What determines the quality of a given video?

Discussion in 'Graphics & Multimedia' started by Shiplu, Aug 11, 2012.

  1. #1
    This is a general discussion.

    How do you determine the quality of a video? Suppose you are given bit rate, bit depth, resolution, encoding etc information. Also note the video is not pixelated. This ensures its not up-scaled. So quality factors will not give false hint.

    As an example I give you media information of two videos. Can you tell which is better/worse? why is it?

    Video 1
    ID                                       : 1
    Format                                   : AVC
    Format/Info                              : Advanced Video Codec
    Format profile                           : High@L3.1
    Format settings, CABAC                   : Yes
    Format settings, ReFrames                : 4 frames
    Codec ID                                 : V_MPEG4/ISO/AVC
    Duration                                 : 3h 2mn
    Nominal bit rate                         : 1 048 Kbps
    Width                                    : 1 280 pixels
    Height                                   : 720 pixels
    Display aspect ratio                     : 16:9
    Frame rate                               : 24.000 fps
    Color space                              : YUV
    Chroma subsampling                       : 4:2:0
    Bit depth                                : 8 bits
    Scan type                                : Progressive
    Bits/(Pixel*Frame)                       : 0.047
    Writing library                          : x264 core 125 r2200 999b753
    Encoding settings                        : cabac=1 / ref=3 / deblock=1:-1:-1 / analyse=0x3:0x113 / me=umh / subme=9 / psy=1 / psy_rd=0.00:0.00 / mixed_ref=1 / me_range=32 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=0 / threads=48 / lookahead_threads=8 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=2pass / mbtree=1 / bitrate=1048 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / aq=1:1.00
    Default                                  : Yes
    Forced                                   : No
    Code (markup):

    Video 2
    ID                                       : 1
    Format                                   : AVC
    Format/Info                              : Advanced Video Codec
    Format profile                           : High@L5.1
    Format settings, CABAC                   : Yes
    Format settings, ReFrames                : 4 frames
    Codec ID                                 : V_MPEG4/ISO/AVC
    Duration                                 : 1h 30mn
    Nominal bit rate                         : 817 Kbps
    Width                                    : 1 280 pixels
    Height                                   : 544 pixels
    Display aspect ratio                     : 2.35:1
    Frame rate                               : 23.976 fps
    Color space                              : YUV
    Chroma subsampling                       : 4:2:0
    Bit depth                                : 8 bits
    Scan type                                : Progressive
    Bits/(Pixel*Frame)                       : 0.049
    Writing library                          : x264 core 120 r2146 bcd41db
    Encoding settings                        : cabac=1 / ref=3 / deblock=1:-1:-1 / analyse=0x3:0x113 / me=umh / subme=9 / psy=1 / psy_rd=0.00:0.00 / mixed_ref=1 / me_range=32 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-2 / threads=12 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=240 / keyint_min=23 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=2pass / mbtree=1 / bitrate=817 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / aq=1:1.00
    Default                                  : Yes
    Forced                                   : No
    Code (markup):
     
    Shiplu, Aug 11, 2012 IP
  2. Ariq

    Ariq Active Member

    Messages:
    103
    Likes Received:
    0
    Best Answers:
    0
    Trophy Points:
    51
    #2
    both are good... the quality... in my experience it totally depends on the user... like if you want a low dimension video to be in full screen without much tear... then its bit rate must to high.... or if you already have a hd video then its bit rate may not be too high for no tearing... :) ...

    as for framerates... it determines the number of images in a second... basically 24 is common and for blu ray quality its 60... I'd say something above 23 is fine... cause they you'll not notice the video looking like a book flipping images... and if you want to slow down a video (using any software) then the more frame rate it has the better result you get... :)

    hope it all helps... :A
     
    Ariq, Aug 14, 2012 IP