Command ffmpeg -ss 5:09 -i foo.mkv -to 5:10 -c copy bar.mkv works exactly like ffmpeg -ss 5:09 -i foo.mkv -t 5:10 -c copy bar.mkv Is it a bug? Using Zeranoe git-bd75651 for Windows 64-bit >ffmpeg -version ffmpeg version N-57906-gbd75651 built on Nov 4 2013 18:09:19 with gcc 4.8.2 (GCC) configuration: --disable-static --enable-shared --enable-gpl --enable-version3 - -disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enabl e-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --ena ble-libcaca --enable-libfreetype --enable-libgsm --enable-libilbc --enable-libmo dplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enab le-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis - -enable-libvpx --enable-libwavpack --enable-libx264 --enable-libxavs --enable-li bxvid --enable-zlib libavutil 52. 51.100 / 52. 51.100 libavcodec 55. 41.100 / 55. 41.100 libavformat 55. 21.100 / 55. 21.100 libavdevice 55. 5.100 / 55. 5.100 libavfilter 3. 90.101 / 3. 90.101 libswscale 2. 5.101 / 2. 5.101 libswresample 0. 17.104 / 0. 17.104 libpostproc 52. 3.100 / 52. 3.100