ZM 1.28.1 and ffmpeg v2.6.1 no image under Gentoo

[christophe_y2k]

Hi, all
i recently upgrade my gentoo tu use mediacenter kodi and remove the older xbmc
have ffmpeg 2.6.1 with this detail:
[ebuild R ~] media-video/ffmpeg-2.6.1:0/54.56.56 USE="X aac alsa amr bluray bzip2 cdio cpudetection encode gpl hardcoded-tables iconv ieee1394 jack jpeg2k lzma mp3 network openal opengl openssl oss postproc pulseaudio samba sdl speex theora threads truetype twolame vaapi vorbis vpx wavpack x264 xcb xvid zlib -aacplus (-altivec) -amrenc (-armv5te) (-armv6) (-armv6t2) (-armvfp) -bs2b -celt -debug -doc -examples -faac -fdk -flite -fontconfig -frei0r -fribidi -gme -gnutls -gsm -iec61883 -ladspa -libass -libcaca -libsoxr -libv4l (-mipsdspr1) (-mipsdspr2) (-mipsfpu) -modplug (-neon) -opus -pic -quvi -rtmp -schroedinger -ssh -static-libs {-test} -v4l -vdpau -webp -x265 -zvbi" ABI_X86="(64) -32 (-x32)" CPU_FLAGS_X86="avx avx2 fma3 mmx mmxext sse sse2 sse3 sse4_1 sse4_2 ssse3 -3dnow -3dnowext -fma4 -xop" FFTOOLS="aviocat cws2fws ffescape ffeval ffhash fourcc2pixfmt graph2dot ismindex pktdumper qt-faststart trasher"

and vlc 2.1.5 with this detail
[ebuild R ] media-video/vlc-2.1.5-r1:0/5-7 USE="X a52 alsa avcodec avformat bluray cdda cddb dbus dirac dts dvb dvbpsi dvd egl encode faad ffmpeg flac fluidsynth gcrypt gnome ieee1394 jack libnotify libsamplerate lirc live matroska mp3 mpeg musepack ncurses ogg opengl png postproc pulseaudio qt4 rtsp samba sdl skins speex svg swscale theora tremor truetype twolame udev upnp vaapi vnc vorbis x264 xcb xml xv -aalib (-altivec) -atmo (-audioqueue) -avahi -bidi -chromaprint -dc1394 -debug -directfb (-directx) (-dxva2) -fdk -fontconfig -gme (-gnutls) -growl -httpd (-ios-vout) -kate -kde -libass -libav -libcaca -libtar -libtiger -linsys -lua (-macosx) (-macosx-audio) (-macosx-dialog-provider) (-macosx-eyetv) (-macosx-qtkit) (-macosx-quartztext) (-macosx-vout) (-media-library) -modplug -mtp (-neon) -omxil -opencv -optimisememory (-opus) -projectm -rdp -run-as-root -schroedinger -sdl-image -sftp -shout -sid -taglib {-test} -v4l -vcdx (-vdpau) -vlm -wma-fixed -zvbi" CPU_FLAGS_X86="mmx sse"

after a rebuild of ZM, now haven't got any image on foscam ffmpeg camera
only pure http cam work