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• Are there any libraries on adding effect to audio, like phone, inner monologue, or sounds like a man/woman ? [closed]

  6 mars, par Mathew

  I'm trying to apply different audio effects, such as making audio sound like a phone call. Below is my current approach. As you can see, I'm using multiple filters and simple algorithms to achieve this effect, but the output quality isn't ideal.

  


  Since I need to implement many sound effects/filters, are there any ready-to-use libraries that could help ?

  


  I've looked into FFmpeg filters and noticed mentions of LADSPA/LV2 plugins. Are these viable solutions ? Any other suggestions would be greatly appreciated.

  


  public static void applySceneEffect(String inputPath, String outputPath, int sceneType) {
    LOGGER.info("apply scene effect {} to {}", sceneType, inputPath);

    try (FFmpegFrameGrabber grabber = new FFmpegFrameGrabber(inputPath);
         FFmpegFrameRecorder recorder = new FFmpegFrameRecorder(outputPath, grabber.getAudioChannels())) {

        grabber.setOption("vn", ""); 
        grabber.start();

       
        recorder.setAudioCodec(avcodec.AV_CODEC_ID_PCM_S16LE); 
        recorder.setSampleRate(grabber.getSampleRate());
        recorder.setAudioChannels(grabber.getAudioChannels());
        recorder.setAudioBitrate(grabber.getAudioBitrate());
        recorder.setFormat("wav"); 


        String audioFilter = String.join(",",
                "aresample=8000",      
                "highpass=f=300, lowpass=f=3400",       
                "acompressor=threshold=-15dB:ratio=4:attack=10:release=100", 
                "volume=1.5",          
                "aecho=0.9:0.4:10:0.6"
        );

        FFmpegFrameFilter f1 = new FFmpegFrameFilter(audioFilter, grabber.getAudioChannels());
        f1.setSampleRate(grabber.getSampleRate());
        f1.start();

        recorder.start();

        Random random = new Random();
        double noiseLevel = 0.02; 

   
        while (true) {
            var frame = grabber.grabFrame(true, false, true, true);
            if (frame == null) {
                break;
            }

            ShortBuffer audioBuffer = (ShortBuffer) frame.samples[0];
            short[] audioData = new short[audioBuffer.remaining()];
            audioBuffer.get(audioData);

            applyElectricNoise(audioData, grabber.getSampleRate());

            audioData = applyDistortion(audioData, 1.5, 30000);

            audioBuffer.rewind();
            audioBuffer.put(audioData);
            audioBuffer.flip();


            f1.push(frame); 
            Frame filteredFrame;
            while ((filteredFrame = f1.pull()) != null) {
                recorder.record(filteredFrame); 
            }
        }

        recorder.stop();
        recorder.release();
        grabber.stop();
        grabber.release();
    } catch (FrameGrabber.Exception | FrameRecorder.Exception | FFmpegFrameFilter.Exception e) {
        throw new RuntimeException(e);
    }
}


private static final double NOISE_LEVEL = 0.005; 
private static final int NOISE_FREQUENCY = 60;  

public static void applyElectricNoise(short[] audioData, int sampleRate) {
    Random random = new Random();

    
    for (int i = 0; i < audioData.length; i++) {
        double noise = Math.sin(2 * Math.PI * NOISE_FREQUENCY * i / sampleRate);

        double electricNoise = random.nextGaussian() * NOISE_LEVEL * Short.MAX_VALUE + noise;

        audioData[i] = (short) Math.max(Math.min(audioData[i] + electricNoise, Short.MAX_VALUE), Short.MIN_VALUE); 
    }
}

public static short[] applyTremolo(short[] audioData, int sampleRate, double frequency, double depth) {
    double phase = 0.0;
    double phaseIncrement = 2 * Math.PI * frequency / sampleRate;

    for (int i = 0; i < audioData.length; i++) {
        double modulator = 1.0 - depth + depth * Math.sin(phase); 
        audioData[i] = (short) (audioData[i] * modulator);

        phase += phaseIncrement;
        if (phase > 2 * Math.PI) {
            phase -= 2 * Math.PI;
        }
    }
    return audioData;
}

public static short[] applyDistortion(short[] audioData, double gain, double threshold) {
    for (int i = 0; i < audioData.length; i++) {
        double sample = audioData[i] * gain;

        if (sample > threshold) {
            sample = threshold;
        } else if (sample < -threshold) {
            sample = -threshold;
        }

        audioData[i] = (short) sample;
    }
    return audioData;
}


  


• Why does ffmpeg have to align to the power of 2 when processing crop_left ?

  13 mai 2021, par hansionz

  If performance is considered, why doesn't crop_top \ crop_left \ crop_right perform power-of-two alignment ?
enter image description here

  


• facing problem in downloading the audio data of a trimmed youtube video using youtube-dl and ffmpeg libraries

  15 mai 2022, par rkc

  I'm trying to download the audio content of a trimmed YouTube video using youtube-dl (v2021.12.17) and FFmpeg (v4.2.2) libraries in python, on Windows 10 PC. I am able to download the audio data when the command is executed on the Pycharm terminal, but not able to download the same content when using os.system() command.

  


  For example, I'm able to download the data when I execute

  


  "ffmpeg -ss 30 -t 10 -i $(youtube-dl -f best -g https://www.youtube.com/watch?v=3NGZcpAZcl0) -- output1.wav"


  


  command on the Pycharm terminal.

  


  But, i'm getting an error, when I try to execute the same in the Editor window as shown below,

  


  os.system('ffmpeg -ss 30 -t 10 -i $(youtube-dl -f best -g https://www.youtube.com/watch?v=3NGZcpAZcl0) -- output1.wav')

error: $(youtube-dl: No such file or directory


  


  I also tried enclosing the $() link in quotes and then executed it. But, after doing this, I am getting a different error as shown below

  


  os.system('ffmpeg -ss 30 -t 10 -i "$(youtube-dl -f best -g https://www.youtube.com/watch?v=3NGZcpAZcl0)" -- output1.wav')

error: $(youtube-dl -f best -g https://www.youtube.com/watch?v=3NGZcpAZcl0): Invalid argument


  


  So, can any of you help me in resolving this error ?