brian
February 10, 2023, 2:30am
27
Your project contains raw flac files. Unfortunately, that is known to be problematic in Shotcut. The underlying FFMPEG library does not seek well with raw flac. And we have not found a solution. FLAC in MKV in works better.
Use Properties > menu > Convert to Edit-friendly.
Alternatively, I suggest to remux that to a mkv file using ffmpeg ffmpeg -i your.flac -c copy your.mkv.
Additional reading:
Windows 10 with Shotcut version 21.06.29
I made a sine wave in Audacity and exported it as FLAC. I imported it in Shotcut, put it on an audio track, split it in 10 places, then exported it using the FLAC preset. It is distorted in many places, and the waveform is visibly distorted in some places when put back into Audacity to analyze it.
Also this is unrelated to splitting audio, but the file was inexplicably 48 ms longer whether it was split or not.
opened 03:03PM - 15 Oct 21 UTC
closed 06:25AM - 16 Mar 23 UTC
### Description
When rendering an MLT file referencing a FLAC audio file, the r… endered output will contain audible artifacts (crackles, pops) if the producers in offset is greater than zero (beginning is cropped), otherwise the audio is clean.
### Reproduction
1. Generate a 2 second sine wave FLAC audio using ffmpeg: `ffmpeg -f lavfi -i "sine=frequency=1000:duration=2" sine.flac`
2. Render a WAV 0 seconds in (duration 2 seconds): `melt -profile atsc_1080p_60 sine.flac in=00:00:00.000 out=00:00:02.000 -consumer avformat:sine_clean.wav`
3. Render a WAV 1 second in (duration 1 second): `melt -profile atsc_1080p_60 sine.flac in=00:00:01.000 out=00:00:02.000 -consumer avformat:sine_crackle.wav`
You will notice that sine_clean.wav is fine, while sine_crackle.wav is distorted.
### Workaround
If you use uncompressed WAV audio instead of FLAC there are no issues whatsoever.
### Technical Info
* MLT version: `7.0.1`
* FFmpeg version: `n4.4`
* OS: `5.10.68-1-MANJARO #1 SMP PREEMPT Wed Sep 22 12:29:47 UTC 2021 x86_64 GNU/Linux`
### Additional Info
I also tried different FLAC bit-depths (16 and 24 bit) as well as sampling-rates (44,1kHz and 48kHz), but the problem stays the same. If I do the same using ffmpeg, there is no distortion:
`ffmpeg -i sine.flac -ss 00:00:01.000 sine_ffmpeg.wav`
I noticed when you are working with imported FLAC audio tracks in shotcut, the audio kind of chops for a split second. Only happens with FLAC, WAV and other formats had no issues at all. Any way to fix that?
I have these audio crackling / popping noises when playing the file back but also in the exported output. Here is an example of this: help.wav - Google Drive
OS: Windows 11 (64 bit)
Shotcut version:22.06.23
Qt version: 5.15.2
Any ideas on what I can do? I don’t want to throw the project away