[FFmpeg-devel] [PATCH v2 1/1] avfilter/buffersink: Add video frame allocation callback

John Cox jc at kynesim.co.uk
Sat Jul 22 19:45:15 EEST 2023


Finger trouble - repost of previous patch - please ignore

Sorry

JC

>Add a callback to enable user allocation of video frames on the final
>stage of a filter chain.
>
>Signed-off-by: John Cox <jc at kynesim.co.uk>
>---
> libavfilter/buffersink.c | 21 +++++++++++++++++++++
> libavfilter/buffersink.h | 27 +++++++++++++++++++++++++++
> libavfilter/version.h    |  2 +-
> 3 files changed, 49 insertions(+), 1 deletion(-)
>
>diff --git a/libavfilter/buffersink.c b/libavfilter/buffersink.c
>index 306c283f77..070b743186 100644
>--- a/libavfilter/buffersink.c
>+++ b/libavfilter/buffersink.c
>@@ -62,6 +62,11 @@ typedef struct BufferSinkContext {
>     int sample_rates_size;
> 
>     AVFrame *peeked_frame;
>+
>+    union {
>+        av_buffersink_alloc_video_frame * video;
>+    } alloc_cb;
>+    void * alloc_v;
> } BufferSinkContext;
> 
> #define NB_ITEMS(list) (list ## _size / sizeof(*list))
>@@ -154,6 +159,21 @@ int attribute_align_arg av_buffersink_get_samples(AVFilterContext *ctx,
>     return get_frame_internal(ctx, frame, 0, nb_samples);
> }
> 
>+static AVFrame * alloc_video_buffer(AVFilterLink *link, int w, int h)
>+{
>+    AVFilterContext * const ctx = link->dst;
>+    BufferSinkContext * const bs = ctx->priv;
>+    return bs->alloc_cb.video ? bs->alloc_cb.video(ctx, bs->alloc_v, w, h) :
>+        ff_default_get_video_buffer(link, w, h);
>+}
>+
>+void av_buffersink_set_alloc_video_frame(AVFilterContext *ctx, av_buffersink_alloc_video_frame * cb, void * v)
>+{
>+    BufferSinkContext * const bs = ctx->priv;
>+    bs->alloc_cb.video = cb;
>+    bs->alloc_v = v;
>+}
>+
> static av_cold int common_init(AVFilterContext *ctx)
> {
>     BufferSinkContext *buf = ctx->priv;
>@@ -381,6 +401,7 @@ static const AVFilterPad avfilter_vsink_buffer_inputs[] = {
>     {
>         .name = "default",
>         .type = AVMEDIA_TYPE_VIDEO,
>+        .get_buffer = {.video = alloc_video_buffer},
>     },
> };
> 
>diff --git a/libavfilter/buffersink.h b/libavfilter/buffersink.h
>index 64e08de53e..73f0ddc476 100644
>--- a/libavfilter/buffersink.h
>+++ b/libavfilter/buffersink.h
>@@ -166,6 +166,33 @@ int av_buffersink_get_frame(AVFilterContext *ctx, AVFrame *frame);
>  */
> int av_buffersink_get_samples(AVFilterContext *ctx, AVFrame *frame, int nb_samples);
> 
>+/**
>+ * Callback from av_buffersink_set_alloc_video_frame to allocate 
>+ * a frame 
>+ *  
>+ * @param ctx pointer to a context of the abuffersink AVFilter.
>+ * @param v opaque pointer passed to 
>+ *          av_buffersink_set_alloc_video_frame
>+ * @param w width of frame to allocate 
>+ * @param height of frame to allocate 
>+ *  
>+ * @return 
>+ *         - The newly allocated frame
>+ *         - NULL if error
>+ */
>+typedef AVFrame * av_buffersink_alloc_video_frame(AVFilterContext * ctx, void * v, int w, int h);
>+
>+/**
>+ * Set a video frame allocation method for buffersink
>+ *
>+ * @param ctx pointer to a context of the abuffersink AVFilter.
>+ * @param cb Callback to the allocation function. If set to NULL 
>+ *           then the default avfilter allocation function will
>+ *           be used.
>+ * @param v  Opaque to pass to the allocation function
>+ */
>+void av_buffersink_set_alloc_video_frame(AVFilterContext *ctx, av_buffersink_alloc_video_frame * cb, void * v);
>+
> /**
>  * @}
>  */
>diff --git a/libavfilter/version.h b/libavfilter/version.h
>index c001693e3c..54950497be 100644
>--- a/libavfilter/version.h
>+++ b/libavfilter/version.h
>@@ -31,7 +31,7 @@
> 
> #include "version_major.h"
> 
>-#define LIBAVFILTER_VERSION_MINOR   8
>+#define LIBAVFILTER_VERSION_MINOR   9
> #define LIBAVFILTER_VERSION_MICRO 102
> 
> 


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