libvips/libvips/foreign/pdfload.c

/* load PDF with libpoppler
 *
 * 7/2/16
 * 	- from openslideload.c
 */

/*

    This file is part of VIPS.
    
    VIPS is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    02110-1301  USA

 */

/*

    These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk

 */

/*
#define DEBUG
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <vips/intl.h>

#ifdef HAVE_POPPLER

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include <vips/vips.h>
#include <vips/buf.h>
#include <vips/internal.h>

#include <cairo.h>
#include <poppler.h>

typedef struct _VipsForeignLoadPdf {
	VipsForeignLoad parent_object;

	/* Load this page.
	 */
	int page_no;

	/* Render at this DPI.
	 */
	double dpi;

	/* Calculate this from DPI. At 72 DPI, we render 1:1 with cairo.
	 */
	double scale;

	PopplerDocument *doc;
	PopplerPage *page;

} VipsForeignLoadPdf;

typedef VipsForeignLoadClass VipsForeignLoadPdfClass;

G_DEFINE_ABSTRACT_TYPE( VipsForeignLoadPdf, vips_foreign_load_pdf, 
	VIPS_TYPE_FOREIGN_LOAD );

static void
vips_foreign_load_pdf_dispose( GObject *gobject )
{
	VipsForeignLoadPdf *pdf = (VipsForeignLoadPdf *) gobject;

	VIPS_UNREF( pdf->page );
	VIPS_UNREF( pdf->doc );

	G_OBJECT_CLASS( vips_foreign_load_pdf_parent_class )->
		dispose( gobject );
}

static int
vips_foreign_load_pdf_build( VipsObject *object )
{
	VipsForeignLoadPdf *pdf = (VipsForeignLoadPdf *) object;

	if( !vips_object_argument_isset( object, "scale" ) )
		pdf->scale = pdf->dpi / 72.0;

	if( VIPS_OBJECT_CLASS( vips_foreign_load_pdf_parent_class )->
		build( object ) )
		return( -1 );

	return( 0 );
}

static VipsForeignFlags
vips_foreign_load_pdf_get_flags_filename( const char *filename )
{
	/* We can render any part of the page on demand.
	 */
	return( VIPS_FOREIGN_PARTIAL );
}

static VipsForeignFlags
vips_foreign_load_pdf_get_flags( VipsForeignLoad *load )
{
	return( VIPS_FOREIGN_PARTIAL );
}

static gboolean
vips_foreign_load_pdf_is_a_buffer( const void *buf, size_t len )
{
	const guchar *str = (const guchar *) buf;

	if( len >= 4 &&
		str[0] == '%' && 
		str[1] == 'P' &&
		str[2] == 'D' &&
		str[3] == 'F' )
		return( 1 );

	return( 0 );
}

static gboolean
vips_foreign_load_pdf_is_a( const char *filename )
{
	unsigned char buf[4];

	if( vips__get_bytes( filename, buf, 4 ) &&
		vips_foreign_load_pdf_is_a_buffer( buf, 4 ) )
		return( 1 );

	return( 0 );
}

/* String-based metadata fields we extract.
 */
typedef struct _VipsForeignLoadPdfMetadata {
	char *(*pdf_fetch)( PopplerDocument *doc );
	char *field;
} VipsForeignLoadPdfMetadata;

static VipsForeignLoadPdfMetadata vips_foreign_load_pdf_metadata[] = {
	{ poppler_document_get_title, "pdf-title" },
	{ poppler_document_get_author, "pdf-author" },
	{ poppler_document_get_subject, "pdf-subject" },
	{ poppler_document_get_keywords, "pdf-keywords" },
	{ poppler_document_get_creator, "pdf-creator" },
	{ poppler_document_get_producer, "pdf-producer" },
	{ poppler_document_get_metadata, "pdf-metadata" },
};
static int n_metadata = VIPS_NUMBER( vips_foreign_load_pdf_metadata );

static void
vips_foreign_load_pdf_parse( VipsForeignLoadPdf *pdf, 
	VipsImage *out )
{
	double width;
	double height;
	double res;
	int i;

	poppler_page_get_size( pdf->page, &width, &height ); 

	/* We need pixels/mm for vips.
	 */
	res = pdf->dpi / 25.4;

	vips_image_init_fields( out, 
		width * pdf->scale, height * pdf->scale, 
		4, VIPS_FORMAT_UCHAR,
		VIPS_CODING_NONE, VIPS_INTERPRETATION_sRGB, res, res );

	/* We render to a linecache, so fat strips work well.
	 */
        vips_image_pipelinev( out, VIPS_DEMAND_STYLE_FATSTRIP, NULL );

	/* Extract and attach metadata.
	 */
	vips_image_set_int( out, "pdf-n_pages", 
		poppler_document_get_n_pages( pdf->doc ) );

	for( i = 0; i < n_metadata; i++ ) {
		VipsForeignLoadPdfMetadata *metadata = 
			&vips_foreign_load_pdf_metadata[i];

		char *str;

		if( (str = metadata->pdf_fetch( pdf->doc )) ) { 
			vips_image_set_string( out, metadata->field, str ); 
			g_free( str );
		}
	}
}

static int
vips_foreign_load_pdf_header( VipsForeignLoad *load )
{
	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( load );
	VipsForeignLoadPdf *pdf = (VipsForeignLoadPdf *) load;

	if( !(pdf->page = poppler_document_get_page( pdf->doc, 
		pdf->page_no )) ) {
		vips_error( class->nickname, 
			_( "unable to load page %d" ), pdf->page_no );
		return( -1 ); 
	}

	vips_foreign_load_pdf_parse( pdf, load->out ); 

	return( 0 );
}

static int
vips_foreign_load_pdf_generate( VipsRegion *or, 
	void *seq, void *a, void *b, gboolean *stop )
{
	VipsForeignLoadPdf *pdf = (VipsForeignLoadPdf *) a;
	VipsRect *r = &or->valid;

	cairo_surface_t *surface;
	cairo_t *cr;
	int x, y;

	/* Pdf won't always paint the background.
	 */
	vips_region_black( or ); 

	surface = cairo_image_surface_create_for_data( 
		VIPS_REGION_ADDR( or, r->left, r->top ), 
		CAIRO_FORMAT_ARGB32, 
		r->width, r->height, 
		VIPS_REGION_LSKIP( or ) );
	cr = cairo_create( surface );
	cairo_surface_destroy( surface );

	cairo_scale( cr, pdf->scale, pdf->scale );
	cairo_translate( cr, 
		-r->left / pdf->scale, -r->top / pdf->scale );

	/* poppler is single-threaded, but we don't need to lock since we're
	 * running inside a non-threaded tilecache.
	 */
	poppler_page_render( pdf->page, cr );

	cairo_destroy( cr );

	/* Cairo makes BRGA, we must byteswap. We might not need to on SPARC,
	 * but I have no way of testing this :( 
	 */
	for( y = 0; y < r->height; y++ ) {
		VipsPel * restrict q;

		q = VIPS_REGION_ADDR( or, r->left, r->top + y );
		for( x = 0; x < r->width; x++ ) {
			VIPS_SWAP( VipsPel, q[0], q[2] );

			q += 4;
		}
	}

	return( 0 ); 
}

static int
vips_foreign_load_pdf_load( VipsForeignLoad *load )
{
	VipsForeignLoadPdf *pdf = (VipsForeignLoadPdf *) load;
	VipsImage **t = (VipsImage **) 
		vips_object_local_array( (VipsObject *) load, 2 );

	/* Read to this image, then cache to out, see below.
	 */
	t[0] = vips_image_new(); 

	vips_foreign_load_pdf_parse( pdf, t[0] ); 
	if( vips_image_generate( t[0], 
		NULL, vips_foreign_load_pdf_generate, NULL, pdf, NULL ) )
		return( -1 );

	/* Don't use tilecache to keep the number of calls to
	 * pdf_page_render() low. Don't thread the cache, we rely on
	 * locking to keep pdf single-threaded.
	 */
	if( vips_linecache( t[0], &t[1],
		"tile_height", 128,
		NULL ) ) 
		return( -1 );
	if( vips_image_write( t[1], load->real ) ) 
		return( -1 );

	return( 0 );
}

static void
vips_foreign_load_pdf_class_init( VipsForeignLoadPdfClass *class )
{
	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
	VipsObjectClass *object_class = (VipsObjectClass *) class;
	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;

	gobject_class->dispose = vips_foreign_load_pdf_dispose;
	gobject_class->set_property = vips_object_set_property;
	gobject_class->get_property = vips_object_get_property;

	object_class->nickname = "pdfload";
	object_class->description = _( "load PDF with pdf" );
	object_class->build = vips_foreign_load_pdf_build;

	load_class->get_flags_filename = 
		vips_foreign_load_pdf_get_flags_filename;
	load_class->get_flags = vips_foreign_load_pdf_get_flags;
	load_class->load = vips_foreign_load_pdf_load;

	VIPS_ARG_INT( class, "page", 10,
		_( "Page" ),
		_( "Load this page from the file" ),
		VIPS_ARGUMENT_OPTIONAL_INPUT,
		G_STRUCT_OFFSET( VipsForeignLoadPdf, page_no ),
		0, 100000, 0 );

	VIPS_ARG_DOUBLE( class, "dpi", 11,
		_( "DPI" ),
		_( "Render at this DPI" ),
		VIPS_ARGUMENT_OPTIONAL_INPUT,
		G_STRUCT_OFFSET( VipsForeignLoadPdf, dpi ),
		0.001, 100000.0, 72.0 );

	VIPS_ARG_DOUBLE( class, "scale", 12,
		_( "Scale" ),
		_( "Scale output by this factor" ),
		VIPS_ARGUMENT_OPTIONAL_INPUT,
		G_STRUCT_OFFSET( VipsForeignLoadPdf, scale ),
		0.001, 100000.0, 1.0 );

}

static void
vips_foreign_load_pdf_init( VipsForeignLoadPdf *pdf )
{
	pdf->dpi = 72.0;
	pdf->scale = 1.0;
}

typedef struct _VipsForeignLoadPdfFile {
	VipsForeignLoadPdf parent_object;

	/* Filename for load.
	 */
	char *filename; 

	char *uri;

} VipsForeignLoadPdfFile;

typedef VipsForeignLoadPdfClass VipsForeignLoadPdfFileClass;

G_DEFINE_TYPE( VipsForeignLoadPdfFile, vips_foreign_load_pdf_file, 
	vips_foreign_load_pdf_get_type() );

static void
vips_foreign_load_pdf_file_dispose( GObject *gobject )
{
	VipsForeignLoadPdfFile *file = 
		(VipsForeignLoadPdfFile *) gobject;

	VIPS_FREE( file->uri );

	G_OBJECT_CLASS( vips_foreign_load_pdf_file_parent_class )->
		dispose( gobject );
}

static int
vips_foreign_load_pdf_file_header( VipsForeignLoad *load )
{
	VipsForeignLoadPdf *pdf = (VipsForeignLoadPdf *) load;
	VipsForeignLoadPdfFile *file = (VipsForeignLoadPdfFile *) load;

	char *path;
	GError *error = NULL;

	/* We need an absolute path for a URI.
	 */
	path = vips_realpath( file->filename );
	if( !(file->uri = g_filename_to_uri( path, NULL, &error )) ) { 
		free( path );
		vips_g_error( &error );
		return( -1 ); 
	}
	free( path );

	if( !(pdf->doc = poppler_document_new_from_file( 
		file->uri, NULL, &error )) ) { 
		vips_g_error( &error );
		return( -1 ); 
	}

	return( vips_foreign_load_pdf_header( load ) );
}

static const char *vips_foreign_pdf_suffs[] = {
	".pdf",
	NULL
};

static void
vips_foreign_load_pdf_file_class_init( 
	VipsForeignLoadPdfFileClass *class )
{
	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
	VipsObjectClass *object_class = (VipsObjectClass *) class;
	VipsForeignClass *foreign_class = (VipsForeignClass *) class;
	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;

	gobject_class->dispose = vips_foreign_load_pdf_file_dispose;
	gobject_class->set_property = vips_object_set_property;
	gobject_class->get_property = vips_object_get_property;

	object_class->nickname = "pdfload";
	object_class->description = _( "load PDF with pdf" );

	foreign_class->suffs = vips_foreign_pdf_suffs;

	load_class->is_a = vips_foreign_load_pdf_is_a;
	load_class->header = vips_foreign_load_pdf_file_header;

	VIPS_ARG_STRING( class, "filename", 1, 
		_( "Filename" ),
		_( "Filename to load from" ),
		VIPS_ARGUMENT_REQUIRED_INPUT, 
		G_STRUCT_OFFSET( VipsForeignLoadPdfFile, filename ),
		NULL );

}

static void
vips_foreign_load_pdf_file_init( VipsForeignLoadPdfFile *file )
{
}

typedef struct _VipsForeignLoadPdfBuffer {
	VipsForeignLoadPdf parent_object;

	/* Load from a buffer.
	 */
	VipsArea *buf;

} VipsForeignLoadPdfBuffer;

typedef VipsForeignLoadPdfClass VipsForeignLoadPdfBufferClass;

G_DEFINE_TYPE( VipsForeignLoadPdfBuffer, vips_foreign_load_pdf_buffer, 
	vips_foreign_load_pdf_get_type() );

static int
vips_foreign_load_pdf_buffer_header( VipsForeignLoad *load )
{
	VipsForeignLoadPdf *pdf = (VipsForeignLoadPdf *) load;
	VipsForeignLoadPdfBuffer *buffer = 
		(VipsForeignLoadPdfBuffer *) load;

	GError *error = NULL;

	if( !(pdf->doc = poppler_document_new_from_data( 
		buffer->buf->data, buffer->buf->length, NULL, &error )) ) { 
		vips_g_error( &error );
		return( -1 ); 
	}

	return( vips_foreign_load_pdf_header( load ) );
}

static void
vips_foreign_load_pdf_buffer_class_init( 
	VipsForeignLoadPdfBufferClass *class )
{
	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
	VipsObjectClass *object_class = (VipsObjectClass *) class;
	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;

	gobject_class->set_property = vips_object_set_property;
	gobject_class->get_property = vips_object_get_property;

	object_class->nickname = "pdfload_buffer";
	object_class->description = _( "load PDF with pdf" );

	load_class->is_a_buffer = vips_foreign_load_pdf_is_a_buffer;
	load_class->header = vips_foreign_load_pdf_buffer_header;

	VIPS_ARG_BOXED( class, "buffer", 1, 
		_( "Buffer" ),
		_( "Buffer to load from" ),
		VIPS_ARGUMENT_REQUIRED_INPUT, 
		G_STRUCT_OFFSET( VipsForeignLoadPdfBuffer, buf ),
		VIPS_TYPE_BLOB );

}

static void
vips_foreign_load_pdf_buffer_init( VipsForeignLoadPdfBuffer *buffer )
{
}

#endif /*HAVE_POPPLER*/