> --export_asr 2 -Z 720x480
> -Z 720x346 -Y -68,0,-66,0 --export_asr 3
>
>Would the sequence of the options significant as ffmpeg? i.e., I want to
>confirm that the order of export_asr and -Z doesn't matter.
That's correct, the sequence of options does not matter.
>Example 2, which uses -Z 720x480 option to change the frame size from
>640x480 to 720x480, wiki says the DAR of 4:3 will remain unchanged.
>Is this has something to do with the black magic behind the -Z option?
>because 640:480 is not equals to 720:480, if I do this in ffmpeg,
>the result will be distorted.
You're forgetting about the PAR. There is no requirement that the PAR
be exactly 1:1 in all cases, and in fact, DVD video uses slightly
different PAR values depending on the DAR and encoded video size (for
example, 720x480 @ DAR 4:3 has a PAR of 8:9). I've clarified this in
the text.
>,-----
>| As mentioned above, *aspect ratios* cannot be stored in AVI files
>`-----
>
>I guess the *aspect ratios* here you meant PAR, correct?
I mean both (which is why I said "aspect ratios" rather than DAR or PAR).
>Still Example 3,
>
>I guess the output frame size of 1024x576 will be the value that movie
>player such as mplayer or vlc use when play the movie on pc. correct?
>and that'll be the size you get if you do a still image snapshot, correct?
That's correct.
>Example 6.
>
>,-----
>| you have a 16:9 DVD containing a 720x576 MPEG2 stream as in Example 4, and
>| you want to display it on a device that has a 640x480 resolution with a PAR
>| of 1:1 (and therefore a DAR of 4:3).
>`-----
>
>That (intended device) is for most LCD televisions and monitors, since
>they have a PAR of 1:1. How about CRT monitors, televisions, and DVD
>players?
If they have a PAR of 1:1, they will work the same way. If not, you
should be able to figure out the appropriate command form the examples on
that page.
>Further, I guess that you forgot to put the --export_asr 2 there in the
>command.
--export_asr is not necessary in this case, as the properties of the
display device are fixed.
--Andrew Church
[EMAIL PROTECTED]
http://achurch.org/
