Commit 53ca051ffa for ffmpeg

commit 53ca051ffafd11eef5c17e7008841e614eac6d8c
Author: Michael Niedermayer <michael@niedermayer.cc>
Date:   Tue Oct 13 06:06:17 2026 +0200

    ffplay: scroll the chapter list bitmap instead of rendering every row again

    When the list scrolls, the pixels of the rows that stay visible are
    moved together with their strips, so only the rows scrolling in and
    those whose content changed are rendered. Rows the popup covered are
    rendered anew, as their pixels moved with the popup's.

    Assisted-by: Claude

diff --git a/fftools/ffplay.c b/fftools/ffplay.c
index 867fb532f7..4600058f80 100644
--- a/fftools/ffplay.c
+++ b/fftools/ffplay.c
@@ -340,6 +340,7 @@ typedef struct VideoState {
     AVFilterContext *chapter_sink;
     ChapterStrip *chapter_strips;
     int nb_chapter_strips;
+    int chapter_first;
     ChapterRow *chapter_rows;
     int nb_chapter_rows;
     char chapter_search[64];
@@ -1542,6 +1543,47 @@ static void chapter_bitmap_touched(VideoState *is, const SDL_Rect *rect)
     is->force_refresh = 1;
 }

+/* moves the pixels and strips of the rows that stay visible when the list scrolls, so that only the rows scrolling in are
+ * rendered; rows the popup covered hold popup pixels and are rendered anew, as is that part of the popup */
+static void chapter_list_scroll(VideoState *is, const ChapterListLayout *l, const ChapterStrip *strips, int nb)
+{
+    int shift = is->chapter_first - l->first, kept = l->nb_rows - FFABS(shift);
+    SDL_Rect block = { 0, l->rows_y, l->width, l->nb_rows * l->line }, popup = { 0, 0, 0, 0 };
+
+    if (!shift || kept <= 0 || is->nb_chapter_strips <= l->nb_rows || nb <= l->nb_rows)
+        return;
+    ChapterStrip *rows = is->chapter_strips + 1;
+    for (int j = 0; j < l->nb_rows; j++) {
+        SDL_Rect slot = { 0, block.y + j * l->line, l->width, l->line };
+
+        if (!SDL_RectEquals(&rows[j].rect, &slot) || !SDL_RectEquals(&strips[j + 1].rect, &slot))
+            return;
+    }
+    for (int i = 0; i < is->nb_chapter_strips; i++) {
+        if (is->chapter_strips[i].background == chapter_popup_color && SDL_HasIntersection(&is->chapter_strips[i].rect, &block)) {
+            SDL_UnionRect(&popup, &is->chapter_strips[i].rect, &popup);
+            is->chapter_strips[i].background = NULL;
+        }
+    }
+    for (int j = 0; j < l->nb_rows; j++)
+        if (SDL_HasIntersection(&rows[j].rect, &popup))
+            rows[j].background = NULL;
+    for (int k = 0; k < kept * l->line; k++) {
+        int y = shift > 0 ? block.y + block.h - 1 - k : block.y + k;
+
+        memcpy(is->chapter_bitmap + y * is->chapter_rect.w * 4, is->chapter_bitmap + (y - shift * l->line) * is->chapter_rect.w * 4,
+               l->width * 4);
+    }
+    for (int j = 0; j < FFABS(shift); j++)
+        av_freep(&rows[shift > 0 ? kept + j : j].script);
+    memmove(rows + FFMAX(shift, 0), rows + FFMAX(-shift, 0), kept * sizeof(*rows));
+    for (int j = 0; j < FFABS(shift); j++)
+        rows[shift > 0 ? j : kept + j] = (ChapterStrip){ { 0 } };
+    for (int j = 0; j < l->nb_rows; j++)
+        rows[j].rect = strips[j + 1].rect;
+    chapter_bitmap_touched(is, &block);
+}
+
 /* brings the bitmap up to date, rendering only the strips whose content, place or background changed */
 static int chapter_list_render(VideoState *is)
 {
@@ -1556,6 +1598,8 @@ static int chapter_list_render(VideoState *is)
         ret = chapter_list_configure(is, &l, &canvas);
     if (ret >= 0)
         ret = chapter_list_strips(is, &l, &strips, &nb);
+    if (ret >= 0)
+        chapter_list_scroll(is, &l, strips, nb);
     /* what the strips no longer cover becomes transparent again; a strip is drawn anew when it changed or lies on what was
      * cleared or drawn before it */
     for (int i = 0; ret >= 0 && i < is->nb_chapter_strips; i++) {
@@ -1590,6 +1634,7 @@ static int chapter_list_render(VideoState *is)
     chapter_strips_free(&is->chapter_strips, &is->nb_chapter_strips);
     is->chapter_strips    = strips;
     is->nb_chapter_strips = nb;
+    is->chapter_first     = l.first;
     return ret;
 }