If you try and process a PDF that is made from images with no OCR text layer or no other text then pdf-narrator is unable to extract any text and gets a bit upset with a few error messages in the log as the .txt file is empty.
Useful tip:
Use ocrmypdf to add an OCR layer to existing PDF files:
ocrmypdf --force-ocr --output-type pdf --rotate-pages --deskew --clean input.pdf output.pdf
If you try and process a PDF that is made from images with no OCR text layer or no other text then pdf-narrator is unable to extract any text and gets a bit upset with a few error messages in the log as the .txt file is empty.
Useful tip:
Use ocrmypdf to add an OCR layer to existing PDF files:
ocrmypdf --force-ocr --output-type pdf --rotate-pages --deskew --clean input.pdf output.pdf