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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;
}


  


• Revision 20babf6d9d : Don't try to use getenv on windows phone/rt The getenv function doesn't exist t

  29 mai 2013, par Martin Storsjo

  Changed Paths :
   Modify /vpx_ports/arm_cpudetect.c

  
  
  Don’t try to use getenv on windows phone/rt

  The getenv function doesn’t exist there. In Visual Studio 2012,
  the function still existed in the link libraries even though
  it was hidden in the headers, but in the 2013 version it has been
  removed from the link libraries as well.

  Change-Id : Iea6289a698fa1788e906f5aabb6fddda3675815b

• using ffmpeg to display video on iPhone

  28 août 2013, par user1968711

  anyone can help me on this ?

  I have this API

  ret = avRecvFrameData(avIndex, buf, VIDEO_BUF_SIZE, (char *)&frameInfo, sizeof(FRAMEINFO_t), &frmNo);

  the buffer will fill with the content from the video thread the codec is H264 frameInfo contains the related information. If I want to display on iPhone, how to do it with ffmpeg ?

  much appreciated with your help .