is there any way to know what will be the size of the output converted file !!
Hi,
Bitrate calculator...Avidemux x264 TWO-PASS average bitrate "VERYSLOW" (!) recode, to fit e.g. a small 640 × 360 px. image sized 90 mn long footage, to 1 ordinary 700 MB CD-ROM, with 192 kbs audio + ~8 MB security —
EXAMPLE:
692 MB wanted file weight / 5400 seconds / 0.0001199 — 192 kbs audio bitrate = VIDEO BITRATE TO APPLY 876 kbs (or 877, but keep it as safe as possible => 876).
Or:
http://www.dr-lex.be/info-stuff/videocalc.html yields the same result, if set to "overhead":
6 (instead of 2 by default).
Enter wanted file weight to "mebiBytes (MiB):" field, fill PRECISELY top right fields duration + audio bitrate, and "6" to "overhead": probably too much but more secure
in case of a fixed capacity, e.g. 700 MB CD-ROM. And press "
Time,size,audio —> video" left button, to read the "Video bitrate" top left field result.
Image quality? Depends on FPS, image size, amount of more or less saturated colors, brightness / contrasts, fast movement or not, lot of cam. pans. or not...
At same bitrate, small image sizes such as 640 × 360 or 720 × 396 pixels + 25 FPS instead of 29.976 + overall dark & calm videos, recode much easier to better visual results.
HD / Full HD? Then, a bright colored 90 mn film with lots of fast movements will NOT fit in 700 MB — while retaining excellent graphical quality (I mean).
For instance, don't complain about "artefacts" on, say... a football game (darn "references"

...) in bright daylight + intense green lawn, with many close-ups!
Try x265 instead; but results not very compatible with all kinds of devices, yet.
.