Skip AUD while extracting SPS and PPS on iOS.

webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_nalu.cc

Index: webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_nalu.cc
diff --git a/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_nalu.cc b/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_nalu.cc
index b0c4bd326d45e8c584a424273e788bea5e62e0d1..b03a72382755d65dec70862b2816a5b66f35c24c 100644
--- a/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_nalu.cc
+++ b/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_nalu.cc
@@ -255,7 +255,15 @@ bool H264AnnexBBufferHasVideoFormatDescription(const uint8_t* annexb_buffer,
   // separately.
   uint8_t first_nalu_type = annexb_buffer[4] & 0x1f;
   bool is_first_nalu_type_sps = first_nalu_type == 0x7;
-  return is_first_nalu_type_sps;
+  if (is_first_nalu_type_sps)
+    return true;
+  bool is_first_nalu_type_delimiter = first_nalu_type == 0x9;
+  // start code + access unit delimiter + start code = 4 + 2 + 4 = 10

[tkchin_webrtc, 2016/08/04 16:49:05]

nit: caps and period // Start code .... = 10. Here and elsewhere.

[jianjunz, 2016/08/05 06:35:32]

Done.

+  if (!is_first_nalu_type_delimiter || annexb_buffer_size <= 10u)
+    return false;
+  uint8_t second_nalu_type = annexb_buffer[10] & 0x1f;
+  bool is_second_nalu_type_sps = second_nalu_type == 0x7;
+  return is_second_nalu_type_sps;
 }
 
 CMVideoFormatDescriptionRef CreateVideoFormatDescription(
@@ -271,6 +279,13 @@ CMVideoFormatDescriptionRef CreateVideoFormatDescription(
   // Parse the SPS and PPS into a CMVideoFormatDescription.
   const uint8_t* param_set_ptrs[2] = {};
   size_t param_set_sizes[2] = {};
+  // Skip AUD
+  if ((annexb_buffer[4] & 0x1f) == 0x9) {

[tkchin_webrtc, 2016/08/04 16:49:05]

suggest having enum for types, and function that returns type given nalu start
ptr
will make this more readable, and can also be applied above

[jianjunz, 2016/08/05 06:35:32]

Included "webrtc/common_video/h264/h264_common.h" for NALU type definition and
parsing.

+    if (!reader.ReadNalu(&param_set_ptrs[0], &param_set_sizes[0])) {
+      LOG(LS_ERROR) << "Failed to read AUD";
+      return nullptr;
+    }
+  }
   if (!reader.ReadNalu(&param_set_ptrs[0], &param_set_sizes[0])) {
     LOG(LS_ERROR) << "Failed to read SPS";
     return nullptr;