add save functions

ChangeLog

@@ -7,7 +7,8 @@
 - added vips_error_freeze() / vips_error_thaw()
 - used freeze() / thaw() to stop file format sniffers logging spurious errors
 - vipsthumbnail uses embedded jpg thumbnails if it can 
-- added vips_webpload(), vips_webpload_buffer()
+- added vips_webpload(), vips_webpload_buffer(), vips_webpsave(),
+  vips_webpsave_buffer(), vips_webpsave_mime()
 
 3/7/13 started 7.34.2
 - lower priority for Matlab load to reduce segvs from Mat_Open(), thanks

TODO

@@ -1,6 +1,4 @@
-- support webp, see:
-
-	https://github.com/jcupitt/libvips/issues/68
+- use mmap to read encoded webp image
 
 - rename vips_diag() as vips_info(), make it work like a log thing ... 
   normally no output, can be turned on with a --vips-verbose flag

libvips/foreign/vips2webp.c

@@ -51,10 +51,47 @@
 
 #include "webp.h"
 
+typedef size_t (*webp_encoder)( const uint8_t *rgb, 
+	int width, int height, int stride, 
+	float quality_factor, uint8_t **output );
+
 int
 vips__webp_write_file( VipsImage *in, const char *filename, int Q )
 {
-	printf( "vips__webp_write_file:\n" ); 
+	webp_encoder encoder;
+	size_t len;
+	uint8_t *buffer;
+	FILE *fp;
+
+	if( vips_image_wio_input( in ) )
+		return( -1 );
+
+	if( in->Bands == 4 )
+		encoder = WebPEncodeRGBA;
+	else
+		encoder = WebPEncodeRGB;
+
+	if( !(len = encoder( VIPS_IMAGE_ADDR( in, 0, 0 ), 
+		in->Xsize, in->Ysize, 
+		VIPS_IMAGE_SIZEOF_LINE( in ),
+		Q, &buffer )) ) {
+		vips_error( "vips2webp", "%s", _( "unable to encode" ) ); 
+		return( -1 );
+	}
+
+	if( !(fp = vips__file_open_write( filename, FALSE )) ) {
+		free( buffer );
+		return( -1 );
+	}
+
+	if( vips__file_write( buffer, len, 1, fp ) ) {
+		fclose( fp );
+		free( buffer );
+		return( -1 );
+	}
+
+	fclose( fp );
+	free( buffer );
 
 	return( 0 );
 }
@@ -62,7 +99,23 @@ vips__webp_write_file( VipsImage *in, const char *filename, int Q )
 int
 vips__webp_write_buffer( VipsImage *in, void **obuf, size_t *olen, int Q )
 {
-	printf( "vips__webp_write_buffer:\n" ); 
+	webp_encoder encoder;
+
+	if( vips_image_wio_input( in ) )
+		return( -1 );
+
+	if( in->Bands == 4 )
+		encoder = WebPEncodeRGBA;
+	else
+		encoder = WebPEncodeRGB;
+
+	if( !(*olen = encoder( VIPS_IMAGE_ADDR( in, 0, 0 ), 
+		in->Xsize, in->Ysize, 
+		VIPS_IMAGE_SIZEOF_LINE( in ),
+		Q, (uint8_t **) obuf )) ) {
+		vips_error( "vips2webp", "%s", _( "unable to encode" ) ); 
+		return( -1 );
+	}
 
 	return( 0 );
 }

libvips/foreign/webp2vips.c

@@ -176,7 +176,7 @@ vips__webp_read_file_header( const char *filename, VipsImage *out )
 	return( 0 );
 }
 
-typedef uint8_t *(*webp_reader)( const uint8_t* data, size_t data_size,
+typedef uint8_t *(*webp_decoder)( const uint8_t* data, size_t data_size,
 	   uint8_t* output_buffer, size_t output_buffer_size, 
 	   int output_stride );
 
@@ -187,7 +187,7 @@ read_image( Read *read, VipsImage *out )
 		vips_object_local_array( VIPS_OBJECT( out ), 3 );
 	char *data; 
 	unsigned int len;
-	webp_reader reader;
+	webp_decoder decoder;
 
 	/* libwebp makes streaming very hard. We have to read to a full memory
 	 * buffer, then copy to out.
@@ -202,11 +202,11 @@ read_image( Read *read, VipsImage *out )
 		return( -1 );
 
 	if( t[0]->Bands == 3 )
-		reader = WebPDecodeRGBInto;
+		decoder = WebPDecodeRGBInto;
 	else
-		reader = WebPDecodeRGBAInto;
+		decoder = WebPDecodeRGBAInto;
 
-	if( !reader( (uint8_t *) data, len, 
+	if( !decoder( (uint8_t *) data, len, 
 		VIPS_IMAGE_ADDR( t[0], 0, 0 ), 
 		VIPS_IMAGE_SIZEOF_IMAGE( t[0] ),
 		VIPS_IMAGE_SIZEOF_LINE( t[0] ) ) ) {