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LibGfx: JPGLoader: Propagate errors properly

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Use our normal error propagation mechanism instead of returning booleans
This commit is contained in:
ericLemanissier 2022-12-22 08:00:54 +01:00 • committed by Tim Flynn
parent 030d380ed2
commit 14eefedbf9
1 changed files with 124 additions and 192 deletions
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316
Userland/Libraries/LibGfx/JPGLoader.cpp
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@ -5,9 +5,11 @@
*/
#include <AK/Debug.h>
#include <AK/Error.h>
#include <AK/HashMap.h>
#include <AK/Math.h>
#include <AK/MemoryStream.h>
#include <AK/Try.h>
#include <AK/Vector.h>
#include <LibGfx/JPGLoader.h>
@ -200,17 +202,17 @@ static void generate_huffman_codes(HuffmanTableSpec& table)
}
}
static Optional<size_t> read_huffman_bits(HuffmanStreamState& hstream, size_t count = 1)
static ErrorOr<size_t> read_huffman_bits(HuffmanStreamState& hstream, size_t count = 1)
{
if (count > (8 * sizeof(size_t))) {
dbgln_if(JPG_DEBUG, "Can't read {} bits at once!", count);
return {};
return Error::from_string_literal("Reading too much huffman bits at once");
}
size_t value = 0;
while (count--) {
if (hstream.byte_offset >= hstream.stream.size()) {
dbgln_if(JPG_DEBUG, "Huffman stream exhausted. This could be an error!");
return {};
return Error::from_string_literal("Huffman stream exhausted.");
}
u8 current_byte = hstream.stream[hstream.byte_offset];
u8 current_bit = 1u & (u32)(current_byte >> (7 - hstream.bit_offset)); // MSB first.
@ -224,15 +226,13 @@ static Optional<size_t> read_huffman_bits(HuffmanStreamState& hstream, size_t co
return value;
}
static Optional<u8> get_next_symbol(HuffmanStreamState& hstream, HuffmanTableSpec const& table)
static ErrorOr<u8> get_next_symbol(HuffmanStreamState& hstream, HuffmanTableSpec const& table)
{
unsigned code = 0;
size_t code_cursor = 0;
for (int i = 0; i < 16; i++) { // Codes can't be longer than 16 bits.
auto result = read_huffman_bits(hstream);
if (!result.has_value())
return {};
code = (code << 1) | (i32)result.release_value();
auto result = TRY(read_huffman_bits(hstream));
code = (code << 1) | (i32)result;
for (int j = 0; j < table.code_counts[i]; j++) {
if (code == table.codes[code_cursor])
return table.symbols[code_cursor];
@ -241,7 +241,7 @@ static Optional<u8> get_next_symbol(HuffmanStreamState& hstream, HuffmanTableSpe
}
dbgln_if(JPG_DEBUG, "If you're seeing this...the jpeg decoder needs to support more kinds of JPEGs!");
return {};
return Error::from_string_literal("This kind of JPEG is not yet supported by the decoder");
}
static inline i32* get_component(Macroblock& block, unsigned component)
@ -271,15 +271,15 @@ static inline i32* get_component(Macroblock& block, unsigned component)
* macroblocks that share the chrominance data. Next two iterations (assuming that
* we are dealing with three components) will fill up the blocks with chroma data.
*/
static bool build_macroblocks(JPGLoadingContext& context, Vector<Macroblock>& macroblocks, u32 hcursor, u32 vcursor)
static ErrorOr<void> build_macroblocks(JPGLoadingContext& context, Vector<Macroblock>& macroblocks, u32 hcursor, u32 vcursor)
{
for (unsigned component_i = 0; component_i < context.component_count; component_i++) {
auto& component = context.components[component_i];
if (component.dc_destination_id >= context.dc_tables.size())
return false;
return Error::from_string_literal("DC destination ID is greater than number of DC tables");
if (component.ac_destination_id >= context.ac_tables.size())
return false;
return Error::from_string_literal("AC destination ID is greater than number of AC tables");
for (u8 vfactor_i = 0; vfactor_i < component.vsample_factor; vfactor_i++) {
for (u8 hfactor_i = 0; hfactor_i < component.hsample_factor; hfactor_i++) {
@ -289,23 +289,15 @@ static bool build_macroblocks(JPGLoadingContext& context, Vector<Macroblock>& ma
auto& dc_table = context.dc_tables.find(component.dc_destination_id)->value;
auto& ac_table = context.ac_tables.find(component.ac_destination_id)->value;
auto symbol_or_error = get_next_symbol(context.huffman_stream, dc_table);
if (!symbol_or_error.has_value())
return false;
// For DC coefficients, symbol encodes the length of the coefficient.
auto dc_length = symbol_or_error.release_value();
auto dc_length = TRY(get_next_symbol(context.huffman_stream, dc_table));
if (dc_length > 11) {
dbgln_if(JPG_DEBUG, "DC coefficient too long: {}!", dc_length);
return false;
return Error::from_string_literal("DC coefficient too long");
}
auto coeff_or_error = read_huffman_bits(context.huffman_stream, dc_length);
if (!coeff_or_error.has_value())
return false;
// DC coefficients are encoded as the difference between previous and current DC values.
i32 dc_diff = coeff_or_error.release_value();
i32 dc_diff = TRY(read_huffman_bits(context.huffman_stream, dc_length));
// If MSB in diff is 0, the difference is -ve. Otherwise +ve.
if (dc_length != 0 && dc_diff < (1 << (dc_length - 1)))
@ -317,14 +309,10 @@ static bool build_macroblocks(JPGLoadingContext& context, Vector<Macroblock>& ma
// Compute the AC coefficients.
for (int j = 1; j < 64;) {
symbol_or_error = get_next_symbol(context.huffman_stream, ac_table);
if (!symbol_or_error.has_value())
return false;
// AC symbols encode 2 pieces of information, the high 4 bits represent
// number of zeroes to be stuffed before reading the coefficient. Low 4
// bits represent the magnitude of the coefficient.
auto ac_symbol = symbol_or_error.release_value();
auto ac_symbol = TRY(get_next_symbol(context.huffman_stream, ac_table));
if (ac_symbol == 0)
break;
@ -334,20 +322,17 @@ static bool build_macroblocks(JPGLoadingContext& context, Vector<Macroblock>& ma
if (j >= 64) {
dbgln_if(JPG_DEBUG, "Run-length exceeded boundaries. Cursor: {}, Skipping: {}!", j, run_length);
return false;
return Error::from_string_literal("Run-length exceeded boundaries");
}
u8 coeff_length = ac_symbol & 0x0F;
if (coeff_length > 10) {
dbgln_if(JPG_DEBUG, "AC coefficient too long: {}!", coeff_length);
return false;
return Error::from_string_literal("AC coefficient too long");
}
if (coeff_length != 0) {
coeff_or_error = read_huffman_bits(context.huffman_stream, coeff_length);
if (!coeff_or_error.has_value())
return false;
i32 ac_coefficient = coeff_or_error.release_value();
i32 ac_coefficient = TRY(read_huffman_bits(context.huffman_stream, coeff_length));
if (ac_coefficient < (1 << (coeff_length - 1)))
ac_coefficient -= (1 << coeff_length) - 1;
@ -358,10 +343,10 @@ static bool build_macroblocks(JPGLoadingContext& context, Vector<Macroblock>& ma
}
}
return true;
return {};
}
static Optional<Vector<Macroblock>> decode_huffman_stream(JPGLoadingContext& context)
static ErrorOr<Vector<Macroblock>> decode_huffman_stream(JPGLoadingContext& context)
{
Vector<Macroblock> macroblocks;
macroblocks.resize(context.mblock_meta.padded_total);
@ -404,13 +389,13 @@ static Optional<Vector<Macroblock>> decode_huffman_stream(JPGLoadingContext& con
}
}
if (!build_macroblocks(context, macroblocks, hcursor, vcursor)) {
if (auto result = build_macroblocks(context, macroblocks, hcursor, vcursor); result.is_error()) {
if constexpr (JPG_DEBUG) {
dbgln("Failed to build Macroblock {}", i);
dbgln("Huffman stream byte offset {}", context.huffman_stream.byte_offset);
dbgln("Huffman stream bit offset {}", context.huffman_stream.bit_offset);
}
return {};
return result.release_error();
}
}
}
@ -418,11 +403,13 @@ static Optional<Vector<Macroblock>> decode_huffman_stream(JPGLoadingContext& con
return macroblocks;
}
static inline bool bounds_okay(const size_t cursor, const size_t delta, const size_t bound)
static inline ErrorOr<void> ensure_bounds_okay(const size_t cursor, const size_t delta, const size_t bound)
{
if (Checked<size_t>::addition_would_overflow(delta, cursor))
return false;
return (delta + cursor) < bound;
return Error::from_string_literal("Bounds are not ok: addition would overflow");
if (delta + cursor >= bound)
return Error::from_string_literal("Bounds are not ok");
return {};
}
static inline bool is_valid_marker(const Marker marker)
@ -486,76 +473,68 @@ static inline Marker read_marker_at_cursor(InputMemoryStream& stream)
return is_valid_marker(marker) ? marker : JPG_INVALID;
}
static bool read_start_of_scan(InputMemoryStream& stream, JPGLoadingContext& context)
static ErrorOr<void> read_start_of_scan(InputMemoryStream& stream, JPGLoadingContext& context)
{
if (context.state < JPGLoadingContext::State::FrameDecoded) {
dbgln_if(JPG_DEBUG, "{}: SOS found before reading a SOF!", stream.offset());
return false;
return Error::from_string_literal("SOS found before reading a SOF");
}
u16 bytes_to_read = read_be_word(stream);
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
bytes_to_read -= 2;
if (!bounds_okay(stream.offset(), bytes_to_read, context.data_size))
return false;
TRY(ensure_bounds_okay(stream.offset(), bytes_to_read, context.data_size));
u8 component_count = 0;
stream >> component_count;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
if (component_count != context.component_count) {
dbgln_if(JPG_DEBUG, "{}: Unsupported number of components: {}!", stream.offset(), component_count);
return false;
return Error::from_string_literal("Unsupported number of components");
}
for (int i = 0; i < component_count; i++) {
u8 component_id = 0;
stream >> component_id;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
auto& component = context.components[i];
if (component.id != component_id) {
dbgln("JPEG decode failed (component.id != component_id)");
return false;
return Error::from_string_literal("JPEG decode failed (component.id != component_id)");
}
u8 table_ids = 0;
stream >> table_ids;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
component.dc_destination_id = table_ids >> 4;
component.ac_destination_id = table_ids & 0x0F;
if (context.dc_tables.size() != context.ac_tables.size()) {
dbgln_if(JPG_DEBUG, "{}: DC & AC table count mismatch!", stream.offset());
return false;
return Error::from_string_literal("DC & AC table count mismatch");
}
if (!context.dc_tables.contains(component.dc_destination_id)) {
dbgln_if(JPG_DEBUG, "DC table (id: {}) does not exist!", component.dc_destination_id);
return false;
return Error::from_string_literal("DC table does not exist");
}
if (!context.ac_tables.contains(component.ac_destination_id)) {
dbgln_if(JPG_DEBUG, "AC table (id: {}) does not exist!", component.ac_destination_id);
return false;
return Error::from_string_literal("AC table does not exist");
}
}
u8 spectral_selection_start = 0;
stream >> spectral_selection_start;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
u8 spectral_selection_end = 0;
stream >> spectral_selection_end;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
u8 successive_approximation = 0;
stream >> successive_approximation;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
// The three values should be fixed for baseline JPEGs utilizing sequential DCT.
if (spectral_selection_start != 0 || spectral_selection_end != 63 || successive_approximation != 0) {
dbgln_if(JPG_DEBUG, "{}: ERROR! Start of Selection: {}, End of Selection: {}, Successive Approximation: {}!",
@ -563,50 +542,45 @@ static bool read_start_of_scan(InputMemoryStream& stream, JPGLoadingContext& con
spectral_selection_start,
spectral_selection_end,
successive_approximation);
return false;
return Error::from_string_literal("Spectral selection is not [0,63] or successive approximation is not null");
}
return true;
return {};
}
static bool read_reset_marker(InputMemoryStream& stream, JPGLoadingContext& context)
static ErrorOr<void> read_reset_marker(InputMemoryStream& stream, JPGLoadingContext& context)
{
u16 bytes_to_read = read_be_word(stream);
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
bytes_to_read -= 2;
if (bytes_to_read != 2) {
dbgln_if(JPG_DEBUG, "{}: Malformed reset marker found!", stream.offset());
return false;
return Error::from_string_literal("Malformed reset marker found");
}
context.dc_reset_interval = read_be_word(stream);
if (stream.handle_any_error())
return false;
return true;
TRY(stream.try_handle_any_error());
return {};
}
static bool read_huffman_table(InputMemoryStream& stream, JPGLoadingContext& context)
static ErrorOr<void> read_huffman_table(InputMemoryStream& stream, JPGLoadingContext& context)
{
i32 bytes_to_read = read_be_word(stream);
if (stream.handle_any_error())
return false;
if (!bounds_okay(stream.offset(), bytes_to_read, context.data_size))
return false;
TRY(stream.try_handle_any_error());
TRY(ensure_bounds_okay(stream.offset(), bytes_to_read, context.data_size));
bytes_to_read -= 2;
while (bytes_to_read > 0) {
HuffmanTableSpec table;
u8 table_info = 0;
stream >> table_info;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
u8 table_type = table_info >> 4;
u8 table_destination_id = table_info & 0x0F;
if (table_type > 1) {
dbgln_if(JPG_DEBUG, "{}: Unrecognized huffman table: {}!", stream.offset(), table_type);
return false;
return Error::from_string_literal("Unrecognized huffman table");
}
if (table_destination_id > 1) {
dbgln_if(JPG_DEBUG, "{}: Invalid huffman table destination id: {}!", stream.offset(), table_destination_id);
return false;
return Error::from_string_literal("Invalid huffman table destination id");
}
table.type = table_type;
@ -617,8 +591,7 @@ static bool read_huffman_table(InputMemoryStream& stream, JPGLoadingContext& con
for (int i = 0; i < 16; i++) {
u8 count = 0;
stream >> count;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
total_codes += count;
table.code_counts[i] = count;
}
@ -629,13 +602,11 @@ static bool read_huffman_table(InputMemoryStream& stream, JPGLoadingContext& con
for (u32 i = 0; i < total_codes; i++) {
u8 symbol = 0;
stream >> symbol;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
table.symbols.append(symbol);
}
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
auto& huffman_table = table.type == 0 ? context.dc_tables : context.ac_tables;
huffman_table.set(table.destination_id, table);
@ -646,9 +617,9 @@ static bool read_huffman_table(InputMemoryStream& stream, JPGLoadingContext& con
if (bytes_to_read != 0) {
dbgln_if(JPG_DEBUG, "{}: Extra bytes detected in huffman header!", stream.offset());
return false;
return Error::from_string_literal("Extra bytes detected in huffman header");
}
return true;
return {};
}
static inline bool validate_luma_and_modify_context(ComponentSpec const& luma, JPGLoadingContext& context)
@ -680,66 +651,58 @@ static inline void set_macroblock_metadata(JPGLoadingContext& context)
context.mblock_meta.total = context.mblock_meta.hcount * context.mblock_meta.vcount;
}
static bool read_start_of_frame(InputMemoryStream& stream, JPGLoadingContext& context)
static ErrorOr<void> read_start_of_frame(InputMemoryStream& stream, JPGLoadingContext& context)
{
if (context.state == JPGLoadingContext::FrameDecoded) {
dbgln_if(JPG_DEBUG, "{}: SOF repeated!", stream.offset());
return false;
return Error::from_string_literal("SOF repeated");
}
i32 bytes_to_read = read_be_word(stream);
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
bytes_to_read -= 2;
if (!bounds_okay(stream.offset(), bytes_to_read, context.data_size))
return false;
TRY(ensure_bounds_okay(stream.offset(), bytes_to_read, context.data_size));
stream >> context.frame.precision;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
if (context.frame.precision != 8) {
dbgln_if(JPG_DEBUG, "{}: SOF precision != 8!", stream.offset());
return false;
return Error::from_string_literal("SOF precision != 8");
}
context.frame.height = read_be_word(stream);
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
context.frame.width = read_be_word(stream);
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
if (!context.frame.width || !context.frame.height) {
dbgln_if(JPG_DEBUG, "{}: ERROR! Image height: {}, Image width: {}!", stream.offset(), context.frame.height, context.frame.width);
return false;
return Error::from_string_literal("Image frame height of width null");
}
if (context.frame.width > maximum_width_for_decoded_images || context.frame.height > maximum_height_for_decoded_images) {
dbgln("This JPEG is too large for comfort: {}x{}", context.frame.width, context.frame.height);
return false;
return Error::from_string_literal("JPEG too large for comfort");
}
set_macroblock_metadata(context);
stream >> context.component_count;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
if (context.component_count != 1 && context.component_count != 3) {
dbgln_if(JPG_DEBUG, "{}: Unsupported number of components in SOF: {}!", stream.offset(), context.component_count);
return false;
return Error::from_string_literal("Unsupported number of components in SOF");
}
for (u8 i = 0; i < context.component_count; i++) {
ComponentSpec component;
stream >> component.id;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
u8 subsample_factors = 0;
stream >> subsample_factors;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
component.hsample_factor = subsample_factors >> 4;
component.vsample_factor = subsample_factors & 0x0F;
@ -757,7 +720,7 @@ static bool read_start_of_frame(InputMemoryStream& stream, JPGLoadingContext& co
stream.offset(),
component.hsample_factor,
component.vsample_factor);
return false;
return Error::from_string_literal("Unsupported luma subsampling factors");
}
} else {
if (component.hsample_factor != 1 || component.vsample_factor != 1) {
@ -765,82 +728,75 @@ static bool read_start_of_frame(InputMemoryStream& stream, JPGLoadingContext& co
stream.offset(),
component.hsample_factor,
component.vsample_factor);
return false;
return Error::from_string_literal("Unsupported chroma subsampling factors");
}
}
stream >> component.qtable_id;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
if (component.qtable_id > 1) {
dbgln_if(JPG_DEBUG, "{}: Unsupported quantization table id: {}!", stream.offset(), component.qtable_id);
return false;
return Error::from_string_literal("Unsupported quantization table id");
}
context.components.append(move(component));
}
return true;
return {};
}
static bool read_quantization_table(InputMemoryStream& stream, JPGLoadingContext& context)
static ErrorOr<void> read_quantization_table(InputMemoryStream& stream, JPGLoadingContext& context)
{
i32 bytes_to_read = read_be_word(stream);
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
bytes_to_read -= 2;
if (!bounds_okay(stream.offset(), bytes_to_read, context.data_size))
return false;
TRY(ensure_bounds_okay(stream.offset(), bytes_to_read, context.data_size));
while (bytes_to_read > 0) {
u8 info_byte = 0;
stream >> info_byte;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
u8 element_unit_hint = info_byte >> 4;
if (element_unit_hint > 1) {
dbgln_if(JPG_DEBUG, "{}: Unsupported unit hint in quantization table: {}!", stream.offset(), element_unit_hint);
return false;
return Error::from_string_literal("Unsupported unit hint in quantization table");
}
u8 table_id = info_byte & 0x0F;
if (table_id > 1) {
dbgln_if(JPG_DEBUG, "{}: Unsupported quantization table id: {}!", stream.offset(), table_id);
return false;
return Error::from_string_literal("Unsupported quantization table id");
}
u32* table = table_id == 0 ? context.luma_table : context.chroma_table;
for (int i = 0; i < 64; i++) {
if (element_unit_hint == 0) {
u8 tmp = 0;
stream >> tmp;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
table[zigzag_map[i]] = tmp;
} else {
table[zigzag_map[i]] = read_be_word(stream);
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
}
}
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
bytes_to_read -= 1 + (element_unit_hint == 0 ? 64 : 128);
}
if (bytes_to_read != 0) {
dbgln_if(JPG_DEBUG, "{}: Invalid length for one or more quantization tables!", stream.offset());
return false;
return Error::from_string_literal("Invalid length for one or more quantization tables");
}
return true;
return {};
}
static bool skip_marker_with_length(InputMemoryStream& stream)
static ErrorOr<void> skip_marker_with_length(InputMemoryStream& stream)
{
u16 bytes_to_skip = read_be_word(stream);
bytes_to_skip -= 2;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
stream.discard_or_error(bytes_to_skip);
return !stream.handle_any_error();
TRY(stream.try_handle_any_error());
return {};
}
static void dequantize(JPGLoadingContext& context, Vector<Macroblock>& macroblocks)
@ -1064,14 +1020,9 @@ static void ycbcr_to_rgb(JPGLoadingContext const& context, Vector<Macroblock>& m
}
}
static bool compose_bitmap(JPGLoadingContext& context, Vector<Macroblock> const& macroblocks)
static ErrorOr<void> compose_bitmap(JPGLoadingContext& context, Vector<Macroblock> const& macroblocks)
{
auto bitmap_or_error = Bitmap::try_create(BitmapFormat::BGRx8888, { context.frame.width, context.frame.height });
if (bitmap_or_error.is_error())
return false;
context.bitmap = bitmap_or_error.release_value_but_fixme_should_propagate_errors();
if (bitmap_or_error.is_error())
return false;
context.bitmap = TRY(Bitmap::try_create(BitmapFormat::BGRx8888, { context.frame.width, context.frame.height }));
for (u32 y = context.frame.height - 1; y < context.frame.height; y--) {
const u32 block_row = y / 8;
@ -1086,22 +1037,20 @@ static bool compose_bitmap(JPGLoadingContext& context, Vector<Macroblock> const&
}
}
return true;
return {};
}
static bool parse_header(InputMemoryStream& stream, JPGLoadingContext& context)
static ErrorOr<void> parse_header(InputMemoryStream& stream, JPGLoadingContext& context)
{
auto marker = read_marker_at_cursor(stream);
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
if (marker != JPG_SOI) {
dbgln_if(JPG_DEBUG, "{}: SOI not found: {:x}!", stream.offset(), marker);
return false;
return Error::from_string_literal("SOI not found");
}
for (;;) {
marker = read_marker_at_cursor(stream);
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
// Set frame type if the marker marks a new frame.
if (marker >= 0xFFC0 && marker <= 0xFFCF) {
@ -1124,30 +1073,26 @@ static bool parse_header(InputMemoryStream& stream, JPGLoadingContext& context)
case JPG_SOI:
case JPG_EOI:
dbgln_if(JPG_DEBUG, "{}: Unexpected marker {:x}!", stream.offset(), marker);
return false;
return Error::from_string_literal("Unexpected marker");
case JPG_SOF0:
if (!read_start_of_frame(stream, context))
return false;
TRY(read_start_of_frame(stream, context));
context.state = JPGLoadingContext::FrameDecoded;
break;
case JPG_DQT:
if (!read_quantization_table(stream, context))
return false;
TRY(read_quantization_table(stream, context));
break;
case JPG_RST:
if (!read_reset_marker(stream, context))
return false;
TRY(read_reset_marker(stream, context));
break;
case JPG_DHT:
if (!read_huffman_table(stream, context))
return false;
TRY(read_huffman_table(stream, context));
break;
case JPG_SOS:
return read_start_of_scan(stream, context);
default:
if (!skip_marker_with_length(stream)) {
if (auto result = skip_marker_with_length(stream); result.is_error()) {
dbgln_if(JPG_DEBUG, "{}: Error skipping marker: {:x}!", stream.offset(), marker);
return false;
return result.release_error();
}
break;
}
@ -1156,20 +1101,19 @@ static bool parse_header(InputMemoryStream& stream, JPGLoadingContext& context)
VERIFY_NOT_REACHED();
}
static bool scan_huffman_stream(InputMemoryStream& stream, JPGLoadingContext& context)
static ErrorOr<void> scan_huffman_stream(InputMemoryStream& stream, JPGLoadingContext& context)
{
u8 last_byte;
u8 current_byte = 0;
stream >> current_byte;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
for (;;) {
last_byte = current_byte;
stream >> current_byte;
if (stream.handle_any_error()) {
dbgln_if(JPG_DEBUG, "{}: EOI not found!", stream.offset());
return false;
return Error::from_string_literal("EOI not found");
}
if (last_byte == 0xFF) {
@ -1177,23 +1121,21 @@ static bool scan_huffman_stream(InputMemoryStream& stream, JPGLoadingContext& co
continue;
if (current_byte == 0x00) {
stream >> current_byte;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
context.huffman_stream.stream.append(last_byte);
continue;
}
Marker marker = 0xFF00 | current_byte;
if (marker == JPG_EOI)
return true;
return {};
if (marker >= JPG_RST0 && marker <= JPG_RST7) {
context.huffman_stream.stream.append(marker);
stream >> current_byte;
if (stream.handle_any_error())
return false;
TRY(stream.try_handle_any_error());
continue;
}
dbgln_if(JPG_DEBUG, "{}: Invalid marker: {:x}!", stream.offset(), marker);
return false;
return Error::from_string_literal("Invalid marker");
} else {
context.huffman_stream.stream.append(last_byte);
}
@ -1202,28 +1144,18 @@ static bool scan_huffman_stream(InputMemoryStream& stream, JPGLoadingContext& co
VERIFY_NOT_REACHED();
}
static bool decode_jpg(JPGLoadingContext& context)
static ErrorOr<void> decode_jpg(JPGLoadingContext& context)
{
InputMemoryStream stream { { context.data, context.data_size } };
if (!parse_header(stream, context))
return false;
if (!scan_huffman_stream(stream, context))
return false;
auto result = decode_huffman_stream(context);
if (!result.has_value()) {
dbgln_if(JPG_DEBUG, "{}: Failed to decode Macroblocks!", stream.offset());
return false;
}
auto macroblocks = result.release_value();
TRY(parse_header(stream, context));
TRY(scan_huffman_stream(stream, context));
auto macroblocks = TRY(decode_huffman_stream(context));
dequantize(context, macroblocks);
inverse_dct(context, macroblocks);
ycbcr_to_rgb(context, macroblocks);
if (!compose_bitmap(context, macroblocks))
return false;
return true;
TRY(compose_bitmap(context, macroblocks));
return {};
}
JPGImageDecoderPlugin::JPGImageDecoderPlugin(u8 const* data, size_t size)
@ -1291,9 +1223,9 @@ ErrorOr<ImageFrameDescriptor> JPGImageDecoderPlugin::frame(size_t index)
return Error::from_string_literal("JPGImageDecoderPlugin: Decoding failed");
if (m_context->state < JPGLoadingContext::State::BitmapDecoded) {
if (!decode_jpg(*m_context)) {
if (auto result = decode_jpg(*m_context); result.is_error()) {
m_context->state = JPGLoadingContext::State::Error;
return Error::from_string_literal("JPGImageDecoderPlugin: Decoding failed");
return result.release_error();
}
m_context->state = JPGLoadingContext::State::BitmapDecoded;
}