Is it possible to force fps around 1 with x264 ?

Hi, I have another question that might be silly but well...consider I try to encode some video with x264 using a basic commandline (--sar 10:11 --preset veryslow --crf 18 for example). Then the encode will be done, that is not the problem. But it seems I can't control fps to vary around 1. It will fluctuate without me interfering, sometimes around 2, sometimes around 6. Then is there a possibility to force fps to remain around 1 ? If I use some enchancement filters trough an avisynth script, the encode may be slow down (fps below one sometimes) but it still can't be controlled either.

what are going to achieve with constant encoding speed???

try something like assumefps(1) in avisynth script then pipe it with ffmpeg ffmpeg -re -i input.avs -f yuv4mpegpipe -

Thanks for your answer Nevilne I will try soon and let you know . Anyway do you think it is a good idea to force that fps while using crf (or 2 pass) ? Will it improve something or not or change something ? Atak_Snajpera, well I would like to control it. In fact, do you think that encoding with fps around 10 on the one hand and with fps around 1 on the other - but using the same x264 settings - will have an impact on the output (quality, frame prediction ect) ?

Here is a picture to show you what fps I'm talking about : I'm referring to the 1.80 fps line. Adding the assumefps(1) line in the AVS script seems to work : the encoding is now done with fps around 1. But my question is what will happen if I use assumefps(10) for example but the same x264 settings ? Does that have an influence on the quality ? I'm still confused about that, sorry. J_Darnley, is there a way to modify "the encoding speed printed during and at the end which is just: frames / (current time - start time)" you refer to ?

CruNcher I'm not sure to have totally understood what you said ; could you please develop more what you mean by "Vsync though it's more complex it all the time adapts the settings so you get always the best output @ the given FPS" and how to use use that if it is possible.

Ok thanks for those precisions. So I think I don't have to worry about that encoding speed nor the framerate of the video, have I ? ; Indeed, that assumeffs(1) line is forcing my video framerate (which is natively at 24 img/s) to 1 img/s which I don't want, so I guess I don't have to include it on the AVS script. J_Darnley : "Yes, edit x264.c and recompile" ; are you serious ? Do you want me to reedit myself the x264 program made by experts ? In fact I aimed at encoding with the slowest encoding speed possible but it seems it has no sence in so far as it will give me the same result, am I wrong ?

anything above medium preset is a waste of time and energy for me. period.