diff options
Diffstat (limited to 'include/qpdf/QPDFWriter.hh')
| -rw-r--r-- | include/qpdf/QPDFWriter.hh | 72 |
1 files changed, 65 insertions, 7 deletions
diff --git a/include/qpdf/QPDFWriter.hh b/include/qpdf/QPDFWriter.hh index 2519ed12..c4bc7846 100644 --- a/include/qpdf/QPDFWriter.hh +++ b/include/qpdf/QPDFWriter.hh @@ -118,14 +118,70 @@ class QPDFWriter QPDF_DLL void setObjectStreamMode(qpdf_object_stream_e); - // Set value of stream data mode. In uncompress mode, we attempt - // to uncompress any stream that we can. In preserve mode, we - // preserve any filtering applied to streams. In compress mode, - // if we can apply all filters and the stream is not already - // optimally compressed, recompress the stream. + // Set value of stream data mode. This is an older interface. + // Instead of using this, prefer setCompressStreams() and + // setDecodeLevel(). This method is retained for compatibility, + // but it does not cover the full range of available + // configurations. The mapping between this and the new methods is + // as follows: + // + // qpdf_s_uncompress: + // setCompressStreams(false) + // setDecodeLevel(qpdf_dl_generalized) + // qpdf_s_preserve: + // setCompressStreams(false) + // setDecodeLevel(qpdf_dl_none) + // qpdf_s_compress: + // setCompressStreams(true) + // setDecodeLevel(qpdf_dl_generalized) + // + // The default is qpdf_s_compress. QPDF_DLL void setStreamDataMode(qpdf_stream_data_e); + // If true, compress any uncompressed streams when writing them. + // Metadata streams are a special case and are not compressed even + // if this is true. This is true by default for QPDFWriter. If you + // want QPDFWriter to leave uncompressed streams uncompressed, + // pass false to this method. + QPDF_DLL + void setCompressStreams(bool); + + // When QPDFWriter encounters streams, this parameter controls the + // behavior with respect to attempting to apply any filters to the + // streams when copying to the output. The decode levels are as + // follows: + // + // qpdf_dl_none: Do not attempt to apply any filters. Streams + // remain as they appear in the original file. Note that + // uncompressed streams may still be compressed on output. You can + // disable that by calling setCompressStreams(false). + // + // qpdf_dl_generalized: This is the default. QPDFWriter will apply + // LZWDecode, ASCII85Decode, ASCIIHexDecode, and FlateDecode + // filters on the input. When combined with + // setCompressStreams(true), which the default, the effect of this + // is that streams filtered with these older and less efficient + // filters will be recompressed with the Flate filter. As a + // special case, if a stream is already compressed with + // FlateDecode and setCompressStreams is enabled, the original + // compressed data will be preserved. + // + // qpdf_dl_specialized: In addition to uncompressing the + // generalized compression formats, supported non-lossy + // compression will also be be decoded. At present, this includes + // the RunLengthDecode filter. + // + // qpdf_dl_all: In addition to generalized and non-lossy + // specialized filters, supported lossy compression filters will + // be applied. At present, this includes DCTDecode (JPEG) + // compression. Note that compressing the resulting data with + // DCTDecode again will accumulate loss, so avoid multiple + // compression and decompression cycles. This is mostly useful for + // retreiving image data. + QPDF_DLL + void setDecodeLevel(qpdf_stream_decode_level_e); + // Set value of content stream normalization. The default is // "false". If true, we attempt to normalize newlines inside of // content streams. Some constructs such as inline images may @@ -434,8 +490,10 @@ class QPDFWriter Buffer* output_buffer; bool normalize_content_set; bool normalize_content; - bool stream_data_mode_set; - qpdf_stream_data_e stream_data_mode; + bool compress_streams; + bool compress_streams_set; + qpdf_stream_decode_level_e stream_decode_level; + bool stream_decode_level_set; bool qdf_mode; bool precheck_streams; bool preserve_unreferenced_objects; |