From 7ab1080749b02e3e545166e67528c6a039e04969 Mon Sep 17 00:00:00 2001
From: nanahi <130121847+na-na-hi@users.noreply.github.com>
Date: Mon, 25 Mar 2024 09:50:24 -0400
Subject: [PATCH] af_scaletempo2: fix false reporting of frame availability

With certain speed settings, the following can happen at the start of
the playback:

- can_perform_wsola returns false, so no frames are written
- mp_scaletempo2_frames_available returns true when
  p->input_buffer_final_frames is 0 and target_block_index < 0

This results in infinite loop and completely stalls audio filter
processing and playback. Fix this by only checking this condition
after the final frame is set.

Fixes: 8080d00d7f31a0e1ba25418e0f08474f1a2f1f61
---
 audio/filter/af_scaletempo2_internals.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/audio/filter/af_scaletempo2_internals.c b/audio/filter/af_scaletempo2_internals.c
index 534f4f672a..6e5b31aeda 100644
--- a/audio/filter/af_scaletempo2_internals.c
+++ b/audio/filter/af_scaletempo2_internals.c
@@ -765,7 +765,8 @@ double mp_scaletempo2_get_latency(struct mp_scaletempo2 *p, double playback_rate
 
 bool mp_scaletempo2_frames_available(struct mp_scaletempo2 *p, double playback_rate)
 {
-    return p->input_buffer_final_frames > p->target_block_index
+    return (p->input_buffer_final_frames > p->target_block_index &&
+            p->input_buffer_final_frames > 0)
         || can_perform_wsola(p, playback_rate)
         || p->num_complete_frames > 0;
 }