rtpdec_qt: Use a local variable instead of RTP_FLAG_KEY

The only case where RTP_FLAG_KEY actually is needed is
in RDT, where such a flag needs to be passed via the
rtpdec parse function's flags parameter.
Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/rtpdec_qt.c

@@ -47,7 +47,8 @@ static int qt_rtp_parse_packet(AVFormatContext *s, PayloadContext *qt,
     AVIOContext pb;
     GetBitContext gb;
     int packing_scheme, has_payload_desc, has_packet_info, alen,
-        has_marker_bit = flags & RTP_FLAG_MARKER;
+        has_marker_bit = flags & RTP_FLAG_MARKER,
+        keyframe;
 
     if (qt->remaining) {
         int num = qt->pkt.size / qt->bytes_per_frame;
@@ -79,8 +80,7 @@ static int qt_rtp_parse_packet(AVFormatContext *s, PayloadContext *qt,
     skip_bits(&gb, 4); // version
     if ((packing_scheme = get_bits(&gb, 2)) == 0)
         return AVERROR_INVALIDDATA;
-    if (get_bits1(&gb))
-        flags          |= RTP_FLAG_KEY;
+    keyframe            = get_bits1(&gb);
     has_payload_desc    = get_bits1(&gb);
     has_packet_info     = get_bits1(&gb);
     skip_bits(&gb, 23); // reserved:7, cache payload info:1, payload ID:15
@@ -196,7 +196,7 @@ static int qt_rtp_parse_packet(AVFormatContext *s, PayloadContext *qt,
 
             qt->pkt.size = 0;
             qt->pkt.data = NULL;
-            pkt->flags        = flags & RTP_FLAG_KEY ? AV_PKT_FLAG_KEY : 0;
+            pkt->flags        = keyframe ? AV_PKT_FLAG_KEY : 0;
             pkt->stream_index = st->index;
             memset(pkt->data + pkt->size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
             return 0;
@@ -211,7 +211,7 @@ static int qt_rtp_parse_packet(AVFormatContext *s, PayloadContext *qt,
         if (av_new_packet(pkt, qt->bytes_per_frame))
             return AVERROR(ENOMEM);
         memcpy(pkt->data, buf + avio_tell(&pb), qt->bytes_per_frame);
-        pkt->flags = flags & RTP_FLAG_KEY ? AV_PKT_FLAG_KEY : 0;
+        pkt->flags = keyframe ? AV_PKT_FLAG_KEY : 0;
         pkt->stream_index = st->index;
         if (qt->remaining > 0) {
             av_freep(&qt->pkt.data);