Fix(record): correct MJPEG upside-down playback

and remove 0-byte AVI residue on encoder open failure

server/2015Remote/Bmp2Video.cpp

@@ -284,13 +284,13 @@ bool BmpToJpeg(LPVOID lpBuffer, int width, int height, int quality,
         return false;
     }
 
-    // 复制数据（注意：DIB 是底部到顶部，需要翻转）
+    // 输入已为 top-down 的紧凑 BGR24（调用方已通过 Process24BitBmp /
+    // ConvertScreenshot32to24 完成翻转与去对齐），此处直接按行拷贝即可
     BYTE* srcData = (BYTE*)lpBuffer;
     BYTE* dstData = (BYTE*)bitmapData.Scan0;
 
     for (int y = 0; y < height; y++) {
-        // DIB 是从底部开始的，所以需要翻转
-        BYTE* srcRow = srcData + (height - 1 - y) * rowSize;
+        BYTE* srcRow = srcData + y * rowSize;
         BYTE* dstRow = dstData + y * bitmapData.Stride;
         memcpy(dstRow, srcRow, width * 3);
     }