When I select two points A and B and then I save using mpeg xvid and aac options, most of the time there is an annoying sound at the very first frames of the cut, it is a kind of electronic sound that ruins the cut. I have to look for other frames and sometimes even if you don't hear anything in the original video, the new one still has this noise.
Why it happens? How can I avoid this?
Thanks for your time!
I never experienced such an issue with Avidemux AAC reencoded audio. Please provide exact steps to reproduce, maybe together with a sample source video.
Ok, for example, the original video is this one:
https://www.youtube.com/watch?v=xN6uLbi475c
I just made a cut as an example of a simple sentence:
https://mega.nz/#!CIN3iawb!QoVDRsJloPI3UzbprGW6Z7KcRKP_M2eZ9_HRNhNaWb0
this is the key in case you are asked
!QoVDRsJloPI3UzbprGW6Z7KcRKP_M2eZ9_HRNhNaWb0
As you may notice in the original video there is no strange sound, but in the cutted video at the start you can hear something. Can you hear it?
Quote from: arnoldpredator on October 26, 2017, 06:21:13 PM
Ok, for example, the original video is this one:
https://www.youtube.com/watch?v=xN6uLbi475c
[info] Available formats for xN6uLbi475c:
format code extension resolution note
139 m4a audio only DASH audio 48k , m4a_dash container, mp4a.40.5@ 48k (22050Hz), 623.51KiB
249 webm audio only DASH audio 50k , opus @ 50k, 587.38KiB
250 webm audio only DASH audio 62k , opus @ 70k, 708.95KiB
171 webm audio only DASH audio 88k , vorbis@128k, 1.09MiB
251 webm audio only DASH audio 109k , opus @160k, 1.26MiB
140 m4a audio only DASH audio 127k , m4a_dash container, mp4a.40.2@128k (44100Hz), 1.62MiB
278 webm 256x144 144p 107k , webm container, vp9, 25fps, video only, 1.27MiB
160 mp4 256x144 DASH video 113k , avc1.4d400c, 25fps, video only, 1.42MiB
242 webm 426x240 240p 239k , vp9, 25fps, video only, 2.42MiB
133 mp4 426x240 DASH video 253k , avc1.4d4015, 25fps, video only, 3.15MiB
243 webm 640x360 360p 449k , vp9, 25fps, video only, 4.41MiB
134 mp4 640x360 DASH video 636k , avc1.4d401e, 25fps, video only, 5.41MiB
244 webm 854x480 480p 842k , vp9, 25fps, video only, 7.44MiB
135 mp4 854x480 DASH video 1163k , avc1.4d401e, 25fps, video only, 10.51MiB
247 webm 1280x720 720p 1717k , vp9, 25fps, video only, 14.75MiB
136 mp4 1280x720 DASH video 2325k , avc1.4d401f, 25fps, video only, 20.08MiB
248 webm 1920x1080 1080p 3115k , vp9, 25fps, video only, 27.25MiB
137 mp4 1920x1080 DASH video 4342k , avc1.640028, 25fps, video only, 38.38MiB
17 3gp 176x144 small , mp4v.20.3, mp4a.40.2@ 24k
36 3gp 320x180 small , mp4v.20.3, mp4a.40.2
43 webm 640x360 medium , vp8.0, vorbis@128k
18 mp4 640x360 medium , avc1.42001E, mp4a.40.2@ 96k
22 mp4 1280x720 hd720 , avc1.64001F, mp4a.40.2@192k (best)
Which formats did you use? What were your exact steps to generate the sample?
QuoteAs you may notice in the original video there is no strange sound, but in the cutted video at the start you can hear something. Can you hear it?
Yes, I can hear it. But I can't reproduce. I used format 22 as source with the FDK, lav and FAAC audio encoders as well as in copy mode. No such (or other) sound artifact whatsoever.
Thanks for your time and your patience.
These are the steps:
video output: Mpeg asp (xvid 4)
Audio output: AAC (fdk)
output format : MP4 muxer
Time A : 36.200
Time B: 39.160
I suppose you will get the same noise if you make a cut using this data.
Arnoldpredator, is the source file a download from YouTube? If so, what format number, as shown in the youtube-dl list, did you request?
Dan.
Yes it is from youtube, I chose the highest quality:
MP4 HP 1080
But I got the same tipe of errors with videos of 720.
Testing completed with current Avidemux builds (all 64 bit) on Linux, Mac and Windows strictly following the given steps: I'm sorry, but no noise.
Quote from: arnoldpredator on October 26, 2017, 09:10:51 PM
Yes it is from youtube, I chose the highest quality:
MP4 HP 1080
This is an audio issue. The info you have provided does not indicate the audio stream included within the MP4 you downloaded. Different YouTube download programs can include different format audio streams. Use the free MediaInfo (https://mediaarea.net/en/MediaInfo) and report what format, what bitrate and how many channels are shown in the audio section of the original clip.
For example:
Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : mp4a-40-2
Duration : 2 s 857 ms
Bit rate mode : Constant
Bit rate : 128 kb/s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 kHz
Frame rate : 43.066 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 44.8 KiB (2%)
Language : unk
Default : Yes
Alternate group : 1
This is from the cut clip, and you have told us that you have re-encoded the audio part to AAC. But what was the original audio format?
Dan.
I'm even not sure that the TO used youtube-dl (which would have used ffmpeg to mux video and audio)... Providing the source video together with the info about its origin would be better than any MediaInfo output.
I tested with format 22 as the only H.264 video with at least 720p resolution which includes audio.
I downloaded the video in 720. There was no higher res available to me.
Using ver 2.7 64bit, applied the settings, made the specified cut, no sound anomalies heard.
Thanks to all the people that tried it, and thanks to all the answers.
The software I used to download the video is IDM.
I myself repeated the process, downloaded the video, WITHOUT CLICKING ON PLAY I choose the times for A and B, I saved the video and got a perfect audio profile.
And I begin to understand what happens. It is related with the space button, it is used to play and stop the video, notice that when you push space to stop the video the video gets frozen, if after that you click on it again, which is play, for a tenth of a second you see the screen in green color and you hear a weird audio sound. My problem is like if I use the space button then when I make the cut that weird audio is recorded.
I use the space button a lot, and it is the only explanation I can think, but I don't have any manner to prove it, I am trying different ways but when I want to get the weird audio I can't :( it is so frustrating.
I put all the data you requested, I used MediaINfo to get it:
Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : mp4a-40-2
Duration : 1 min 47 s
Bit rate mode : Variable
Bit rate : 126 kb/s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 kHz
Frame rate : 43.066 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 1.60 MiB (9%)
Title : ISO Media file produced by Google Inc.
Encoded date : UTC 2016-08-14 05:00:32
Tagged date : UTC 2016-08-14 05:00:32
This is very unlikely that space bar can be related, because the encoding dialog is modal and neither evaluates events from pressing the space bar itself nor allows them to reach the main window (well, for couple of days this was broken in nightlies; this is fixed in the latest 2 or 3 nightlies already).
I don't get any weird sound from unpausing video in Avidemux.
I got it again, I tell you what process I use to cut videos, so maybe you can reproduce it:
-I look for something interesting
-I pause the video and go back 2 seconds several times so I can hear it again (frame by frame is too slow, 5 seconds is too much, and with 1 second I noticed I had to click too many times)
-Once it is clear I have to cut I try to pause the video as close as possible before the first word
-Then with 1 frame forward, and reading the lips (because there is no audio) I try to cut in the exact frame when the word is pronounced and I mark the point A
-Then I stop when I think it is proper to do so, when the sentence has been said, and I mark the point B
-I try to see if I will get a correct video, so I use "go to A" and then play
-I do the same with B, and play
After that I click on save with the settings I said.
As you see there is a lot of going forward and backward to capture the right sequence, and reading the lips is not always easy, I use a lot the pause button, go to A, go to B, reproduce...
I am sure that it is how I use this buttons, that is producing that weird sound.
I promise it is a real problem because for every, let's say 4 cuts, there is 1 with that weird sound. I try to repare it moving the point A several frames away and sometimes work, but other times I have to move A too much frames away from the original point and I can't record properly the start of the sentence. The frustrating thing is to notice that in the original audio in those frames there is not any weird sound at all.
Just to add that if I close the software, and start it again, and set the points A and B without using the space bar the video is saved properly.
Don't ask me why.
Thank you, I could reproduce the issue with different samples a couple of times. Might be related to filler audio samples Avidemux uses to synchronise audio with video.
You could try adding some minor (<50 ms) negative audio shift as a workaround.
Quote from: eumagga0x2a on October 31, 2017, 12:18:00 AM
Thank you, I could reproduce the issue with different samples a couple of times. Might be related to filler audio samples Avidemux uses to synchronise audio with video.
So happy to read that, honestly.
I don't know exactly how to add those 50 ms, ANy tutorial anywhere?
I will try to search for it tomorrow, it is very late here.
edit:
apparently is here
https://www.hecticgeek.com/2013/02/fix-audio-video-sync-save-permanently-avidemux/
I also know this issue, had it also when cutting the beginning of TS-File recordings. I though some kind of nullyfier Filter for audio with start and stop position would be great, like black in video...
Quote from: jan771 on November 02, 2017, 05:53:40 PM
I also know this issue, had it also when cutting the beginning of TS-File recordings. I though some kind of nullyfier Filter for audio with start and stop position would be great, like black in video...
Let's see if some expert can tell us the reason behind it.
I have uploaded two files with the audio problem:
Just conversion in matroska
ToneBlobStartSource.ts
ToneBlobStartCut.mkv
cutting results in corrupted sound.
ToneCutStartSourceTS.TS
ToneCutStartSource.mkv
ToneCutStartCut.mkv
https://c.gmx.net/@334663428440331676/djXXsvFRRsaWTpYg-9jgbQ
all have different sound, although they should have the same. It might also be due to the built in audio-delay, there seem to be multiple bugs.
Quote from: jan771 on November 05, 2017, 10:53:48 PM
I have uploaded two files with the audio problem:
Just conversion in matroska
ToneBlobStartSource.ts
ToneBlobStartCut.mkv
cutting results in corrupted sound.
ToneCutStartSourceTS.TS
ToneCutStartSource.mkv
ToneCutStartCut.mkv
https://c.gmx.net/@334663428440331676/djXXsvFRRsaWTpYg-9jgbQ
all have different sound, although they should have the same. It might also be due to the built in audio-delay, there seem to be multiple bugs.
I can't help, let's see if other people more expert understand this.
I found when using v.2.5 that a stray frame would be included at the start of the converted copy. That frame is where the play point had been sitting. So I try to set the last play frame at black. When jumping to the start of the video that stray frame appears there.