video-pc/libs/Recorder/record_desktop_gdi.cpp

#include "record_desktop_gdi.h"

#include "error_define.h"
#include "log_helper.h"

namespace am {
record_desktop_gdi::record_desktop_gdi()
{
    _data_type = RECORD_DESKTOP_DATA_TYPES::AT_DESKTOP_BGRA;
    _buffer = NULL;
    _buffer_size = 0;

    _draw_cursor = true;

    _hdc = NULL;
    _bmp = NULL;
    _bmp_old = NULL;
    _ci = {0};
}

record_desktop_gdi::~record_desktop_gdi()
{
    stop();
    clean_up();
}

int record_desktop_gdi::init(const RECORD_DESKTOP_RECT &rect, const int fps)
{
    int error = AE_NO;
    if (_inited == true) {
        return error;
    }

    _fps = fps;
    _rect = rect;

    do {
        _width = rect.right - rect.left;
        _height = rect.bottom - rect.top;
        _buffer_size = (_width * 32 + 31) / 32 * _height * 4;
        _buffer = new uint8_t[_buffer_size];

        _start_time = av_gettime_relative();
        _time_base = {1, AV_TIME_BASE};
        _pixel_fmt = AV_PIX_FMT_BGRA;

        _inited = true;
    } while (0);

    al_info("init gdi finished,error: %s %ld", err2str(error), GetLastError());

    return error;
}

int record_desktop_gdi::start()
{
    if (_running == true) {
        al_warn("record desktop gdi is already running");
        return AE_NO;
    }

    if (_inited == false) {
        return AE_NEED_INIT;
    }

    _running = true;
    _thread = std::thread(std::bind(&record_desktop_gdi::record_func, this));

    return AE_NO;
}

int record_desktop_gdi::pause()
{
    _paused = true;
    return AE_NO;
}

int record_desktop_gdi::resume()
{
    _paused = false;
    return AE_NO;
}

int record_desktop_gdi::stop()
{
    _running = false;
    if (_thread.joinable())
        _thread.join();

    return AE_NO;
}

void record_desktop_gdi::clean_up()
{
    _inited = false;

    if (_buffer)
        delete[] _buffer;

    _buffer = nullptr;
}

void record_desktop_gdi::draw_cursor(HDC hdc)
{
    if (!(_ci.flags & CURSOR_SHOWING))
        return;

    //is cursor in the tartet zone
    if (_ci.ptScreenPos.x < _rect.left || _ci.ptScreenPos.x > _rect.right
        || _ci.ptScreenPos.y < _rect.top || _ci.ptScreenPos.y > _rect.bottom)
        return;

    HICON icon;
    ICONINFO ii;

    icon = CopyIcon(_ci.hCursor);
    if (!icon)
        return;

    int dstx = 0, dsty = 0;
    dstx = abs(_ci.ptScreenPos.x - _rect.left);
    dsty = abs(_ci.ptScreenPos.y - _rect.top);

    if (GetIconInfo(icon, &ii)) {
        POINT pos;
        DrawIconEx(hdc, dstx, dsty, icon, 0, 0, 0, NULL, DI_NORMAL);

        DeleteObject(ii.hbmColor);
        DeleteObject(ii.hbmMask);
    }

    DestroyIcon(icon);
}

int record_desktop_gdi::do_record()
{
    //int width = GetSystemMetrics(SM_CXVIRTUALSCREEN);
    //int height = GetSystemMetrics(SM_CYVIRTUALSCREEN);
    HDC hdc_screen = NULL, hdc_mem = NULL;
    HBITMAP hbm_mem = NULL;

    int error = AE_ERROR;

    do {
        hdc_screen = GetWindowDC(NULL);
        if (!hdc_screen) {
            al_error("get window dc failed:%lu", GetLastError());
            error = AE_GDI_GET_DC_FAILED;
            break;
        }

        hdc_mem = CreateCompatibleDC(hdc_screen);
        if (!hdc_mem) {
            al_error("create compatible dc failed:%lu", GetLastError());
            error = AE_GDI_CREATE_DC_FAILED;
            break;
        }

        hbm_mem = CreateCompatibleBitmap(hdc_screen, _width, _height);
        if (!hbm_mem) {
            al_error("create compatible bitmap failed:%lu", GetLastError());
            error = AE_GDI_CREATE_BMP_FAILED;
            break;
        }

        SelectObject(hdc_mem, hbm_mem);

        //must have CAPTUREBLT falg,otherwise some layered window can not be captured
        if (!BitBlt(hdc_mem,
                    0,
                    0,
                    _width,
                    _height,
                    hdc_screen,
                    _rect.left,
                    _rect.top,
                    SRCCOPY | CAPTUREBLT)) {
            al_error("bitblt data failed:%lu", GetLastError());
            //error = AE_GDI_BITBLT_FAILED;
            //administrator UAC will trigger invalid handle error
            break;
        }

        memset(&_ci, 0, sizeof(CURSORINFO));
        _ci.cbSize = sizeof(CURSORINFO);
        if (GetCursorInfo(&_ci)) {
            draw_cursor(hdc_mem);
        }

        BITMAPINFOHEADER bi;

        bi.biSize = sizeof(BITMAPINFOHEADER);
        bi.biWidth = _width;
        bi.biHeight = _height * (-1);
        bi.biPlanes = 1;
        bi.biBitCount = 32; //should get from system color bits
        bi.biCompression = BI_RGB;
        bi.biSizeImage = 0;
        bi.biXPelsPerMeter = 0;
        bi.biYPelsPerMeter = 0;
        bi.biClrUsed = 0;
        bi.biClrImportant = 0;

        //scan colors by line order
        int ret
            = GetDIBits(hdc_mem, hbm_mem, 0, _height, _buffer, (BITMAPINFO *) &bi, DIB_RGB_COLORS);
        if (ret <= 0 || ret == ERROR_INVALID_PARAMETER) {
            al_error("get dibits failed:%lu", GetLastError());
            error = AE_GDI_GET_DIBITS_FAILED;
            break;
        }

#if 0
			//save bmp to test
			BITMAPFILEHEADER bf;
			bf.bfType = 0x4d42;
			bf.bfReserved1 = 0;
			bf.bfReserved2 = 0;
			bf.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
			bf.bfSize = bf.bfOffBits + _width * _height * 4;

			FILE *fp = fopen("..\\..\\save.bmp", "wb+");

			fwrite(&bf, 1, sizeof(bf), fp);
			fwrite(&bi, 1, sizeof(bi), fp);
			fwrite(_buffer, 1, _buffer_size, fp);

			fflush(fp);
			fclose(fp);
#endif
        error = AE_NO;
    } while (0);

    if (hbm_mem)
        DeleteObject(hbm_mem);

    if (hdc_mem)
        DeleteObject(hdc_mem);

    if (hdc_screen)
        ReleaseDC(NULL, hdc_screen);

    return AE_NO;
}

void record_desktop_gdi::do_sleep(int64_t dur, int64_t pre, int64_t now)
{
    int64_t delay = now - pre;
    dur = delay > dur ? max(0, dur - (delay - dur)) : (dur + dur - delay);

    // 优化：使用更精确的睡眠机制，减少延迟抖动
    if (dur > 0) {
        // 对于小于2ms的延迟，使用忙等待以获得更精确的时序
        if (dur < 2000) {  // 2ms
            int64_t start = av_gettime_relative();
            while (av_gettime_relative() - start < dur) {
                // 忙等待，但让出CPU时间片
                std::this_thread::yield();
            }
        } else {
            av_usleep(dur);
        }
    }
}

void record_desktop_gdi::record_func()
{
    AVFrame *frame = av_frame_alloc();

    int64_t pre_pts = 0;
    int64_t dur = AV_TIME_BASE / _fps;
    
    // 优化：预分配光标信息结构，减少每帧的内存分配开销
    memset(&_ci, 0, sizeof(CURSORINFO));
    _ci.cbSize = sizeof(CURSORINFO);

    int ret = AE_NO;
    while (_running) {
        int64_t frame_start = av_gettime_relative();
        
        ret = do_record();
        if (ret != AE_NO) {
            if (_on_error)
                _on_error(ret);
            break;
        }

        // 使用相对时间戳，与muxer的_base_time保持一致
        frame->pts = frame_start;  // 使用帧开始时间作为时间戳
        frame->pkt_dts = frame->pts;

        frame->width = _width;
        frame->height = _height;
        frame->format = AV_PIX_FMT_BGRA;
        frame->pict_type = AV_PICTURE_TYPE_I;
        frame->pkt_size = _width * _height * 4;

        av_image_fill_arrays(frame->data,
                             frame->linesize,
                             _buffer,
                             AV_PIX_FMT_BGRA,
                             _width,
                             _height,
                             1);

        if (_on_data)
            _on_data(frame);

        // 优化：更精确的帧率控制
        int64_t frame_end = av_gettime_relative();
        int64_t processing_time = frame_end - frame_start;
        int64_t sleep_time = dur - processing_time;
        
        if (sleep_time > 0) {
            do_sleep(sleep_time, pre_pts, frame_end);
        }

        pre_pts = frame_end;
    }

    av_frame_free(&frame);
}
} // namespace am