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solidpixel merged 2 commits into from
Jun 2, 2026
Merged

Improve image load error messages #632

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ce0eec7
Improve image load error messages
solidpixel Jun 2, 2026
0ddf1b9
Typos
solidpixel Jun 2, 2026
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6 changes: 4 additions & 2 deletions Docs/ChangeLog-5x.md
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Original file line number Diff line number Diff line change
Expand Up @@ -18,8 +18,8 @@ The 5.5.0 release is a minor maintenance release.
* **Update:** Update Wuffs to v0.3.4.
* **Update:** Update TinyEXR to v1.0.13.
* **Bug fix:** Throw errors in the command line wrapper for cases where
".astc" input image sizes would result in integer overflow in calculations
of total block count or data size.
`.astc`, `.dds`, and `.ktx` input image sizes would result in integer
overflow in calculations of total block count or data size.
* **Bug fix:** Throw errors in the library API for cases where input image
sizes would result in integer overflow in calculations of total texel
count, total block count, or compressed image byte size.
Expand All @@ -32,6 +32,8 @@ The 5.5.0 release is a minor maintenance release.
triggered by NaNs generated by `atan2()` calls where both inputs are zero.
* **Bug fix:** Avoid undefined behavior on left shift of negative integer,
that is triggered for some HDR encodings in `hdr_alpha_unpack()`.
* **Bug fix:** Report error messages for failed `.dds` and `.ktx` input image
loading to stderr, to match other formats.

<!-- ---------------------------------------------------------------------- -->
## 5.4.0
Expand Down
5 changes: 3 additions & 2 deletions Source/astcenccli_image_external.cpp
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Expand Up @@ -52,14 +52,15 @@
#define WUFFS_CONFIG__MODULE__DEFLATE
#define WUFFS_CONFIG__MODULE__PNG
#define WUFFS_CONFIG__MODULE__ZLIB

/**
* @brief Trap image load failures and convert into a runtime error.
*/
static void astcenc_runtime_assert(bool condition)
{
if (!condition)
{
print_error("ERROR: Corrupt input image\n");
print_error("ERROR: Image header corrupt\n");
exit(1);
}
}
Expand Down Expand Up @@ -91,7 +92,7 @@ astcenc_image* load_png_with_wuffs(
std::ifstream file(filename, std::ios::binary | std::ios::ate);
if (!file)
{
print_error("ERROR: Failed to load image %s (can't fopen)\n", filename);
print_error("ERROR: File open failed '%s'\n", filename);
return nullptr;
}

Expand Down
88 changes: 43 additions & 45 deletions Source/astcenccli_image_load_store.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -104,7 +104,7 @@ static astcenc_image* load_image_with_tinyexr(
int load_res = LoadEXR(&image, &dim_x, &dim_y, filename, &err);
if (load_res != TINYEXR_SUCCESS)
{
print_error("ERROR: Failed to load image %s (%s)\n", filename, err);
print_error("ERROR: Image load failed '%s' (%s)\n", filename, err);
free(reinterpret_cast<void*>(const_cast<char*>(err)));
return nullptr;
}
Expand Down Expand Up @@ -160,7 +160,7 @@ static astcenc_image* load_image_with_stb(
}
}

print_error("ERROR: Failed to load image %s (%s)\n", filename, stbi_failure_reason());
print_error("ERROR: Image load failed '%s' (%s)\n", filename, stbi_failure_reason());
return nullptr;
}

Expand Down Expand Up @@ -940,7 +940,7 @@ static astcenc_image* load_ktx_uncompressed_image(
FILE *f = fopen(filename, "rb");
if (!f)
{
printf("Failed to open file %s\n", filename);
print_error("ERROR: File open failed '%s'\n", filename);
return nullptr;
}

Expand All @@ -949,14 +949,14 @@ static astcenc_image* load_ktx_uncompressed_image(

if (header_bytes_read != sizeof(hdr))
{
printf("Failed to read header of KTX file %s\n", filename);
print_error("ERROR: File read failed '%s'\n", filename);
fclose(f);
return nullptr;
}

if (memcmp(hdr.magic, ktx_magic, 12) != 0 || (hdr.endianness != 0x04030201 && hdr.endianness != 0x01020304))
{
printf("File %s does not have a valid KTX header\n", filename);
print_error("ERROR: Image header corrupt '%s'\n", filename);
fclose(f);
return nullptr;
Comment thread
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}
Expand All @@ -970,7 +970,7 @@ static astcenc_image* load_ktx_uncompressed_image(

if (hdr.gl_type == 0 || hdr.gl_format == 0)
{
printf("File %s appears to be compressed, not supported as input\n", filename);
print_error("ERROR: Image uses unsupported KTX format '%s'\n", filename);
fclose(f);
return nullptr;
}
Expand Down Expand Up @@ -1007,7 +1007,7 @@ static astcenc_image* load_ktx_uncompressed_image(
components = 2;
break;
default:
printf("KTX file %s has unsupported GL type\n", filename);
print_error("ERROR: Image uses unsupported KTX format '%s'\n", filename);
fclose(f);
return nullptr;
}
Expand Down Expand Up @@ -1152,27 +1152,26 @@ static astcenc_image* load_ktx_uncompressed_image(
break;
}
default:
printf("KTX file %s has unsupported GL format\n", filename);
print_error("ERROR: Image uses unsupported KTX format '%s'\n", filename);
fclose(f);
return nullptr;
}

if (hdr.number_of_mipmap_levels > 1)
{
printf("WARNING: KTX file %s has %u mipmap levels; only the first one will be encoded.\n", filename, hdr.number_of_mipmap_levels);
printf("WARNING: Only first of %u mipmap levels will be compressed '%s'.\n", hdr.number_of_mipmap_levels, filename);
}

if (hdr.number_of_array_elements > 1)
{
printf("WARNING: KTX file %s contains a texture array with %u layers; only the first one will be encoded.\n", filename, hdr.number_of_array_elements);
printf("WARNING: Only first of %u array layers will be compressed '%s'.\n", hdr.number_of_array_elements, filename);
}

if (hdr.number_of_faces > 1)
{
printf("WARNING: KTX file %s contains a cubemap with 6 faces; only the first one will be encoded.\n", filename);
printf("WARNING: Only first of %u cube faces will be compressed '%s'.\n", hdr.number_of_faces, filename);
}


unsigned int dim_x = hdr.pixel_width;
unsigned int dim_y = astc::max(hdr.pixel_height, 1u);
unsigned int dim_z = astc::max(hdr.pixel_depth, 1u);
Expand All @@ -1184,7 +1183,7 @@ static astcenc_image* load_ktx_uncompressed_image(
size_t sb_read = fread(&specified_bytes_of_surface, 1, 4, f);
if (sb_read != 4)
{
printf("Failed to read header of KTX file %s\n", filename);
print_error("ERROR: File read failed '%s'\n", filename);
fclose(f);
return nullptr;
}
Expand All @@ -1211,8 +1210,8 @@ static astcenc_image* load_ktx_uncompressed_image(

if (overflow || bytes_per_image != specified_bytes_of_surface)
{
print_error("ERROR: Image header corrupt '%s'\n", filename);
fclose(f);
printf("%s: KTX file inconsistency: computed surface size is %zu bytes, but specified size is %u bytes\n", filename, bytes_per_image, specified_bytes_of_surface);
return nullptr;
}

Expand All @@ -1221,12 +1220,12 @@ static astcenc_image* load_ktx_uncompressed_image(
fclose(f);
if (bytes_read != specified_bytes_of_surface)
{
print_error("ERROR: File read failed '%s'\n", filename);
delete[] buf;
printf("Failed to read file %s\n", filename);
return nullptr;
}

// perform an endianness swap on the surface if needed.
// Perform an endianness swap on the surface if needed.
if (switch_endianness)
{
if (hdr.gl_type_size == 2)
Expand Down Expand Up @@ -1291,23 +1290,23 @@ bool load_ktx_compressed_image(
FILE *f = fopen(filename, "rb");
if (!f)
{
printf("Failed to open file %s\n", filename);
print_error("ERROR: File open failed '%s'\n", filename);
return true;
}

ktx_header hdr;
size_t actual = fread(&hdr, 1, sizeof(hdr), f);
if (actual != sizeof(hdr))
{
printf("Failed to read header from %s\n", filename);
print_error("ERROR: File read failed '%s'\n", filename);
fclose(f);
return true;
}

if (memcmp(hdr.magic, ktx_magic, 12) != 0 ||
(hdr.endianness != 0x04030201 && hdr.endianness != 0x01020304))
{
printf("File %s does not have a valid KTX header\n", filename);
print_error("ERROR: Image header corrupt '%s'\n", filename);
fclose(f);
return true;
}
Expand All @@ -1322,25 +1321,24 @@ bool load_ktx_compressed_image(
if (hdr.gl_type != 0 || hdr.gl_format != 0 || hdr.gl_type_size != 1 ||
hdr.gl_base_internal_format != GL_RGBA)
{
printf("File %s is not a compressed ASTC file\n", filename);
print_error("ERROR: Image uses unsupported KTX format '%s'\n", filename);
fclose(f);
return true;
}

const format_entry* fmt = get_format(hdr.gl_internal_format);
if (!fmt)
{
printf("File %s is not a compressed ASTC file\n", filename);
print_error("ERROR: Image uses unsupported KTX format '%s'\n", filename);
fclose(f);
return true;
}

// Skip over any key-value pairs
int seekerr;
seekerr = fseek(f, hdr.bytes_of_key_value_data, SEEK_CUR);
int seekerr = fseek(f, hdr.bytes_of_key_value_data, SEEK_CUR);
if (seekerr)
{
printf("Failed to skip key-value pairs in %s\n", filename);
print_error("ERROR: File read failed '%s'\n", filename);
fclose(f);
return true;
}
Expand All @@ -1350,7 +1348,7 @@ bool load_ktx_compressed_image(
actual = fread(&data_len, 1, sizeof(data_len), f);
if (actual != sizeof(data_len))
{
printf("Failed to read mip 0 size from %s\n", filename);
print_error("ERROR: File read failed '%s'\n", filename);
fclose(f);
return true;
}
Expand All @@ -1365,7 +1363,7 @@ bool load_ktx_compressed_image(
actual = fread(data, 1, data_len, f);
if (actual != data_len)
{
printf("Failed to read mip 0 data from %s\n", filename);
print_error("ERROR: File read failed '%s'\n", filename);
fclose(f);
delete[] data;
return true;
Expand Down Expand Up @@ -1757,10 +1755,10 @@ struct dds_header
struct dds_header_dx10
{
uint32_t dxgi_format;
uint32_t resource_dimension; // 2=1d-texture, 3=2d-texture or cubemap, 4=3d-texture
uint32_t misc_flag; // 4 if cubemap, else 0
uint32_t array_size; // size of array in case of a texture array; set to 1 for a non-array
uint32_t reserved; // set to 0.
uint32_t resource_dimension; // Set to 2 (1D tex), 3 (2D tex or cube), or 4 (3D tex)
uint32_t misc_flag; // Set to 4 if cubemap, else 0
uint32_t array_size; // Set to size of array if texture array; else 1
uint32_t reserved; // Set to 0.
};

#define DDS_MAGIC 0x20534444
Expand All @@ -1785,7 +1783,7 @@ static astcenc_image* load_dds_uncompressed_image(
FILE *f = fopen(filename, "rb");
if (!f)
{
printf("Failed to open file %s\n", filename);
print_error("ERROR: File open failed '%s'\n", filename);
return nullptr;
}

Expand All @@ -1794,7 +1792,7 @@ static astcenc_image* load_dds_uncompressed_image(
size_t magic_bytes_read = fread(&magic, 1, sizeof(uint32_t), f);
if (magic_bytes_read != 4)
{
printf("Failed to read magic number from file %s\n", filename);
print_error("ERROR: File read failed '%s'\n", filename);
fclose(f);
return nullptr;
}
Expand All @@ -1805,7 +1803,7 @@ static astcenc_image* load_dds_uncompressed_image(

if (magic != DDS_MAGIC)
{
printf("File %s has incorrect magic number\n", filename);
print_error("ERROR: Image header corrupt '%s'\n", filename);
fclose(f);
return nullptr;
}
Expand All @@ -1815,13 +1813,13 @@ static astcenc_image* load_dds_uncompressed_image(
size_t header_bytes_read = fread(&hdr, 1, sizeof(hdr), f);
if (header_bytes_read != sizeof(hdr))
{
printf("Failed to read header from file %s\n", filename);
print_error("ERROR: File read failed '%s'\n", filename);
fclose(f);
return nullptr;
}

#if defined(ASTCENC_BIG_ENDIAN)
// DDS header fields all 32-bit words
// DDS header fields are all 32-bit words
uint32_t* words = reinterpret_cast<uint32_t*>(&hdr);
size_t word_count = sizeof(hdr) / sizeof(uint32_t);

Expand All @@ -1834,7 +1832,7 @@ static astcenc_image* load_dds_uncompressed_image(

if (hdr.size != 124)
{
printf("File %s has incorrect header\n", filename);
print_error("ERROR: Image header corrupt '%s'\n", filename);
fclose(f);
return nullptr;
}
Expand All @@ -1848,7 +1846,7 @@ static astcenc_image* load_dds_uncompressed_image(
}
else
{
printf("DDS file %s is compressed, not supported\n", filename);
print_error("ERROR: Image uses unsupported DDS format '%s'\n", filename);
fclose(f);
return nullptr;
}
Expand All @@ -1860,7 +1858,7 @@ static astcenc_image* load_dds_uncompressed_image(
size_t dx10_header_bytes_read = fread(&dx10_header, 1, sizeof(dx10_header), f);
if (dx10_header_bytes_read != sizeof(dx10_header))
{
printf("Failed to read header of DDS file %s\n", filename);
print_error("ERROR: File read failed '%s'\n", filename);
fclose(f);
return nullptr;
}
Expand Down Expand Up @@ -1942,7 +1940,7 @@ static astcenc_image* load_dds_uncompressed_image(

if (!did_select_format)
{
printf("DDS file %s: DXGI format not supported by codec\n", filename);
print_error("ERROR: Image uses unsupported DDS format '%s'\n", filename);
fclose(f);
return nullptr;
}
Expand Down Expand Up @@ -2030,7 +2028,7 @@ static astcenc_image* load_dds_uncompressed_image(
}
else
{
printf("DDS file %s: Non-DXGI format not supported by codec\n", filename);
print_error("ERROR: Image uses unsupported DDS format '%s'\n", filename);
fclose(f);
return nullptr;
}
Expand All @@ -2055,7 +2053,7 @@ static astcenc_image* load_dds_uncompressed_image(

if (overflow)
{
printf("DDS file %s has invalid dimensions\n", filename);
print_error("ERROR: Image header corrupt '%s'\n", filename);
fclose(f);
return nullptr;
}
Expand All @@ -2067,7 +2065,7 @@ static astcenc_image* load_dds_uncompressed_image(
}
catch (...)
{
printf("Failed to allocate memory for file %s\n", filename);
print_error("ERROR: Image memory allocation failed '%s'\n", filename);
fclose(f);
return nullptr;
}
Expand All @@ -2076,7 +2074,7 @@ static astcenc_image* load_dds_uncompressed_image(
fclose(f);
if (bytes_read != bytes_per_image)
{
printf("Failed to read file %s\n", filename);
print_error("ERROR: File read failed '%s'\n", filename);
delete[] buf;
return nullptr;
}
Expand Down Expand Up @@ -2555,7 +2553,7 @@ int load_cimage(
unsigned int magicval = unpack_bytes(hdr.magic[0], hdr.magic[1], hdr.magic[2], hdr.magic[3]);
if (magicval != ASTC_MAGIC_ID)
{
print_error("ERROR: Image header not recognized '%s'\n", filename);
print_error("ERROR: Image header corrupt '%s'\n", filename);
return 1;
}

Expand Down Expand Up @@ -2607,7 +2605,7 @@ int load_cimage(
file.read(reinterpret_cast<char*>(buffer), data_size);
if (file.fail())
{
print_error("ERROR: Image data size exceeded file size '%s'\n", filename);
print_error("ERROR: File read failed '%s'\n", filename);
delete[] buffer;
return 1;
}
Expand Down
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