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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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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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???? -
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 -
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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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%)
In another one I tested (where I did make some edits) the GOPs (not sure what they are??) were altered too,. -
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.
SONY 75" Full array 200Hz LED TV, Yamaha A1070 amp, Zidoo UHD3000, BeyonWiz PVR V2 (Enigma2 clone), Chromecast, Windows 11 Professional, QNAP NAS TS851 -
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. -
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"
SONY 75" Full array 200Hz LED TV, Yamaha A1070 amp, Zidoo UHD3000, BeyonWiz PVR V2 (Enigma2 clone), Chromecast, Windows 11 Professional, QNAP NAS TS851 -
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:
https://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 11:43.
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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 12:22. Reason: grammar
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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 -
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.
SONY 75" Full array 200Hz LED TV, Yamaha A1070 amp, Zidoo UHD3000, BeyonWiz PVR V2 (Enigma2 clone), Chromecast, Windows 11 Professional, QNAP NAS TS851 -
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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.
SONY 75" Full array 200Hz LED TV, Yamaha A1070 amp, Zidoo UHD3000, BeyonWiz PVR V2 (Enigma2 clone), Chromecast, Windows 11 Professional, QNAP NAS TS851 -
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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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.
SONY 75" Full array 200Hz LED TV, Yamaha A1070 amp, Zidoo UHD3000, BeyonWiz PVR V2 (Enigma2 clone), Chromecast, Windows 11 Professional, QNAP NAS TS851