Files
ustreamer/src/libs/unjpeg.c
2024-03-22 15:57:16 +02:00

104 lines
3.7 KiB
C

/*****************************************************************************
# #
# uStreamer - Lightweight and fast MJPEG-HTTP streamer. #
# #
# Copyright (C) 2018-2024 Maxim Devaev <mdevaev@gmail.com> #
# #
# This program is free software: you can redistribute it and/or modify #
# it under the terms of the GNU General Public License as published by #
# the Free Software Foundation, either version 3 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 General Public License for more details. #
# #
# You should have received a copy of the GNU General Public License #
# along with this program. If not, see <https://www.gnu.org/licenses/>. #
# #
*****************************************************************************/
#include "unjpeg.h"
#include <stdio.h>
#include <setjmp.h>
#include <assert.h>
#include <jpeglib.h>
#include <linux/videodev2.h>
#include "types.h"
#include "logging.h"
#include "frame.h"
typedef struct {
struct jpeg_error_mgr mgr; // Default manager
jmp_buf jmp;
const us_frame_s *frame;
} _jpeg_error_manager_s;
static void _jpeg_error_handler(j_common_ptr jpeg);
int us_unjpeg(const us_frame_s *src, us_frame_s *dest, bool decode) {
assert(us_is_jpeg(src->format));
volatile int retval = 0;
struct jpeg_decompress_struct jpeg;
jpeg_create_decompress(&jpeg);
// https://stackoverflow.com/questions/19857766/error-handling-in-libjpeg
_jpeg_error_manager_s jpeg_error;
jpeg.err = jpeg_std_error((struct jpeg_error_mgr*)&jpeg_error);
jpeg_error.mgr.error_exit = _jpeg_error_handler;
jpeg_error.frame = src;
if (setjmp(jpeg_error.jmp) < 0) {
retval = -1;
goto done;
}
jpeg_mem_src(&jpeg, src->data, src->used);
jpeg_read_header(&jpeg, TRUE);
jpeg.out_color_space = JCS_RGB;
jpeg_start_decompress(&jpeg);
US_FRAME_COPY_META(src, dest); // cppcheck-suppress redundantAssignment
dest->format = V4L2_PIX_FMT_RGB24; // cppcheck-suppress redundantAssignment
dest->width = jpeg.output_width; // cppcheck-suppress redundantAssignment
dest->height = jpeg.output_height; // cppcheck-suppress redundantAssignment
dest->stride = jpeg.output_width * jpeg.output_components; // cppcheck-suppress redundantAssignment
dest->used = 0; // cppcheck-suppress redundantAssignment
if (decode) {
JSAMPARRAY scanlines;
scanlines = (*jpeg.mem->alloc_sarray)((j_common_ptr) &jpeg, JPOOL_IMAGE, dest->stride, 1);
us_frame_realloc_data(dest, ((dest->width * dest->height) << 1) * 2);
while (jpeg.output_scanline < jpeg.output_height) {
jpeg_read_scanlines(&jpeg, scanlines, 1);
us_frame_append_data(dest, scanlines[0], dest->stride);
}
jpeg_finish_decompress(&jpeg);
}
done:
jpeg_destroy_decompress(&jpeg);
return retval;
}
static void _jpeg_error_handler(j_common_ptr jpeg) {
_jpeg_error_manager_s *jpeg_error = (_jpeg_error_manager_s*)jpeg->err;
char msg[JMSG_LENGTH_MAX];
(*jpeg_error->mgr.format_message)(jpeg, msg);
US_LOG_ERROR("Can't decompress JPEG: %s", msg);
longjmp(jpeg_error->jmp, -1);
}