ffmpeg -i /media/Data/shows/Spice\ and\ Wolf/spice_and_wolf_01\[1280x720.h264.flac\]\[niizk\].mkv -acodec copy output.mp4
ffmpeg version git-2012-12-10-a933698 Copyright (c) 2000-2012 the FFmpeg developers
  built on Dec  9 2012 22:12:26 with gcc 4.4.3 (Ubuntu 4.4.3-4ubuntu5.1)
  configuration: --enable-gpl --enable-libfaac --enable-libfdk-aac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libvpx --enable-x11grab --enable-libx264 --enable-nonfree --enable-version3 --enable-libass
  libavutil      52. 12.100 / 52. 12.100
  libavcodec     54. 79.101 / 54. 79.101
  libavformat    54. 49.100 / 54. 49.100
  libavdevice    54.  3.102 / 54.  3.102
  libavfilter     3. 26.101 /  3. 26.101
  libswscale      2.  1.103 /  2.  1.103
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
Input #0, matroska,webm, from '/media/Data/shows/Spice and Wolf/spice_and_wolf_01[1280x720.h264.flac][niizk].mkv':
  Metadata:
    creation_time   : 2009-04-28 23:52:12
  Duration: 00:23:45.02, start: 0.000000, bitrate: 2964 kb/s
    Chapter #0.0: start 0.000000, end 90.007000
    Metadata:
      title           : Chapter 1
    Chapter #0.1: start 90.007000, end 1329.997000
    Metadata:
      title           : Chapter 2
    Chapter #0.2: start 1329.997000, end 1420.003000
    Metadata:
      title           : Chapter 3
    Chapter #0.3: start 1420.003000, end 1425.015000
    Metadata:
      title           : Chapter 4
    Stream #0:0: Video: h264 (High), yuv420p, 1280x720, SAR 1:1 DAR 16:9, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
    Metadata:
      title           : Episode01: The Wolf and One's Best Clothes
    Stream #0:1(jpn): Audio: flac, 48000 Hz, stereo, s16 (default)
    Metadata:
      title           : 2.0 FLAC
    Stream #0:2(eng): Subtitle: ssa (default)
    Metadata:
      title           : ASS
    Stream #0:3(eng): Subtitle: subrip
    Metadata:
      title           : SRT
Codec 0x18000 is not in the full list.
    Stream #0:4: Attachment: unknown_codec
    Metadata:
      filename        : StackCnd-Bold.ttf
      mimetype        : application/x-truetype-font
Codec 0x18000 is not in the full list.
    Stream #0:5: Attachment: unknown_codec
    Metadata:
      filename        : FromageCondOblique.ttf
      mimetype        : application/x-truetype-font
File 'output.mp4' already exists. Overwrite ? [y/N] y
using SAR=1/1
[libx264 @ 0x9f13dc0] using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE4.1 Cache64
[libx264 @ 0x9f13dc0] profile High, level 3.1
[libx264 @ 0x9f13dc0] 264 - core 129 r2 1cffe9f - H.264/MPEG-4 AVC codec - Copyleft 2003-2012 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=3 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=23 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
[mp4 @ 0xa01f920] track 1: could not find tag, codec not currently supported in container
Output #0, mp4, to 'output.mp4':
  Metadata:
    encoder         : Lavf54.49.100
    Chapter #0.0: start 0.000000, end 90.007000
    Metadata:
      title           : Chapter 1
    Chapter #0.1: start 90.007000, end 1329.997000
    Metadata:
      title           : Chapter 2
    Chapter #0.2: start 1329.997000, end 1420.003000
    Metadata:
      title           : Chapter 3
    Chapter #0.3: start 1420.003000, end 1425.015000
    Metadata:
      title           : Chapter 4
    Stream #0:0: Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=-1--1, 24k tbn, 23.98 tbc (default)
    Metadata:
      title           : Episode01: The Wolf and One's Best Clothes
    Stream #0:1(jpn): Audio: flac, 48000 Hz, stereo (default)
    Metadata:
      title           : 2.0 FLAC
Stream mapping:
  Stream #0:0 -> #0:0 (h264 -> libx264)
  Stream #0:1 -> #0:1 (copy)
Could not write header for output file #0 (incorrect codec parameters ?): Operation not permitted