avfilter/asubprocess: move subprocess frame processing to update_state

Signed-off-by: Stefan Westerfeld <stefan@space.twc.de>

libavfilter/af_asubprocess.c

@@ -236,6 +236,8 @@ sp_read(SP *sp, char *buffer, size_t count)
     }
 }
 
+static int try_read_frame(AVFilterContext *ctx);
+
 static int update_state(AVFilterContext *ctx)
 {
     AVFilterLink *outlink = ctx->outputs[0];
@@ -320,6 +322,7 @@ static int update_state(AVFilterContext *ctx)
         }
     }
     if (s->state == STATE_IN_DATA_CHUNK) {
+        int ret;
         int bytes_per_sample = s->out_bit_depth / 8 * outlink->ch_layout.nb_channels;
         size_t expect_bytes = (s->nb_input_samples - s->nb_output_samples) * bytes_per_sample;
         if ((s->nb_input_samples * bytes_per_sample) % 2) // padding byte for odd length input
@@ -328,6 +331,11 @@ static int update_state(AVFilterContext *ctx)
             av_log(ctx, AV_LOG_ERROR, "Subprocess produced more output data than expected.\n");
             return AVERROR_INVALIDDATA;
         }
+        do {
+            ret = try_read_frame(ctx);
+            if (ret < 0)
+                return ret;
+        } while (ret > 0);
     }
     return 0;
 }
@@ -586,6 +594,7 @@ static int write_frame(AVFilterContext *ctx, ASubProcessContext *s, AVFilterLink
             return AVERROR(ENOMEM);
         }
         av_frame_copy_props(out, in);
+        // TODO: LEAK
     }
     ff_framequeue_add(&s->frame_queue, out);
     return ret;
@@ -639,10 +648,6 @@ static int activate(AVFilterContext *ctx)
 
     FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
 
-    ret = try_read_frame(ctx);
-    if (ret != 0)
-        return ret;
-
     ret = ff_inlink_consume_frame(inlink, &in);
     if (ret < 0)
         return ret;
@@ -666,9 +671,6 @@ static int activate(AVFilterContext *ctx)
                 return ret;
         }
     }
-    ret = try_read_frame(ctx);
-    if (ret != 0)
-        return ret;
 
     if (s->eof) {
         if (s->state != STATE_IN_DATA_CHUNK) {