid; lo = mid + 1; } else { hi = mid - 1; }
+            }
+            return ans;
+        }
+
+        function render() {
+            if (!data || data.recs.length === 0) {
+                return;
+            }
+            const t = parseFloat(slider.value);
+            const idx = currentIndex(t);
+            timeLabel.textContent = formatHms(t) + "（OCR @" + formatHms(data.recs[idx][0]) + "）";
+            drawFrame(canvas, data.space, data.recs[idx][1]);
+        }
+
+        function load(partNum) {
+            const seq = ++loadSeq;
+            data = null;
+            showStatus("加载中…");
+            tabs.forEach(function (tab) {
+                tab.classList.toggle("font-bold", tab.dataset.ocrPart === String(partNum));
+            });
+            fetch(urls[partNum])
+                .then((response) => {
+                    if (!response.ok) { throw new Error("HTTP " + response.status); }
+                    return response.json();
+                })
+                .then((payload) => {
+                    if (seq !== loadSeq) { return; }
+                    data = payload;
+                    slider.max = payload.recs.length ? Math.floor(payload.recs[payload.recs.length - 1][0]) : 0;
+                    showStatus("");
+                    render();
+                })
+                .catch(() => {
+                    if (seq !== loadSeq) { return; }
+                    showStatus("OCR 数据加载失败");
+                });
+        }
+
+        slider.addEventListener("input", render);
+        tabs.forEach(function (tab) {
+            tab.addEventListener("click", function () {
+                slider.value = 0;
+                load(tab.dataset.ocrPart);
+            });
+        });
+        const firstPart = Object.keys(urls)[0];
+        if (firstPart !== undefined) {
+            load(firstPart);
+        }
+    }
+
+    // 节目详情页：服务器注入的单帧快照
+    function initSnapshots(scope) {
+        (scope || document).querySelectorAll("canvas[data-ocr-frame]").forEach(function (canvas) {
+            const frame = JSON.parse(canvas.dataset.ocrFrame);
+            drawFrame(canvas, frameSpace(frame.lines), frame.lines);
+        });
+    }
+
+    window.OcrCanvas = {
+        drawFrame: drawFrame,
+        initPlayer: initPlayer,
+        initSnapshots: initSnapshots,
+    };
+})();