Yes, ok theoretically your calculation could also work, but you'll have the same visual quality by playing the video natively at 360p recoded, from the original 1080p, but if you try to reproduce it at 1080p the 360p recoded, you'll have the degrade of the image , you will never get the same (definition/pixel), especially when it comes to
games, the majority and the most ordinary today at 1080p.

But that is the whole point of this topic! :rolleyes:
Its about recoding game videos from original(FullHD mostly) into a low res vids to save space, and is directed for game repackers! Of course we are not going to get same fidelity, the idea is to get reasonable enough(read watchable) quality for 1/4- of saved space.

Here is how you recode bink videos while preserving their original multi-audio tracks:

Example of original file with multiple audio tracks(note track ID start at 100):
Attachment 20716

Recoding this video make it lose them all:
Attachment 20717

What to do now:
Attachment 20718
^Select newly recoded video and click "Mix in sound", select original video that contained all tracks(remember their ID's), select new(or same) video for output, select compression(recommended 4), select what ID number will new audio track be, select ID track number from original video you want to inject, ten click "Mix". New video will be created with sound injected into appropriate track ID(video quality unaffected).

Audio ID track number of original and into new file must be selected same for games to work properly!
You need to process each track injection separately, remember to select last created bink file as new "Mix in sound" source. Remember however you can batch process this with small batch list modification, either directly in RAD Tools batch list or through .bat file shell script.

Here is example where I already inserted 2 audio tracks from original:
Attachment 20719

Nothing stop us now from recoding bink videos without fear of losing audio.

EDIT:
Here is how to automate it:

^Where "a" is a folder with recoded videos while current dir contain original ones. "/#" is a key flag to use for batch process, otherwise you have to click "ok" after every single op.

Recently I encountered games whose videos consist of short period length(10s - ~1min), but with incredibly big size for such length(80-200mb). These and few other cases, like videos with quick movements/transitions may need higher bitrate as 320k can be on the edge(even for 360p resolution). 640k-768k can be considered. I found that for these special cases even higher bitrate doesn't create files bigger than ~10% of original. For example, recently I recoded 4.2gb vids to ~320mb with 768k. This was for mp4(h264) not bink, maybe thats why, but 320k work on them in majority of cases as well.

What I am saying is that sometimes, certain input content behave "specially" to encoders in terms of output and ratio. In those cases, 320k would create files way too small(say under 1mb of like ~60mb+ original). Based on that too high ratio you would know something is not right, where you normally get ~4-8x less size using 320k now you see ~50x+ less, which is suspicious. In those cases, dont worry increasing(up to 640-768k should be enough) bitrate as you are still going to get *extremely good* ratio. This also mean that ratio comparison between original and recoded size with visual quick preview is an important practice to find and treat those "special cases".

Here is another example, as I am repacking FFXII I recoded webm vids in it. I used 768k bitrate for this, its vp8 format.
Default:
Attachment 21107
Recoded:
Attachment 21108

Now the thing is, how much space did I saved? Original videos dir was: 10gb. Recoded: 625mb. Dont forget that it is blurrier also because of lowered resolution to 640x360.
EDIT:
Here is same recoded again but with original resolution
Attachment 21109

Less blurry but some pixelation already visible. 360p is better. Note that while on these pics blur may look too big, in motion this is much less of problem and video appear very solid in perception.

any idea how to sync audio and video wav and avi after changing frame rate from 30fps to 24fps ?

Not really, haven't needs for doing so yet, I would probably use rad tools or some ffmpeg frontend gui.

Yeah, theres not much of difference when you play the video using Bink Player but when the game playes it it shows color imbalance(color haze). Mostly if you reduce the video resolution

Useful topic, I think I should take a look on GTA V, there are almost 2.5G of biks, recoding them should make them smaller, and then I can use bpk

If they are binks, 2.5G should go to about ~300M, then bpk will further shrink that to about ~260m. For reference I recoded recently FF XV 12GB => 2GB and then srep it to 1.6G(because gain from dedup was > bpk). Still, my repack was only 3-4G less than FG's which disappointed me badly.

That said, I think its time to refresh the main post with new info.

260mb should be amazing, my main game is 50G(1.0.350.1) because I resized textures and so after encoding biks it will be about 47.5G, and probably pzlib+srep+dlz should make it like 25G(There are lots of dds textures)