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  1. Using Womble MPEG Video Wizard, which claims not to re-encode video after editing, I'm finding the bitrate of my edited file much less than the original (eg 2000 Kbps down to 1500 Kbps).

    How can this be so if it hasn't re-encoded? I want to be sure I'm not losing any data, this doesn't fill me with confidence!


    Also, can I get it to display where I-frames are, or to jump to the nearest i-Frame when I want to make an edit?
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  2. Member hech54's Avatar
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    If you are doing straight cuts/no filters or transitions(from say MPEG2 to MPEG2) then it should do AT LEAST smart rendering.
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  3. I'm not sure what it's doing hech54!

    I've just made a little test of importing an MPEG, not making any edits at all and resaving it and it's still reduced the bitrate, from 2522Kbps to 2006 Kbps. It wrote the file in seconds though, no chance to re-render????
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  4. Member
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    Originally Posted by Gibson's Squares View Post

    I've just made a little test of importing an MPEG, not making any edits at all and resaving it and it's still reduced the bitrate, from 2522Kbps to 2006 Kbps.
    MediaInfo for both before and after files might shed some light on this...
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    Originally Posted by Gibson's Squares View Post
    Also, can I get it to display where I-frames are, or to jump to the nearest i-Frame when I want to make an edit?
    I could not find a way to make MPEG Video Wizard display the frame type in the Input window. There are keyboard shortcuts for I-frame and P-frame navigation.

    Go to next I-frame = Ctrl + Right Arrow
    Go to previous I-frame = Ctrl + Left Arrow

    Go to next P-frame = Shift + Right Arrow
    Go to previous P-frame = Shift + Left Arrow
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  6. What's the source of the original files and how are you determining the bitrates? They could contain some padding that's just removed.
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  7. Thanks for the shortcuts @usually_quiet.

    The source file is an MPEG-TS of a TV broadcast (no conversion/re-compression, just captured as streamed), recorded using an Elgata EyeTV device (Mac).
    I got the bitrates I quoted from MediaInfo.
    When you say padding, why might that be? Seems a funny thing to overinflate a file??

    Here's the two MediaInfo specs from the file I resaved without editing and still got the bitrate reduction from:

    General
    ID : 20544 (0x5040)
    Complete name : original_file.mpg
    Format : MPEG-TS
    File size : 18.7 MiB
    Duration : 1mn 2s
    Start time : UTC 2014-03-28 22:59:32
    End time : UTC 2014-03-28 23:00:33
    Overall bit rate mode : Variable
    Overall bit rate : 2 522 Kbps
    Country : GBR / IRL
    Timezone : +00:00:00 / +00:00:00

    Video
    ID : 201 (0xC9)
    Menu ID : 22226 (0x56D2)
    Format : MPEG Video
    Format version : Version 2
    Format profile : Main@Main
    Format settings, BVOP : Yes
    Format settings, Matrix : Custom
    Format settings, GOP : M=3, N=36
    Codec ID : 2
    Duration : 1mn 0s
    Bit rate mode : Variable
    Bit rate : 2 268 Kbps
    Maximum bit rate : 15.0 Mbps
    Width : 544 pixels
    Height : 576 pixels
    Display aspect ratio : 16:9
    Active Format Description : Full frame 16:9 image
    Frame rate : 25.000 fps
    Color space : YUV
    Chroma subsampling : 4:2:0
    Bit depth : 8 bits
    Scan type : Interlaced
    Scan order : Top Field First
    Compression mode : Lossy
    Bits/(Pixel*Frame) : 0.290
    Stream size : 16.4 MiB (88%)

    Audio
    ID : 202 (0xCA)
    Menu ID : 22226 (0x56D2)
    Format : MPEG Audio
    Format version : Version 1
    Format profile : Layer 2
    Mode : Joint stereo
    Codec ID : 4
    Duration : 1mn 2s
    Bit rate mode : Constant
    Bit rate : 128 Kbps
    Channel(s) : 2 channels
    Sampling rate : 48.0 KHz
    Compression mode : Lossy
    Stream size : 970 KiB (5%)
    Language : English

    Menu
    ID : 727 (0x2D7)
    Menu ID : 22226 (0x56D2)
    Duration : 1mn 2s
    List : 201 (0xC9) (MPEG Video) / 202 (0xCA) (MPEG Audio, English)
    Language : / English
    Service name : Network21
    Service type : digital television
    General
    ID : 16 (0x10)
    Complete name : resaved_file_with_no_edits.mpg
    Format : MPEG-TS
    File size : 14.8 MiB
    Duration : 1mn 1s
    Overall bit rate mode : Variable
    Overall bit rate : 2 006 Kbps

    Video
    ID : 201 (0xC9)
    Menu ID : 22226 (0x56D2)
    Format : MPEG Video
    Format version : Version 2
    Format profile : Main@Main
    Format settings, BVOP : Yes
    Format settings, Matrix : Custom
    Format settings, GOP : M=3, N=36
    Codec ID : 2
    Duration : 1mn 1s
    Bit rate mode : Variable
    Bit rate : 1 778 Kbps
    Maximum bit rate : 15.0 Mbps
    Width : 544 pixels
    Height : 576 pixels
    Display aspect ratio : 16:9
    Active Format Description : Full frame 16:9 image
    Frame rate : 25.000 fps
    Color space : YUV
    Chroma subsampling : 4:2:0
    Bit depth : 8 bits
    Scan type : Interlaced
    Scan order : Top Field First
    Compression mode : Lossy
    Bits/(Pixel*Frame) : 0.227
    Stream size : 13.1 MiB (88%)
    Writing library : (dvd5: Jun 16 2014)

    Audio
    ID : 202 (0xCA)
    Menu ID : 22226 (0x56D2)
    Format : MPEG Audio
    Format version : Version 1
    Format profile : Layer 2
    Mode : Joint stereo
    Codec ID : 3
    Duration : 1mn 1s
    Bit rate mode : Constant
    Bit rate : 128 Kbps
    Channel(s) : 2 channels
    Sampling rate : 48.0 KHz
    Compression mode : Lossy
    Stream size : 968 KiB (6%)
    You'll see it's stripped out the broadcast data, but also reduced the filesize, and made it one second shorter?!

    In another one I tested (where I did make some edits) the GOPs (not sure what they are??) were altered too,.
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  8. Member netmask56's Avatar
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    On the output window are you choosing a template or running automatic. If the input file is a stock standard mpeg file and you use automatic then it should be the same. You can do cuts ie remove commercials etc without any re-encoding, likewise if you do a cross fade it will only re-encode around the cross fade. A trick you can do with cross fades and other effects is to put additional "splits" either side of the real edit point. This will ensure any re-encoding around the edit point will truly be constrained to a small section. Make sure you highlight either side of the edit point before applying the effect.
    TheVoiceIsAnotherPerson ~ BeyonWiz DP-P1 and T3 PVR's ~ Popcorn C200 ~ Samsung ES8000 65" LED TV ~ Windows 7 ~ Yamaha RX-A1030 http://www.openwiz.org/wiki/ProjectX
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  9. In the example above I definately chose 'automatic'.
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  10. Member
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    Originally Posted by Gibson's Squares View Post
    Thanks for the shortcuts @usually_quiet.

    The source file is an MPEG-TS of a TV broadcast (no conversion/re-compression, just captured as streamed), recorded using an Elgata EyeTV device (Mac).
    I got the bitrates I quoted from MediaInfo.
    When you say padding, why might that be? Seems a funny thing to overinflate a file??

    Here's the two MediaInfo specs from the file I resaved without editing and still got the bitrate reduction from:

    General
    ID : 20544 (0x5040)
    Complete name : original_file.mpg
    Format : MPEG-TS
    File size : 18.7 MiB
    Duration : 1mn 2s
    Start time : UTC 2014-03-28 22:59:32
    End time : UTC 2014-03-28 23:00:33
    Overall bit rate mode : Variable
    Overall bit rate : 2 522 Kbps
    Country : GBR / IRL
    Timezone : +00:00:00 / +00:00:00

    Video
    ID : 201 (0xC9)
    Menu ID : 22226 (0x56D2)
    Format : MPEG Video
    Format version : Version 2
    Format profile : Main@Main
    Format settings, BVOP : Yes
    Format settings, Matrix : Custom
    Format settings, GOP : M=3, N=36
    Codec ID : 2
    Duration : 1mn 0s
    Bit rate mode : Variable
    Bit rate : 2 268 Kbps
    Maximum bit rate : 15.0 Mbps
    Width : 544 pixels
    Height : 576 pixels
    Display aspect ratio : 16:9
    Active Format Description : Full frame 16:9 image
    Frame rate : 25.000 fps
    Color space : YUV
    Chroma subsampling : 4:2:0
    Bit depth : 8 bits
    Scan type : Interlaced
    Scan order : Top Field First
    Compression mode : Lossy
    Bits/(Pixel*Frame) : 0.290
    Stream size : 16.4 MiB (88%)

    Audio
    ID : 202 (0xCA)
    Menu ID : 22226 (0x56D2)
    Format : MPEG Audio
    Format version : Version 1
    Format profile : Layer 2
    Mode : Joint stereo
    Codec ID : 4
    Duration : 1mn 2s
    Bit rate mode : Constant
    Bit rate : 128 Kbps
    Channel(s) : 2 channels
    Sampling rate : 48.0 KHz
    Compression mode : Lossy
    Stream size : 970 KiB (5%)
    Language : English

    Menu
    ID : 727 (0x2D7)
    Menu ID : 22226 (0x56D2)
    Duration : 1mn 2s
    List : 201 (0xC9) (MPEG Video) / 202 (0xCA) (MPEG Audio, English)
    Language : / English
    Service name : Network21
    Service type : digital television
    General
    ID : 16 (0x10)
    Complete name : resaved_file_with_no_edits.mpg
    Format : MPEG-TS
    File size : 14.8 MiB
    Duration : 1mn 1s
    Overall bit rate mode : Variable
    Overall bit rate : 2 006 Kbps

    Video
    ID : 201 (0xC9)
    Menu ID : 22226 (0x56D2)
    Format : MPEG Video
    Format version : Version 2
    Format profile : Main@Main
    Format settings, BVOP : Yes
    Format settings, Matrix : Custom
    Format settings, GOP : M=3, N=36
    Codec ID : 2
    Duration : 1mn 1s
    Bit rate mode : Variable
    Bit rate : 1 778 Kbps
    Maximum bit rate : 15.0 Mbps
    Width : 544 pixels
    Height : 576 pixels
    Display aspect ratio : 16:9
    Active Format Description : Full frame 16:9 image
    Frame rate : 25.000 fps
    Color space : YUV
    Chroma subsampling : 4:2:0
    Bit depth : 8 bits
    Scan type : Interlaced
    Scan order : Top Field First
    Compression mode : Lossy
    Bits/(Pixel*Frame) : 0.227
    Stream size : 13.1 MiB (88%)
    Writing library : (dvd5: Jun 16 2014)

    Audio
    ID : 202 (0xCA)
    Menu ID : 22226 (0x56D2)
    Format : MPEG Audio
    Format version : Version 1
    Format profile : Layer 2
    Mode : Joint stereo
    Codec ID : 3
    Duration : 1mn 1s
    Bit rate mode : Constant
    Bit rate : 128 Kbps
    Channel(s) : 2 channels
    Sampling rate : 48.0 KHz
    Compression mode : Lossy
    Stream size : 968 KiB (6%)
    You'll see it's stripped out the broadcast data, but also reduced the filesize, and made it one second shorter?!

    In another one I tested (where I did make some edits) the GOPs (not sure what they are??) were altered too,.
    Broadcast transport stream contain a lot of overhead that is used for for error correction as the stream is received by the tuner. When VideoReDo "repackages" a .ts in its own version of a transport stream container, some of the extra data that wasn't useful anymore was probably discarded.

    Did VideoReDo perform any error correction? That might account for the shorter length. Even if no error correction was done, the one second difference isn't significant.
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  11. Member netmask56's Avatar
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    Another good thing to do is to demux the TS file using ProjectX (free program). It cleans up the TS file of transmission errors etc. VideRedo can do the same although that is payware, but nonetheless a good program to have in one's toolkit. Personally I use ProjectX to demux and to edit out commercials thereby maintaining subtitle sync followed by Womble to marry the audio and video and maybe put a fade in at the top and fade out at the end etc. Womble also has a cleanup mode as well as demuxing awkwardly called "DeMultiplexer"
    TheVoiceIsAnotherPerson ~ BeyonWiz DP-P1 and T3 PVR's ~ Popcorn C200 ~ Samsung ES8000 65" LED TV ~ Windows 7 ~ Yamaha RX-A1030 http://www.openwiz.org/wiki/ProjectX
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  12. Originally Posted by usually_quiet View Post
    Broadcast transport stream contain a lot of overhead that is used for for error correction as the stream is received by the tuner. When VideoReDo "repackages" a .ts in its own version of a transport stream container, some of the extra data that wasn't useful anymore was probably discarded.

    Did VideoReDo perform any error correction? That might account for the shorter length. Even if no error correction was done, the one second difference isn't significant.
    It was Womble I was using, not VideoReDo. But I don't know if it performs error correction itself, is there any way to check?

    Is there any way to test that with whatever I'm using I'm not losing any picture data (other than by physically looking)?
    Eg I saw in this thread a guy was having the oposite problem (Womble increasing file size when claiming it wasn't) and he used an AVISynth script to show differences:
    http://forum.videohelp.com/threads/343619-Womble-MPEG-Video-Wizard-DVD-is-re-encoding-...to-%28FIXED%29
    Anyone know how I would do that?

    Or any way to inspect the original file to verify that the suspected padding is just padding?
    Last edited by Gibson's Squares; 29th Jun 2014 at 12:43.
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    Originally Posted by Gibson's Squares View Post
    Originally Posted by usually_quiet View Post
    Broadcast transport stream contain a lot of overhead that is used for for error correction as the stream is received by the tuner. When VideoReDo "repackages" a .ts in its own version of a transport stream container, some of the extra data that wasn't useful anymore was probably discarded.

    Did VideoReDo perform any error correction? That might account for the shorter length. Even if no error correction was done, the one second difference isn't significant.
    It was Womble I was using, not VideoReDo.

    But I don't know if it performs error correction itself, is there any way to check?

    Is there any way to test that I'm not losing any picture data (other than by physically comparing)?
    Or any way to inspect the original file to verify the suspect padding is just padding?
    Sorry, I mis-remembered which software you were using. Unlike VideoReDo, MPEG Video Wizard doesn't do any error correction to compensate for missing or corrupt audio/video data in order to keep audio and video in sync when exporting video. When VideoReDo "fixes" audio and video desynchronization, it may remove a few frames here or there and re-encode any affected GOPs. (If the video exhibits pixelation and/or tiny audio drop outs or pops those are the result of transmission errors.)

    If MPEG Video Wizard were doing a significant amount of re-encoding, then exporting the file would be a good bit slower than simply copying the file. If MPEG Video Wizard exports the video about as fast as Windows can copy the file, then you have your answer.
    Last edited by usually_quiet; 29th Jun 2014 at 13:22. Reason: grammar
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    Originally Posted by Gibson's Squares View Post
    [


    Is there any way to test that with whatever I'm using I'm not losing any picture data (other than by physically looking)?
    Eg I saw in this thread a guy was having the oposite problem (Womble increasing file size when claiming it wasn't) and he used an AVISynth script to show differences:
    http://forum.videohelp.com/threads/343619-Womble-MPEG-Video-Wizard-DVD-is-re-encoding-...to-%28FIXED%29
    Anyone know how I would do that?

    That method uses an amplifed subtract script . If you don't know how to use avisynth already there is a bit of a learning curve. This method is good for visualization to see the differences, but you need to manually go frame by frame to be sure (imagine going through hours of footage)

    Basically you need to load the video (I would use DGIndex for MPEG2 sources)

    Code:
    A=Mpeg2Source("input.d2v")
    B=Mpeg2Source("output.d2v")
    Subtract(A,B).Levels(127, 1, 129, 0, 255)


    Other methods
    1) other variations on avisynth compare script - there are many different variations of these scripts, showing differences or amplified differences, or subtract

    2) PSNR, SSIM testing e.g. MSU VQMT, avisynth, other 3rd party tools

    3) raw YUV md5 testing e.g. decode to raw yuv and do md5/crc check with various md5/crc file analysis checking tools

    4) per frame md5 testing e.g. ffmpeg - essentially this is the same as #3, but on a per frame basis

    ffmpeg -i input.mpeg -f framemd5 input.framemd5
    ffmpeg -i output.mpeg -f framemd5 output.framemd5

    It outputs a text file that you can compare the hash check values - this is the way I would probably do it . The visualization methods are good to "see" what is different, less important for what you want to do for pure verification, more important to examine the effects of lossy encoding, or filters
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  15. Member netmask56's Avatar
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    In my earlier post I said Womble does have an error correction section under tools. The help file built in shows you how to use all the Womble facilities. I do think however you need to Demux using ProjectX which still has one of the best error correction abilities. You would then drop the video and audio files into Womble to make a remuxed mpeg2 file, it shouldn't re encode after being corrected by ProjectX. If you need any assistance setting up ProjectX PM me and I will send you a replacement ini file ( X.ini ) that will automatically set it up for you except for the subtitle page number. Not sure what UK uses.
    TheVoiceIsAnotherPerson ~ BeyonWiz DP-P1 and T3 PVR's ~ Popcorn C200 ~ Samsung ES8000 65" LED TV ~ Windows 7 ~ Yamaha RX-A1030 http://www.openwiz.org/wiki/ProjectX
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  16. Member hech54's Avatar
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    Originally Posted by Gibson's Squares View Post
    The source file is an MPEG-TS of a TV broadcast (no conversion/re-compression, just captured as streamed), recorded using an Elgata EyeTV device (Mac).
    I would look for a setting in the capture program to automatically transcode the TS file to straight MPEG. It takes a minute or two to complete(at least in WinTV like I use) but it's worth the wait.
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  17. Member netmask56's Avatar
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    That could well be a solution for the OP but going straight to mpeg will lose the subtitles if needed. The best way is to bite the bullet and demux with ProjectX or VideRedo. I've been using this method for about 7 years now from files recorded on a Topfield 5000 and the Beyonwiz P1 and T3 and have not missed a beat. Subs are important for me and certain friends.Transmissions from digital tv stations in Australia nearly always have between 9 and 27 errors as reported by ProjectX mainly due to either distance or geographic situation. Australia's digital TV system is the same as the OP describes ie MPEG2 video and mpa and either or AC3 sometimes Dolby surround. Subs here are on page 801 English only. They are starting to add hbbtv into the signal as well and as the 5 networks have about 4 program streams in their mux it's getting a bit crowded.
    TheVoiceIsAnotherPerson ~ BeyonWiz DP-P1 and T3 PVR's ~ Popcorn C200 ~ Samsung ES8000 65" LED TV ~ Windows 7 ~ Yamaha RX-A1030 http://www.openwiz.org/wiki/ProjectX
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    Originally Posted by netmask56 View Post
    In my earlier post I said Womble does have an error correction section under tools.
    What kind of error correction are you talking about? I have an older version of MPEG Video Wizard from 2009. It can only do very limited error correction that wouldn't affect the playback time. (It is able to correct GOP time code and PTS errors.) It doesn't remove any frames to correct audio and video de-synchronization like VideoReDo does when there are transmission losses.
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  19. Member netmask56's Avatar
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    I only mentioned the error correction in Womble as a passing comment as there seems to be resistance to try and use ProjectX which is still by far the best program for fixing transmission errors in PAL TV land. VideRedo is also good by reputation but I no longer have it. TSDoctor also has an effective error correction ability.
    TheVoiceIsAnotherPerson ~ BeyonWiz DP-P1 and T3 PVR's ~ Popcorn C200 ~ Samsung ES8000 65" LED TV ~ Windows 7 ~ Yamaha RX-A1030 http://www.openwiz.org/wiki/ProjectX
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