dshow: drop initial audio packets with weird timestamps

Signed-off-by: rogerdpack <rogerpack2005@gmail.com>

libavdevice/dshow_pin.c

@@ -320,6 +320,14 @@ libAVMemInputPin_Receive(libAVMemInputPin *this, IMediaSample *sample)
     } else {
         int64_t dummy;
         IMediaSample_GetTime(sample, &curtime, &dummy);
+        if(curtime > 400000000000000000LL) {
+            /* initial frames sometimes start < 0 (shown as a very large number here,
+               like 437650244077016960 which FFmpeg doesn't like.
+               TODO figure out math. For now just drop them. */
+            av_log(NULL, AV_LOG_DEBUG,
+                "dshow dropping initial (or ending) audio frame with odd PTS too high %"PRId64"\n", curtime);
+            return S_OK;
+        }
         curtime += pin->filter->start_time;
     }