[FFmpeg-devel] [PATCH] avcodec/decode: Return EAGAIN instead of overwriting unused packet

[Andreas Rheinhardt]

Should fix #10457, a regression caused by
69516ab3e917a6e91d26e38d04183c60fd71cbab.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
I am not sure about this one. The problem is that avcodec_send_packet()
and avcodec_receive_frame() must not return EAGAIN at the same time.
If buffer_frame contains a frame when entering avcodec_send_packet(),
the next call to avcodec_receive_frame() will not return EAGAIN.
But is this actually guaranteed if buffer_pkt is not empty?

 libavcodec/decode.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/decode.c b/libavcodec/decode.c
index 269633ce10..6595c3ca34 100644
--- a/libavcodec/decode.c
+++ b/libavcodec/decode.c
@@ -666,6 +666,9 @@ int attribute_align_arg avcodec_send_packet(AVCodecContext *avctx, const AVPacke
     if (avpkt && !avpkt->size && avpkt->data)
         return AVERROR(EINVAL);
 
+    if (!AVPACKET_IS_EMPTY(avci->buffer_pkt))
+        return AVERROR(EAGAIN);
+
     av_packet_unref(avci->buffer_pkt);
     if (avpkt && (avpkt->data || avpkt->side_data_elems)) {
         ret = av_packet_ref(avci->buffer_pkt, avpkt);
-- 
2.34.1