Do not queue invalid PTS

Configuration packets produced by MediaCodec have no valid PTS, and do
not produce frame. Do not queue their (invalid) PTS not to break the
matching between frames and their PTS.

app/src/decoder.c

@@ -19,6 +19,7 @@
 #define BUFSIZE 0x10000
 
 #define HEADER_SIZE 12
+#define NO_PTS UINT64_C(-1)
 
 static struct frame_meta *frame_meta_new(uint64_t pts) {
     struct frame_meta *meta = malloc(sizeof(*meta));
@@ -89,7 +90,7 @@ static int read_packet_with_meta(void *opaque, uint8_t *buf, int buf_size) {
         uint64_t pts = buffer_read64be(header);
         state->remaining = buffer_read32be(&header[8]);
 
-        if (!receiver_state_push_meta(state, pts)) {
+        if (pts != NO_PTS && !receiver_state_push_meta(state, pts)) {
             LOGE("Could not store PTS for recording");
             // we cannot save the PTS, the recording would be broken
             return -1;