Automatic Refreshrate Changer (5 Viewers)

[kenwonders]

I finally got time to install this the other day. It's got the frame rate right every time. If you could maybe push again for it being part of the core svn?

Thanks for your great work.

 

[diablosv]

I finally got time to install this the other day. It's got the frame rate right every time. If you could maybe push again for it being part of the core svn?

Thanks for your great work.

Yes this works well, i don't understand why this isn't a standard feature (have it disabled by default of course), almost everyone thats a serious media guru (unless judder doesn't bother you) will encounter this whether it's 25fps TV or 24 fps HD.

 

[lordarcane]

I would defently vote for it to be a standard feauture! It works quite flawlessly. Even though i had to complete it with recklock to keep the audio in place.

 

[Slurm]

I would defently vote for it to be a standard feauture! It works quite flawlessly. Even though i had to complete it with recklock to keep the audio in place.

The audio/video sync problem with some framerates seems to be a bug in MP.

 

[lordarcane]

Okey.. Well.. That would explain a lot of things. =/

 

[edterbak]

I dont know the exact facts. But I thought the audio / video out of sync thing had to do with the way you handle your audio output. If your output is bit-perfect to your receiver, than the audio playback speed is fixed. This way the video also has to be played on the same speed.
If you use analog audio out, than MP/codec can use the option to speed up or slow down the audio with a couple of percent (+/-5%) to match the video framerate. 5% speedup you wont hear. In case you use the bit-perfect audio output, reclock can match the two speeds where other programs/codecs cannot.
This is what idea I had about this. Im absolutely not sure if this is true, so if Im talking BullS**t shoot me... (or give the correct facts preferably )

 

[Slurm]

I dont know the exact facts. But I thought the audio / video out of sync thing had to do with the way you handle your audio output. If your output is bit-perfect to your receiver, than the audio playback speed is fixed. This way the video also has to be played on the same speed.
If you use analog audio out, than MP/codec can use the option to speed up or slow down the audio with a couple of percent (+/-5%) to match the video framerate. 5% speedup you wont hear. In case you use the bit-perfect audio output, reclock can match the two speeds where other programs/codecs cannot.
This is what idea I had about this. Im absolutely not sure if this is true, so if Im talking BullS**t shoot me... (or give the correct facts preferably )

Well, noone's shooting anybody

I guess you are right about bitperfect output, but I don't know why there should be a source with different playtime for audio and video (especially if you are playing 24fps hd content on 24Hz as it's meant to be played in cinemas too).

Besides it plays well without problems outside of mp, i.e. in wmp (also 24fps on 24Hz with exactly the same codecs and without reclock).

 

[tourettes]

If you use analog audio out, than MP/codec can use the option to speed up or slow down the audio with a couple of percent (+/-5%) to match the video framerate. 5% speedup you wont hear.

5% change is definately heard, just check following samples and you will change your mind

PAL Speedup: Examples

Such 5% change is almose as bíg change as tuning guitar from E to Eb, so it definately isnt an amount that can be ignored.

 

[edterbak]

Yeah, if you listen to the samples right after eachother its very clear and obvious. Nice samples Tourettes But still, humans are weird creatures... ghehehe.. some (read:most) dont see 60hz CRT flickering, some do. Some dont hear high pitched sounds, and again some do.
I think the same is true in this case. If you compare them, most people will probably notice. But I also think that 95% of all people arent even aware of the speedup/slowdown of the audio. And Im not even talking about the people who can hear the difference.

Anyway, besides this. I still dont fully understand in which situation the sound/video speed is altered. The reason why MP has a problem with it is also unclear.

[edit]
just clicked one link further...

Movies and many television series are shot on film that runs at 24 frames per second. That's also the framerate at which movies are projected in movie theaters.
If you'd like to convert that movie to television you have a problem, because regular television sets don't run at 24Hz (= frames per second).

This is how the Americans solve that problem:
The video standard in american television is NTSC. NTSC runs at 60 Hz. To make 60 Hz from 24 fps, you double the first frame, triple the second frame, double the third frame, triple the fourth frame and so forth. Now 12 of the original 24 frames in one second are doubled (12 * 2 = 24) and the other 12 are tripled (12 * 3 = 36).
And because 24 + 36 = 60, you can use this new framerate for conversion into NTSC. Unfortunately, since not all frames are displayed for equal amounts of time using this so-called 3:2-Pulldown method, the film does not run quite as smoothly as in movie theatres.

This is how the Europeans solve the problem:
Europe's television standard is PAL which runs at 50 Hz. Unfortunately, you can't make 50 from 24 just doubling or tripling every other frame, at least not evenly. So the film is sped up 4% to 25 frames per second, those 25 frames are then doubled, and the end result is 50 Hz.
And that's why almost all programs are too fast and too highly pitched by 4% in Europe. And it doesn't even matter if the program is english language, some european language or if it's a dubbing, everything originally made on film or NTSC is affected. Which is essentially everything except european television productions that are shot using PAL television cameras.

 

[tourettes]

Anyway, besides this. I still dont fully understand in which situation the sound/video speed is altered. The reason why MP has a problem with it is also unclear.

Generally audio shouldn't drift even when playing at "wrong" fps rate. This is because audio is always used as the source clock in directshow applications and the video renderer will adapt to that by dropping frames or displaying some frames twice (of cource in ideal case the video renderer doest drop a single frame during a movie).

Somesystems might have audio & video clock that drifts a little bit and this is where Reclock could be useful (in addition to different features that it has, like the PAL speed up if you dont have native 24fps display). Reclock will resample the audio so that video render wont have to drop or display dual frames as its less audioble to the user when the audio is slighly distorted (speed changed, pitch remaining the same) than stuttering video.