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fb2 to html5 loose images after conversion #5847

Open XCanG opened 4 years ago

XCanG commented 4 years ago

pandoc 2.7.3 Compiled with pandoc-types 1.17.5.4, texmath 0.11.2.2, skylighting 0.8.1

I have fb2 with images, however I need to create html5 file to be able to read it later, but the problem, what image data are lost after conversion.

Code example:

<?xml version="1.0" encoding="UTF-8"?>
<FictionBook xmlns="http://www.gribuser.ru/xml/fictionbook/2.0" xmlns:l="http://www.w3.org/1999/xlink">
...
<body>
<title>...</title>
<image l:href="#img_10887"/>
<p>...</p>
...
</body>
<binary id="img_10887" content-type="image/jpeg">...</binary><binary id="img_13353" content-type="image/jpeg">...</binary>...
</FictionBook>

between binary tags there a lot of data, image itself, and there several images used there.

Tags are converted into this:

<img src="img_10887" />

But image info are not copied.

What you can do here is paste base64 images straight into src tag, example 1x1px transparent png:

<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8/5+hHgAHggJ/PchI7wAAAABJRU5ErkJggg==">
jgm commented 4 years ago

Have you tried with --extract-media=PATH?

XCanG commented 4 years ago

No, I didn't know about that parameter. With even --extract-media=. it would work, but it not create extension for image which is a bit of a problem.

Is there any way to convert and put base64 into src="" argument itself?

For part data:image/XXX;base64, you may determine by reading binary data of first characters and check which format is encoding here.

I have some example from other language This is python language and it determine a lot types of media, however if you remove and leave only to, probably, `jpg`, `png`, `gif` that would be fine (`webp` also image, but it probably wont support in other formats, `tiff` not used as embed image as well). Built-in libraries from code example: [`struct`](https://docs.python.org/3/library/struct.html#struct.pack) and [`os`](https://docs.python.org/3/library/os.path.html#os.path.getsize) ```python def get_image_metadata(file_path: str): size = os.path.getsize(file_path) with open(file_path, "rb") as input: width, height = -1, -1 data = input.read(32) if (size >= 10) and data[:6] in (b"GIF87a", b"GIF89a"): # GIF type, format = "img", GIF w, h = struct.unpack("= 24) and data.startswith(b"\211PNG\r\n\032\n") and (data[12:16] == b"IHDR")): # PNG type, format = "img", PNG w, h = struct.unpack(">LL", data[16:24]) width, height = int(w), int(h) elif (size >= 16) and data.startswith(b"\211PNG\r\n\032\n"): # older PNG type, format = "img", PNG w, h = struct.unpack(">LL", data[8:16]) width, height = int(w), int(h) elif (size >= 2) and data.startswith(b"\377\330"): # JPEG type, format = "img", JPEG input.seek(0) input.read(2) b = input.read(1) try: while (b and ord(b) != 0xDA): while (ord(b) != 0xFF): b = input.read(1) while (ord(b) == 0xFF): b = input.read(1) if (ord(b) >= 0xC0 and ord(b) <= 0xC3): input.read(3) h, w = struct.unpack(">HH", input.read(4)) break else: input.read(int(struct.unpack(">H", input.read(2))[0]) - 2) b = input.read(1) width, height = int(w), int(h) except struct.error as e: return None # UnknownImageFormat("StructError" + msg) except ValueError as e: return None # UnknownImageFormat("ValueError" + msg) except Exception as e: return None # UnknownImageFormat(e.__class__.__name__) elif (size >= 26) and data.startswith(b"BM"): # BMP type, format = "img", BMP headersize = struct.unpack("= 40: w, h = struct.unpack("= 8) and data[:4] in (b"II\052\000", b"MM\000\052"): # Standard TIFF, big- or little-endian # BigTIFF and other different but TIFF-like formats are not # supported currently type, format = "img", TIFF byteOrder = data[:2] boChar = ">" if byteOrder == "MM" else "<" # maps TIFF type id to size (in bytes) # and python format char for struct tiffTypes = { 1: (1, boChar + "B"), # BYTE 2: (1, boChar + "c"), # ASCII 3: (2, boChar + "H"), # SHORT 4: (4, boChar + "L"), # LONG 5: (8, boChar + "LL"), # RATIONAL 6: (1, boChar + "b"), # SBYTE 7: (1, boChar + "c"), # UNDEFINED 8: (2, boChar + "h"), # SSHORT 9: (4, boChar + "l"), # SLONG 10: (8, boChar + "ll"), # SRATIONAL 11: (4, boChar + "f"), # FLOAT 12: (8, boChar + "d") # DOUBLE } ifdOffset = struct.unpack(boChar + "L", data[4:8])[0] try: countSize = 2 input.seek(ifdOffset) ec = input.read(countSize) ifdEntryCount = struct.unpack(boChar + "H", ec)[0] # 2 bytes: TagId + 2 bytes: type + 4 bytes: count of values + 4 # bytes: value offset ifdEntrySize = 12 for i in range(ifdEntryCount): entryOffset = ifdOffset + countSize + i * ifdEntrySize input.seek(entryOffset) tag = input.read(2) tag = struct.unpack(boChar + "H", tag)[0] if (tag == 256 or tag == 257): # if type indicates that value fits into 4 bytes, value # offset is not an offset but value itself type = input.read(2) type = struct.unpack(boChar + "H", type)[0] if type not in tiffTypes: return None # UnknownImageFormat("Unkown TIFF field type:" + str(type)) typeSize, typeChar = tiffTypes[type][0:2] input.seek(entryOffset + 8) value = input.read(typeSize) value = int(struct.unpack(typeChar, value)[0]) if tag == 256: width = value else: height = value if width > -1 and height > -1: break except Exception as e: return None elif size >= 0 and data[4:8] == b"ftyp" and data[8:12] in [b"isom", b"mp42", b"mp41", b"qt "]: # MP4 type, format = "video", MP4 elif size >= 0 and data[24:32] == b"matroska": # MKV type, format = "video", MKV elif size >= 0 and data[26:30] == b"webm": # WEBM type, format = "video", WEBM elif size >= 0 and data[0:4] == b"RIFF" and data[8:12] == b"WEBP": # WEBP https://developers.google.com/speed/webp/docs/riff_container type, format = "img", WEBP # static if data[12:16] == b"VP8X": width = int.from_bytes(data[24:27], byteorder="little") + 1 height = int.from_bytes(data[27:30], byteorder="little") + 1 elif data[12:16] == b"ANMF": width = int.from_bytes(data[18:21], byteorder="little") + 1 height = int.from_bytes(data[21:24], byteorder="little") + 1 else: return None elif size >= 2: #correct that # see http://en.wikipedia.org/wiki/ICO_(file_format) type, format = "img", ICO input.seek(0) reserved = input.read(2) if 0 != struct.unpack(" 1: import warnings warnings.warn("ICO File contains more than one image") # http://msdn.microsoft.com/en-us/library/ms997538.aspx w, h = input.read(1), input.read(1) width, height = ord(w), ord(h) else: return None return {"path": file_path, "type": type, "format": format, "file_size": size, "width": width, "height": height} ```
wiscat commented 3 years ago

Also, this option can be useful, to built-in images into the result: https://pandoc.org/MANUAL.html#option--self-contained