[FFmpeg-cvslog] avfilter/vsrc_gradients: make rotation always continuous if speed changes

[Paul B Mahol]

ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Sun Dec  3 18:41:31 2023 +0100| [e3e3531d1ed85e6c0a123491c247d4de2e171a9e] | committer: Paul B Mahol

avfilter/vsrc_gradients: make rotation always continuous if speed changes

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=e3e3531d1ed85e6c0a123491c247d4de2e171a9e
---

 libavfilter/vsrc_gradients.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavfilter/vsrc_gradients.c b/libavfilter/vsrc_gradients.c
index d3264b96c8..2d7c0fa681 100644
--- a/libavfilter/vsrc_gradients.c
+++ b/libavfilter/vsrc_gradients.c
@@ -37,6 +37,7 @@ typedef struct GradientsContext {
     int64_t pts;
     int64_t duration;           ///< duration expressed in microseconds
     float speed;
+    float angle;
 
     uint8_t color_rgba[8][4];
     float  color_rgbaf[8][4];
@@ -392,10 +393,12 @@ static int activate(AVFilterContext *ctx)
 
     if (ff_outlink_frame_wanted(outlink)) {
         AVFrame *frame = ff_get_video_buffer(outlink, s->w, s->h);
-        float angle = (s->speed > 0.f) ? fmodf(s->pts * s->speed, 2.f * M_PI) : 1.f;
+        float angle = fmodf(s->angle, 2.f * M_PI);
         const float w2 = s->w / 2.f;
         const float h2 = s->h / 2.f;
 
+        s->angle = angle + s->speed;
+
         s->fx0 = (s->x0 - w2) * cosf(angle) - (s->y0 - h2) * sinf(angle) + w2;
         s->fy0 = (s->x0 - w2) * sinf(angle) + (s->y0 - h2) * cosf(angle) + h2;