$ cmake -DCMAKE_BUILD_TYPE=RELEASE

-- The C compiler identification is GNU 4.9.2
-- The CXX compiler identification is GNU 4.9.2
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Checking to see if CXX compiler accepts flag -flto
-- Checking to see if CXX compiler accepts flag -flto - yes
-- HTS_VERSION=2.1.1
-- Configuring done
-- Generating done
-- Build files have been written to: /tmp/pvr.hts-master

$ make

Scanning dependencies of target hts
[  7%] Building C object lib/libhts/CMakeFiles/hts.dir/htsbuf.c.o
[ 15%] Building C object lib/libhts/CMakeFiles/hts.dir/htsmsg_binary.c.o
[ 23%] Building C object lib/libhts/CMakeFiles/hts.dir/htsmsg.c.o
[ 30%] Building C object lib/libhts/CMakeFiles/hts.dir/htsstr.c.o
[ 38%] Building C object lib/libhts/CMakeFiles/hts.dir/sha1.c.o
[ 46%] Building C object lib/libhts/CMakeFiles/hts.dir/net_posix.c.o
Linking C static library libhts.a
[ 46%] Built target hts
Scanning dependencies of target pvr.hts
[ 53%] Building CXX object CMakeFiles/pvr.hts.dir/src/AsyncState.cpp.o
[ 61%] Building CXX object CMakeFiles/pvr.hts.dir/src/CircBuffer.cpp.o
[ 69%] Building CXX object CMakeFiles/pvr.hts.dir/src/client.cpp.o
[ 76%] Building CXX object CMakeFiles/pvr.hts.dir/src/HTSPConnection.cpp.o
[ 84%] Building CXX object CMakeFiles/pvr.hts.dir/src/HTSPDemuxer.cpp.o
In file included from /tmp/pvr.hts-master/src/HTSPDemuxer.cpp:35:0:
/tmp/pvr.hts-master/src/xbmc_codec_descriptor.hpp:23:27: fatal error: libXBMC_codec.h: No such file or directory
 #include "libXBMC_codec.h"
                           ^
compilation terminated.
CMakeFiles/pvr.hts.dir/build.make:146: recipe for target 'CMakeFiles/pvr.hts.dir/src/HTSPDemuxer.cpp.o' failed
make[2]: *** [CMakeFiles/pvr.hts.dir/src/HTSPDemuxer.cpp.o] Error 1
CMakeFiles/Makefile2:91: recipe for target 'CMakeFiles/pvr.hts.dir/all' failed
make[1]: *** [CMakeFiles/pvr.hts.dir/all] Error 2
Makefile:137: recipe for target 'all' failed
make: *** [all] Error 2

------------------------------------------------------------------------------
Let's try setting CMAKE_CXX_FLAGS (on clean source tree):

$ cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_FLAGS="-I/usr/share/kodi/addons/library.xbmc.codec -I/usr/include/kodi"

-- The C compiler identification is GNU 4.9.2
-- The CXX compiler identification is GNU 4.9.2
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Checking to see if CXX compiler accepts flag -flto
-- Checking to see if CXX compiler accepts flag -flto - yes
-- HTS_VERSION=2.1.1
-- Configuring done
-- Generating done
-- Build files have been written to: /tmp/pvr.hts-master

$ make

Scanning dependencies of target hts
[  7%] Building C object lib/libhts/CMakeFiles/hts.dir/htsbuf.c.o
[ 15%] Building C object lib/libhts/CMakeFiles/hts.dir/htsmsg_binary.c.o
[ 23%] Building C object lib/libhts/CMakeFiles/hts.dir/htsmsg.c.o
[ 30%] Building C object lib/libhts/CMakeFiles/hts.dir/htsstr.c.o
[ 38%] Building C object lib/libhts/CMakeFiles/hts.dir/sha1.c.o
[ 46%] Building C object lib/libhts/CMakeFiles/hts.dir/net_posix.c.o
Linking C static library libhts.a
[ 46%] Built target hts
Scanning dependencies of target pvr.hts
[ 53%] Building CXX object CMakeFiles/pvr.hts.dir/src/AsyncState.cpp.o
[ 61%] Building CXX object CMakeFiles/pvr.hts.dir/src/CircBuffer.cpp.o
[ 69%] Building CXX object CMakeFiles/pvr.hts.dir/src/client.cpp.o
[ 76%] Building CXX object CMakeFiles/pvr.hts.dir/src/HTSPConnection.cpp.o
[ 84%] Building CXX object CMakeFiles/pvr.hts.dir/src/HTSPDemuxer.cpp.o
In file included from /tmp/pvr.hts-master/src/xbmc_codec_descriptor.hpp:23:0,
                 from /tmp/pvr.hts-master/src/HTSPDemuxer.cpp:35:
/usr/share/kodi/addons/library.xbmc.codec/libXBMC_codec.h:37:7: error: redefinition of ‘class CHelper_libXBMC_codec’
 class CHelper_libXBMC_codec
       ^
In file included from /tmp/pvr.hts-master/src/client.h:28:0,
                 from /tmp/pvr.hts-master/src/Tvheadend.h:24,
                 from /tmp/pvr.hts-master/src/HTSPDemuxer.cpp:22:
/usr/include/kodi/libXBMC_codec.h:37:7: error: previous definition of ‘class CHelper_libXBMC_codec’
 class CHelper_libXBMC_codec
       ^
CMakeFiles/pvr.hts.dir/build.make:146: recipe for target 'CMakeFiles/pvr.hts.dir/src/HTSPDemuxer.cpp.o' failed
make[2]: *** [CMakeFiles/pvr.hts.dir/src/HTSPDemuxer.cpp.o] Error 1
CMakeFiles/Makefile2:91: recipe for target 'CMakeFiles/pvr.hts.dir/all' failed
make[1]: *** [CMakeFiles/pvr.hts.dir/all] Error 2
Makefile:137: recipe for target 'all' failed
make: *** [all] Error 2