diff --git a/libavformat/au.c b/libavformat/au.c
index 2c1daffa39..9f95334fc1 100644
--- a/libavformat/au.c
+++ b/libavformat/au.c
@@ -170,39 +170,20 @@ static int au_read_header(AVFormatContext *s)
     st->codec->codec_id = codec;
     st->codec->channels = channels;
     st->codec->sample_rate = rate;
+    st->codec->block_align = FFMAX(bps * st->codec->channels / 8, 1);
     if (data_size != AU_UNKNOWN_SIZE)
     st->duration = (((int64_t)data_size)<<3) / (st->codec->channels * (int64_t)bps);
     avpriv_set_pts_info(st, 64, 1, rate);
     return 0;
 }
 
-#define BLOCK_SIZE 1024
-
-static int au_read_packet(AVFormatContext *s,
-                          AVPacket *pkt)
-{
-    int ret;
-    int bpcs = av_get_bits_per_sample(s->streams[0]->codec->codec_id);
-
-    if (!bpcs)
-        return AVERROR(EINVAL);
-    ret= av_get_packet(s->pb, pkt, BLOCK_SIZE *
-                       s->streams[0]->codec->channels *
-                       bpcs >> 3);
-    if (ret < 0)
-        return ret;
-    pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
-    pkt->stream_index = 0;
-    return 0;
-}
-
 #if CONFIG_AU_DEMUXER
 AVInputFormat ff_au_demuxer = {
     .name           = "au",
     .long_name      = NULL_IF_CONFIG_SMALL("Sun AU"),
     .read_probe     = au_probe,
     .read_header    = au_read_header,
-    .read_packet    = au_read_packet,
+    .read_packet    = ff_pcm_read_packet,
     .read_seek      = ff_pcm_read_seek,
     .codec_tag      = (const AVCodecTag* const []){ codec_au_tags, 0 },
 };