[FFmpeg-cvslog] avcodec/v4l2_m2m_enc: buffer frame if it cannot be enqueued

[Andriy Gelman]

ffmpeg | branch: master | Andriy Gelman <andriy.gelman at gmail.com> | Sun Aug 23 13:33:37 2020 -0400| [8bc7f69cefbcbb265b41717608dc8436dc864a55] | committer: Andriy Gelman

avcodec/v4l2_m2m_enc: buffer frame if it cannot be enqueued

Currently if the frame buffers are full, the frame is unrefed and
dropped.  Instead buffer the frame so that it is enqueued in the
next v4l2_receive_packet() call.  The behavior was observed on
DragonBoard 410c.

Signed-off-by: Andriy Gelman <andriy.gelman at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8bc7f69cefbcbb265b41717608dc8436dc864a55
---

 libavcodec/v4l2_m2m.c     | 1 +
 libavcodec/v4l2_m2m_enc.c | 8 ++++++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/libavcodec/v4l2_m2m.c b/libavcodec/v4l2_m2m.c
index 31600617fd..cdfd579810 100644
--- a/libavcodec/v4l2_m2m.c
+++ b/libavcodec/v4l2_m2m.c
@@ -329,6 +329,7 @@ static void v4l2_m2m_destroy_context(void *opaque, uint8_t *context)
     sem_destroy(&s->refsync);
 
     close(s->fd);
+    av_frame_unref(s->frame);
     av_frame_free(&s->frame);
     av_packet_unref(&s->buf_pkt);
 
diff --git a/libavcodec/v4l2_m2m_enc.c b/libavcodec/v4l2_m2m_enc.c
index af0ed1e306..4230a415fd 100644
--- a/libavcodec/v4l2_m2m_enc.c
+++ b/libavcodec/v4l2_m2m_enc.c
@@ -295,16 +295,20 @@ static int v4l2_receive_packet(AVCodecContext *avctx, AVPacket *avpkt)
     if (s->draining)
         goto dequeue;
 
+    if (!frame->buf[0]) {
     ret = ff_encode_get_frame(avctx, frame);
     if (ret < 0 && ret != AVERROR_EOF)
         return ret;
 
     if (ret == AVERROR_EOF)
         frame = NULL;
+    }
 
     ret = v4l2_send_frame(avctx, frame);
-    av_frame_unref(frame);
-    if (ret < 0)
+    if (ret != AVERROR(EAGAIN))
+        av_frame_unref(frame);
+
+    if (ret < 0 && ret != AVERROR(EAGAIN))
         return ret;
 
     if (!output->streamon) {