avcodec/elbg: Add persistent ELBGContext

It will be used in future commits to avoid having to allocate and free
all the buffers used.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/libavcodec/elbg.c b/libavcodec/elbg.c
index ac5c53161d..9eac802688 100644
--- a/libavcodec/elbg.c
+++ b/libavcodec/elbg.c
@@ -466,12 +466,17 @@ static int init_elbg(int *points, int dim, int numpoints, int *codebook,
     return ret;
 }
 
-int avpriv_do_elbg(int *points, int dim, int numpoints,
+int avpriv_elbg_do(ELBGContext **elbgp, int *points, int dim, int numpoints,
                    int *codebook, int num_cb, int max_steps,
                    int *closest_cb, AVLFG *rand_state)
 {
+    ELBGContext *const elbg = *elbgp ? *elbgp : av_mallocz(sizeof(*elbg));
     int ret;
 
+    if (!elbg)
+        return AVERROR(ENOMEM);
+    *elbgp = elbg;
+
     ret = init_elbg(points, dim, numpoints, codebook,
                     num_cb, max_steps, closest_cb, rand_state);
     if (ret < 0)
@@ -479,3 +484,8 @@ int avpriv_do_elbg(int *points, int dim, int numpoints,
     return do_elbg (points, dim, numpoints, codebook,
                     num_cb, max_steps, closest_cb, rand_state);
 }
+
+av_cold void avpriv_elbg_free(ELBGContext **elbgp)
+{
+    av_freep(elbgp);
+}