mp4: skip 0 size trun samples

media/formats/mp4/mp4_stream_parser.cc

Index: media/formats/mp4/mp4_stream_parser.cc
diff --git a/media/formats/mp4/mp4_stream_parser.cc b/media/formats/mp4/mp4_stream_parser.cc
index 23f2d2401636e4634fbbe9afec29c335848f6d02..60a8e7eb04dd493aa3ca35f578bc5817fdadad35 100644
--- a/media/formats/mp4/mp4_stream_parser.cc
+++ b/media/formats/mp4/mp4_stream_parser.cc
@@ -33,6 +33,10 @@
 namespace media {
 namespace mp4 {
 
+namespace {
+const int kMaxEmptySampleLogs = 20;
+}

[wolenetz, 2016/09/23 19:14:54]

nit: // namespace

+
 MP4StreamParser::MP4StreamParser(const std::set<int>& audio_object_types,
                                  bool has_sbr)
     : state_(kWaitingForInit),
@@ -43,8 +47,8 @@ MP4StreamParser::MP4StreamParser(const std::set<int>& audio_object_types,
       has_video_(false),
       audio_object_types_(audio_object_types),
       has_sbr_(has_sbr),
-      num_top_level_box_skipped_(0) {
-}
+      num_top_level_box_skipped_(0),

[wolenetz, 2016/09/23 19:14:54]

aside: this other counter is no longer used. we should remove it.

+      num_emtpy_samples_skipped_(0) {}
 
 MP4StreamParser::~MP4StreamParser() {}
 
@@ -557,6 +561,16 @@ bool MP4StreamParser::EnqueueSample(BufferQueueMap* buffers, bool* err) {
   queue_.PeekAt(runs_->sample_offset() + moof_head_, &buf, &buf_size);
   if (buf_size < runs_->sample_size()) return false;
 
+  if (runs_->sample_size() == 0) {
+    // Generally not expected, but spec allows it. Code below this block assumes
+    // the current sample is not empty.
+    LIMITED_MEDIA_LOG(DEBUG, media_log_, num_emtpy_samples_skipped_,
+                      kMaxEmptySampleLogs)
+        << " Skipping 'trun' sample with size of 0.";
+    runs_->AdvanceSample();
+    return true;
+  }
+
   std::unique_ptr<DecryptConfig> decrypt_config;
   std::vector<SubsampleEntry> subsamples;
   if (runs_->is_encrypted()) {