WindowsAPI - avicap32.dll 参数详解：
WM_CAP_START= WM_USER=1024;
// start of unicode messages
WM_CAP_UNICODE_START= WM_USER+100; //开始
WM_CAP_GET_CAPSTREAMPTR= (WM_CAP_START+ 1); //获得 CAPSTR EAMPTR
WM_CAP_SET_CALLBACK_ERROR= (WM_CAP_START+ 2); //设置回调错误
WM_CAP_SET_CALLBACK_STATUS= (WM_CAP_START+ 3); //设置回调状态
WM_CAP_SET_CALLBACK_YIELD= (WM_CAP_START+ 4); //设置回调出产
WM_CAP_SET_CALLBACK_FRAME= (WM_CAP_START+ 5); //设置回调结构
WM_CAP_SET_CALLBACK_VIDEOSTREAM= (WM_CAP_START+ 6); //设置回调视频流
WM_CAP_SET_CALLBACK_WAVESTREAM= (WM_CAP_START+ 7); //设置回调视频波流
WM_CAP_GET_USER_DATA =(WM_CAP_START+ 8); //获得使用者数据
WM_CAP_SET_USER_DATA =(WM_CAP_START+ 9) ; //设置使用者数据
WM_CAP_DRIVER_CONNECT =(WM_CAP_START+ 10); //驱动程序连接
WM_CAP_DRIVER_DISCONNECT =(WM_CAP_START+ 11); //断开启动程序连接
WM_CAP_DRIVER_GET_NAME =(WM_CAP_START+ 12); //获得驱动程序名字
WM_CAP_DRIVER_GET_VERSION =(WM_CAP_START+ 13); //获得驱动程序版本
WM_CAP_DRIVER_GET_CAPS =(WM_CAP_START+ 14); //获得驱动程序性能
WM_CAP_FILE_SET_CAPTURE_FILE =(WM_CAP_START+ 20); //设置捕获文件的文件名
WM_CAP_FILE_GET_CAPTURE_FILE =(WM_CAP_START+ 21); //获得捕获文件的文件名
WM_CAP_FILE_SAVEAS =(WM_CAP_START+ 23); //另存文件为
WM_CAP_FILE_SAVEDIB =(WM_CAP_START+ 25); //保存文件
// out of order to save on ifdefs
WM_CAP_FILE_ALLOCATE =(WM_CAP_START+ 22); //分派文件, 为捕获文件建一个指定大小的文件
WM_CAP_FILE_SET_INFOCHUNK =(WM_CAP_START+ 24); //设置开始文件
WM_CAP_EDIT_COPY =(WM_CAP_START+ 30); //编辑复制,把图象考入剪贴板
WM_CAP_SET_AUDIOFORMAT =(WM_CAP_START+ 35); //设置音频格式
WM_CAP_GET_AUDIOFORMAT =(WM_CAP_START+ 36); //捕获音频格式
WM_CAP_DLG_VIDEOFORMAT =(WM_CAP_START+ 41); //1065 打开视频格式设置对话框, 选择数字视频的框架大小和视频图像的色深，以及捕获视频图像的压缩格式。
WM_CAP_DLG_VIDEOSOURCE =(WM_CAP_START+ 42); //1066 打开属性设置对话框，设置对比度、亮度等。(视频源对话框) 选择视频输入通道和视频图像的动态参数。
WM_CAP_DLG_VIDEODISPLAY =(WM_CAP_START+ 43); //1067 打开视频显示对话框
WM_CAP_GET_VIDEOFORMAT =(WM_CAP_START+ 44); //1068 获得视频格式
WM_CAP_SET_VIDEOFORMAT =(WM_CAP_START+ 45); //1069 设置视频格式
WM_CAP_DLG_VIDEOCOMPRESSION =(WM_CAP_START+ 46); //1070 打开压缩设置对话框
WM_CAP_SET_PREVIEW =(WM_CAP_START+ 50); //设置预览模式
WM_CAP_SET_OVERLAY =(WM_CAP_START+ 51); //设置覆盖
WM_CAP_SET_PREVIEWRATE =(WM_CAP_START+ 52); //设置预览模式下图像的帧速度
WM_CAP_SET_SCALE =(WM_CAP_START+ 53); //设置预览视频的缩放比例
WM_CAP_GET_STATUS =(WM_CAP_START+ 54); //获得状态
WM_CAP_SET_SCROLL =(WM_CAP_START+ 55); //设置卷
WM_CAP_GRAB_FRame =(WM_CAP_START+ 60); //逮捕结构
WM_CAP_GRAB_FRame_NOSTOP =(WM_CAP_START+ 61); //停止逮捕结构,截取当前图象
WM_CAP_SEQUENCE =(WM_CAP_START+ 62); //次序，捕捉到文件
WM_CAP_SEQUENCE_NOFILE =(WM_CAP_START+ 63); //没有文件
WM_CAP_SET_SEQUENCE_SETUP =(WM_CAP_START+ 64); //设置当前捕获的帧频率
WM_CAP_GET_SEQUENCE_SETUP =(WM_CAP_START+ 65); //获得当前捕获的帧频率
WM_CAP_SET_MCI_DEVICE =(WM_CAP_START+ 66); //设置媒体控制接口
WM_CAP_GET_MCI_DEVICE =(WM_CAP_START+ 67); //获得媒体控制接口
WM_CAP_STOP =(WM_CAP_START+ 68); //停止捕捉
WM_CAP_ABORT =(WM_CAP_START+ 69); //异常中断
WM_CAP_SINGLE_FRame_OPEN =(WM_CAP_START+ 70); //打开单一的结构
WM_CAP_SINGLE_FRame_CLOSE =(WM_CAP_START+ 71); //关闭单一的结构
WM_CAP_SINGLE_FRame =(WM_CAP_START+ 72); //单一的结构
WM_CAP_PAL_OPEN =(WM_CAP_START+ 80); //打开视频
WM_CAP_PAL_SAVE =(WM_CAP_START+ 81); //保存视频
WM_CAP_PAL_PASTE =(WM_CAP_START+ 82); //粘贴视频
WM_CAP_PAL_AUTOCREATE =(WM_CAP_START+ 83); //自动创造
WM_CAP_PAL_MANUALCREATE =(WM_CAP_START+ 84); //手动创造
// Following added post VFW 1.1
WM_CAP_SET_CALLBACK_CAPCONTROL =(WM_CAP_START+ 85); // 设置收回的错误
WM_CAP_END =WM_CAP_SET_CALLBACK_CAPCONTROL