From 939924439d3dce9cbfae97cd34b004aee01ac043 Mon Sep 17 00:00:00 2001
From: Erik Zandvliet <erik.zandvliet@ddvtech.com>
Date: Fri, 8 Apr 2016 10:03:38 +0200
Subject: [PATCH] Nasty hack for fixing H264 init data on FLV

---
 lib/bitfields.h |  2 +-
 lib/flv_tag.cpp | 13 +++++++++++++
 lib/h264.cpp    |  6 ++++++
 lib/h264.h      |  3 ++-
 4 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/lib/bitfields.h b/lib/bitfields.h
index 0ca119a4..8fb8dc98 100644
--- a/lib/bitfields.h
+++ b/lib/bitfields.h
@@ -15,7 +15,7 @@ namespace Bit{
   //Host to binary/binary to host functions - similar to kernel ntoh/hton functions.
 
   /// Retrieves a short in network order from the pointer p.
-  inline unsigned short btohs(char * p) {
+  inline unsigned short btohs(const char * p) {
     return ((unsigned short)p[0] << 8) | p[1];
   }
 
diff --git a/lib/flv_tag.cpp b/lib/flv_tag.cpp
index 9d2289e5..d4f5cf18 100644
--- a/lib/flv_tag.cpp
+++ b/lib/flv_tag.cpp
@@ -11,6 +11,9 @@
 #include <string.h> //memcpy
 #include <sstream>
 
+
+#include "h264.h" //Needed for init data parsing in case of invalid values from FLV init
+
 /// Holds the last FLV header parsed.
 /// Defaults to a audio+video header on FLV version 0x01 if no header received yet.
 char FLV::Header[13] = {'F', 'L', 'V', 0x01, 0x05, 0, 0, 0, 0x09, 0, 0, 0, 0};
@@ -1099,6 +1102,16 @@ JSON::Value FLV::Tag::toJSON(DTSC::Meta & metadata, AMF::Object & amf_storage, u
         }
         metadata.tracks[reTrack].init = std::string((char *)data + 12, (size_t)len - 16);
       }
+      ///this is a hacky way around invalid FLV data (since it gets ignored nearly everywhere, but we do need correct data...
+      if (!metadata.tracks[reTrack].width || !metadata.tracks[reTrack].height || !metadata.tracks[reTrack].fpks){
+        h264::sequenceParameterSet sps;
+        sps.fromDTSCInit(metadata.tracks[reTrack].init);
+        h264::SPSMeta spsChar = sps.getCharacteristics();
+        metadata.tracks[reTrack].width = spsChar.width;
+        metadata.tracks[reTrack].height = spsChar.height;
+        metadata.tracks[reTrack].fpks = spsChar.fps * 1000;
+
+      }
       pack_out.null();
       return pack_out; //skip rest of parsing, get next tag.
     }
diff --git a/lib/h264.cpp b/lib/h264.cpp
index 6d6efd3b..591cf725 100644
--- a/lib/h264.cpp
+++ b/lib/h264.cpp
@@ -81,6 +81,12 @@ namespace h264 {
 
   sequenceParameterSet::sequenceParameterSet(const char * _data, unsigned long _dataLen) : data(_data), dataLen(_dataLen) {}
 
+  //DTSC Initdata is the payload for an avcc box. init[8+] is data, init[6-7] is a network-encoded length
+  void sequenceParameterSet::fromDTSCInit(const std::string & dtscInit){
+    data = dtscInit.data() + 8;
+    dataLen = Bit::btohs(dtscInit.data() + 6);
+  }
+
   SPSMeta sequenceParameterSet::getCharacteristics()  const {
     SPSMeta result;
 
diff --git a/lib/h264.h b/lib/h264.h
index 28cc693b..23dec794 100644
--- a/lib/h264.h
+++ b/lib/h264.h
@@ -50,7 +50,8 @@ namespace h264 {
 
   class sequenceParameterSet {
     public:
-      sequenceParameterSet(const char * _data, unsigned long _dataLen);
+      sequenceParameterSet(const char * _data = NULL, unsigned long _dataLen = 0);
+      void fromDTSCInit(const std::string & dtscInit);
       SPSMeta getCharacteristics() const;
     private:
       const char * data;