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View Full Version : Cropping avi file makes the new file too large?


shevegen
28th March 2004, 11:31
Hi, not sure if it belongs to this forum but anyway here is the problem:

Original File (I Called it "X" as i dont like long names while working with files): Size 204MB
G-Spot showed Video Codec: mp43, Name: S-Mpeg 4 version 3
x:y rate of 352x240 (1.47:1)
Audio: MPEG-2 Layer 3
and Stream as - OpenDML AVI

The Quality of the video wasnt very good when i started so i didnt expect to get any good result at all anyway, and there were some black bars on top and on bottom, and a nagging logo on bottom as well.

For reasons unknown to me,however, this file didnt play in media player classic or winamp, but after i loaded it in virtual dub and did direct stream copy, save avi, i got this new file:
/Same size as above
Video Codec: DIV3/mp43 (DivX 3 Low-Motion)
same audio codec as above and a Bitrate of 553 kb/s and roughyl 15 frames per second. Then this new file could be played, the last thing i wanted to do is just remove the black bars on top and bottom, however this produced a 4 GB file (!), way too much. I cant think that removing information (the black pixesl on top and bottom) results in a larger file so i must have done something wrong.

this new file has these props:
bitrate 5317 kb/s (eh...)
4cc: YV12, name: "Identical to IYUV but the order of the U and V planes is switched"

i then compressed this large file with xvid to 400 mb, but i would prefer if the size would be almost identical... because i removed info.

I am grateful for any help, thanks for reading thru!

killingspree
28th March 2004, 17:15
hi
well your results are not at all surprising :)

here's a little explanation:
to your first problem: by doing a direct stream copy in vdub you rewrote the header of the avi file. obviously it was in some way corrupted and therefore wasn't playable in wmp (or alike)

secobnd problem (oversized):
well unfortunately you cannot crop/resize the video without reencoding (apart from playback filters). so what you did, was crop/resize the video, and then 'reencode' it to an uncompressed avi. this is why you got such a huge file. if you really want to resize/crop this movie you will have to choose a decent codec in the video settings in vdub. but anyway, as you mentioned the video doesn't really have a good quality already, so reencoding it will only make things worse!

hth
steVe