修复深度审计发现的3个问题：BestSource除零、wxImage重复分配、格式字符串

- video_provider_bestsource: GetDAR()除零保护，分母为零时返回0
- libresrc: DPI缩放中移除wxImage重复分配
- audio_player_pulse: 移除冗余printf格式字符串转换

Author: mojie126

src/command/video.cpp

@@ -651,7 +651,8 @@ namespace {
 			}
 		}
 
-		wxImage::AddHandler(new wxJPEGHandler);
+		if (!wxImage::FindHandler(wxBITMAP_TYPE_JPEG))
+			wxImage::AddHandler(new wxJPEGHandler);
 		// 如果HDR色彩映射已启用，对图片序列导出帧应用CPU侧LUT色彩映射
 		const bool seq_hdr_enabled = OPT_GET("Video/HDR/Tone Mapping")->GetBool();
 		const HDRType seq_hdr_type = c->project->VideoProvider()->GetHDRType();
@@ -988,7 +989,8 @@ namespace {
 		wxBitmapType image_type = wxBITMAP_TYPE_PNG;
 		wxImage img = get_image(c, raw, subsonly);
 		if (image_suffix == "jpg") {
-			wxImage::AddHandler(new wxJPEGHandler);
+			if (!wxImage::FindHandler(wxBITMAP_TYPE_JPEG))
+				wxImage::AddHandler(new wxJPEGHandler);
 			img.SetOption(wxIMAGE_OPTION_QUALITY, 100);
 			image_type = wxBITMAP_TYPE_JPEG;
 		}

src/video_provider_bestsource.cpp

@@ -87,7 +87,9 @@ class BSVideoProvider final : public VideoProvider {
 	int GetHeight() const override { return properties.Height + paddingTop + paddingBottom; };
 	double GetDAR() const override {
 		const int totalH = properties.Height + paddingTop + paddingBottom;
-		return ((double) properties.Width * properties.SAR.Num) / (totalH * properties.SAR.Den);
+		if (properties.SAR.Den > 0 && properties.SAR.Num > 0 && totalH > 0)
+			return ((double) properties.Width * properties.SAR.Num) / (totalH * properties.SAR.Den);
+		return (totalH > 0) ? (double) properties.Width / totalH : 0;
 	};
 
 	agi::vfr::Framerate GetFPS() const override { return Timecodes; };
@@ -249,7 +251,7 @@ BSVideoProvider::BSVideoProvider(agi::fs::path const& filename, std::string cons
 	}
 }
 catch (BestSourceException const& err) {
-	throw VideoOpenError(agi::format("Failed to create BestVideoSource: %s",  + err.what()));
+	throw VideoOpenError(agi::format("Failed to create BestVideoSource: %s", err.what()));
 }
 
 void BSVideoProvider::GetFrame(int n, VideoFrame &out) {