@@ -102,6 +102,7 @@ typedef struct ShortenContext {

     int blocksize;

     int bitindex;

     int32_t lpcqoffset;

+    int got_header;

 } ShortenContext;

 static av_cold int shorten_decode_init(AVCodecContext * avctx)

@@ -386,6 +387,8 @@ static int read_header(ShortenContext *s)

     s->cur_chan = 0;

     s->bitshift = 0;

+    s->got_header = 1;

+

     return 0;

 }

@@ -438,8 +441,7 @@ static int shorten_decode_frame(AVCodecContext *avctx,

     skip_bits(&s->gb, s->bitindex);

     /* process header or next subblock */

-    if (!s->blocksize)

-    {

+    if (!s->got_header) {

         if ((ret = read_header(s)) < 0)

             return ret;

         *data_size = 0;