@@ -101,9 +101,30 @@ static int wv_read_block_header(AVFormatContext *ctx, ByteIOContext *pb)

     bpp = ((wc->flags & 3) + 1) << 3;

     chan = 1 + !(wc->flags & WV_MONO);

     rate = wv_rates[(wc->flags >> 23) & 0xF];

-    if(rate == -1){

-        av_log(ctx, AV_LOG_ERROR, "Unknown sampling rate\n");

-        return -1;

+    if(rate == -1 && !wc->block_parsed){

+        int64_t block_end = url_ftell(pb) + wc->blksize - 24;

+        if(url_is_streamed(pb)){

+            av_log(ctx, AV_LOG_ERROR, "Cannot determine custom sampling rate\n");

+            return -1;

+        }

+        while(url_ftell(pb) < block_end){

+            int id, size;

+            id = get_byte(pb);

+            size = (id & 0x80) ? get_le24(pb) : get_byte(pb);

+            size <<= 1;

+            if(id&0x40)

+                size--;

+            if((id&0x3F) == 0x27){

+                rate = get_le24(pb);

+                break;

+            }else{

+                url_fskip(pb, size);

+            }

+        }

+        if(rate == -1){

+            av_log(ctx, AV_LOG_ERROR, "Cannot determine custom sampling rate\n");

+            return -1;

+        }

     }

     if(!wc->bpp) wc->bpp = bpp;

     if(!wc->chan) wc->chan = chan;

@@ -117,7 +138,7 @@ static int wv_read_block_header(AVFormatContext *ctx, ByteIOContext *pb)

         av_log(ctx, AV_LOG_ERROR, "Channels differ, this block: %i, header block: %i\n", chan, wc->chan);

         return -1;

     }

-    if(wc->flags && rate != wc->rate){

+    if(wc->flags && rate != -1 && rate != wc->rate){

         av_log(ctx, AV_LOG_ERROR, "Sampling rate differ, this block: %i, header block: %i\n", rate, wc->rate);

         return -1;

     }