rename decode_to_raw_rgb->encode_file + updates

Allow now decoding to arbitrary of supported formats (.png, .pnm
etc.) accordinh to the provided extension (gpujpeg_image_save_to_file
supports that if metadata struct provided).

Author: MartinPulec

examples/CMakeLists.txt

@@ -18,8 +18,8 @@ target_link_libraries(decode_minimal gpujpeg)
 add_executable(decode_to_pnm decode_to_pnm.c)
 target_link_libraries(decode_to_pnm gpujpeg)
 
-add_executable(decode_to_raw_rgb decode_to_raw_rgb.c)
-target_link_libraries(decode_to_raw_rgb gpujpeg)
+add_executable(decode_to_file decode_to_file.c)
+target_link_libraries(decode_to_file gpujpeg)
 
 include(CheckLanguage)
 check_language(CUDA)

examples/decode_to_raw_rgb.c examples/decode_to_file.cexamples/decode_to_raw_rgb.c renamed to examples/decode_to_file.c

@@ -1,3 +1,12 @@
+/**
+ * @file decode_to_file.c
+ *
+ * This demonstrates decoding input file to output file.
+ *
+ * Changelog:
+ * - 2020-08-11 - initial implelemtation
+ * - 2026-02-18 - rename, support for abitrary output format
+ */
 #include <libgpujpeg/gpujpeg_common.h>
 #include <libgpujpeg/gpujpeg_decoder.h>
 #include <stdbool.h>
@@ -11,11 +20,13 @@
 
 static void usage(const char *progname) {
         printf("Usage:\n");
-        printf("\t%s file.jpg\n", progname);
+        printf("\t%s input.jpg [output.ext]\n", progname);
+        printf(
+            "\noptional output file should can use one of recognized extensions (eg. png); defaults to <input>.rgb\n");
 }
 
 static bool check_params(int argc, char *argv[]) {
-        if (argc != 2 || strrchr(argv[1], '.') == NULL) {
+        if ( (argc < 2 || argc > 3) || strrchr(argv[1], '.') == NULL ) {
                 return false;
         }
         const char *ext = strrchr(argv[1], '.') + 1;
@@ -29,7 +40,8 @@ struct decode_data {
         uint8_t *input_image;
 };
 
-static int decode(const char *input_filename, struct decode_data *d)
+static int
+decode(const char* input_filename, const char* output_filename, struct decode_data* d)
 {
         // create decoder
         if ((d->decoder = gpujpeg_decoder_create(0)) == NULL) {
@@ -52,15 +64,20 @@ static int decode(const char *input_filename, struct decode_data *d)
                 return 1;
         }
 
-        // create output file name
-        d->out_filename = malloc(strlen(input_filename) + 1);
-        strcpy(d->out_filename, input_filename);
-        strcpy(strrchr(d->out_filename, '.') + 1, "rgb");
+        if (output_filename != nullptr) {
+                d->out_filename = strdup(output_filename);
+        } else { // create output file name with .rgb extension
+            d->out_filename = malloc(strlen(input_filename) + 1);
+            strcpy(d->out_filename, input_filename);
+            strcpy(strrchr(d->out_filename, '.') + 1, "rgb");
+        }
 
         // write the decoded image
-        if (gpujpeg_image_save_to_file(d->out_filename, decoder_output.data, decoder_output.data_size, NULL) != 0) {
-                return 1;
+        if ( gpujpeg_image_save_to_file(d->out_filename, decoder_output.data, decoder_output.data_size,
+                                        &decoder_output.param_image) != 0 ) {
+               return 1;
         }
+        printf("File %s successfully written.\n", d->out_filename);
 
         return 0;
 }
@@ -72,7 +89,7 @@ int main(int argc, char *argv[]) {
         }
 
         struct decode_data d = { 0 };
-        int rc = decode(argv[1], &d);
+        int rc = decode(argv[1], argv[2], &d);
 
         free(d.out_filename);
         gpujpeg_image_destroy(d.input_image);

libgpujpeg/gpujpeg_common.h

@@ -1,6 +1,6 @@
 /**
  * @file
- * Copyright (c) 2011-2025, CESNET
+ * Copyright (c) 2011-2026, CESNET
  * Copyright (c) 2011, Silicon Genome, LLC.
  *
  * All rights reserved.
@@ -430,7 +430,8 @@ gpujpeg_image_load_from_file(const char* filename, uint8_t** image, size_t* imag
  * @param filaname  Image filename
  * @param image  Image data buffer
  * @param image_size  Image data buffer size
- * @param param_image Image properties (may be NULL)
+ * @param param_image Image properties (may be NULL); must be set if outputting image
+ *                    in a container (PNG, PNM et all.), otherwise just data outputted
  * @return 0 if succeeds, otherwise nonzero
  */
 GPUJPEG_API int