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JPGLoader: Use HashMap to store huffman tables

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This patch rids us of the ugly hack that we had to go through while
handling table redefinitons.
This commit is contained in:
devashish 2020-11-30 09:21:22 +05:30 • committed by Andreas Kling
parent 8cada744df
commit 2a332d8669
Notes: sideshowbarker 2024-07-19 01:09:55 +09:00
1 changed files with 17 additions and 54 deletions
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71
Libraries/LibGfx/JPGLoader.cpp
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@ -211,8 +211,8 @@ struct JPGLoadingContext {
HashMap<u8, ComponentSpec> components; HashMap<u8, ComponentSpec> components;
RefPtr<Gfx::Bitmap> bitmap; RefPtr<Gfx::Bitmap> bitmap;
u16 dc_reset_interval { 0 }; u16 dc_reset_interval { 0 };
Vector<HuffmanTableSpec> dc_tables; HashMap<u8, HuffmanTableSpec> dc_tables;
Vector<HuffmanTableSpec> ac_tables; HashMap<u8, HuffmanTableSpec> ac_tables;
HuffmanStreamState huffman_stream; HuffmanStreamState huffman_stream;
i32 previous_dc_values[3] = { 0 }; i32 previous_dc_values[3] = { 0 };
MacroblockMeta mblock_meta; MacroblockMeta mblock_meta;
@ -308,8 +308,8 @@ static bool build_macroblocks(JPGLoadingContext& context, Vector<Macroblock>& ma
u32 mb_index = (vcursor + vfactor_i) * context.mblock_meta.hpadded_count + (hfactor_i + hcursor); u32 mb_index = (vcursor + vfactor_i) * context.mblock_meta.hpadded_count + (hfactor_i + hcursor);
Macroblock& block = macroblocks[mb_index]; Macroblock& block = macroblocks[mb_index];
auto& dc_table = context.dc_tables[component.dc_destination_id]; auto& dc_table = context.dc_tables.find(component.dc_destination_id)->value;
auto& ac_table = context.ac_tables[component.ac_destination_id]; auto& ac_table = context.ac_tables.find(component.ac_destination_id)->value;
auto symbol_or_error = get_next_symbol(context.huffman_stream, dc_table); auto symbol_or_error = get_next_symbol(context.huffman_stream, dc_table);
if (!symbol_or_error.has_value()) if (!symbol_or_error.has_value())
@ -399,15 +399,15 @@ static Optional<Vector<Macroblock>> decode_huffman_stream(JPGLoadingContext& con
dbg() << "Image height: " << context.frame.height; dbg() << "Image height: " << context.frame.height;
dbg() << "Macroblocks in a row: " << context.mblock_meta.hpadded_count; dbg() << "Macroblocks in a row: " << context.mblock_meta.hpadded_count;
dbg() << "Macroblocks in a column: " << context.mblock_meta.vpadded_count; dbg() << "Macroblocks in a column: " << context.mblock_meta.vpadded_count;
dbg() << "Mblock meta padded total: " << context.mblock_meta.padded_total; dbg() << "Macroblock meta padded total: " << context.mblock_meta.padded_total;
#endif #endif
// Compute huffman codes for DC and AC tables. // Compute huffman codes for DC and AC tables.
for (auto& dc_table : context.dc_tables) for (auto it = context.dc_tables.begin(); it != context.dc_tables.end(); ++it)
generate_huffman_codes(dc_table); generate_huffman_codes(it->value);
for (auto& ac_table : context.ac_tables) for (auto it = context.ac_tables.begin(); it != context.ac_tables.end(); ++it)
generate_huffman_codes(ac_table); generate_huffman_codes(it->value);
for (u32 vcursor = 0; vcursor < context.mblock_meta.vcount; vcursor += context.vsample_factor) { for (u32 vcursor = 0; vcursor < context.mblock_meta.vcount; vcursor += context.vsample_factor) {
for (u32 hcursor = 0; hcursor < context.mblock_meta.hcount; hcursor += context.hsample_factor) { for (u32 hcursor = 0; hcursor < context.mblock_meta.hcount; hcursor += context.hsample_factor) {
@ -575,23 +575,16 @@ static bool read_start_of_scan(InputMemoryStream& stream, JPGLoadingContext& con
return false; return false;
} }
bool dc_table_exists = false; if (!context.dc_tables.contains(component->dc_destination_id)) {
bool ac_table_exists = false;
for (unsigned t = 0; t < context.dc_tables.size(); t++) {
dc_table_exists = dc_table_exists || (context.dc_tables[t].destination_id == component->dc_destination_id);
ac_table_exists = ac_table_exists || (context.ac_tables[t].destination_id == component->ac_destination_id);
}
if (!dc_table_exists) {
#ifdef JPG_DEBUG #ifdef JPG_DEBUG
dbg() << stream.offset() << ": Invalid DC huffman table destination id: " << component->dc_destination_id; dbgln("DC table (id: {}) does not exist!", component->dc_destination_id);
#endif #endif
return false; return false;
} }
if (!ac_table_exists) { if (!context.ac_tables.contains(component->ac_destination_id)) {
#ifdef JPG_DEBUG #ifdef JPG_DEBUG
dbg() << stream.offset() << ": Invalid AC huffman table destination id: " << component->ac_destination_id; dbgln("AC table (id: {}) does not exist!", component->ac_destination_id);
#endif #endif
return false; return false;
} }
@ -639,38 +632,6 @@ static bool read_reset_marker(InputMemoryStream& stream, JPGLoadingContext& cont
return true; return true;
} }
static bool huffman_table_reset_helper(HuffmanTableSpec& src, JPGLoadingContext& context)
{
auto& table = src.type == 0 ? context.dc_tables : context.ac_tables;
if (src.destination_id == 0) {
if (table.is_empty())
table.append(move(src));
else
table[0] = move(src);
return true;
}
if (src.destination_id == 1) {
if (table.size() < 1) {
String table_str = src.type == 0 ? "DC" : "AC";
#ifdef JPG_DEBUG
dbg() << table_str << "[1] showed up before " << table_str << "[0]!";
#endif
return false;
}
if (table.size() == 1)
table.append(move(src));
else
table[1] = move(src);
return true;
}
#ifdef JPG_DEBUG
dbg() << "Unsupported huffman table destination id: " << src.destination_id;
#endif
return false;
}
static bool read_huffman_table(InputMemoryStream& stream, JPGLoadingContext& context) static bool read_huffman_table(InputMemoryStream& stream, JPGLoadingContext& context)
{ {
i32 bytes_to_read = read_be_word(stream); i32 bytes_to_read = read_be_word(stream);
@ -700,6 +661,7 @@ static bool read_huffman_table(InputMemoryStream& stream, JPGLoadingContext& con
#endif #endif
return false; return false;
} }
table.type = table_type; table.type = table_type;
table.destination_id = table_destination_id; table.destination_id = table_destination_id;
u32 total_codes = 0; u32 total_codes = 0;
@ -728,8 +690,9 @@ static bool read_huffman_table(InputMemoryStream& stream, JPGLoadingContext& con
if (stream.handle_any_error()) if (stream.handle_any_error())
return false; return false;
if (!huffman_table_reset_helper(table, context)) auto& huffman_table = table.type == 0 ? context.dc_tables : context.ac_tables;
return false; huffman_table.set(table.destination_id, table);
ASSERT(huffman_table.size() <= 2);
bytes_to_read -= 1 + 16 + total_codes; bytes_to_read -= 1 + 16 + total_codes;
} }