[FIX] Allow all oem modes with tesseract v4

docs/CHANGES.TXT

@@ -19,6 +19,7 @@
 - Fix: General code clean up / reformatting
 - Fix: Fix multiple definitions with new -fno-common default in GCC 10
 - Fix: Mac now builds reproducibly again without errors on the date command (#1230)
+- Fix: Allow all oem modes with tesseract v4 (#1264)
 - Doc: Updated ccextractor.cnf.sample.
 
 0.88 (2019-05-21)

src/lib_ccx/ccx_common_option.c

@@ -69,7 +69,7 @@ void init_options(struct ccx_s_options *options)
 	options->hardsubx = 0;		  // By default, don't try to extract hard subtitles
 	options->dvblang = NULL;	  // By default, autodetect DVB language
 	options->ocrlang = NULL;	  // By default, autodetect .traineddata file
-	options->ocr_oem = 0;		  // By default, set Tesseract OEM mode OEM_TESSERACT_ONLY (0)
+	options->ocr_oem = -1;		  // By default, OEM mode depends on the tesseract version
 	options->ocr_quantmode = 1;	  // CCExtractor's internal
 	options->mkvlang = NULL;	  // By default, all the languages are extracted
 	options->ignore_pts_jumps = 1;

src/lib_ccx/hardsubx.c

@@ -248,13 +248,16 @@ struct lib_hardsubx_ctx *_init_hardsubx(struct ccx_s_options *options)
 	if (!strncmp("4.", TessVersion(), 2))
 	{
 		char tess_path[1024];
+		if (ccx_options.ocr_oem < 0)
+			ccx_options.ocr_oem = 1;
 		snprintf(tess_path, 1024, "%s%s%s", tessdata_path, "/", "tessdata");
-		//ccx_options.ocr_oem are deprecated and only supported mode is OEM_LSTM_ONLY
-		ret = TessBaseAPIInit4(ctx->tess_handle, tess_path, lang, 1, NULL, 0, &pars_vec,
+		ret = TessBaseAPIInit4(ctx->tess_handle, tess_path, lang, ccx_options.ocr_oem, NULL, 0, &pars_vec,
 				       &pars_values, 1, false);
 	}
 	else
 	{
+		if (ccx_options.ocr_oem < 0)
+			ccx_options.ocr_oem = 0;
 		ret = TessBaseAPIInit4(ctx->tess_handle, tessdata_path, lang, ccx_options.ocr_oem, NULL, 0, &pars_vec,
 				       &pars_values, 1, false);
 	}

src/lib_ccx/ocr.c

@@ -178,12 +178,15 @@ void *init_ocr(int lang_index)
 	{
 		char tess_path[1024];
 		snprintf(tess_path, 1024, "%s%s%s", tessdata_path, "/", "tessdata");
-		//ccx_options.ocr_oem are deprecated and only supported mode is OEM_LSTM_ONLY
-		ret = TessBaseAPIInit4(ctx->api, tess_path, lang, 1, NULL, 0, &pars_vec,
+		if (ccx_options.ocr_oem < 0)
+			ccx_options.ocr_oem = 1;
+		ret = TessBaseAPIInit4(ctx->api, tess_path, lang, ccx_options.ocr_oem, NULL, 0, &pars_vec,
 				       &pars_values, 1, false);
 	}
 	else
 	{
+		if (ccx_options.ocr_oem < 0)
+			ccx_options.ocr_oem = 0;
 		ret = TessBaseAPIInit4(ctx->api, tessdata_path, lang, ccx_options.ocr_oem, NULL, 0, &pars_vec,
 				       &pars_values, 1, false);
 	}

src/lib_ccx/params.c

@@ -681,10 +681,14 @@ void print_usage(void)
 	mprint("                       0: Don't quantize at all.\n");
 	mprint("                       1: Use CCExtractor's internal function (default).\n");
 	mprint("                       2: Reduce distinct color count in image for faster results.\n");
-	mprint("                 -oem: Select the OEM mode for Tesseract, could be 0, 1 or 2.\n");
-	mprint("                       0: OEM_TESSERACT_ONLY - default value, the fastest mode.\n");
+	mprint("                 -oem: Select the OEM mode for Tesseract.\n");
+	mprint("                       Available modes :\n");
+	mprint("                       0: OEM_TESSERACT_ONLY - the fastest mode.\n");
 	mprint("                       1: OEM_LSTM_ONLY - use LSTM algorithm for recognition.\n");
 	mprint("                       2: OEM_TESSERACT_LSTM_COMBINED - both algorithms.\n");
+	mprint("                       Default value depends on the tesseract version linked :\n");
+	mprint("                       Tesseract v3 : default mode is 0,\n");
+	mprint("                       Tesseract v4 : default mode is 1.\n");
 	mprint("             -mkvlang: For MKV subtitles, select which language's caption\n");
 	mprint("                       stream will be processed. e.g. 'eng' for English.\n");
 	mprint("                       Language codes can be either the 3 letters bibliographic\n");