VideoUtils.cpp

#include "VideoUtils.hpp"
#ifndef __APPLE__
#include <Vfw.h>
#include <vector>
#include <windows.h>

#pragma comment(lib, "Vfw32.lib")
using namespace VideoUtils;

PAVIFILE pfile;
PAVISTREAM stream;
AVIFILEINFOA info;
long current_frame = 0;
long max_frames = 0;
std::vector<Image> cache{};

void VideoUtils::get_video_info() {
  AVIFileInfo(pfile, &info, sizeof(AVIFILEINFO));
}

long VideoUtils::num_frames() { return AVIStreamLength(stream); }

void VideoUtils::open_video(const char *video_path) {
  cache.clear();
  AVIFileInit();
  current_frame = 0;
  max_frames = 0;
  AVIFileOpen(&pfile, video_path, OF_READ, NULL);
  HRESULT hr = AVIStreamOpenFromFile(&stream, video_path, streamtypeVIDEO, 0,
                                     OF_READ, NULL);
  get_video_info();
  max_frames = num_frames();
  debugger("frame: %d", max_frames);
  cache.resize(max_frames);
}

Image VideoUtils::get_frame(int frame_index) {
  current_frame = frame_index;
  // if (cache[frame_index].contain_content())
  //    return cache[frame_index];
  BITMAPINFOHEADER bih;
  ZeroMemory(&bih, sizeof(BITMAPINFOHEADER));
  bih.biBitCount = 24;
  bih.biClrImportant = 0;
  bih.biClrUsed = 0;
  bih.biCompression = BI_RGB;
  bih.biPlanes = 1;
  bih.biSize = 40;
  bih.biXPelsPerMeter = 0;
  bih.biYPelsPerMeter = 0;
  bih.biSizeImage = (((bih.biWidth * 3) + 3) & 0xFFFC) * bih.biHeight;

  PGETFRAME pframe = AVIStreamGetFrameOpen(stream, NULL);
  BYTE *pDIB = (BYTE *)AVIStreamGetFrame(pframe, current_frame);
  if (pDIB == NULL) {
    debugger("reading failed");
    Image tmp;
    // return an empty image
    return tmp;
  }
  // reading is fine
  RtlMoveMemory(&bih.biSize, pDIB, sizeof(BITMAPINFOHEADER));
  BYTE *Bits = new BYTE[bih.biSizeImage];
  RtlMoveMemory(Bits, pDIB + sizeof(BITMAPINFOHEADER), bih.biSizeImage);
  AVIStreamGetFrameClose(pframe); // rmb to close the frame decoder, otherwise
                                  // it can cause decoder failure
  Image tmp;
  tmp.set(Bits, bih.biWidth, bih.biHeight);
  // cache[frame_index] = tmp;
  return tmp;
}

Image VideoUtils::next_frame() {
  current_frame = (current_frame + 1) % (max_frames);
  debugger("current: %d", current_frame);
  return get_frame(current_frame);
}
#else

void VideoUtils::get_video_info() {}
long VideoUtils::num_frames() {}
void VideoUtils::open_video(const char *video_path) {}
Image VideoUtils::get_frame(int frame_index) {}
Image VideoUtils::next_frame() {}

#endif