bbMPEG mux problem with TMPG VBR

[BGane]

I'm having a problem with "skipping video" when I attempt to use VBR encoding in TMPG with DVD2SVCD.

Note that for my application, I'm not trying to burn a VCD - I stop at the point where I have created an MPG, and I'm attempting to play my file with a computer player. Also note that this problem occurs regardless of the player that I use, so I am reasonably sure that it is not a player issue (I have tried both PowerDVD and Windows Media Player, and the playback problem occurs in exactly the same manner in both players). Also note - I am working with MPEG1, not MPEG2.

I have searched the board for observations of a similar problem. Nothing seemed to be appropriate, but if there is a relevant discussion, I would appreciate a pointer.

More detail on the nature of the problem: The bbMPEG_Muxed_File00.MPG file that is created, as output from bbMPEG, in the last stages of my encode, will play properly for about 1 minute 20 seconds. After that, the video freezes for about a second or two, then skips to catch up with the audio, then skips again. This continues until completion of playback. The audio plays Ok throughout.

In an attempt to isolate the problem, I have tried the following. I used TMPG MPEG Tools to manually mux the MPV and Mp2 files that were created by DVD2SVCD and related tools. My TMPG manually muxed version of the MPG file plays Ok - no problems.

I have noticed that this problem will only occur when I select either CQ_VBR or 2-pass VBR (didn't try single pass VBR). This problem does NOT occur if I use CQ or CBR.

Of further note, when I use either VBR mode, I have changed the bitrate settings (using bitrate tab in DVD2SVCD) to Max 1500, Min 900 from their defaults of 1150.

From all of this, I conclude that there is some issue with bbMPEG when I am attempting to mux a variably encoded TMPG video file. So I tried experimenting with some of the settings in bbMPEG. I saw one suggestion to change the timestamps to I-frames only. I tried this - it didnt' help - same problem. I tried changing the video stream option at the top of the bbMPEG options panel from VCD to MPEG-1 - that didn't help either.

I am out of ideas. I'm afraid I don't have CCE, so I can't try that to see if it would generate a more bbMPEG "friendly" output. Can anyone make any other suggestions for me to try?

EDIT: Actually, this is somewhat similar to the problem being experienced by girotour (few posts away), but there are differences in my circumstances. I am trying to create VCD, not SVCD - bitrates are much lower. Also I have most definitely used internal routines to rip the DVD. And I have tried all of the suggestions for bbMPEG settings suggested elsewhere in the post, to no avail.


LOG FILE:
=========
(Note: In this run, I was using CQ_VBR option of TMPG, CQ set to 100, bitrate max/min to 1500/900)


WNASPI32.DLL 4.6.0.1021
Key found: E4387EE5E4
--------------------------------------------------------
- 12/02/2003 2:10:42 PM
- DVD to SVCD Conversion
- DVD2VCD ver. 1.1.0 build 1c
--------------------------------------------------------
Initializing
Initializing finished.

--------------------------------------------------------
- 12/02/2003 2:10:53 PM
- Free on drive C: 13074.60 mb
- Internal rip
--------------------------------------------------------
Preparing vobfiles to be ripped:
- D:\VIDEO_TS\VTS_01_1.vob
- D:\VIDEO_TS\VTS_01_2.vob
- D:\VIDEO_TS\VTS_01_3.vob
- D:\VIDEO_TS\VTS_01_4.vob
- D:\VIDEO_TS\VTS_01_5.vob

Ripping: D:\VIDEO_TS\VTS_01_2.vob
Ripping finished. Speed: 8604

--------------------------------------------------------
- 12/02/2003 2:11:23 PM
- DVD2AVI
--------------------------------------------------------
Creating DVD2AVI INI file:
- C:\Program Files\DVD2SVCD\DVD2AVI\DVD2AVI.INI

Variable settings:
iDCT_Algorithm: 32-bit SSE MMX

Executing DVD2AVI.
Executing DVD2AVI. Commandline:
"C:\Program Files\DVD2SVCD\DVD2AVI\DVD2AVI.exe" -CS=2 -YR=1 -EXIT -OF=[C:\Program Files\DVD2SVCD\Movie\DVD2AVI_Project_file] -IF=[C:\Program Files\DVD2SVCD\Movie\VTS_01_1.vob]
Analyzing DVD2AVI Project file
Force Film NOT activated!
Framerate: 29970
DVD2AVI processing done.

--------------------------------------------------------
- 12/02/2003 2:11:58 PM
- Free on drive C: 13074.57 mb
- AUDIO Extraction
--------------------------------------------------------
Found AC3 stream id: 0x80
Filename: C:\Program Files\DVD2SVCD\Movie\Extracted_audio_1.ac3
Audio1 delay: -203 ms
Audio extraction finished.

--------------------------------------------------------
- 12/02/2003 2:12:25 PM
- Free on drive C: 13074.57 mb
- AUDIO conversion
--------------------------------------------------------

Encoding Audio. Filename: C:\Program Files\DVD2SVCD\Movie\Extracted_audio_1.ac3
Executing BeSweet. Commandline:
"C:\Program Files\DVD2SVCD\BeSweet\BeSweet.exe" -core( -input "C:\Program Files\DVD2SVCD\Movie\Extracted_audio_1.ac3" -output "C:\PROGRA~1\DVD2SVCD\Movie\Encoded_audio_1.mp2" -logfile "C:\PROGRA~1\DVD2SVCD\Movie\Encoded_audio_1.log" ) -azid( -L -3db -c normal -s surround -g max ) -ota( -d -203 ) -shibatch( --rate 44100 ) -2lame( -e -b 224 -m j )
Audio conversion of C:\Program Files\DVD2SVCD\Movie\Extracted_audio_1.ac3 finished.

Audio conversion finished.

--------------------------------------------------------
- 12/02/2003 2:15:34 PM
- Free on drive C: 13074.77 mb
- Video Encoding using TMPGEnc
--------------------------------------------------------
- Encoding C:\Program Files\DVD2SVCD\Movie\AviSynth_Script_file.avs
StreamSectors: 771537788
AudioSectors: 8594152
VideoPAPO: 11818404
ScanOffsetBytes: 0
SeqAligningBytes: 0
DVDBytes: 0
VideoEndHeader: 4
SubtitleSectors: 0
EmptySectors: 238.00
PictureSectors: 0.00
PureMPEGStream: 751125228.00
Seconds: 302.83
CalcMPEGStream: 751125228.00
Frames: 8866
CDSize: 740.00
Number of CDs: 1
Cut point 736.00
Using CQ Value: 100.00
Executing TMPGEnc. Commandline:
"C:\Program Files\TMPGEnc\TMPGEnc.exe" "C:\Program Files\DVD2SVCD\Movie\TMPGEnc_Project_file.tpr" /Encode /Close
Video Encoding finished.

--------------------------------------------------------
- 12/02/2003 2:45:55 PM
- Free on drive C: 13129.55 mb
- Converting Pictures from ES to PS
--------------------------------------------------------
Saving bbMPEG settings: C:\Program Files\DVD2SVCD\bbMPEG\default.ini
--------------------------------------------------------
- 12/02/2003 2:46:06 PM
- Free on drive C: 13129.55 mb
- Converting Pictures from ES to PS
--------------------------------------------------------
Saving bbMPEG settings: C:\Program Files\DVD2SVCD\bbMPEG\default.ini
--------------------------------------------------------
- 12/02/2003 2:46:16 PM
- Free on drive C: 13129.55 mb
- Converting Pictures from ES to PS
--------------------------------------------------------
Saving bbMPEG settings: C:\Program Files\DVD2SVCD\bbMPEG\default.ini
--------------------------------------------------------
- 12/02/2003 2:46:27 PM
- Free on drive C: 13129.54 mb
- Multiplexing and cutting
--------------------------------------------------------
Saving bbMPEG settings: C:\Program Files\DVD2SVCD\bbMPEG\default.ini
Offset in Seconds: 0
Executing bbMPEG.
Variable Settings:
Movie offset: 0 seconds
Cut point: 736 mb

Executing RunbbMPEG. Commandline:
"C:\Program Files\DVD2SVCD\bbMPEG\RunbbMPEG.exe" "C:\Program Files\DVD2SVCD\Movie\bbMPEG_Muxed_File.mpg"
Multiplexing and cutting finished.

CD-Image creation finished.

--------------------------------------------------------
- 12/02/2003 2:47:34 PM
- Free on drive C: 13073.64 mb
- SVCD Creation finished!
--------------------------------------------------------

[hoozdapimp]

well dvd2svcd is more for making svcd's...however, i have a couple suggestions:

1) update dvd2svcd to the latest build
2) update (if necessary tmpge) to the latest build.
3) change your offset from 0 to 2 seconds (in bbmpeg tab) as it is known to cause desynch problems (maybe it will fix your skipping problems?) kinda far fetched but worth a shot..

but at any rate, in the end, at least you have a working movie! :)

[BGane]

I'm not that far off the latest build for DVD2SVCD and I wasn't aware of anything in the change log that indicated any issues with respect to bbMPEG being addressed. As far as I know, bbMPEG is still 1.24 beta 18, correct?

I am on the latest build of TMPGENc.

I tried changing the offset. It has no effect.

However, I have noticed a major issue during muxing that I didn't see before. I opened up the bbMPEG window to see what it was doing. Although there is nothing reported to the DVD2SVCD log, bbMPEG is reporting several hundred packet underflow errors. This is the problem.

Can anyone explain to me what is a packet underflow, and what settings should I be using, given that my bitrate is 1500/900 (Max/Min)?

I believe there is a setting for force mux rate in dvd2svcd.ini that affects this problem. I would prefer to let this be dynamically set, but I read elsewhere that there may be a problem with the auto setting of "0". Is this still a problem with bbMPEG and dvd2svcd? Is the mux rate my problem? What should mux rate be set to, given the above?

Thanks.

[markrb]

Those errors are muxing errors and are to be avoided as much as possible.

Are you trying to make a VCD and not a SVCD? Are you using mpeg-1 and not mpeg-2? This is your problem and there are relevant discussions on the board already, but might be hard to find.

The problem is that with a VCD automatic muxing is not used. A set value is used, but this assumes a VCD compliant audio and video streams which you do not have. You have two choices to fix this.

1. Return to 1150 and 224 for your bitrates on your VCD.
2. Manually adjust the Force Mux rate.

#2 is a guessing game and can take several tries to get it right. Your goal is to raise the mux rate to the exact right setting.
You do this by starting a restore clicking on the BBmpeg advanced settings and changing the force mux rate higher, go to muxing and cutting, watching the mux to make sure there are no errors. If there are you need to raise this mux rate higher. If not try lowering it until you do get an error and the raise it until it just goes away. Start about 500 points higher.

Mark

[BGane]

Hi Mark:

Thanks for the suggestions. Originally, I did an encode at 1150, but decided to try a variable encode because I was finding the constant encode too blocky. There would be no point in doing a variable encode if I left the bitrate at 1150 as I would get the same results, so I upped it to 1500.

You say that automatic muxing is not used by VCD? Well, I just tried it. I set the bbMPEG force mux rate to "0", and guess what - I got a file that both Windows Media Player and PowerDVD can play.

Is there something that I am missing, or should we not argue with success? Is there a downside to using automatic muxing?