Helix DNA & Variable Framerate

[Kaiousama]

While i'm reading to the Helix documentation, this option caught my attention:

"maxFrameRate: The maximum frame rate that the codec will attempt to reach.The higher the bit rate, the more likely it is the codec will be able to achieve the frame rate specified at the desired quality."

this explaination seems to suggest that RV9 has variable framerate support... is it right? (are the players -realone & mpc- actually supporting this feature?)

If yes.... do you know a method (via avisynth or what else) to convert an anime 24fps episode in a variable framerate episode by eliminating all the duplicate frames and having in output the remaining sequences each one with his own framerate? (if a filter like this doesn't actually exist, i think a little modification of Donald's dup filter would solve the problem ;) )

Thanks :)

[Sirber]

The variable bitrate is that, if there is not enough bits and you reached the minimum quality, the codec will drop frames. For anime I use 15FPS@250kbps, 32kbps for the sound, voice codec.

[Kaiousama]

Originally posted by Sirber
The variable bitrate is that, if there is not enough bits and you reached the minimum quality, the codec will drop frames. For anime I use 15FPS@250kbps, 32kbps for the sound, voice codec.

Ehm... i've not well understood.... i was hoping for a variable "frame"rate... and i was thinking about how could be possible to create a variable bitrate avs script from an anime with 24fps-12fps and 8fps sequences, and how to feed the Real producer with it... is it possible?

tnx :p

[Sirber]

I don't think so... Real's codecs were created for streaming in mimd... variable framerate is for that too :)

[iwod]

Originally posted by Kaiousama
Ehm... i've not well understood.... i was hoping for a variable "frame"rate... and i was thinking about how could be possible to create a variable bitrate avs script from an anime with 24fps-12fps and 8fps sequences, and how to feed the Real producer with it... is it possible?

tnx :p

After a bit of research i would want to know if it is possible as well with current producer or with small modification.

Could Karl Answer this?

[iwod]

push

[karl_lillevold]

I am not sure what would happen if you fed a variable framerate Avisynth script to Producer. Try it out...

However, if frames are repeated in a high framerate source, the encoder will spend almost no bits on the repeated frames. This is true for almost all video codecs.

[Sirber]

It's true, but killing repetitives frames is better IMO. The encoding process will be faster and decoding will be faster too.

[karl_lillevold]

Sirber: you are right, it would significantly speed up the encoding process. I can not think of any reasons why a variable framerate input would not work, but there are lot of components in Producer I don't know, so I may well be wrong. It would be an interesting experiment.

[Sirber]

But will this scenario be possible?

Input: 24/25/30 FPS
Output: Variable

Would be great for animes :D

[karl_lillevold]

I don't think we have any resources right now to look into killing repeated frames inside the codec, but if someone wants to try to come up with an Avisynth script that does it, I will look into any problems that arise from feeding Producer with such a script.

[Atamido]

Unfortunately the AVISynth group has no intentions of supporting variable frame rate as this would no longer be "AVI" synthesizing. Though perhaps it could generate a dropped frame in the place of a duplicate one, I am not sure on this.

How does RV9 handle dropped frames in its container?

[iwod]

Originally posted by karl_lillevold
Sirber: you are right, it would significantly speed up the encoding process. I can not think of any reasons why a variable framerate input would not work, but there are lot of components in Producer I don't know, so I may well be wrong. It would be an interesting experiment.

Woo........... i read up a lot on the Dup filter lately, spending 10+ hours and interested in the idea..... and finially i got karl's reply.... ( ::crying:: too good to be true. )

I thought Karl is the sinor enginerr in Real......
And he doesn't know everything inside the Producer :confused:

Any way, so if the codec detects the frame are the same, if will use virtually 0 bits, but how does producer know if they are the same? I assume in this case it compares it as well............( and it is making me confuse why to use dup... )

[iwod]

Originally posted by Pamel
Unfortunately the AVISynth group has no intentions of supporting variable frame rate as this would no longer be "AVI" synthesizing. Though perhaps it could generate a dropped frame in the place of a duplicate one, I am not sure on this.

How does RV9 handle dropped frames in its container?

That is why i am thinking. Dropping a frame........... i will have to test it my self.......

[Sirber]

It's great to see new ideas for RV9 :D