Sync issue with MEP 17 and variable bit rate mpegs.

TGL1 wrote on 10/28/2019, 9:29 PM

The imported video is variable bit rate 720 x480, 29.97 fps (which i see from other topics may be a problem) and the audio is 224 kbs , 48 khz 2 channel AC-3. Sound seems on pace but the video looks quite accelerated in the editor and when burned to dvd or bluray. Running on windows 7 machine. I have rebuilt the frame table several times with no luck. I assume this is not a new topic so:

Is there a work around?
if it has been posted previously, can you point me in that direction?
other thoughts

any help would be much appreciated

ID                                       : 224 (0xE0)
Format                                   : MPEG Video
Format version                           : Version 2
Format profile                           : Main@Main
Format settings                          : CustomMatrix / BVOP
Format settings, BVOP                    : Yes
Format settings, Matrix                  : Custom
Format settings, GOP                     : Variable
Duration                                 : 29 min 15 s
Bit rate mode                            : Variable
Bit rate                                 : 4 569 kb/s
Maximum bit rate                         : 9 800 kb/s
Width                                    : 720 pixels
Height                                   : 480 pixels

thanks!

Tim

Comments

johnebaker wrote on 10/29/2019, 3:18 AM

@TGL1

. . . . Sync issue with MEP 17 and variable bit rate mpegs . . . .

Do you mean MEP 17 or MEP version 17.x.x.x ?

Variable bitrate video is not an issue with MEP, and creating a new frametable usually fixes the sync issue when it occurs.

However I suspect the issue is not the variable Bitrate but variable Frame rate - the video data does not give us the full picture of what is in the MPEG, can you post a full MediaInfo analysis of the source video.

John EB

TGL1 wrote on 10/29/2019, 7:23 AM

Thank you for your quick response John

v. 17.0.3.178 upd 3

Here is the analysis from one of the vob files. Does the following provide enough info:

General
180506)\VIDEO_TS\VTS_01_2.VOB
Format                                   : MPEG-PS
File size                                : 1 024 MiB
Duration                                 : 29 min 16 s
Overall bit rate mode                    : Variable
Overall bit rate                         : 4 890 kb/s

Video
ID                                       : 224 (0xE0)
Format                                   : MPEG Video
Format version                           : Version 2
Format profile                           : Main@Main
Format settings                          : CustomMatrix / BVOP
Format settings, BVOP                    : Yes
Format settings, Matrix                  : Custom
Format settings, GOP                     : Variable
Duration                                 : 29 min 15 s
Bit rate mode                            : Variable
Bit rate                                 : 4 569 kb/s
Maximum bit rate                         : 9 800 kb/s
Width                                    : 720 pixels
Height                                   : 480 pixels
Display aspect ratio                     : 16:9
Frame rate                               : 23.976 (24000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Scan order                               : 2:3 Pulldown
Compression mode                         : Lossy
Bits/(Pixel*Frame)                       : 0.551
Time code of first frame                 : 00:29:12:20
Time code source                         : Group of pictures header
GOP, Open/Closed                         : Closed
Stream size                              : 956 MiB (93%)

Audio
ID                                       : 189 (0xBD)-128 (0x80)
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Commercial name                          : Dolby Digital
Muxing mode                              : DVD-Video
Duration                                 : 29 min 16 s
Bit rate mode                            : Constant
Bit rate                                 : 224 kb/s
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 48.0 kHz
Frame rate                               : 31.250 FPS (1536 SPF)
Compression mode                         : Lossy
Delay relative to video                  : -628 ms
Stream size                              : 46.9 MiB (5%)
Service kind                             : Complete Main

johnebaker wrote on 10/30/2019, 3:19 AM

@TGL1

Thanks for the full MediaInfo data.

There is something 'odd' with the video - from the analysis:

Scan type : Progressive
Scan order : 2:3 Pulldown

The above suggest that the video is either:

'Inverse Telecine' ie the original frame rate was not the same as that in the video file and video rates and the original was possibly Interlaced video.

OR
has been scanned from film which has a different frame rate.

This in conjunction with the time code syncing

Time code source : Group of pictures header

is likely to introduce errors in the audio sync - this is supported by your original comment -

'Sound seems on pace but the video looks quite accelerated in the editor'

I would suggest you try the following:

run the vobs through a video converter to an AVI video format to see if the sync issue improves

OR
in MEP, use the Speed effect to slow down the video to what appears to be 'normal pace' and check the Interpolate intermediate images option in the Speed function. If the audio is still out of sync unlink it from the video and adjust (stretch) the audio to match.

Note: if the video has been ripped from a commercial DVD, the original protection applied to the DVD has done its job.

HTH

John EB