How to get info about ac3 fps ?

[mateo4x4]

What is in your opinion the easiest way to get an information about FPS of ac3 file ?

[Matthew]

AC3 does not have fps. Regardless of what format the video is in, each frame is 32 miliseconds in length and is (4*bitrate) bytes.

[mateo4x4]

But there is an option in BeSweet GUI called "Presets" where we can set NTSC->PAL or PAL->NTSC. Doesn't it work for ac3 stream ?

[KpeX]

For the billionth time, AC3 does not have a framerate conversion. The option you're referring to in besweet is a time shift operation used in conjunction with a change in the video framerate, as in NTSC > PAL conversions.

This is outlined in the Audio FAQ #19. (http://forum.doom9.org/showthread.php?s=&threadid=68300#post424063)

[mateo4x4]

The option you're referring to in besweet is a time shift operation used in conjunction with a change in the video framerate, as in NTSC > PAL conversions.
So, If I'm going to change the frame rate of my video stream I also have to usue this option for audio stream that I want to connect to my movie. Am I right ?

[KpeX]

Yes, with the same ratio change as used in the FRC of the video.

[keithmac]

Use the -ota switch in besweet, but you`ll have to output the files to waves and then re-encode with Softencode or similar, the ac3enc.dll used by bestweet gives seriously low volume ac3`s.

[mateo4x4]

Thank You very much :)

[mateo4x4]

Hi !
I've got one more question. Is there possible any loss of the quality by this time shifting operation (NTSC->PAL or PAL->NTSC) in BeSweet ? Can we say that this is the recompression of ac3 ?

[keithmac]

I haven`t noticed any quality loss at all really, there maybe some due to besweet decompressing the ac3 and softencode recompressing it but it isn`t noticable.