video_to_ascii

main.cpp

#include <SFML/Audio.hpp>
#include <chrono>
#include <iostream>
#include <opencv2/opencv.hpp>
#include <thread>

using namespace std;
using namespace cv;

void playAudio(const string& audio_path) {
  sf::Music music;
  if (!music.openFromFile(audio_path)) {
    cout << "Error loading audio from video." << endl;
    return;
  }
  music.play();
  while (music.getStatus() == sf::Music::Playing) {
    std::this_thread::sleep_for(
        std::chrono::milliseconds(10));  // Sleep for a short duration
  }
}

string pixelToASCII(int pixel_intensity) {
  // const string ASCII_CHARS = "@$%#&!*+=-_.                ";
  // const string ASCII_CHARS =
  // "@B%8WM#*oahkbdpwmZO0QCJYXzcvunxrjft/\|()1{}[]?-_+~<>i!lI;:,\"^`'. "; const
  // string ASCII_CHARS = "@#&!*+=-_.     ";
  const string ASCII_CHARS = "   ._-=+*!&#%$@";
  string s =
      string(1, ASCII_CHARS[pixel_intensity * ASCII_CHARS.length() / 256]);
  return s;
}

int main(int argc, char** argv) {
  if (argc < 3) {
    cout << "Usage: " << argv[0] << " <video_path> <audio_path>" << endl;
    return -1;
  }
  string video_path = argv[1];
  string audio_path = argv[2];
  VideoCapture cap(video_path);

  double fps = cap.get(CAP_PROP_FPS);

  // cout << fps << endl;

  int frame_duration_ms = 1000 / fps;

  int width = 85;
  int height = 30;

  int frame_width = cap.get(CAP_PROP_FRAME_WIDTH);
  int frame_height = cap.get(CAP_PROP_FRAME_HEIGHT);
  // cout << frame_width << " " << frame_height << endl;
  // 4096 2160
  // 751 × 944

  // height = (width * frame_height / frame_width) * 0.4194;

  Mat frame, gray_frame, resized_frame;

  auto video_start_time = std::chrono::high_resolution_clock::now();
  bool isFirstFrame = true;
  for (int frame_number = 0;; ++frame_number) {
    cap >> frame;
    if (frame.empty()) break;

    cv::cvtColor(frame, gray_frame, cv::COLOR_BGR2GRAY);
    resize(gray_frame, resized_frame, Size(width, height), 0, 0, INTER_LINEAR);

    string ascii_frame;
    for (int i = 0; i < height; i++) {
      for (int j = 0; j < width; j++) {
        ascii_frame += pixelToASCII(resized_frame.at<uchar>(i, j));
      }
      ascii_frame += "\n";
    }

    system("clear");
    cout << ascii_frame;

    if (isFirstFrame) {
      std::thread audioThread(playAudio, audio_path);
      audioThread.detach();
      isFirstFrame = false;
    }

    auto current_time = std::chrono::high_resolution_clock::now();
    auto since_video_start =
        std::chrono::duration_cast<std::chrono::milliseconds>(current_time -
                                                              video_start_time);
    auto next_frame_time = frame_number * frame_duration_ms;

    if (since_video_start.count() < next_frame_time) {
      std::this_thread::sleep_for(std::chrono::milliseconds(
          next_frame_time - since_video_start.count()));
    }
  }
  return 0;
}

build.sh

You need install SFML and OpenCV first.

g++ -std=c++11 `pkg-config --cflags opencv4` `pkg-config --libs opencv4` -lsfml-audio -o video_to_ascii main.cpp

Getting Started

Download the video and mp3. Then run the program

./video_to_ascii demo.mp4 demo.mp3

And you get the gif.