From 28060d211388baf64d184d1d88e864fa82538a95 Mon Sep 17 00:00:00 2001
From: Thulinma <jaron@vietors.com>
Date: Fri, 16 Oct 2020 14:45:45 +0200
Subject: [PATCH] AAC RTMP/FLV input now ignore metadata and instead parse init
 data for channel count and sampling rate

---
 lib/adts.h      | 30 ++++++++++++++++++++----------
 lib/flv_tag.cpp |  5 +++++
 2 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/lib/adts.h b/lib/adts.h
index 8e759515..1725fbc8 100644
--- a/lib/adts.h
+++ b/lib/adts.h
@@ -53,26 +53,36 @@ namespace aac {
           default: return 0;
         }
       }
-      static inline uint16_t channels(const std::string & conf){
+      static inline uint16_t channels(const std::string &conf){
         Utils::bitstream bs;
         bs.append(conf.data(), conf.size());
-        if (bs.get(5) == 31){bs.skip(6);}//skip object type
-        if (bs.get(4) == 15){bs.skip(24);}//frequency index
-        return bs.get(4);//channel configuration
+        if (bs.get(5) == 31){bs.skip(6);}// skip object type
+        if (bs.get(4) == 15){bs.skip(24);}// frequency index
+        uint8_t chanConfig = bs.get(4);
+        if (chanConfig == 0){
+          WARN_MSG("Unimplemented AAC AOT Specific Config parsing");
+          return 8;
+        }
+        if (chanConfig > 7){
+          WARN_MSG("Unimplemented AAC channel configuration %" PRIu8, chanConfig);
+          return 8;
+        }
+        if (chanConfig == 7){return 8;}
+        return chanConfig;
       }
-      static inline uint8_t objtype(const std::string & conf){
+      static inline uint8_t objtype(const std::string &conf){
         Utils::bitstream bs;
         bs.append(conf.data(), conf.size());
         uint8_t ot = bs.get(5);
-        if (ot == 31){return bs.get(6)+32;}
+        if (ot == 31){return bs.get(6) + 32;}
         return ot;
       }
-      static inline uint16_t samples(const std::string & conf){
+      static inline uint16_t samples(const std::string &conf){
         Utils::bitstream bs;
         bs.append(conf.data(), conf.size());
-        if (bs.get(5) == 31){bs.skip(6);}//skip object type
-        if (bs.get(4) == 15){bs.skip(24);}//frequency index
-        bs.skip(4);//channel configuration
+        if (bs.get(5) == 31){bs.skip(6);}// skip object type
+        if (bs.get(4) == 15){bs.skip(24);}// frequency index
+        bs.skip(4);                           // channel configuration
         if (bs.get(1)){
           return 960;
         }else{
diff --git a/lib/flv_tag.cpp b/lib/flv_tag.cpp
index 8f98d0a0..8052b9ad 100644
--- a/lib/flv_tag.cpp
+++ b/lib/flv_tag.cpp
@@ -6,6 +6,7 @@
 #include "rtmpchunks.h"
 #include "timing.h"
 #include "util.h"
+#include "adts.h"
 #include <fcntl.h> //for Tag::FileLoader
 #include <sstream>
 #include <stdio.h>  //for Tag::FileLoader
@@ -890,6 +891,10 @@ void FLV::Tag::toMeta(DTSC::Meta &metadata, AMF::Object &amf_storage, unsigned i
       }else{
         metadata.tracks[reTrack].init = std::string((char *)data + 12, (size_t)len - 16);
       }
+      if (metadata.tracks[reTrack].codec == "AAC"){
+        metadata.tracks[reTrack].rate = aac::AudSpecConf::rate(metadata.tracks[reTrack].init);
+        metadata.tracks[reTrack].channels = aac::AudSpecConf::channels(metadata.tracks[reTrack].init);
+      }
     }
   }