Questing about filtering with one of your guides

[Oni87]

first off,this is my first post so hi everyone. i have been reading through the forums and there is alot of useful information in here

i wanted to add a sub of a movie in avi that i had.. just for testing. i also wanted the movie to have black edges so the sub wont be on the movie itself because i dont like it.
first of i tried to add the sub to the movie file using https://forum.videohelp.com/topic272736.html.
everything went well beside the fact that i lost around 100mega from the movie and it looked quited "bad". bad as, some ppl will call it a dvdrip. i wouldnt.
so my first question is why did that happen(or more like, can i add a sub to a movie without selecting a decoder, i just want the subs to go into the movie and change nothing that was done by the gifted creater of the file

i took it another step because i wasnt the one going to watch the movie so i didnt care it looked that bad.
this time i did something that i read here about adding the black edges, resized.
so i went into filtering, added resize and pressed "Expand frame and letterbox image".
at the old frame width/height i had 320/240.
when i pressed expand i had the same numbers at the new width/height. changed the new height to 400 and the old width to 532. that makes a movie with the same ratio for width and height (with my calculation atleast.. im new to this so).
and i added a filtering to the subs again.
at the video compression i did divx codec 6.8(once)
and then tried xvid mpeg-4 codec because the file was that. i even changed some at configure for the new file to be as close as possible on details as the old one.

and again,i saw the quality going down.

so i took a picture, of the file information inside virtualdubmod, before and after the editing.



so the main question is, how can i resize (or add subs to the black edges without resizing and without it being cut when i burn it) and add the subs to a file without ruining it, because what i am doing now is ruinning it.[/b]

[Baldrick]

You must reconvert when you add burned in subtitles and you will then lose some video quality. Try increase the video bitrate a bit if you lose too much quality, under video->compression->xvid or divx and click settings/configuration.

[Oni87]

tnx alot for the reply, im gonna try it.

[Oni87]

been a while but im back
i guess this time im going for it.. (i like perfection and last time i just couldnt stand the fact that my subbed movies looked bad).
this time i got a lot close:
was trying to add subs to a movie who was decompressed with: ffdshow video codec. kept the same data rate and forced the number of key frames i wanted.
(EDIT: after more testing, i found out that forcing key frames in ffdshow decomepressor would give me the exact key frame (frames in movie devided by the key frames in the original file gives the number for how many frames for each key frame force, somehow after creating the new file i dont get the same key frame size [ not to mention key frame/delta frame min-max-avg etc]
my question is, can i control min/avg/max/total key frames and delta frames on ffdshow video codec and xvid one?

i also wanted to show what are those KEY/DELTA frames and does they effect the quality of the movie?

[redwudz]

'I' frames (Keyframes) are a complete frame of video. 'B' and 'P' frames are incomplete frames referenced to 'I' frames: https://www.videohelp.com/glossary?I#I%20Frame

Increasing 'I' frames will also increase the file size of the video. This frame arrangement is how the video is compressed. Xvid and Divx usually have the 'I' frame rate set at about every 300 frames by default. You can set the 'I' frame rate in the Xvid encoder settings.

In general, when you want to encode to the same quality as the original, or minimize the quality loss from encoding, you need to increase the bitrate and this will also increase the file size. A simple way with Xvid is to use the Target quantizer set at about 2. That should give you close to the original quality.

[Oni87]

i can control how many key frames there will be but i cant control how many delta frames Ill have and min/max for the key/delta frames. can it be done in xvid for example?

[Oni87]

sorry for upping, if no one will answer i wont reply on this thread again..