lavfi/mptestsrc: use outlink->frame_count

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavfilter/vsrc_mptestsrc.c

@@ -52,7 +52,6 @@ enum test_type {
 
 typedef struct MPTestContext {
     const AVClass *class;
-    unsigned int frame_nb;
     AVRational frame_rate;
     int64_t pts, max_pts, duration;
     int hsub, vsub;
@@ -260,7 +259,6 @@ static av_cold int init(AVFilterContext *ctx)
 
     test->max_pts = test->duration >= 0 ?
         av_rescale_q(test->duration, AV_TIME_BASE_Q, av_inv_q(test->frame_rate)) : -1;
-    test->frame_nb = 0;
     test->pts = 0;
 
     av_log(ctx, AV_LOG_VERBOSE, "rate:%d/%d duration:%f\n",
@@ -303,7 +301,7 @@ static int request_frame(AVFilterLink *outlink)
     AVFrame *picref;
     int w = WIDTH, h = HEIGHT,
         cw = FF_CEIL_RSHIFT(w, test->hsub), ch = FF_CEIL_RSHIFT(h, test->vsub);
-    unsigned int frame = test->frame_nb;
+    unsigned int frame = outlink->frame_count;
     enum test_type tt = test->test;
     int i;
 
@@ -338,7 +336,6 @@ static int request_frame(AVFilterLink *outlink)
     case TEST_RING2:      ring2_test(picref->data[0], picref->linesize[0], frame%30); break;
     }
 
-    test->frame_nb++;
     return ff_filter_frame(outlink, picref);
 }