From 315a4496ea1690deb28b2de84032b2eb13019657 Mon Sep 17 00:00:00 2001
From: Paul B Mahol <onemda@gmail.com>
Date: Sun, 17 Nov 2019 16:20:58 +0100
Subject: [PATCH] avfilter/f_loop: switch aloop to activate

---
 libavfilter/f_loop.c | 50 ++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 46 insertions(+), 4 deletions(-)

diff --git a/libavfilter/f_loop.c b/libavfilter/f_loop.c
index 879db621ef..0a029f0104 100644
--- a/libavfilter/f_loop.c
+++ b/libavfilter/f_loop.c
@@ -116,6 +116,7 @@ static int push_samples(AVFilterContext *ctx, int nb_samples)
             return ret;
 
         if (s->current_sample >= s->nb_samples) {
+            s->duration = s->pts;
             s->current_sample = 0;
 
             if (s->loop > 0)
@@ -205,13 +206,55 @@ static int arequest_frame(AVFilterLink *outlink)
         ret = push_samples(ctx, 1024);
     }
 
-    if (ret == AVERROR_EOF && s->nb_samples > 0 && s->loop != 0) {
-        ret = push_samples(ctx, outlink->sample_rate);
+    if (s->eof && s->nb_samples > 0 && s->loop != 0) {
+        ret = push_samples(ctx, 1024);
     }
 
     return ret;
 }
 
+static int aactivate(AVFilterContext *ctx)
+{
+    AVFilterLink *inlink = ctx->inputs[0];
+    AVFilterLink *outlink = ctx->outputs[0];
+    LoopContext *s = ctx->priv;
+    AVFrame *frame = NULL;
+    int ret, status;
+    int64_t pts;
+
+    FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
+
+    if (!s->eof && (s->nb_samples < s->size || !s->loop || !s->size)) {
+        ret = ff_inlink_consume_frame(inlink, &frame);
+        if (ret < 0)
+            return ret;
+        if (ret > 0)
+            return afilter_frame(inlink, frame);
+    }
+
+    if (!s->eof && ff_inlink_acknowledge_status(inlink, &status, &pts)) {
+        if (status == AVERROR_EOF) {
+            s->size = s->nb_samples;
+            s->eof = 1;
+        }
+    }
+
+    if (s->eof && (!s->loop || !s->size)) {
+        ff_outlink_set_status(outlink, AVERROR_EOF, s->duration);
+        return 0;
+    }
+
+    if (!s->eof && (!s->size ||
+        (s->nb_samples < s->size) ||
+        (s->nb_samples >= s->size && s->loop == 0))) {
+        FF_FILTER_FORWARD_WANTED(outlink, inlink);
+    } else if (s->loop && s->nb_samples == s->size) {
+        return arequest_frame(outlink);
+    }
+
+    return FFERROR_NOT_READY;
+}
+
 static const AVOption aloop_options[] = {
     { "loop",  "number of loops",               OFFSET(loop),  AV_OPT_TYPE_INT,   {.i64 = 0 }, -1, INT_MAX,   AFLAGS },
     { "size",  "max number of samples to loop", OFFSET(size),  AV_OPT_TYPE_INT64, {.i64 = 0 },  0, INT32_MAX, AFLAGS },
@@ -225,7 +268,6 @@ static const AVFilterPad ainputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_AUDIO,
-        .filter_frame = afilter_frame,
         .config_props = aconfig_input,
     },
     { NULL }
@@ -235,7 +277,6 @@ static const AVFilterPad aoutputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_AUDIO,
-        .request_frame = arequest_frame,
     },
     { NULL }
 };
@@ -245,6 +286,7 @@ AVFilter ff_af_aloop = {
     .description   = NULL_IF_CONFIG_SMALL("Loop audio samples."),
     .priv_size     = sizeof(LoopContext),
     .priv_class    = &aloop_class,
+    .activate      = aactivate,
     .uninit        = auninit,
     .inputs        = ainputs,
     .outputs       = aoutputs,