avdevice/alsa_dec: make sure we have enough data in non-blocking mode

Otherwise we might return 1-2 samples per packet if av_read_frame() call rate is
only sligthly less than the stream sample rate.

Signed-off-by: Marton Balint <cus@passwd.hu>

1 files changed, 5 insertions, 0 deletions

diff --git a/libavdevice/alsa.c b/libavdevice/alsa.c
index 117b2ea144..ee282fac16 100644
--- a/libavdevice/alsa.c
+++ b/libavdevice/alsa.c
@@ -286,6 +286,10 @@ av_cold int ff_alsa_open(AVFormatContext *ctx, snd_pcm_stream_t mode,
         }
     }
 
+    s->pkt = av_packet_alloc();
+    if (!s->pkt)
+        goto fail1;
+
     s->h = h;
     return 0;
 
@@ -308,6 +312,7 @@ av_cold int ff_alsa_close(AVFormatContext *s1)
     if (CONFIG_ALSA_INDEV)
         ff_timefilter_destroy(s->timefilter);
     snd_pcm_close(s->h);
+    av_packet_free(&s->pkt);
     return 0;
 }