doc/examples/transcode: stop using avfilter_graph_create_filter() incorrectly

See previous commits for details.

doc/examples/transcode.c

@@ -283,10 +283,10 @@ static int init_filter(FilteringContext* fctx, AVCodecContext *dec_ctx,
             goto end;
         }
 
-        ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
+        buffersink_ctx = avfilter_graph_alloc_filter(filter_graph, buffersink, "out");
-                NULL, NULL, filter_graph);
+        if (!buffersink_ctx) {
-        if (ret < 0) {
             av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n");
+            ret = AVERROR(ENOMEM);
             goto end;
         }
 
@@ -297,6 +297,12 @@ static int init_filter(FilteringContext* fctx, AVCodecContext *dec_ctx,
             av_log(NULL, AV_LOG_ERROR, "Cannot set output pixel format\n");
             goto end;
         }
+
+        ret = avfilter_init_dict(buffersink_ctx, NULL);
+        if (ret < 0) {
+            av_log(NULL, AV_LOG_ERROR, "Cannot initialize buffer sink\n");
+            goto end;
+        }
     } else if (dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
         char buf[64];
         buffersrc = avfilter_get_by_name("abuffer");
@@ -322,10 +328,10 @@ static int init_filter(FilteringContext* fctx, AVCodecContext *dec_ctx,
             goto end;
         }
 
-        ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
+        buffersink_ctx = avfilter_graph_alloc_filter(filter_graph, buffersink, "out");
-                NULL, NULL, filter_graph);
+        if (!buffersink_ctx) {
-        if (ret < 0) {
             av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer sink\n");
+            ret = AVERROR(ENOMEM);
             goto end;
         }
 
@@ -352,6 +358,12 @@ static int init_filter(FilteringContext* fctx, AVCodecContext *dec_ctx,
             av_log(NULL, AV_LOG_ERROR, "Cannot set output sample rate\n");
             goto end;
         }
+
+        ret = avfilter_init_dict(buffersink_ctx, NULL);
+        if (ret < 0) {
+            av_log(NULL, AV_LOG_ERROR, "Cannot initialize audio buffer sink\n");
+            goto end;
+        }
     } else {
         ret = AVERROR_UNKNOWN;
         goto end;