fix: flag to indicate origin of header duration

packager/media/base/stream_info.h

@@ -110,7 +110,9 @@ class StreamInfo {
   uint32_t get_default_sample_duration() const {
     return default_sample_duration_;
   }
-  bool is_mehd_header_duration() const { return mehd_header_carryover_; };
+  int64_t get_default_fragment_duration() const {
+    return default_fragment_duration_;
+  };
 
   void set_duration(int64_t duration) { duration_ = duration; }
   void set_codec(Codec codec) { codec_ = codec; }
@@ -133,8 +135,8 @@ class StreamInfo {
     default_sample_duration_ = duration;
   }
 
-  void set_mehd_header_carryover(bool mehd_header_carryover) {
-    mehd_header_carryover_ = mehd_header_carryover;
+  void set_default_fragment_duration(int64_t default_fragment_duration) {
+    default_fragment_duration_ = default_fragment_duration;
   }
 
  private:
@@ -166,9 +168,9 @@ class StreamInfo {
   // repackaging an init segment alone.
   uint32_t default_sample_duration_ = 0;
 
-  // Flag to indicate whether the duration originated in the movie extends
-  // header and should carry over to the output segment.
-  bool mehd_header_carryover_ = false;
+  // Data to indicate whether the fragment duration originated in the movie
+  // extends header and should carry over to the output segment.
+  int64_t default_fragment_duration_ = 0;
 
   // Not using DISALLOW_COPY_AND_ASSIGN here intentionally to allow the compiler
   // generated copy constructor and assignment operator. Since the extra data is

packager/media/formats/mp4/mp4_media_parser.cc

@@ -410,17 +410,16 @@ bool MP4MediaParser::ParseMoov(BoxReader* reader) {
 
     // Calculate duration (based on timescale).
     int64_t duration = 0;
-    bool mehd_header_carryover = false;
-    if (track->media.header.duration > 0 &&
-        track->media.header.duration != std::numeric_limits<uint64_t>::max()) {
+    int64_t default_fragment_duration = 0;
+    if (track->media.header.duration > 0) {
       duration = track->media.header.duration;
-    } else if (moov_->extends.header.fragment_duration > 0 &&
-               moov_->extends.header.fragment_duration !=
-                   std::numeric_limits<uint64_t>::max()) {
+    } else if (moov_->extends.header.fragment_duration > 0) {
       DCHECK(moov_->header.timescale != 0);
       duration = Rescale(moov_->extends.header.fragment_duration,
                          moov_->header.timescale, timescale);
-      mehd_header_carryover = true;
+      if (duration > 0) {
+        default_fragment_duration = duration;
+      }
     } else if (moov_->header.duration > 0 &&
                moov_->header.duration != std::numeric_limits<uint64_t>::max()) {
       DCHECK(moov_->header.timescale != 0);
@@ -595,7 +594,7 @@ bool MP4MediaParser::ParseMoov(BoxReader* reader) {
           num_channels, sampling_frequency, seek_preroll_ns, codec_delay_ns,
           max_bitrate, avg_bitrate, track->media.header.language.code,
           is_encrypted));
-      streams.back()->set_mehd_header_carryover(mehd_header_carryover);
+      streams.back()->set_default_fragment_duration(default_fragment_duration);
 
       const EditList& edit_list = track->edit.list;
       if (edit_list.edits.size() == 1u) {
@@ -789,7 +788,8 @@ bool MP4MediaParser::ParseMoov(BoxReader* reader) {
           break;
         }
       }
-      video_stream_info->set_mehd_header_carryover(mehd_header_carryover);
+      video_stream_info->set_default_fragment_duration(
+          default_fragment_duration);
 
       streams.push_back(video_stream_info);
     }

packager/media/formats/mp4/mp4_muxer.cc

@@ -248,10 +248,9 @@ Status MP4Muxer::DelayInitializeMuxer() {
       ftyp->compatible_brands.push_back(FOURCC_cmfc);
 
     // Carry over movie extends header duration from init segment.
-    if (streams()[0].get()->duration() > 0 &&
-        streams()[0].get()->is_mehd_header_duration()) {
-      moov->extends.header.fragment_duration = streams()[0].get()->duration();
-    }
+    if (streams()[0].get()->get_default_fragment_duration() > 0)
+      moov->extends.header.fragment_duration =
+          streams()[0].get()->get_default_fragment_duration();
   }
 
   moov->header.creation_time = IsoTimeNow();