[FFmpeg-devel] [PATCH] avfilter/vf_alphamerge: use refcounting for planar formats

[FFmpeg-devel] [PATCH] avfilter/vf_alphamerge: use refcounting for planar formats

[Jorge Estrada]

Use reference plane when handling planar formats. Should address
https://code.ffmpeg.org/FFmpeg/FFmpeg/issues/20153

Example:
ffmpeg -f lavfi -i "color=red:s=640x480:d=5,format=yuva420p" \
       -f lavfi -i "color=black:s=640x480:d=5,format=yuv420p,geq=lum='255*gt(150,hypot(X-W/2,Y-H/2))':a=0" \
       -f lavfi -i "color=blue:s=640x480:d=5,format=yuv420p" \
       -filter_complex "[0:v][1:v]alphamerge[merged_with_alpha];[2:v][merged_with_alpha]overlay" \
       -c:v libx264 \
       -y out.mp4
---
 libavfilter/vf_alphamerge.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/libavfilter/vf_alphamerge.c b/libavfilter/vf_alphamerge.c
index f5779484a9..9f53806537 100644
--- a/libavfilter/vf_alphamerge.c
+++ b/libavfilter/vf_alphamerge.c
@@ -28,12 +28,12 @@
 #include "libavutil/imgutils.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixfmt.h"
+#include "libavutil/frame.h"
 #include "avfilter.h"
 #include "drawutils.h"
 #include "formats.h"
 #include "filters.h"
 #include "framesync.h"
-#include "video.h"
 
 enum { Y, U, V, A };
 
@@ -78,11 +78,23 @@ static int do_alphamerge(FFFrameSync *fs)
             }
         }
     } else {
-        const int main_linesize = main_buf->linesize[A];
-        const int alpha_linesize = alpha_buf->linesize[Y];
-        av_image_copy_plane(main_buf->data[A], main_linesize,
-                            alpha_buf->data[Y], alpha_linesize,
-                            FFMIN(main_linesize, alpha_linesize), alpha_buf->height);
+        AVBufferRef *alpha_plane_buf = av_frame_get_plane_buffer(alpha_buf, Y);
+
+        if (!alpha_plane_buf) {
+            av_log(ctx, AV_LOG_ERROR, "Could not get buffer for alpha plane.\n");
+            return AVERROR(EINVAL);
+        }
+
+        av_buffer_unref(&main_buf->buf[A]);
+
+        main_buf->buf[A] = av_buffer_ref(alpha_plane_buf);
+        if (!main_buf->buf[A]) {
+            av_log(ctx, AV_LOG_ERROR, "Failed to reference alpha plane buffer.\n");
+            return AVERROR(ENOMEM);
+        }
+
+        main_buf->data[A] = alpha_buf->data[Y];
+        main_buf->linesize[A] = alpha_buf->linesize[Y];
     }
 
     return ff_filter_frame(ctx->outputs[0], main_buf);
@@ -212,4 +224,4 @@ const FFFilter ff_vf_alphamerge = {
     FILTER_QUERY_FUNC2(query_formats),
     .uninit         = uninit,
     .activate       = activate,
-};
+};
\ No newline at end of file
-- 
2.34.1

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Re: [FFmpeg-devel] [PATCH] avfilter/vf_alphamerge: use refcounting for planar formats

[James Almer]

[-- Attachment #1.1.1: Type: text/plain, Size: 2742 bytes --]

On 8/7/2025 4:58 PM, Jorge Estrada wrote:
> Use reference plane when handling planar formats. Should address
> https://code.ffmpeg.org/FFmpeg/FFmpeg/issues/20153
> 
> Example:
> ffmpeg -f lavfi -i "color=red:s=640x480:d=5,format=yuva420p" \
>         -f lavfi -i "color=black:s=640x480:d=5,format=yuv420p,geq=lum='255*gt(150,hypot(X-W/2,Y-H/2))':a=0" \
>         -f lavfi -i "color=blue:s=640x480:d=5,format=yuv420p" \
>         -filter_complex "[0:v][1:v]alphamerge[merged_with_alpha];[2:v][merged_with_alpha]overlay" \
>         -c:v libx264 \
>         -y out.mp4
> ---
>   libavfilter/vf_alphamerge.c | 26 +++++++++++++++++++-------
>   1 file changed, 19 insertions(+), 7 deletions(-)
> 
> diff --git a/libavfilter/vf_alphamerge.c b/libavfilter/vf_alphamerge.c
> index f5779484a9..9f53806537 100644
> --- a/libavfilter/vf_alphamerge.c
> +++ b/libavfilter/vf_alphamerge.c
> @@ -28,12 +28,12 @@
>   #include "libavutil/imgutils.h"
>   #include "libavutil/opt.h"
>   #include "libavutil/pixfmt.h"
> +#include "libavutil/frame.h"
>   #include "avfilter.h"
>   #include "drawutils.h"
>   #include "formats.h"
>   #include "filters.h"
>   #include "framesync.h"
> -#include "video.h"
>   
>   enum { Y, U, V, A };
>   
> @@ -78,11 +78,23 @@ static int do_alphamerge(FFFrameSync *fs)
>               }
>           }
>       } else {
> -        const int main_linesize = main_buf->linesize[A];
> -        const int alpha_linesize = alpha_buf->linesize[Y];
> -        av_image_copy_plane(main_buf->data[A], main_linesize,
> -                            alpha_buf->data[Y], alpha_linesize,
> -                            FFMIN(main_linesize, alpha_linesize), alpha_buf->height);
> +        AVBufferRef *alpha_plane_buf = av_frame_get_plane_buffer(alpha_buf, Y);
> +
> +        if (!alpha_plane_buf) {
> +            av_log(ctx, AV_LOG_ERROR, "Could not get buffer for alpha plane.\n");
> +            return AVERROR(EINVAL);
> +        }
> +

> +        av_buffer_unref(&main_buf->buf[A]);
> +
> +        main_buf->buf[A] = av_buffer_ref(alpha_plane_buf);

av_buffer_replace()

> +        if (!main_buf->buf[A]) {
> +            av_log(ctx, AV_LOG_ERROR, "Failed to reference alpha plane buffer.\n");
> +            return AVERROR(ENOMEM);
> +        }
> +
> +        main_buf->data[A] = alpha_buf->data[Y];
> +        main_buf->linesize[A] = alpha_buf->linesize[Y];
>       }
>   
>       return ff_filter_frame(ctx->outputs[0], main_buf);
> @@ -212,4 +224,4 @@ const FFFilter ff_vf_alphamerge = {
>       FILTER_QUERY_FUNC2(query_formats),
>       .uninit         = uninit,
>       .activate       = activate,
> -};
> +};
> \ No newline at end of file
Please fix this.


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[FFmpeg-devel] use av_buffer_replace

[Jorge Estrada]

Addressed. Uses av_buffer_replace now

---
 libavfilter/vf_alphamerge.c | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/libavfilter/vf_alphamerge.c b/libavfilter/vf_alphamerge.c
index f5779484a9..69c0dd04ea 100644
--- a/libavfilter/vf_alphamerge.c
+++ b/libavfilter/vf_alphamerge.c
@@ -28,12 +28,12 @@
 #include "libavutil/imgutils.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixfmt.h"
+#include "libavutil/frame.h"
 #include "avfilter.h"
 #include "drawutils.h"
 #include "formats.h"
 #include "filters.h"
 #include "framesync.h"
-#include "video.h"
 
 enum { Y, U, V, A };
 
@@ -78,11 +78,21 @@ static int do_alphamerge(FFFrameSync *fs)
             }
         }
     } else {
-        const int main_linesize = main_buf->linesize[A];
-        const int alpha_linesize = alpha_buf->linesize[Y];
-        av_image_copy_plane(main_buf->data[A], main_linesize,
-                            alpha_buf->data[Y], alpha_linesize,
-                            FFMIN(main_linesize, alpha_linesize), alpha_buf->height);
+        AVBufferRef *alpha_plane_buf = av_frame_get_plane_buffer(alpha_buf, Y);
+
+        if (!alpha_plane_buf) {
+            av_log(ctx, AV_LOG_ERROR, "Could not get buffer for alpha plane.\n");
+            return AVERROR(EINVAL);
+        }
+
+        ret = av_buffer_replace(&main_buf->buf[A], alpha_plane_buf);
+        if (ret < 0) {
+            av_log(ctx, AV_LOG_ERROR, "Failed to replace alpha plane buffer.\n");
+            return ret;
+        }
+
+        main_buf->data[A] = alpha_buf->data[Y];
+        main_buf->linesize[A] = alpha_buf->linesize[Y];
     }
 
     return ff_filter_frame(ctx->outputs[0], main_buf);
@@ -212,4 +222,4 @@ const FFFilter ff_vf_alphamerge = {
     FILTER_QUERY_FUNC2(query_formats),
     .uninit         = uninit,
     .activate       = activate,
-};
+};
\ No newline at end of file
-- 
2.34.1

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Re: [FFmpeg-devel] [PATCH] avfilter/vf_alphamerge: use refcounting for planar formats

[Jorge Estrada]

[-- Attachment #1: Type: text/plain, Size: 3339 bytes --]

Addressed and attached the updated patch. I sent my previous email
incorrectly. My bad.

On Thu, Aug 7, 2025 at 1:13 PM James Almer <jamrial@gmail.com> wrote:

> On 8/7/2025 4:58 PM, Jorge Estrada wrote:
> > Use reference plane when handling planar formats. Should address
> > https://code.ffmpeg.org/FFmpeg/FFmpeg/issues/20153
> >
> > Example:
> > ffmpeg -f lavfi -i "color=red:s=640x480:d=5,format=yuva420p" \
> >         -f lavfi -i
> "color=black:s=640x480:d=5,format=yuv420p,geq=lum='255*gt(150,hypot(X-W/2,Y-H/2))':a=0"
> \
> >         -f lavfi -i "color=blue:s=640x480:d=5,format=yuv420p" \
> >         -filter_complex
> "[0:v][1:v]alphamerge[merged_with_alpha];[2:v][merged_with_alpha]overlay" \
> >         -c:v libx264 \
> >         -y out.mp4
> > ---
> >   libavfilter/vf_alphamerge.c | 26 +++++++++++++++++++-------
> >   1 file changed, 19 insertions(+), 7 deletions(-)
> >
> > diff --git a/libavfilter/vf_alphamerge.c b/libavfilter/vf_alphamerge.c
> > index f5779484a9..9f53806537 100644
> > --- a/libavfilter/vf_alphamerge.c
> > +++ b/libavfilter/vf_alphamerge.c
> > @@ -28,12 +28,12 @@
> >   #include "libavutil/imgutils.h"
> >   #include "libavutil/opt.h"
> >   #include "libavutil/pixfmt.h"
> > +#include "libavutil/frame.h"
> >   #include "avfilter.h"
> >   #include "drawutils.h"
> >   #include "formats.h"
> >   #include "filters.h"
> >   #include "framesync.h"
> > -#include "video.h"
> >
> >   enum { Y, U, V, A };
> >
> > @@ -78,11 +78,23 @@ static int do_alphamerge(FFFrameSync *fs)
> >               }
> >           }
> >       } else {
> > -        const int main_linesize = main_buf->linesize[A];
> > -        const int alpha_linesize = alpha_buf->linesize[Y];
> > -        av_image_copy_plane(main_buf->data[A], main_linesize,
> > -                            alpha_buf->data[Y], alpha_linesize,
> > -                            FFMIN(main_linesize, alpha_linesize),
> alpha_buf->height);
> > +        AVBufferRef *alpha_plane_buf =
> av_frame_get_plane_buffer(alpha_buf, Y);
> > +
> > +        if (!alpha_plane_buf) {
> > +            av_log(ctx, AV_LOG_ERROR, "Could not get buffer for alpha
> plane.\n");
> > +            return AVERROR(EINVAL);
> > +        }
> > +
>
> > +        av_buffer_unref(&main_buf->buf[A]);
> > +
> > +        main_buf->buf[A] = av_buffer_ref(alpha_plane_buf);
>
> av_buffer_replace()
>
> > +        if (!main_buf->buf[A]) {
> > +            av_log(ctx, AV_LOG_ERROR, "Failed to reference alpha plane
> buffer.\n");
> > +            return AVERROR(ENOMEM);
> > +        }
> > +
> > +        main_buf->data[A] = alpha_buf->data[Y];
> > +        main_buf->linesize[A] = alpha_buf->linesize[Y];
> >       }
> >
> >       return ff_filter_frame(ctx->outputs[0], main_buf);
> > @@ -212,4 +224,4 @@ const FFFilter ff_vf_alphamerge = {
> >       FILTER_QUERY_FUNC2(query_formats),
> >       .uninit         = uninit,
> >       .activate       = activate,
> > -};
> > +};
> > \ No newline at end of file
> Please fix this.
>
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>
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> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>

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