ffmpeg help/GUI

[Nineballo]

so im trying to transcode a .flv video to .mp4 and compress it using some sort of hw acceleration QS/NVENC(cuda) to speed up the process, problem is its 6AM and i dont know how to use ffmpeg and any documentation is from like 2009 and doesn't work any more.

 

so my question is what settings would i use for trans coding a 1080p60 16:9 .flv video to a smaller 1080p60 .mp4 video and are there any good gui's for ffmpeg on windows?

 

 

its 6am so if something dosent make sense yell at me and if i dont respond i prob passed out...

[Theguywhobea]

You could try Hand Brake?

[Nineballo]

using the nvenc_h264 at a slow preset i ended up with a larger file... Is there anything better or am i stuck with slow x264?

 

[mariushm]

Your flv is most likely already encoded with h264 for video and mp3/aac for audio.

So to get smaller size, you basically have to figure out the average bitrate and re-encode using a lower bitrate. Depending on content (ex regular motion video vs powerpoint presentation type of video vs anime/cartoon style video) some tweaks can be made to improve quality and reduce bitrate.

 

if you can upload somewhere the flv file, or a portion of it (pm me with the link) i can try to make suggestions on how to encode it

 

[WereCatf]

1 hour ago, NineBall-uwu said:

so im trying to transcode a .flv video to .mp4

First of all, open the file with VLC, then when it's playing, check Tools -> Codec-information. If it says H.264, you don't need to transcode it and can instead just remux it into an MP4 with e.g. ffmpeg -i midgetpr0n.flv -c:v copy -c:a copy midgetpr0n.mp4

 

On the other hand, if it's not H.264, take a screenshot of the codec-info and post here, and we'll help you transcode it with either ffmpeg or Handbrake.

[Nineballo]

i know how to remux its more the compression part, generally il use x264 medium to achive a file that is 1/3rd the original... The problem is that its loud (comp fans) and it takes forever (50fps) so i was trying to find some way of speeding it up.

[WereCatf]

59 minutes ago, NineBall-uwu said:

using the nvenc_h264 at a slow preset i ended up with a larger file... Is there anything better or am i stuck with slow x264?

 

The slow-preset has nothing to do with filesize, it's about how much CPU-resources it's gonna throw at trying to squeeze as much quality into the video as possible. Either bitrate or constant-quality factor (CQP for NVENC, CRF for x264) determines the filesize.

[Nineballo]

basically the file was encoded with nvenc so its massive, then i would transcode it and it would become a reasonable size.

 

Quote

The slow-preset has nothing to do with filesize, it's about how much CPU-resources it's gonna throw at trying to squeeze as much quality into the video as possible. Either bitrate or constant-quality factor (CQP for NVENC, CRF for x264) determines the filesiz

 

but then you said this... so why is it so much smaller?

[WereCatf]

2 minutes ago, NineBall-uwu said:

but then you said this... so why is it so much smaller?

Bitrate.

[Nineballo]

so what should i limit the bitrate to?

 

this is how i see it nvenc has low quality per bit and x264 has higher quality per bit so to maintain the same quality you need less bits.

 

but then there is the bit were nvenc looks worse then x264 med so now my head hurts.

[Nineballo]

Im gonna go to bed, il experiment tomorrow. thx for the help!

[WereCatf]

13 minutes ago, NineBall-uwu said:

so what should i limit the bitrate to?

Find out what the video's bitrate is by e.g. playing through it in VLC or ffmpeg, and then use something lower than that. Don't forget to use 2-pass encoding.

 

An easier way that achieves the same result is to just use Handbrake and set constant-quality instead -- you may have to try a couple of times to find what quality-setting looks good in your eyes -- 22-25 might be a good value to try --, but you can then in the future use that same quality-value for all videos.