Avidemux Forum

Quote from: Boflox on April 18, 2025, 12:27:16 PMThe function to speed up the project is vital for me

Try FFMpeg:
ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=0.8*PTS[v];[0:a]atempo=1.25[a]" -map "[v]" -map "[a]" output.mp4- this speeds up the video "input.mp4"  by 25%.

To achieve the best results, you have to first apply the "Change FPS" filter.
Then, in the Audio filters, selecting the "Custom" Frame rate change, the default value will be optimal.
 

Quote from: Avidummy on February 24, 2025, 02:16:43 PM

Quote from: MilosP008 on February 07, 2025, 06:44:07 PM

Quote from: szlldm on March 03, 2021, 08:35:16 PMMaybe you overlooked it:

QuoteYou save with copy mode the preceding half, then the part after the bad segment (both cut at keyframe). Fix and reencode the bad part, then append the 3 part together.

If there is a problem with the audio after appending, you still can merge in the audio fom the original file.

You still didn't answer the question, i have the same issue, i need to encode only stuff that i cutted and not whole video so i wont wait 2 hours for encoding

I do that all the time without issue and I really don't know much about this stuff. I would cut the video into 3 pieces at the key frames.  1st piece ends with the key frame just before the error.  Save that as Video A.  The 2nd piece is the small piece with the error.  Save that as Video B.  The 3rd piece is what's left.  Save that as Video C.

Edit Video B and reencode using the exact same parameters as before.  Then drop Video A into the avidemux window, then drop Video B into the window, then drop Video C into the window.  Select copy for audio and video.  Click save.

Be sure to use version 2.7.8 or newer.

I understand what you just said, but still its a lot of a job, it would be a lot faster if the avidemux could do it instead of you, but i guess its not possible since you can change origian video encoding format (i don't know how it works from developer perspective)

Quote from: eumagga0x2a on April 18, 2025, 12:33:39 PMUse "Change FPS" video filter (eventually followed in the filter chain by "Resample FPS" to bring the actual FPS down to the original value) to speed up the video track. If the video is sufficiently long, some loss of sync at the end may still happen due to limited precision.

(edit: Obviously, video filters are not applicable and therefore not available in copy mode, select a video encoder first to access the filter manager.)

Thanks anyway but this way it becomes difficult... I hope you can implement, in the future, this function in your future updates and upgrades... I will try to search for more... Thanks for the help. Regards.

Use "Change FPS" video filter (eventually followed in the filter chain by "Resample FPS" to bring the actual FPS down to the original value) to speed up the video track. If the video is sufficiently long, some loss of sync at the end may still happen due to limited precision.

(edit: Obviously, video filters are not applicable and therefore not available in copy mode, select a video encoder first to access the filter manager.)

This topic has been moved to Main version 2.6.

https://avidemux.org/smif/index.php?topic=20697.0

Good afternoon to all of you,

I tried Avidemux on the fly (for the first time) and I managed to speed up the audio track. I couldn't do it for the video track, so much so that the audio ends before the video. Is there a way to speed up both the audio and the video in a synchronized way? Thanks.

I don't know if you also find this but Avidemux is one of the few programs that can speed up an audio track (Time-Stretching) without it undergoing annoying flanger and/or Chorus effects. Up to now the best program that speeds up a project without ruining the audio too much is Movavi Video Editor (which however lacks the H265 codec). Then Avidemux - Olive Video Editor - And Magix Video Deluxe (which however is always heavy and a bit cumbersome...). I tend to make video tutorials with my voice, but to try to be as clear as possible (in speaking) I have to speak slowly and this means making long videos with a boring voice... The function to speed up the project is vital for me but I can assure you that, of the most bombastic video editing programs, only those mentioned above by me (and perhaps others that I have not tried) are able to speed up the audio track without ruining the speech too much. The rest of the programs tend to create a strange flanger (or chorus) effect that I can't explain to myself (and no one has ever been able to explain to me...). Perhaps, before reducing the video time, you need to convert the audio track to mono, but again, there aren't many programs that can do that.

I am sorry, but we need all the headers. Additionally, depending on desired compatibility with older NVIDIA graphics driver versions, staying away from the bleeding edge (from git master) of nv-codec-headers may make sense. Please have a look at the Debian Bookworm appImage build environment setup script regarding nv-codec-headers.

you can use Python scripting:
forward 20 keyframe script:
#PY  <- Needed to identify #
adm=Avidemux()
g=Gui()

g.QtGuiSetBusyCursor(1)
adm.seekKeyFrame(20)
g.QtGuiSetBusyCursor(0)

backward 20 keyframe script:
#PY  <- Needed to identify #
adm=Avidemux()
g=Gui()

g.QtGuiSetBusyCursor(1)
adm.seekKeyFrame(-20)
g.QtGuiSetBusyCursor(0)

save these into the custom script folder
then you can keybind to ALT + something shortcuts in the Tools menu / Script Shortcuts

small ffmpeg test, if cudo / nvenc is enabled|build:
echo '## ffmpeg Nvdia check cuda ##' && ffmpeg -hide_banner -hwaccels | grep cuda

Quotecuda

echo '## ffmpeg Nvdia check nvenc ##' && ffmpeg -hide_banner -encoders | grep nvenc

QuoteV....D av1_nvenc            NVIDIA NVENC av1 encoder (codec av1)
 V....D h264_nvenc           NVIDIA NVENC H.264 encoder (codec h264)
 V....D hevc_nvenc           NVIDIA NVENC hevc encoder (codec hevc)