GUAC-240: Move PNG encoder to own file, writing directly to an img stream.

This commit is contained in:
Michael Jumper 2015-08-11 09:35:23 -07:00
parent 8ff071bf04
commit e73ef09fdd
5 changed files with 518 additions and 0 deletions

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@ -64,6 +64,7 @@ libguacinc_HEADERS = \
noinst_HEADERS = \
client-handlers.h \
encode-png.h \
palette.h \
wav_encoder.h
@ -71,6 +72,7 @@ libguac_la_SOURCES = \
audio.c \
client.c \
client-handlers.c \
encode-png.c \
error.c \
hash.c \
instruction.c \

402
src/libguac/encode-png.c Normal file
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@ -0,0 +1,402 @@
/*
* Copyright (C) 2015 Glyptodon LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "config.h"
#include "encode-png.h"
#include "error.h"
#include "palette.h"
#include "protocol.h"
#include "stream.h"
#include <png.h>
#include <cairo/cairo.h>
#ifdef HAVE_PNGSTRUCT_H
#include <pngstruct.h>
#endif
#include <inttypes.h>
#include <setjmp.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
/**
* Data describing the current write state of PNG data.
*/
typedef struct guac_png_write_state {
/**
* The socket over which all PNG blobs will be written.
*/
guac_socket* socket;
/**
* The Guacamole stream to associate with each PNG blob.
*/
guac_stream* stream;
/**
* Buffer of pending PNG data.
*/
char buffer[6048];
/**
* The number of bytes currently stored in the buffer.
*/
int buffer_size;
} guac_png_write_state;
/**
* Writes the contents of the PNG write state as a blob to its associated
* socket.
*
* @param write_state
* The write state to flush.
*/
static void guac_png_flush_data(guac_png_write_state* write_state) {
/* Send blob */
guac_protocol_send_blob(write_state->socket, write_state->stream,
write_state->buffer, write_state->buffer_size);
/* Clear buffer */
write_state->buffer_size = 0;
}
/**
* Appends the given PNG data to the internal buffer of the given write state,
* automatically flushing the write state as necessary.
* socket.
*
* @param write_state
* The write state to append the given data to.
*
* @param data
* The PNG data to append.
*
* @param length
* The size of the given PNG data, in bytes.
*/
static void guac_png_write_data(guac_png_write_state* write_state,
const void* data, int length) {
const unsigned char* current = data;
/* Append all data given */
while (length > 0) {
/* Calculate space remaining */
int remaining = sizeof(write_state->buffer) - write_state->buffer_size;
/* If no space remains, flush buffer to make room */
if (remaining == 0) {
guac_png_flush_data(write_state);
remaining = sizeof(write_state->buffer);
}
/* Calculate size of next block of data to append */
int block_size = remaining;
if (block_size > length)
block_size = length;
/* Append block */
memcpy(write_state->buffer + write_state->buffer_size,
current, block_size);
/* Next block */
current += block_size;
write_state->buffer_size += block_size;
length -= block_size;
}
}
/**
* Writes the given buffer of PNG data to the buffer of the given write state,
* flushing that buffer to blob instructions if necessary. This handler is
* called by Cairo when writing PNG data via
* cairo_surface_write_to_png_stream().
*
* @param closure
* Pointer to arbitrary data passed to cairo_surface_write_to_png_stream().
* In the case of this handler, this data will be the guac_png_write_state.
*
* @param data
* The buffer of PNG data to write.
*
* @param length
* The size of the given buffer, in bytes.
*
* @return
* A Cairo status code indicating whether the write operation succeeded.
* In the case of this handler, this will always be CAIRO_STATUS_SUCCESS.
*/
static cairo_status_t guac_png_cairo_write_handler(void* closure,
const unsigned char* data, unsigned int length) {
guac_png_write_state* write_state = (guac_png_write_state*) closure;
/* Append data to buffer, writing as necessary */
guac_png_write_data(write_state, data, length);
return CAIRO_STATUS_SUCCESS;
}
/**
* Implementation of guac_png_write() which uses Cairo's own PNG encoder to
* write PNG data, rather than using libpng directly.
*
* @param socket
* The socket to send PNG blobs over.
*
* @param stream
* The stream to associate with each blob.
*
* @param surface
* The Cairo surface to write to the given stream and socket as PNG blobs.
*
* @return
* Zero if the encoding operation is successful, non-zero otherwise.
*/
static int guac_png_cairo_write(guac_socket* socket, guac_stream* stream,
cairo_surface_t* surface) {
guac_png_write_state write_state;
/* Init write state */
write_state.socket = socket;
write_state.stream = stream;
write_state.buffer_size = 0;
/* Write surface as PNG */
if (cairo_surface_write_to_png_stream(surface,
guac_png_cairo_write_handler,
&write_state) != CAIRO_STATUS_SUCCESS) {
guac_error = GUAC_STATUS_INTERNAL_ERROR;
guac_error_message = "Cairo PNG backend failed";
return -1;
}
/* Flush remaining PNG data */
guac_png_flush_data(&write_state);
return 0;
}
/**
* Writes the given buffer of PNG data to the buffer of the given write state,
* flushing that buffer to blob instructions if necessary. This handler is
* called by libpng when writing PNG data via png_write_png().
*
* @param png
* The PNG compression state structure associated with the write operation.
* The pointer to arbitrary data will have been set to the
* guac_png_write_state by png_set_write_fn(), and will be accessible via
* png->io_ptr or png_get_io_ptr(png), depending on the version of libpng.
*
* @param data
* The buffer of PNG data to write.
*
* @param length
* The size of the given buffer, in bytes.
*/
static void guac_png_write_handler(png_structp png, png_bytep data,
png_size_t length) {
/* Get png buffer structure */
guac_png_write_state* write_state;
#ifdef HAVE_PNG_GET_IO_PTR
write_state = (guac_png_write_state*) png_get_io_ptr(png);
#else
write_state = (guac_png_write_state*) png->io_ptr;
#endif
/* Append data to buffer, writing as necessary */
guac_png_write_data(write_state, data, length);
}
/**
* Flushes any PNG data within the buffer of the given write state as a blob
* instruction. If no data is within the buffer, this function has no effect.
* This handler is called by libpng when it has finished writing PNG data via
* png_write_png().
*
* @param png
* The PNG compression state structure associated with the write operation.
* The pointer to arbitrary data will have been set to the
* guac_png_write_state by png_set_write_fn(), and will be accessible via
* png->io_ptr or png_get_io_ptr(png), depending on the version of libpng.
*/
static void guac_png_flush_handler(png_structp png) {
/* Get png buffer structure */
guac_png_write_state* write_state;
#ifdef HAVE_PNG_GET_IO_PTR
write_state = (guac_png_write_state*) png_get_io_ptr(png);
#else
write_state = (guac_png_write_state*) png->io_ptr;
#endif
/* Flush buffer */
guac_png_flush_data(write_state);
}
int guac_png_write(guac_socket* socket, guac_stream* stream,
cairo_surface_t* surface) {
png_structp png;
png_infop png_info;
png_byte** png_rows;
int bpp;
int x, y;
guac_png_write_state write_state;
/* Get image surface properties and data */
cairo_format_t format = cairo_image_surface_get_format(surface);
int width = cairo_image_surface_get_width(surface);
int height = cairo_image_surface_get_height(surface);
int stride = cairo_image_surface_get_stride(surface);
unsigned char* data = cairo_image_surface_get_data(surface);
/* If not RGB24, use Cairo PNG writer */
if (format != CAIRO_FORMAT_RGB24 || data == NULL)
return guac_png_cairo_write(socket, stream, surface);
/* Flush pending operations to surface */
cairo_surface_flush(surface);
/* Attempt to build palette */
guac_palette* palette = guac_palette_alloc(surface);
/* If not possible, resort to Cairo PNG writer */
if (palette == NULL)
return guac_png_cairo_write(socket, stream, surface);
/* Calculate BPP from palette size */
if (palette->size <= 2) bpp = 1;
else if (palette->size <= 4) bpp = 2;
else if (palette->size <= 16) bpp = 4;
else bpp = 8;
/* Set up PNG writer */
png = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png) {
guac_error = GUAC_STATUS_INTERNAL_ERROR;
guac_error_message = "libpng failed to create write structure";
return -1;
}
png_info = png_create_info_struct(png);
if (!png_info) {
png_destroy_write_struct(&png, NULL);
guac_error = GUAC_STATUS_INTERNAL_ERROR;
guac_error_message = "libpng failed to create info structure";
return -1;
}
/* Set error handler */
if (setjmp(png_jmpbuf(png))) {
png_destroy_write_struct(&png, &png_info);
guac_error = GUAC_STATUS_IO_ERROR;
guac_error_message = "libpng output error";
return -1;
}
/* Init write state */
write_state.socket = socket;
write_state.stream = stream;
write_state.buffer_size = 0;
/* Set up writer */
png_set_write_fn(png, &write_state,
guac_png_write_handler,
guac_png_flush_handler);
/* Copy data from surface into PNG data */
png_rows = (png_byte**) malloc(sizeof(png_byte*) * height);
for (y=0; y<height; y++) {
/* Allocate new PNG row */
png_byte* row = (png_byte*) malloc(sizeof(png_byte) * width);
png_rows[y] = row;
/* Copy data from surface into current row */
for (x=0; x<width; x++) {
/* Get pixel color */
int color = ((uint32_t*) data)[x] & 0xFFFFFF;
/* Set index in row */
row[x] = guac_palette_find(palette, color);
}
/* Advance to next data row */
data += stride;
}
/* Write image info */
png_set_IHDR(
png,
png_info,
width,
height,
bpp,
PNG_COLOR_TYPE_PALETTE,
PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT,
PNG_FILTER_TYPE_DEFAULT
);
/* Write palette */
png_set_PLTE(png, png_info, palette->colors, palette->size);
/* Write image */
png_set_rows(png, png_info, png_rows);
png_write_png(png, png_info, PNG_TRANSFORM_PACKING, NULL);
/* Finish write */
png_destroy_write_struct(&png, &png_info);
/* Free palette */
guac_palette_free(palette);
/* Free PNG data */
for (y=0; y<height; y++)
free(png_rows[y]);
free(png_rows);
return 0;
}

53
src/libguac/encode-png.h Normal file
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@ -0,0 +1,53 @@
/*
* Copyright (C) 2015 Glyptodon LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef GUAC_ENCODE_PNG_H
#define GUAC_ENCODE_PNG_H
#include "config.h"
#include "socket.h"
#include "stream.h"
#include <cairo/cairo.h>
/**
* Encodes the given surface as a PNG, and sends the resulting data over the
* given stream and socket as blobs.
*
* @param socket
* The socket to send PNG blobs over.
*
* @param stream
* The stream to associate with each blob.
*
* @param surface
* The Cairo surface to write to the given stream and socket as PNG blobs.
*
* @return
* Zero if the encoding operation is successful, non-zero otherwise.
*/
int guac_png_write(guac_socket* socket, guac_stream* stream,
cairo_surface_t* surface);
#endif

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@ -647,6 +647,40 @@ int guac_protocol_send_jpeg(guac_socket* socket, guac_composite_mode mode,
const guac_layer* layer, int x, int y, cairo_surface_t* surface,
int quality);
/**
* Sends an img instruction over the given guac_socket connection.
*
* If an error occurs sending the instruction, a non-zero value is
* returned, and guac_error is set appropriately.
*
* @param socket
* The guac_socket connection to use when sending the img instruction.
*
* @param stream
* The stream over which the image data will be sent.
*
* @param mode
* The composite mode to use when drawing the image over the destination
* layer.
*
* @param layer
* The destination layer.
*
* @param x
* The X coordinate of the upper-left corner of the destination rectangle
* within the destination layer, in pixels.
*
* @param y
* The Y coordinate of the upper-left corner of the destination rectangle
* within the destination layer, in pixels.
*
* @return
* Zero if the instruction was successfully sent, non-zero on error.
*/
int guac_protocol_send_img(guac_socket* socket, const guac_stream* stream,
guac_composite_mode mode, const guac_layer* layer,
const char* mimetype, int x, int y);
/**
* Sends a pop instruction over the given guac_socket connection.
*

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@ -1400,6 +1400,33 @@ int guac_protocol_send_png(guac_socket* socket, guac_composite_mode mode,
}
int guac_protocol_send_img(guac_socket* socket, const guac_stream* stream,
guac_composite_mode mode, const guac_layer* layer,
const char* mimetype, int x, int y) {
int ret_val;
guac_socket_instruction_begin(socket);
ret_val =
guac_socket_write_string(socket, "3.img,")
|| __guac_socket_write_length_int(socket, stream->index)
|| guac_socket_write_string(socket, ",")
|| __guac_socket_write_length_int(socket, mode)
|| guac_socket_write_string(socket, ",")
|| __guac_socket_write_length_int(socket, layer->index)
|| guac_socket_write_string(socket, ",")
|| __guac_socket_write_length_string(socket, mimetype)
|| guac_socket_write_string(socket, ",")
|| __guac_socket_write_length_int(socket, x)
|| guac_socket_write_string(socket, ",")
|| __guac_socket_write_length_int(socket, y)
|| guac_socket_write_string(socket, ";");
guac_socket_instruction_end(socket);
return ret_val;
}
int guac_protocol_send_pop(guac_socket* socket, const guac_layer* layer) {
int ret_val;