Replace bottom Examples + top stats card with one demo button

- Remove the 'Run summary' tile card at the top of the output
column; the four output panels (vis video, charts, canvas,
raw JSON accordion) are enough.
- Remove the bottom 'Demo video' card with three example rows;
sat awkwardly below the layout.
- Add a single 'Load demo video' button right under the upload
widget in the Input card. One click fills every control with
a curated preset (sbs · combined · log · GOP=dynamic · 1024
patches) and loads the bundled demo clip.
- Button is hidden when examples/demo_codec_heatmap.mp4 is
missing so the UI degrades cleanly on stripped checkouts.
- process() is back to its 4-output signature.

app.py

@@ -40,6 +40,26 @@ import numpy as np
 
 PATCH_CHOICES = [14, 16, 28]
 
+DEMO_VIDEO_PATH = os.path.join(
+    os.path.dirname(os.path.abspath(__file__)),
+    "examples", "demo_codec_heatmap.mp4",
+)
+DEMO_PRESET = (
+    DEMO_VIDEO_PATH,  # video_in
+    16,               # sample_frames
+    14,               # patch_size
+    1024,             # total_patches
+    150000,           # max_pixels
+    "sbs",            # viz_mode
+    0.55,             # heatmap_alpha
+    0.0, 0.0,         # start_sec, end_sec
+    "combined",       # saliency_signal
+    True,             # score_log_scale
+    96.0,             # bitcost_pct
+    0.55,             # fade_strength
+    "dynamic",        # gop
+)
+
 
 def smart_resize(frame: np.ndarray, max_pixels: int, factor: int) -> np.ndarray:
     """Resize so h,w are multiples of `factor` and h*w <= max_pixels."""
@@ -452,41 +472,6 @@ def pack_canvas(
     return canvas, n
 
 
-def render_stats_html(
-    *, total_selected: int, n_groups: int, gop_label: str,
-    n_sampled: int, total_frames: int, canvas_resolution: str,
-    saliency_signal: str, score_log_scale: bool, elapsed_sec: float,
-    grid_label: str, n_uniform: int, codec: str = "",
-) -> str:
-    """Format the run's headline numbers as a grid of brand-colored tiles."""
-    sig = saliency_signal + (" · log" if score_log_scale else "")
-    gop_disp = (
-        gop_label if gop_label in ("global", "dynamic") else f"GOP={gop_label}"
-    )
-    cells = [
-        ("selected patches",  f"{total_selected:,}"),
-        ("groups",            f"{n_groups} · {gop_disp}"),
-        ("sampled frames",    f"{n_sampled} / {total_frames}"),
-        ("canvas",            canvas_resolution),
-        ("uniform baseline",  f"{n_uniform} frame{'s' if n_uniform != 1 else ''}"),
-        ("saliency",          sig),
-        ("patch grid / frame", grid_label),
-        ("elapsed",           f"{elapsed_sec:.2f}s"),
-    ]
-    if codec:
-        cells.insert(2, ("input codec", codec))
-    parts = ['<div class="ovc-stats">']
-    for label, value in cells:
-        parts.append(
-            f'<div class="ovc-stat">'
-            f'<div class="value">{value}</div>'
-            f'<div class="label">{label}</div>'
-            f'</div>'
-        )
-    parts.append("</div>")
-    return "".join(parts)
-
-
 def make_charts(
     grids: List[np.ndarray],
     masks: List[np.ndarray],
@@ -609,7 +594,7 @@ def process(
     progress=gr.Progress(track_tqdm=False),
 ):
     if not video_path:
-        return None, None, "Please upload a video.", None, EMPTY_STATS
+        return None, None, "Please upload a video.", None
 
     t0 = time.time()
     progress(0.05, desc="Reading metadata")
@@ -619,7 +604,7 @@ def process(
         return None, None, json.dumps(
             {"error": "Could not read frame count.", "metadata": meta},
             indent=2, ensure_ascii=False,
-        ), None, EMPTY_STATS
+        ), None
 
     progress(0.10, desc="Sampling frames")
     fps = float(meta.get("fps") or 0.0)
@@ -649,7 +634,7 @@ def process(
         return None, None, json.dumps(
             {"error": "Failed to decode frames.", "metadata": meta},
             indent=2, ensure_ascii=False,
-        ), None, EMPTY_STATS
+        ), None
 
     progress(0.25, desc="smart_resize")
     resized = [smart_resize(f, int(max_pixels), int(patch_size)) for f in raw]
@@ -764,27 +749,11 @@ def process(
         groups=groups, gop_label=gop_resolved,
     )
 
-    stats_html = render_stats_html(
-        total_selected=int(actual_selected),
-        n_groups=len(groups),
-        gop_label=gop_resolved,
-        n_sampled=len(fids),
-        total_frames=int(total),
-        canvas_resolution=f"{canvas.shape[1]}×{canvas.shape[0]}",
-        saliency_signal=saliency_signal,
-        score_log_scale=bool(score_log_scale),
-        elapsed_sec=round(time.time() - t0, 2),
-        grid_label=f"{hb}×{wb}",
-        n_uniform=int(n_uniform),
-        codec=str(meta.get("codec") or ""),
-    )
-
     progress(1.0, desc="Done")
     return (
         vis_path, canvas_path,
         json.dumps(info, indent=2, ensure_ascii=False),
         chart_fig,
-        stats_html,
     )
 
 
@@ -1203,20 +1172,6 @@ FLOW_HTML = """
 </div>
 """
 
-EMPTY_STATS = (
-    '<div class="ovc-stats">'
-    '<div class="ovc-stat" style="grid-column: 1 / -1; text-align:center; '
-    'background: linear-gradient(135deg, rgba(79,70,229,0.04), rgba(6,182,212,0.03));">'
-    '<div class="value" style="font-size:1.05rem; font-weight:600; '
-    '-webkit-background-clip: initial; background-clip: initial; color: #64748b;">'
-    'Hit <span style="background: var(--ovc-grad); -webkit-background-clip:text; '
-    'background-clip:text; color:transparent;">Run pipeline</span>, '
-    'or pick a row in <i>Demo video</i> below.'
-    '</div>'
-    '<div class="label" style="margin-top:6px;">key numbers will land here</div>'
-    '</div>'
-    '</div>'
-)
 
 
 with gr.Blocks(**_BLOCK_KW) as demo:
@@ -1229,6 +1184,11 @@ with gr.Blocks(**_BLOCK_KW) as demo:
             with gr.Group(elem_classes="ovc-card"):
                 gr.Markdown("### Input")
                 video_in = gr.Video(label="Video", sources=["upload"], height=240)
+                with gr.Row(elem_classes="ovc-preset"):
+                    btn_demo = gr.Button(
+                        "Load demo video", size="sm",
+                        visible=os.path.exists(DEMO_VIDEO_PATH),
+                    )
 
             with gr.Group(elem_classes="ovc-card"):
                 gr.Markdown("### Pipeline")
@@ -1321,10 +1281,6 @@ with gr.Blocks(**_BLOCK_KW) as demo:
 
         # ─── Outputs (wide column) ───────────────────────────────────────
         with gr.Column(scale=6, min_width=420):
-            with gr.Group(elem_classes="ovc-card ovc-card-primary"):
-                gr.Markdown("### Run summary")
-                stats_out = gr.HTML(value=EMPTY_STATS)
-
             with gr.Group(elem_classes="ovc-card ovc-card-primary"):
                 gr.Markdown("### Patch selection visualization")
                 vis_out = gr.Video(
@@ -1363,46 +1319,6 @@ with gr.Blocks(**_BLOCK_KW) as demo:
                                 label="", language="json", lines=18,
                             )
 
-    DEMO_VIDEO = os.path.join(
-        os.path.dirname(os.path.abspath(__file__)),
-        "examples", "demo_codec_heatmap.mp4",
-    )
-    if os.path.exists(DEMO_VIDEO):
-        with gr.Group(elem_classes="ovc-card"):
-            gr.Markdown("### Demo video")
-            gr.Markdown(
-                "<small>Click any row below to load the bundled clip with a "
-                "preset configuration. Or upload your own video at the top.</small>"
-            )
-            gr.Examples(
-                examples=[
-                    [
-                        DEMO_VIDEO, 16, 14, 1024, 150000,
-                        "selection", 0.55, 0.0, 0.0,
-                        "gradient", False, 99.0, 0.55, "global",
-                    ],
-                    [
-                        DEMO_VIDEO, 16, 14, 1024, 150000,
-                        "heatmap", 0.55, 0.0, 0.0,
-                        "combined", True, 96.0, 0.55, "dynamic",
-                    ],
-                    [
-                        DEMO_VIDEO, 24, 14, 2048, 150000,
-                        "sbs", 0.55, 0.0, 0.0,
-                        "combined", True, 95.0, 0.55, "8",
-                    ],
-                ],
-                inputs=[
-                    video_in, sample_frames, patch_size, top_k, max_pixels,
-                    viz_mode, heatmap_alpha, start_sec, end_sec,
-                    saliency_signal, score_log_scale, bitcost_pct,
-                    fade_strength, gop,
-                ],
-                label="",
-                cache_examples=False,
-                examples_per_page=5,
-            )
-
     gr.HTML(
         '<div id="ovc-footer">'
         '<b>OneVision Encoder</b> · codec-style patch saliency demo · '
@@ -1432,7 +1348,18 @@ with gr.Blocks(**_BLOCK_KW) as demo:
             saliency_signal, score_log_scale, bitcost_pct, fade_strength,
             gop,
         ],
-        outputs=[vis_out, canvas_out, info_out, chart_out, stats_out],
+        outputs=[vis_out, canvas_out, info_out, chart_out],
+    )
+
+    btn_demo.click(
+        lambda: DEMO_PRESET,
+        inputs=None,
+        outputs=[
+            video_in, sample_frames, patch_size, top_k, max_pixels,
+            viz_mode, heatmap_alpha, start_sec, end_sec,
+            saliency_signal, score_log_scale, bitcost_pct, fade_strength,
+            gop,
+        ],
     )