getting artifacts when creating mpeg2's from bmp stills

[dreamer-71]

Hi all,
I'm trying to create a "movie credits" mpeg2 for a SVCD I'm creating of home movies. The credits are a series of still images, with background music.
I'm using TMPGEnc to encode the stills from BMP to mpeg2. When I play back the mpegs though, I get these weird spots of brightness that start from nothing, grow brighter over the next 2-3 seconds, disappear, then the cycle begins again and repeats for the length of the mpeg.
I'd include a pic but I can't figure out how to do a screen capture from a video file. (alt-Print Screen just gives an empty black box.)
Any idea what's causing this, and how I can avoid it? If I need to use another encoder, my options are limited to freeware as I am on a somewhat strict budget.
I also tried creating stills with VCDEasy but then I can't mux them with TMPG because it gives me an "Illegal MPEG video stream" error when I try to open it there. Grrr....

[BJ_M]

go into the gop settings and select all I frames or use 2 I , 5 P , 0 , B and max 15 gop size ..

i would suggest for bmp you use CBR . not CQ or VBR - though what ever you want would work ..

remember your source should be set as progressive - not interlaced. in progressive mode field order dont mater .. but out put can be anything you want fps wise .. though id used on dvd player , 29.97 and interlaced .. or 24 and treat as film

[dreamer-71]

Thanks, I'm already using CBR & non-interlaced as settings. I'll give those GOP settings a try. That's one aspect of video I'm still not too clear on, I've been using whatever GOP settings TMPGEnc was already set to.

[BJ_M]

just a thought also -- are you sure the source files are ok ? in windows you can make your own little "show" in explorer to check this .. in the directory with the files - set view options to thumbnail , then make the explorer window very narrow about the width of 1 or two thumbnails - then scroll quickly with a wheel mouse or slidder and you can see if there are any changes to the picture that resemble the pattern you describe ..

[jackhyde]

I was not aware that you could send BMPs directly to TMPGEnc. How do you determine the length of time that each still is on screen?
I've always used an editing program like Studio 7 or Premeire to turn the BMPs into an avi file that you can then run through TMPGEnc to make MPEG1/2s. This way you can choose the length of each still and the transistion between them.

[BJ_M]

1 bitmap (or targa or jpeg) = 1 frame

frame serving targa by targa is how film to dvd is done w/ software encoders - 6 meg per frame x 24fps = a lot of storage

[dreamer-71]

Thanks, the 2I/5P/0B GOP settings worked nicely. I also tried all I-frames, but the quality came out rather poor.

To the person asking about the source files: yes, they are of very high quality.

To the person asking about converting BMP's into MPEG: in TMPG, just use a BMP file as the video source, and TMPG will convert it into a 1-frame (IIRC) MPEG video file. (VCDEasy also does this, and has nicely adjustable settings.) Once you have your short mpeg you can use it as a menu by having your VCD loop back infinitely with it until a selection is made.

If you want to convert a BMP into an mpeg of a certain duration, you will need to create a silent (or null) audio track of the length you want it to be. You can use many audio programs to do this, I use Goldwave (www.goldwave.com). For instance if you want to convert a BMP into a 5-second mpeg video, just create a 5-sec. audio file. Then in TMPG use the BMP as the video source and your blank track as audio.

Of course the audio doesn't have to be null, you can substitute the track of your choice, like music or a recording explaining the picture.

You can also create a slideshow by making several BMPs into their own short mpeg videos, then stringing them together. Then use multiplexing to add a music soundtrack. That's what I did to create a "credits" for a home video I transferred to SVCD.