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  1. Hi everybody,

    i've already posted a thread about uprezing to prores, but what finally worked pretty fine with a file, didn't work with another one.

    Here's the deal.

    source specs:
    Video : 00:03:55,880, 25,000 ips interlaced, 1440x1080x12, MPEG-2
    Audio : 00:03:55,880, 48*000 Hz; Stéréo, MPEG Layer 2

    output specs:
    video: Apple PRO RES 422HQ 1920x1080 ~220 Mb/s, 25 fps, YUV colorspace
    audio: mp2, 48 kHz, 16 bits, 384 kb/s, 2 channels (stereo)

    ffmbc -i input.m2t -vcodec prores -qscale 1 -r 25 -acodec mp2 -sample_fmt s16 -ar 48000 -ab 384k -ac 2 -vf scale=1920:1080 output.mov

    I never get a bitrate up to 150 mb (minimum bitrateso the video is accpted by my uplaod system).

    can anyone help me with this one.

    I don't really understand what makes a video conversion go fine with one and bad with another.

    Thanks in advance


    Vincent
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  2. Member
    Join Date: Sep 2007
    Location: Canada
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    The resultant bitrate is determined by the source content complexity. For example, if it was still image, the bitrate might be 50Mb/s . If there was lots of action and noise it might be 350Mb/s

    You probably don't have enough real details or content complexity (motion, noise, details) in the source video - and have saturated the encoder

    The solution is to add a bit of grain or noise
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  3. I'll search the web anyway, but is there a better command to put noise in an image.

    thanks in advance

    Vincent
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  4. Member
    Join Date: Sep 2007
    Location: Canada
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    Also, if that is an interlaced source (looks like "PAL" spec HDV ? ), you need to add "-tff" to the commandline

    I don't know if ffmbc/ffmpeg has a noise generator offhand, but you can use some filters in avisynth

    EDIT: looks like ffmpeg has an add noise filter
    http://www.ffmpeg.org/ffmpeg-filters.html#noise
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  5. I'm a MEGA Super Moderator Baldrick's Avatar
    Join Date: Aug 2000
    Location: Sweden
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    ffmpegx is not ffmbc. Moving you to our video conversion section.
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  6. Well thank you poisondeathray I'm gonna check that;
    The point is the video is Black and White that's perhaps the reason why i get a low bitrate

    Thanks you a lot
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