debug dump SOF0

src/gpujpeg_reader.c

@@ -691,6 +691,9 @@ static const char *array_serialize(int comp_count, const uint8_t *comp_id) {
     return buffer;
 }
 
+/**
+ * checks component ID to determine if JPEG is in YCbCr (component IDs 1, 2, 3) or RGB (component IDs 'R', 'G', 'B')
+ */
 static enum gpujpeg_color_space gpujpeg_reader_process_cid(int comp_count, uint8_t *comp_id, enum gpujpeg_color_space header_color_space) {
     _Static_assert(GPUJPEG_MAX_COMPONENT_COUNT >= 3, "An array of at least 3 components expected");
     static const uint8_t ycbcr_ids[] = { 1, 2, 3 };
@@ -727,6 +730,21 @@ static enum gpujpeg_color_space gpujpeg_reader_process_cid(int comp_count, uint8
     return GPUJPEG_NONE;
 }
 
+static void
+sof0_dump(int comp_count, const struct gpujpeg_component_sampling_factor* sampling_factor, const uint8_t* id,
+          const int* map)
+{
+    printf("SOF0 subsampling:");
+    for (int comp = 0; comp < comp_count; ++comp) {
+        printf(" %dx%d", sampling_factor[comp].horizontal, sampling_factor[comp].vertical);
+    }
+    printf("\nSOF0 component quantization tab usage:");
+    for (int comp = 0; comp < comp_count; ++comp) {
+        printf(" %" PRIu8 "->%d", id[comp], map[comp]);
+    }
+    printf("\n");
+}
+
 /**
  * Read start of frame block from image
  *
@@ -791,6 +809,10 @@ gpujpeg_reader_read_sof0(struct gpujpeg_parameters * param, struct gpujpeg_image
         length -= 3;
     }
 
+    if (param->verbose >= LL_DEBUG2) {
+        sof0_dump(param->comp_count, param->sampling_factor, comp_id, quant_map);
+    }
+
     // Deduce color space if not known from headers
     enum gpujpeg_color_space detected_color_space = gpujpeg_reader_process_cid(param->comp_count, comp_id, header_color_space);
     if (header_color_space == GPUJPEG_NONE && detected_color_space != GPUJPEG_NONE) {