mpegaudiodecheader: check the header in avpriv_mpegaudio_decode_header

Almost all the places from which this function is called already check
the header manually and in the two that don't (the mp3 muxer) the check
should not cause any problems.

1 files changed, 4 insertions, 3 deletions

diff --git a/libavcodec/libmp3lame.c b/libavcodec/libmp3lame.c
index 966212dcae..e4d0e00103 100644
--- a/libavcodec/libmp3lame.c
+++ b/libavcodec/libmp3lame.c
@@ -239,11 +239,12 @@ static int mp3lame_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
     if (s->buffer_index < 4)
         return 0;
     h = AV_RB32(s->buffer);
-    if (ff_mpa_check_header(h) < 0) {
+
+    ret = avpriv_mpegaudio_decode_header(&hdr, h);
+    if (ret < 0) {
         av_log(avctx, AV_LOG_ERROR, "Invalid mp3 header at start of buffer\n");
         return AVERROR_BUG;
-    }
-    if (avpriv_mpegaudio_decode_header(&hdr, h)) {
+    } else if (ret) {
         av_log(avctx, AV_LOG_ERROR, "free format output not supported\n");
         return -1;
     }