I want to avoid transcoding problems

studur · Post by **studur** » Mon Oct 23, 2006 8:23 pm

Hi, I am using VS10Plus on a celeron 2.4GHz/1GbRAM/LeadtekWinFastPVR2000 tv card

I tried to capture from tv tuner in VS10 but I don't like the capture features because it is so hungry on computer ressources and I cannot get a decent quality. I did the acquisition from Virtualdub using the latest Divx codec and PCM audio (de-interlace filter applied).

When I tried to transcode the file in VS10 in order to burn it on a DVD, it took 15 hours. The quality was worst than the starting file

Is there a way to capture in MPEG format using virtualdub and feed it to VS10 to author a DVD ???

DVDDoug · Post by **DVDDoug** » Tue Oct 24, 2006 2:25 am

I tried to capture from tv tuner in VS10 but I don't like the capture features because it is so hungry on computer ressources and I cannot get a decent quality.

Your TV card is supposed to have a built-in hardware MPEG encoder, and that should take much of the load off of your computer. There is still quite a lot of data being transfered, but your computer is plenty fast-enough.

No matter how fast your computer is, I never recommend multitasking during real-time capture. Real-time capture is always tricky with a computer because the CPU is always getting interrupted by the operating system and doing stuff in the background, even if you are only running one application. (This is not a problem with stand-alone DVD recorders and DVRs.)

As long as your computer can keep-up with the real-time data-flow, the quality is determined by the capture card's analog-to-digital converter and it's MPEG encoder. The computer is just moving digital data around, and it shouldn't affect the video quality at all!

Ulead may have trouble taking advantage of the hardware MPEG encoder, and I have no idea if VirtualDub can take advantage of it. I don't use VirtualDub, but I don't think it comes with a software MPEG-2 encoder, due to licensing issues.

Sometimes a capture device will come with Ulead software as well as some other special capture software that's designed specifically to work with your hardware. (My Hauppauge card came with Hauppauge capture software and I use it for the capture step.) But, if your hardware only came with Ulead, then it should work with it! And, the special "SE" version might even be tweaked for the hardware.

I did the acquisition from Virtualdub using the latest Divx codec and PCM audio (de-interlace filter applied).

DivX is a bad idea, unless you just want to watch on your computer. Everybody complains about the time it takes to transcode (or crashing during transcoding), and you loose quality whenever you convert from one lossy format to a different lossy format. (Actually, you loose quality if you re-code to the same lossy format too!)

And, I don't see the need to de-interlace. Normal NTSC and PAL DVDs are interlaced.

jchunter · Post by **jchunter** » Tue Oct 24, 2006 2:27 am

When I checked the Leadtek website I saw: "Built-in ¡§Hardware MPEG-II Encoder¡¨ provides excellent video quality with minimal CPU usage," which tells me that your Leadtek card can capture video in Mpeg2 fomat - just what you need for your DVD. Also, just what you need for editing in Video Studio, if you should want to do that. Just set up the controls properly and you will have editable, burnable video.

Forget about VirtualDub, Divx and all that other stuff.

studur · Post by **studur** » Tue Oct 24, 2006 1:57 pm

Thank you all for your advices. I worked on tv capture yesterday and I found that using recommended settings found in this forum gave a very decent quality MPEG movie file. I used 640*480 instead of 720*480 because the 'on the fly' encoding is better and I don't loose frames.

I also realized that Divx codec is much better for capturing video for watching on a PC screen than MPEG. But MPEG gives a better result once burned on a DVD.

I understand now that highly compressed videos do not give good results once transcoded on a DVD.

maddrummer3301 · Post by **maddrummer3301** » Tue Oct 24, 2006 2:35 pm

DVDDoug · Post by **DVDDoug** » Tue Oct 24, 2006 8:17 pm

I used 640*480 instead of 720*480 because the 'on the fly' encoding is better and I don't loose frames.

OK... You might be stuck with 640x480. Just be aware that your video will be re-coded to 720x480 per the DVD spec when you make a DVD.

Post by **Ken Berry** » Tue Oct 24, 2006 9:56 pm

...And in case any of the foregoing is a little cryptic, 640 x 480 is not one of the DVD-standard formats, and to burn a DVD successfully, you have to use one of the DVD-compliant formats. 720 x 480 is the quintessential standard one, but there are others including 704 x 480 which you might want to play around with to see if they work the same as 640 x 480.

The problem with using the latter is that, as Doug has just said, it will need to be re-encoded to make it DVD-compliant. And, while there are ways to minimise the loss, re-encoding mpeg files is widely regarded as involving loss of quality. And that is something you want to try to avoid if at all possible.

As a footnote, I must say I am a little surprised that the Winfast on-board software (quite apart from the hardware mpeg-encoder) does not give you good results. I have a Winfast DV2000 TV capture card in one of my computers, and I invariably use the Winfast software to capture DVD-compatible mpeg-2 because it is designed for the card, it gives good quality and, indeed, it gives me more levels of quality control than Video Studio does for the same purpose.

studur · Post by **studur** » Wed Oct 25, 2006 2:00 am

Thank you everybody for your kind help

First, I tweaked my system to acquire in 720 x 480 using the recommended settings. No antivirus, no internet connection, nothing else than VS10 loaded on my system. I have no dropped frames as long as I do not move the mouse !! My CPU is working at 100% under these conditions. It give great results...

Here are my specs :

Asus P4S800-MX, Celeron 320D 2.4GHz, 2 x 512 Mb DDR, 160 Gb Seagate Barracuda 7200 rpm (UDMA enabled), ATI Radeon 9250 128 Mb, Leadtek WinFast TV2000 XP expert (conexant chip), WinXP SP2, display at 1280*1024 @ 32 bit

Second, I tried the WinFast PVR software bundled with the TV card, I am using the latest drivers and software. BUT it is not reliable. It crashed a couple times.. Especially when using direct-burn function. Geez, my VCR never crashed !!! Winfast PVR acts weirdly sometimes : Once, I was recording a tv show segmented in 1 Gb files (Mpeg-2 (640*480), PCM audio) and all the files created after the first one did not have sound. I was not happy because I needed a reliable software to record TV shows for my wife. And I am sure you know why ... It is difficult to justify (to my wife) software/hardware purchases when you get problems afterwards... Anyway, I am relieved now since I found an alternative to my toaster to burn a DVD

I will continue to tweak with the software to get what I want : Record TV and burn it on a DVD...