vocenc: use new header from codec tag 4

this matches sox and should fix ticket1119
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/vocenc.c

@@ -52,7 +52,7 @@ static int voc_write_packet(AVFormatContext *s, AVPacket *pkt)
     AVIOContext *pb = s->pb;
 
     if (!voc->param_written) {
-        if (enc->codec_tag > 0xFF) {
+        if (enc->codec_tag > 3) {
             avio_w8(pb, VOC_TYPE_NEW_VOICE_DATA);
             avio_wl24(pb, pkt->size + 12);
             avio_wl32(pb, enc->sample_rate);

tests/ref/lavf/voc_s16

-1d7be2b6527b76a33d2185ec6fb23f91 *./tests/data/lavf/lavf.s16.voc
-180437 ./tests/data/lavf/lavf.s16.voc
+a8225786fdbf5a2a19d1eeaf15f28632 *./tests/data/lavf/lavf.s16.voc
+180439 ./tests/data/lavf/lavf.s16.voc
 ./tests/data/lavf/lavf.s16.voc CRC=0x7bd585ff