Tvheadend

Summary: some sleuthing here leads me to think that you're now relying on a later version of ffmpeg than ships with at least Oneiric (0.7.6-4:0.7.6-0ubuntu0.11.10.2) - I think that you're now relying on functions in libavformat that aren't there in my version, perhaps as of this commit. That's going to cause self-build problems, but will it also create dependency issues if you're expecting shared libraries? Do we need to move users to specific PPAs for later ffmpeg packages?

./configure --disable-libav works around it for now, though...

My system was failing to build tvheadend because the -Werror flag in the Makefile was stopping it on a couple of warnings:

/home/xbmc/tvheadend/src/muxer/muxer_libav.c: In function ‘lav_muxer_add_stream’:
/home/xbmc/tvheadend/src/muxer/muxer_libav.c:69:3: error: implicit declaration of function ‘avformat_new_stream’ [-Werror=implicit-function-declaration]
/home/xbmc/tvheadend/src/muxer/muxer_libav.c:69:6: error: assignment makes pointer from integer without a cast [-Werror]
cc1: all warnings being treated as errors

make: *** [build.linux/src/muxer/muxer_libav.o] Error 1

Over-riding this (no matter how rash!) finally got me to a real error:

xbmc@revo:~/tvheadend$ make -j4
CC              build.linux/src/main.o
CC              build.linux/src/utils.o
...
... all the modules that worked okay ...
...
CC              build.linux/src/cwc.o
CC              build.linux/src/capmt.o
/home/xbmc/tvheadend/src/muxer/muxer_libav.c: In function ‘lav_muxer_add_stream’:
/home/xbmc/tvheadend/src/muxer/muxer_libav.c:69:3: warning: implicit declaration of function ‘avformat_new_stream’ [-Wimplicit-function-declaration]
/home/xbmc/tvheadend/src/muxer/muxer_libav.c:69:6: warning: assignment makes pointer from integer without a cast [enabled by default]
CC              build.linux/src/ffdecsa/ffdecsa_interface.o
CC              build.linux/src/ffdecsa/ffdecsa_sse2.o
CC              build.linux/src/version.o
CC              build.linux/tvheadend
./build.linux/src/muxer/muxer_libav.o: In function `lav_muxer_add_stream':
/home/xbmc/tvheadend/src/muxer/muxer_libav.c:69: undefined reference to `avformat_new_stream'
collect2: ld returned 1 exit status
make: *** [build.linux/tvheadend] Error 1

Looking at the tvh code, there's no declaration for this function, so it's clearly intended to be brought in from elsewhere (ffmpeg is my guess, since libavformat is their demesne). Looking at my system include files (/usr/include), though, I can find no reference to avformat_new_stream.

Checking on a later ffmpeg code I downloaded for compskip, and - lo and behold - libavformat/avformat.h does indeed include the function declaration for avformat_new_stream. So I suspect it appears in ffmpeg between 0.7.6 and now...