--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -1178,6 +1178,10 @@ typedef struct AVStreamGroup {
 
 struct AVCodecParserContext *av_stream_get_parser(const AVStream *s);
 
+// Chromium: We use the internal field first_dts vvv
+int64_t    av_stream_get_first_dts(const AVStream *st);
+// Chromium: We use the internal field first_dts ^^^
+
 #define AV_PROGRAM_RUNNING 1
 
 /**
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -51,6 +51,13 @@
  * various utility functions for use within FFmpeg
  */
 
+// Chromium: We use the internal field first_dts vvv
+int64_t av_stream_get_first_dts(const AVStream *st)
+{
+  return ffstream(st)->first_dts;
+}
+// Chromium: We use the internal field first_dts ^^^
+
 /* an arbitrarily chosen "sane" max packet size -- 50M */
 #define SANE_CHUNK_SIZE (50000000)