Capturing VHS with MEncoder (Help)

[the98]

Hi everyone, this is my first post and I need your help. I'm a complete newbie with this capturing video stuff, and I wanted to capture some VHS. This videos' norm is NTSC and I'm trying to capture them with mencoder, using a GNU/Linux OS (Debian).

So this is what happens when I capture them with the following line:

mencoder tv:// -tv driver=v4l2:norm=NTSC:width=480:height=360:input=1:fps=25:amode=1:audiorate=48000:forceaudio:immediatemode=0 -oac pcm -msglevel all=9 -ovc xvid -xvidencopts pass=1:bitrate=800 -vf pp=lb -o test-xvid.avi

This is the result:



As you can see, it does not look good. I get a video "lag" or something when there's a fast change of direction from the camera.

What would you recommend?

Thank you.

[danno78]

mencoder tv:// -tv driver=v4l2:norm=NTSC:width=480:height=360:input=1 :fps=25

1. NTSC have 29.97 FPS. Your settings is 25fps which right for PAL and wrong for NTSC. Correct the mistake.
2. Check the CPU usage. Be sure that you have enough power to encode in mpeg4 codec.
The ideal path is to capture in intermediate codec with low or no compression (Lagarith or Huffyuv) and encode later in final storage format.
3. Times base error may lead to dropped frames. To avoid this a vcr with TBC is necessary or external TBC.

[the98]

Ok, thanks for the answer, I've used this command this time:

mencoder tv:// -tv driver=v4l2:norm=NTSC:width=352:height=240:input=1:fps=29,97:amode=1:audiorate=48000:forceaudio:immediatemode=0 -oac copy -msglevel all=9 -ovc xvid -xvidencopts pass=1 -vf pp=lb -o /media/Shared/Temporal/test-xvid.avi

And I got this messege at the end:

v4l2: 203005 frames successfully processed, -9500 frames dropped.

What does it mean by -9500 frames dropped?

Picture looks better, there is less "lag" when there is movement, but there is some there. I don't have any trouble with the CPU usage.

Any ideas?

[danno78]

mencoder tv:// -tv driver=v4l2:norm=NTSC:width=352:height=240:input=1:fps=29,97:amode=1:audiorate=48000:forceaudio:immediatemode=0 -oac copy -msglevel all=9 -ovc xvid -xvidencopts pass=1 -vf pp=lb -o /media/Shared/Temporal/test-xvid.avi

You thrown away half of resolution in both dimensions. The right size for NTSC should be: width=720, height=480. This resolution need more CPU power when encoding with xvid codec.

v4l2: 203005 frames successfully processed, -9500 frames dropped.

What does it mean by -9500 frames dropped?

9500 frames are gone because they not appear at the right time (jitter) or synchronization signals are corrupted. You need to heal the signal before hit the capture card.

3. Times base error may lead to dropped frames. To avoid this a vcr with TBC is necessary or external TBC.

[the98]

I don't have a VCR with TBC, or an external TBC, and It's impossible for me to afford one right now.

Only solution is TBC?

Isn't 352x240 NTSC's original resolution?

Thanks again danno78!

EDIT:

When I don't use any codec, and I let it "copy", it does the same thing.

I think Mplayer plays the video the same way mencoder captures it. So maybe there is some other problem going on.

[danno78]

Only solution is TBC?

Unfortunately, yes. But, you can find DVD recorders with TBC built-in and use them in passthrogouh mode. Some models from Panasonic ES10, ES15, EH57, some Pioneer models, etc.
See this thread:
https://forum.videohelp.com/threads/317476-Problems-with-flashing-colours-on-VHS-SVHS-capture

Isn't 352x240 NTSC's original resolution?

To get the best from your tape, 720x480 resolution is recommended.

When I don't use any codec, and I let it "copy", it does the same thing.

I think Mplayer plays the video the same way mencoder captures it. So maybe there is some other problem going on.

I don`t have Linux experience so I can`t help you more. Windows is more user friendly.
HuffYUV is supported by MPlayer as a part of libavcodec`svideo codecs or as Video For Windows codec family (I think in Wine). See MPlayer documentation. With HuffYUV the compression is lossless (30 Gb~hour) and is my favorite codec for capture. Later I do encoding.

[the98]

Windows is more user friendly.

That's not true

I've tried on Windows with the software that came with the card, it was worse. I didn't make a lot of tests though.

With Pal I get almost no dropped frames.

Maybe the norm is wrong, it might be NTSC-M, or some other. I'm not sure.

[danno78]

Think at this: VHS is interlaced content. Ntsc have 29.97 frames per second and every frame consists of two fields. The frame rate for NTSC is 29.97i (i from interlaced). The capture card scan 59.94 fields/s. The problem may could come from how MPlayer see the frame rate as progressive 29.97p (29,97 frames, no fields are for progressive) or as 29.97i (29,97 frames and 59.94 fields). If see as progressive then is wrong.
I recommend to try to capture on separate hard disk with the folowing settings: 720x480, FPS:59,94, codec: HufYUV and play the file with VLC.
Your tapes are NTSC. Are from US? The vcr is NTSC or PAL?
For Windows are far more tolls for this job.

[the98]

Ok, so I've tried with a PAL vhs that has a lot of motion. Same thing happens, so it's not a "norm" problem. The problem is when there is a lot of motion in the tape. Must be that my computer is slow, or the card isn't that good. Or maybe I need more RAM.

VCR is both PAL and NTSC.

[danno78]

Read this thead may help:
https://forum.videohelp.com/threads/104098-Why-does-your-system-drop-frames
True multi system vcr are very rare. Most of PAL vcr can play NTSC tapes in PAL60 mode, a mixt between NTSC and PAL. So to capture NTSC tapes with PAL vcr a capture card that can handle PAL60.
Start debuging with a good signal from a digital camcorder, live analogue camcorder, DVD or cable TV box. You will see if the problems are related with vcr/tapes or are related with computer settings.

[the98]

I've tried to make a capture with my PlayStation. I got some dropped frames, so I supposed the problem relies on my computer or my card.