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  1. Code:
    General
     Complete name                    : G:\21.avi
     Format                           : AVI
     Format/Info                      : Audio Video Interleave
     File size                        : 700 MiB
     Duration                         : 1h 57mn
     Overall bit rate                 : 832 Kbps
     Writing application              : VirtualDubMod 1.5.10.2 (build 2540/release)
     Writing library                  : VirtualDubMod build 2540/release
     
     Video
     ID                               : 0
     Format                           : MPEG-4 Visual
     Format settings, BVOP            : Yes
     Format settings, QPel            : No
     Format settings, GMC             : No warppoints
     Format settings, Matrix          : Default (H.263)
     Muxing mode                      : Packed bitstream
     Codec ID                         : DX50
     Codec ID/Hint                    : DivX 5
     Duration                         : 1h 57mn
     Bit rate                         : 713 Kbps
     Width                            : 608 pixels
     Height                           : 336 pixels
     Display aspect ratio             : 16:9
     Frame rate                       : 25.000 fps
     Color space                      : YUV
     Chroma subsampling               : 4:2:0
     Bit depth                        : 8 bits
     Scan type                        : Progressive
     Bits/(Pixel*Frame)               : 0.140
     Stream size                      : 600 MiB (86%)
     Writing library                  : DivX 6.8.0 (UTC 2007-12-04)
     
     Audio
     ID                               : 1
     Format                           : MPEG Audio
     Format version                   : Version 1
     Format profile                   : Layer 3
     Mode                             : Joint stereo
     Mode extension                   : MS Stereo
     Codec ID                         : 55
     Codec ID/Hint                    : MP3
     Duration                         : 1h 57mn
     Bit rate mode                    : Constant
     Bit rate                         : 112 Kbps
     Channel(s)                       : 2 channels
     Sampling rate                    : 44.1 KHz
     Stream size                      : 94.3 MiB (13%)
     Alignment                        : Split accross interleaves
     Interleave, duration             : 80 ms (2.00 video frames)
     Interleave, preload duration     : 500 ms
     Writing library                  : LAME3.97 
     Encoding settings                : -m j -V 4 -q 2 -lowpass 15.6 -b 112
     Language                         : English
    How was the File Size was determined. I can't calculate properly with file size = (video bitrate + audio bitrate) * running time

    Also, what is difference between Two Pass- 1st pas and Two Pass - 2nd Pass, as such i want to make movie within file size and quality is very important, no problem if more CPU and time is used.
    Respected: jagabo, guns1inger and redwudz
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  2. Explorer Case's Avatar
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    Originally Posted by cyberlion View Post
    How was the File Size was determined. I can't calculate properly with file size = (video bitrate + audio bitrate) * running time
    Duration: 1h 57mn = 117 min = 7020 seconds (+/- 59 seconds)
    Audio bitrate: 112 Kbps (CBR); 112 * 7020 = 786,240 kilobits = 98,280 kilobyte = 95.98 MB. Pretty close to the reported 94.3 MiB.
    Video bitrate: 713 Kbps (VBR?); 713 * 7020 = 5,005,260 kilobits = 625,657.5 kiliobyte = 611 MB. Not too far off from the reported 600 MiB.
    Overall bit rate: 832 Kbps; 832 * 7020 = ... = 713 MB. Not too far off from the reported 700 MiB.
    The differences come from the fact that the encoder uses variable bitrate, so you won't know the actual size until the encoding is done, no matter what target bitrate you specify.
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  3. video bitrate = 713 kbps
    audio bitrate = 112 kbps
    running time = 7020 seconds (117 minutes)

    (713 + 112) * 7020 = 5,791,500 kbits

    divide by 8 to get kbytes

    5791500 / 8 ~= 723938 kbytes or 723,938,000 bytes

    But all those numbers are decimal. MiB is based on 1024*1024, not 1000*1000. So take the number of bytes and divide by 1024 twice:

    723,938,000 / 1024 / 1024 = 690 MiB.

    Adding a little overhead for the AVI container to bring the full size to 700 MiB, as reported by MediaInfo. Use a bitrate calculator program to take care all those calculations for you.

    During the first pass of a two pass encode the codec is examining the video to see how much relative bitrate each frame needs. During the second pass it uses that information to distribute bitrate to deliver the best quality for the desired average bitrate. Ie, frames that need more bitrate get more bitrate, frames that need less get less, in the end the requested average bitrate is achieved (and hence the expected file size).
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  4. Member PuzZLeR's Avatar
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    Good work guys, and I will add to this:
    Originally Posted by cyberlion View Post
    Also, what is difference between Two Pass- 1st pas and Two Pass - 2nd Pass, as such i want to make movie within file size and quality is very important, no problem if more CPU and time is used.
    Since the encoder doesn't know in advance until it "sees" the entire movie first it will do one pass to gather information. Then on the second pass it allocates the bitrate to what it believes are scenes that need it most such as more bitrate to complex scenes (like motion) and less to more simple scenes.

    Since, in theory, it works with a finite amount of bitrate (the file size limit you give it), it will attempt to give you the best quality at that size.

    This is why you shouldn't use something like CBR (Constant Bitrate) for video, which is one pass (especially since you don't care about CPU time). This method will give the exact amount of bitrate for every scene, but will likely give too little for complex scenes and too much for simple scenes. Same file size, but less quality. You save one pass, but the result is not efficient.

    Since you mention that quality is important to you, let me suggest Constant Quality mode if your encoder supports it, which is what the more experienced encoders here seem to like.

    This works the opposite - ask it the quality you want and it decides the minimum bitrate at the end. Since, in theory, it works with an infinite amount of bitrate (no file size limit restrictions), it will scan through the entire movie - in only one pass - and give this appropriate minimum bitrate for each scene.

    It doesn't guarantee you a file size but guarantees you the quality.
    I hate VHS. I always did.
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  5. I actually want quality in minimal size with more CPU and time usage.

    x264 or Xvid, which is globally accepted.

    If I make an 700 MB Xvid, will it same quality in x264 in 350 MB
    Respected: jagabo, guns1inger and redwudz
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  6. Member PuzZLeR's Avatar
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    Originally Posted by cyberlion View Post
    I actually want quality in minimal size with more CPU and time usage. x264 or Xvid, which is globally accepted.
    Although you won't know the file size till after the encode, Constant Quality (CFR in x264 and CQ in Xvid) will give you the minimum file size at the quality you ask it. It will not bloat your file.

    But, if you want an exact file size, and highest quality, then go ahead and use 2 pass at the slower settings (such as Slower, Very Slow, Placebo with x264). And if you want max quality when using bitrate encoding for your end result, then just avoid CBR (also called ABR)
    Originally Posted by cyberlion View Post
    If I make an 700 MB Xvid, will it same quality in x264 in 350 MB
    It depends but likely not. Yes, x264 has better compression than Xvid, especially at the lower bitrates, but I doubt twice as much. I would say 450MB-550MB might be a better answer.

    Actually, using a similar Constant Quality setting with both, Xvid and x264, will shed light on an answer as to what each yields in file size with respect to the Source. But every Source will be different.
    Last edited by PuzZLeR; 10th Oct 2010 at 13:04.
    I hate VHS. I always did.
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  7. So which is better, confused between Xvid and x264, on top of that i know Xvid, Which format Xvid or x264 is accepted by all systems and run freely.

    I can only do simple maths like you guys. Is there no program, where the movie file gets loaded and I put only my size limit and it shows Video Bit-Rate. It is head ache to learn each movie length act through it.

    Also what does Target size and Target bitrate mean in Xvid configuration of Vdub of two passes.
    Respected: jagabo, guns1inger and redwudz
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    Target size means it will manipulate the bitrate/quality to provide a size of the video that you specify.
    Target bitrate means it will manipulate the "quality" to provide the average bitrate you specify.

    In both cases, since it's two-pass, bit's are allocated on demand; eg. high action scenes get more bits.
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  9. Member PuzZLeR's Avatar
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    Originally Posted by cyberlion View Post
    So which is better, confused between Xvid and x264, on top of that i know Xvid, Which format Xvid or x264 is accepted by all systems and run freely.
    Depends.

    If you're looking at less encoding time and better compatibility among DvD and blu-ray players, particularly those with certification (like DivX), then Xvid is "better"

    If you're looking at better compression (less file size per quality level) then x264 is "better".

    However, x264's compatibility is still expanding and highly dependent on profile (QuickTime, iPod, PS3, blu-ray, DXVA, etc.) If you don't want to fiddle with profiles, but want it to "just play" outside of your PC, then you would need to look into a media box for this format.
    I hate VHS. I always did.
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  10. I did this setup and still it had gone to 1.67 GB

    General
    Complete name : C:\Users\IREG\Desktop\21-3.avi
    Format : AVI
    Format/Info : Audio Video Interleave
    File size : 1.67 GiB
    Duration : 1h 57mn
    Overall bit rate : 2 037 Kbps
    Writing application : VirtualDubMod 1.5.10.2 (build 2540/release)
    Writing library : VirtualDub build 32817/release

    Video
    ID : 0
    Format : MPEG-4 Visual
    Format profile : Simple@L3
    Format settings, BVOP : No
    Format settings, QPel : No
    Format settings, GMC : No warppoints
    Format settings, Matrix : Default (H.263)
    Codec ID : XVID
    Codec ID/Hint : XviD
    Duration : 1h 57mn
    Bit rate : 1 915 Kbps
    Width : 608 pixels
    Height : 336 pixels
    Display aspect ratio : 16:9
    Frame rate : 25.000 fps
    Color space : YUV
    Chroma subsampling : 4:2:0
    Bit depth : 8 bits
    Scan type : Progressive
    Bits/(Pixel*Frame) : 0.375
    Stream size : 1.57 GiB (94%)
    Writing library : XviD 1.2.1 (UTC 2008-12-04)

    Audio
    ID : 1
    Format : MPEG Audio
    Format version : Version 1
    Format profile : Layer 3
    Mode : Joint stereo
    Mode extension : MS Stereo
    Codec ID : 55
    Codec ID/Hint : MP3
    Duration : 1h 57mn
    Bit rate mode : Constant
    Bit rate : 112 Kbps
    Channel(s) : 2 channels
    Sampling rate : 44.1 KHz
    Stream size : 94.3 MiB (5%)
    Alignment : Split accross interleaves
    Interleave, duration : 40 ms (1.00 video frame)
    Interleave, preload duration : 500 ms
    Writing library : LAME3.97
    Encoding settings : -m j -V 4 -q 2 -lowpass 15.6 -b 112
    My BitRate Settings never end up - properly, after putting only Target bitrate in Xvid Config, it goes double the size. I have turned on deblocking and deriling in Xvid decoder option.


    How can i turn on BOVP.
    Last edited by cyberlion; 10th Oct 2010 at 17:30.
    Respected: jagabo, guns1inger and redwudz
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  11. Why do you have FPS set to 15? Your video is 25 fps. Did you run the first pass and the second pass with the same settings?
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  12. Are there different settings for both pass. I just calculated Xvid configuration to get that. Its not at all, acting to the settings, is there any variable change happening to settings to give quality.

    Though I have seen in two passes, the movie is run two times i think, my go in one line and closes after the process is over in 16 min. Really don't know whether VDub did it with two passes,.
    Respected: jagabo, guns1inger and redwudz
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  13. To do a 2-pass compression in VirtualDub you set everything up (open video file, set filters, etc) and set Xvid to "Twopass - 1st pass" and select any other Xvid options you want. Then select File -> Save as AVI. During the first pass Xvid is only examining the video, the file that's created will only have black frames. Once that is done you go back to the Xvid config dialog and change it to "Twopass - 2nd pass", select the desired size or bitrate (don't change any other VirtualDub settings), then File -> Save as AVI again. This time Xvid will produce an output file with your video.
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  14. So Is there no provision, that it works one after other, I have to intervene in between when 1st pass over.
    Respected: jagabo, guns1inger and redwudz
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  15. Originally Posted by cyberlion View Post
    So Is there no provision, that it works one after other, I have to intervene in between when 1st pass over.
    You can use VirtualDub's batch processing to perform the two passes. The setup procedure is the same, but instead of File -> Save as AVI you select File -> Queue Batch Operation -> Save as AVI. You do that for both passes then start up the batch processor to perform the two passes with File -> Job Control.
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    A second option is Avidemux. It does both passes automatically - although I found it to be a little slower than Vdub.
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  17. I find AviDemux to be pretty unreliable overall. Many crashes, aborts, lockups, etc.
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  18. Member
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    You are right about the somewhat unpredictable nature of Avidemux.
    I had version 253 installed, and decided to update to one of the more recent SVN builds.

    The newer release crashed when handling the ac3 audio on a file I had previously processed without problems (on the older
    release). Reinstalled the older release and back in business. These kinds of problems plague this product for some reason.

    I've found the 253 release version to work reasonably well.
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