How to speed up and slow down a video while maintaining a good audio quality

vanny_f
vanny_f Posts: 77 Just Starting Out*

Hi all,

I have several composite shots with animations and voiceovers and I would like to speed up or slow the animation and the corresponding voiceovers. If I do it like it is for example explained in this video https://www.youtube.com/watch?v=UBAjyoe_jD4&ab_channel=RaqibZaman by using the "SpeedUp and Duration" menu, the voiceover sounds ridiciously unrealistic and bad. When speeding it up for only 10 % the voiceover have an unrealisticly high pitch which sounds quite unnatural. And vice versa, when slowing down the voiceovers they have an unrealisticly low pitch which also sounds quite bad.

If you, for example, change the speed of videos in Youtube, the audio quality remains quite good and the pitch of the voice does not change drastically, even when speeding it up (or slowing down) for more than 50 %.

Does anyone have any idea how I can change the speed of the video while still having a realistic and natural pitch of the voiceovers?

Answers

  • Andy001z
    Andy001z Posts: 3,291 Ambassador

    I have had some success when using the Pitch effect to bring the pitch back to a better level.

    Of course you could try unlinking the video and audio, but you may end up with sink issues for effects and actions.

  • Stargazer54
    Stargazer54 Posts: 3,741 Ambassador

    Personally, I would do what Andy said and unlink the audio and video. Perform your speed change on the video file and then slice and dice the audio file to better match the visuals. Also if you have your audio separated you could just write out a .wav and import that into a dedicated audio editor such as Audacity (which is free) and work with changing the timing there, then write out a new .wav and re-import back into HF.

    Audio management in HF is pretty basic so exporting your audio and manipulating it in a dedicated audio editor often provides better results.

  • vanny_f
    vanny_f Posts: 77 Just Starting Out*
    edited May 8

    Thanks a lot Andy001z and Stargazer54 for your answers,

    it's a pitty to hear that Hilfilm Express does not provide native tools for comfortably doing this because the audio sounds extremely bad and premetive after manipulating it with Hiltfilm Express.

    @Andy001z : What do you mean by "unlinking the video and audio" and "sink issues for effects and actions"?

    @Stargazer54 : What do you mean by "if you have your audio separated"? I have a voiceover that consists of different slices. I recorded the voiceover by using the recording tool of Hiltfilm Express.

  • Stargazer54
    Stargazer54 Posts: 3,741 Ambassador

    Unlinking - right click on the video clip and select "Unlink" from the pop-up. Then you can slide the audio and video around independently.

    Conversely you can hold down the Ctl key and select unlinked audio and video, the right click and select "Link" to put them back together.

    You can also export audio only to it's own file and then read that into a dedicated audio editing program to change pitch, do noise reduction, etc. Then write out a new file and read that back into HF to replace the original audio.

  • spyresca
    spyresca Posts: 231 Enthusiast

    It's embarassing that Hitfilm can't handle this easily. Even many open source (i.e. free) options do so without hassle.

  • vanny_f
    vanny_f Posts: 77 Just Starting Out*

    Thanks Stargazer54 and spyresca for your comments,

    is there any freeware tool that can can just do the speeding for both the video and the audio simultaneously and that has good audio quality. I assume if I started separating video and audio it will be quite difficult to match them again perfectly. Any yes, it is totally embarassing how the audio sounds in Hitfilm Express. It is ridiculous and I was kind of suprised after hearing the "converted audio". I did not anticipate at all that it would sound so bad.

  • Triem23
    Triem23 Posts: 20,514 Ambassador

    Audacity. It's free, been around since the 1990's - so is mature and solid software - and Stargazer had previously mentioned it.

  • vanny_f
    vanny_f Posts: 77 Just Starting Out*

    @Triem23 : Thanks for your answer,

    Audacity looks like a tool only for audio. Do you know if I can directly import my video file (which containts the audio in it) and speed up or slow down the video and audio simultaneously?

  • Triem23
    Triem23 Posts: 20,514 Ambassador

    @vanny_f yeah Audacity is primarily for audio, but there are add on plugs ins which allow import of video and some very minor video editing. Here, Google is your friend. I don't actually use Audacity myself. Vegas Pro is my audio editor.

    I miss Presonus Time Machine. Long discontinued, it's the best time/pitch shift program (it was stand alone) I've ever come across. It's about the only one ever that didn't have ugly artifacts in the output.

    Above you commented that YouTube's speed algorithm sounds good? Nah, it sounds terrible and puts a subtle clicking in the audio track. Even after hearing damage from too long working in too loud conditions I can hear the processing working.

    (At least it's not Autotune. That makes me cringe.)

  • vanny_f
    vanny_f Posts: 77 Just Starting Out*

    Thanks Triem23 for your answer,

    does anybody have another suggestion next to Audacity which is free and which is capable of editing a video with the audio simultanesouly regarding the sound? I'll highly appreciate every suggestion.

    Regarding the Youtube speed algorithm. Of course it is not perfect. But compared to Hitfilm it is 100 time better and actually would be enough for my ambitions :-). But of course, if somebody knows a free toll that produces better results, I'd be quite happy to get to know that.

  • NormanPCN
    NormanPCN Posts: 4,122 Enthusiast

    You could try using VirtualDub 2 to do your speed change. It is not a terribly clean process but it is doable. You cannot preview your filtered results in playback. You have to render a test result and play that. ffmpeg can do this but that is a command line tool. Vdub2 offers the same functions of ffmpeg just with some GUI.

    Before posting this here I tried a trivial test with a 2x speed up of a video. My source video was 1080p29.97. I rendered a Cineform 422 MOV file (video compression menu option), still at a 29.97 frame rate but just sped up (and thus shorter).

    The simplest way to do this you change the frame rate setting the video tab. In source rate adjustment you put your desired interpreted frame rate. I was doing a 2x speed up so I entered 59.94. You can enter any decimal value. You want a 10% change then do that. Any decimal value is acceptable. The value entered here does not change the source frames in any way. It is changing how Vdub interprets the source frame rate. In my test, Vdub simply reads/plays the frames twice as fast.

    In the Convert to fps, this interpolates the source rate to a desired result/output rate. Here you would normally be entering the actual frame rate of your source. In my test case, 29.97.

    Sample Video frame rate dialog.


    Then you need audio to be in full processing mode, and advanced filtering be enabled. I leave the audio at uncompressed output since I was going to save a Cineform MOV file which allows uncompressed PCM audio. Then you need to create filter graph for the audio stream. You add an input, then add a time stretch, and then add an output. Then double click the time stretch node to enter the time stretch setting. In my test case I entered 0.5. I wanted the existing audio to take half as much time since I was speeding up the video 2x. There is a test button, and a timeline, to hear the audio result. No video.

    Sample Audio filters dialog.


    Finally to save your video via Save Video menu option. Choose MOV for the output type. The video and audios settings should be set up for you.

  • vanny_f
    vanny_f Posts: 77 Just Starting Out*

    @NormanPCN thanks for your answer and effort, I really appreciate it,

    your suggested solution sounds quite complex. Is there not a freeware tool where you can just add any percentage number and it will adjust the video and audio accordingly? Actually the same way as Hitfilm is doing but just with better audio quality?

  • vanny_f
    vanny_f Posts: 77 Just Starting Out*

    Does nobody have another idea or suggestion about an easy-to-use tool for doing this? I'll highly appreciate every further comment because the options so far and not good. Hitfilm is transforming the sound in an embarrassingly ridiculous way. When using Audacity, it will be quite difficult to synch the video and audio and this will not sound good. And the solution described by NormanPCN is way too complex for someone who has no experience with the tool (VirtualDub 2) he suggested (although I appreciate this answer).

    The task should not be too difficult to do, as I am fully satisfied with the way YouTube is doing. I think it sound quite okay (at least 100 times better than in Hitfilm). Can you think about a free tool that produces similar results as YouTube (might be even a little worse but not 100 time worse as in Hitfilm) and that is easy to use?

  • Triem23
    Triem23 Posts: 20,514 Ambassador

    You can try this one, but the bottom line is there aren't many free audio time/shift pitching tools available. The majority are commercial plug ins for commercial software.


  • vanny_f
    vanny_f Posts: 77 Just Starting Out*

    Thanks Triem23 for your answer, unfortunately your suggested tool is not suitable as it is written that "It is suitable only for extreme sound stretching of the audio (like 50x)" and I don't think it works with videos.

    It's really a pitty that there are no free tools for that and that Hitfilm is rubbish for this. Is it possible to speed a clip in YouTube by 10% or 5% only? If so, I could try to use it for changing the speed as the quality of the YouTube sound tranformation is very good.

  • vanny_f
    vanny_f Posts: 77 Just Starting Out*
    edited May 12

    Does nobody have a further suggestion for a free tool that handles both video and audio simultaneously and that at least generates better results than Hitfilm Express? So my ambitions are not that high, so I am aware that it is unrealistic to expect the tool to generate outcomes that are as good as the speeding on YouTube. But there should be a tool that at least is doing this better than Hitfilm Express. So, I 'll highly appreciate every further suggestion.

  • NormanPCN
    NormanPCN Posts: 4,122 Enthusiast

    Google can be your friend to find some things to try.

    "video speed change online"

    The third item in the search results might be worth trying.


  • vanny_f
    vanny_f Posts: 77 Just Starting Out*

    Okay, thanks all for your comments. I will think about what to do but at least I got some options. I appreciate your feedback