手里有马达加斯加3，不知音频格式是不是原生5.1

各位懂的来看看，HDC 不能是低音质重新编码的，必须是原生5.1的。这句什么意思
II\Madagascar.3.Europes.Most.Wanted.2012.720p.BluRay.x264-SPARKS\sparks-madagascar3-720\madagascar.3.europes.most.wanted.2012.720p.bluray.x264-sparks.mkv
  General
    Complete name : II\Madagascar.3.Europes.Most.Wanted.2012.720p.BluRay.x264-SPARKS\sparks-madagascar3-720\madagascar.3.europes.most.wanted.2012.720p.bluray.x264-sparks.mkv
    Format : Matroska
    File size : 2.18 GiB
    Duration : 1h 33mn
    Overall bit rate : 3 349 Kbps
    Writing application : mkvmerge v4.1.1 ('Bouncin' Back') built on Jul  3 2010 22:54:08
    Writing library : libebml v1.0.0 + libmatroska v1.0
  Video #1
    ID : 1
    Format : AVC
    Format/Info : Advanced Video Codec
    Format profile : High@L4.1
    Format settings, CABAC : Yes
    Format settings, ReFrames : 5 frames
    Format settings, GOP : M=2, N=32
    Codec ID : V_MPEG4/ISO/AVC
    Duration : 1h 33mn
    Bit rate : 2 707 Kbps
    Width : 1 280 pixels
    Height : 720 pixels
    Display aspect ratio : 16:9
    Frame rate : 23.976 fps
    Color space : YUV
    Chroma subsampling : 4:2:0
    Bit depth : 8 bits
    Scan type : Progressive
    Bits/(Pixel*Frame) : 0.123
    Stream size : 1.72 GiB (79%)
    Writing library : x264 core 128 r2216 198a7ea
    Encoding settings : cabac=1 / ref=5 / deblock=1:0:0 / **yse=0x3:0x133 / me=umh / 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=0 / chroma_qp_offset=-2 / threads=12 / lookahead_threads=2 / 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=2pass / mbtree=1 / bitrate=2707 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / aq=1:1.00
    Language : English
Audio #2
    ID : 2
    Format : AC-3
    Format/Info : Audio Coding 3
    Mode extension : CM (complete main)
    Codec ID : A_AC3
    Duration : 1h 33mn
    Bit rate mode : Constant
    Bit rate : 640 Kbps
    Channel(s) : 6 channels
    Channel positions : Front: L C R, Side: L R, LFE
    Sampling rate : 48.0 KHz
    Bit depth : 16 bits
    Stream size : 428 MiB (19%)
    Language : English
  Text #3
    ID : 3
    Format : UTF-8
    Codec ID : S_TEXT/UTF8
    Codec ID/Info : UTF-8 Plain Text
    Language : English
  Text #4
    ID : 4
    Format : UTF-8
    Codec ID : S_TEXT/UTF8
    Codec ID/Info : UTF-8 Plain Text
    Language : English