challenging audio Lip synch problem - help

Vincej · Post by **Vincej** » Tue May 30, 2006 7:06 pm

I have a backlog of 30 home video tapes recorded on an analogue PAL Sony camera.

GOAL: is to achive all of these off onto DVD without any cute special affects of any kind. Now I live in Canada so I want to convert the tapes to NTSC. I have read the sticky on success DVD creation and followed the steps.

PROBLEM DEFINED: I create a video file from the PAL source adn convert to NTSC at this stage. The final burned DVD with NTSC conversion show no lip synch problems at the beginning of the video. By the end of 40 minutes there is a 5 second seperation between lips and voice.

PROPERTIES of orginal PAL video:
MPEG 2, Upper Field First
24 bits, 720x576, 4:3
25.00 frames / sec
variable bit rate 8000kbps

MPEG Audio layer 2 files
48khz 16 bit, stereo

PROPERTIES of NTSC Converted video:
MPEG 2, Upper Field First
24 bits, 720x480, 4:3
29.970 frames / sec
variable bit rate 8000kbps

LPCM audio
48khz 16 bit, stereo

capture device: ADS cap wiz

INCONSITENT ANALYSIS: Many posts on this forum say that PAL to NTSC conversion is hard - near impossible. I have a Samsung multistand vhs and this hardware device will convert PAL DVD's to NTSC in *real time* without any loss of quality or lip synch probelms.

I have read that there is a new ADS device DX2 with lip synch lock - could this help ?

DVDDoug · Post by **DVDDoug** » Tue May 30, 2006 9:01 pm

I've never done any conversions between PAL and NTSC, but I've had lots of sync problems with MPEGs.

All of my sync problems have been due to corrupt MPEGs. A corrupt MPEG will often play back OK, but it can get out of sync when it's re-coded or re-multiplexed. (In fact, the sync problem is probably getting introduced when the corruption is getting fixed.... i.e. bad video frames beinng thrown-away.)

You may have better luck if you can get your hands on a capture device that captures to AVI/DV. Let Video Studio do the DV to MPEG conversion as the last step before burning.

Perhaps the MPEGs are being corrupted by the PAL to NTSC conversion process????

I have a Samsung multistand vhs and this hardware device will convert PAL DVD's to NTSC in *real time* without any loss of quality or lip synch probelms.

Can this thing play your PAL tapes & output an NTSC signal? If so, try letting it do the PAL to NTSC conversion.

without any cute special affects of any kind.

Are you doing any editing.... any cutting, splicing, or transisions? If so, try an unedited project. My MPEGs were corrupted simply by editing them, and I had to buy a special-purpose MPEG editor.

I have read that there is a new ADS device DX2 with lip synch lock - could this help ?

Probably not. The audio & video are multiplexed (interwoven) in an MPEG file. They can't get out of sync 'till you demultiplex them. Once you do anything that requires demultiplexing, that "synch-lock" is gone. I assume that the synch-lock feature is designed to keep them in sync during capture, but that doesn't seem to be your problem.

Post by **Ken Berry** » Tue May 30, 2006 9:15 pm

This has nothing to do with your sync problem, but I thought I would note that you are in effect merely wasting space by capturing and processing analogue video at a bitrate of 8000 kbps. This is the sort of rate you would use for high quality *digital* video, but the analogy of the highest bitrate equals the highest quality, doesn't necessarily apply to analogue video.

Most people would say that a capture and processing rate of 4000 or 4500 is more than enough to capture analogue at equal quality to the original. You are never going to be able to improve the quality of the original, and certainly not by simply increasing the bitrate. All you are in effect doing is increasing the amount of space that the larger files made with 8000 kbps take up on your hard disk and eventually your DVD blank.

I personally am capturing my analogue tapes using a Sony Digital 8 camera which will actually play my old 8mm (and also Hi8) tapes direct to my computer as a digital signal, but even with these, I don't use more than 6000 kbps.

Vincej · Post by **Vincej** » Tue May 30, 2006 9:51 pm

You may have better luck if you can get your hands on a capture device that captures to AVI/DV. Let Video Studio do the DV to MPEG conversion as the last step before burning.

Stupid Question: I thought that all analogue cameras captured to Mpeg. My Capwiz Device captures to MPEG without offering any choices. Can youexplain what AVI /DV is and does and how it will help me when the orginal video is MPEG.

Can this thing play your PAL tapes & output an NTSC signal? If so, try letting it do the PAL to NTSC conversion.

this thing can take any format in and covert to any format out - one snag though - there is no way of getting the output onto a highquality ( non vhs) source.

Are you doing any editing.... any cutting, splicing, or transisions? If so, try an unedited project. My MPEGs were corrupted simply by editing them, and I had to buy a special-purpose MPEG editor.

Not one little bit of editing - I just want it straight onto DVD.

TDK1044 · Post by **TDK1044** » Tue May 30, 2006 11:04 pm

Make sure that 'smart render' is disabled when you make the NTSC video file. I use MPEG 2 capture, edit, render and burn all the time with no editing or sync problems. The only time I ever had audio sync issues was with 'smart render' enabled.