diff options
| -rw-r--r-- | include/tinyff/common.h | 17 | ||||
| -rw-r--r-- | include/tinyff/image/png.h | 5 | ||||
| -rw-r--r-- | src/common.c | 8 | ||||
| -rw-r--r-- | src/format/image/png.c | 59 |
4 files changed, 85 insertions, 4 deletions
diff --git a/include/tinyff/common.h b/include/tinyff/common.h new file mode 100644 index 0000000..d53adae --- /dev/null +++ b/include/tinyff/common.h @@ -0,0 +1,17 @@ +// Common header for tinyff library +// Not recommended to be included directly +#ifndef TINYFF_COMMON_H +#define TINYFF_COMMON_H + +#include <stdint.h> + +// Human readable number types +// NOTE: The only reason I created these was so +// that debugging will be easier +typedef uint8_t ff_byte; + +// Functions + +static inline uint32_t get_big_endian(const uint8_t *buffer); + +#endif
\ No newline at end of file diff --git a/include/tinyff/image/png.h b/include/tinyff/image/png.h index 78b92e4..95ab94f 100644 --- a/include/tinyff/image/png.h +++ b/include/tinyff/image/png.h @@ -5,9 +5,10 @@ #include <stdio.h> #include <stdbool.h> #include <string.h> +#include <stdlib.h> #include "tinyff/result.h" - +#include "tinyff/common.h" static const unsigned char PNG_SIGNATURE[8] = { @@ -50,6 +51,6 @@ typedef struct { ff_result ff_png_isvalid(FILE *file); ff_result ff_open_png(const char *filepath, ff_png_ctx **out_ctx); - +ff_result ff_next_chunk(FILE *file, ff_png_chunk **out_chunk); #endif diff --git a/src/common.c b/src/common.c new file mode 100644 index 0000000..9dea3e4 --- /dev/null +++ b/src/common.c @@ -0,0 +1,8 @@ +#include "tinyff/common.h" + +static inline uint32_t get_big_endian(const uint8_t *buffer) { + return (uint32_t)(buffer[0] << 24) | + (uint32_t)(buffer[1] << 16) | + (uint32_t)(buffer[2] << 8) | + (uint32_t)(buffer[3]); +}
\ No newline at end of file diff --git a/src/format/image/png.c b/src/format/image/png.c index 6adfe86..266f4f6 100644 --- a/src/format/image/png.c +++ b/src/format/image/png.c @@ -5,13 +5,13 @@ ff_result ff_png_isvalid(FILE *file) { char raw_sig[8]; if (fread(raw_sig, sizeof(char), 8, file) != 8) { - // Inable to read first 8 bytes + // Unable to read first 8 bytes fclose(file); return FF_RESULT_ERROR_INVALID_FILE; } if (memcmp(raw_sig, PNG_SIGNATURE, 8) != 0) { - // Signiture did not match + // Signature did not match fclose(file); return FF_RESULT_ERROR_INVALID_FILE_SIGNITURE; } @@ -34,4 +34,59 @@ ff_result ff_open_png(const char *filepath, ff_png_ctx **out_ctx) { } // TODO: Parse +} + +ff_result ff_next_chunk(FILE *file, ff_png_chunk **out_chunk) { + // 1. Read length (4 bytes): We have to read the first 4 bytes to know how many bytes to read for data + uint32_t length_buffer; + + if (fread(&length_buffer, sizeof(sizeof(ff_byte) * 4), 1, file) != 1) { + return FF_RESULT_ERROR_READ_FILE_FAILURE; + } + + // Get the big endian value of the length buffer + uint32_t data_chunk_length = get_big_endian(length_buffer); + + // 2. Read type (ditto) + // (we are really just doing the same as before and we don't have to move any positions cause + // thank god, FILE can already do that, *ascends*) + uint32_t type_buffer; + + if (fread(&type_buffer, sizeof(sizeof(ff_byte) * 4), 1, file) != 1) { + return FF_RESULT_ERROR_READ_FILE_FAILURE; + } + + // Get the big endian value of the type buffer + // It needs to be mapped to the enum though + uint32_t chunk_type = get_big_endian(type_buffer); + + // 3. Read data (data_chunk_length bytes) + uint32_t *data_buffer = (uint32_t)malloc(data_chunk_length * sizeof(ff_byte)); + + if (fread(data_buffer, sizeof(ff_byte), data_chunk_length, file) != data_chunk_length) { + free(data_buffer); + return FF_RESULT_ERROR_READ_FILE_FAILURE; + } + + // 4. Read CRC (4 bytes) + // However, I don't think we need to use the data right now + // so we can just read and store it + uint32_t crc_buffer; + + if (fread(&crc_buffer, sizeof(sizeof(ff_byte) * 4), 1, file) != 1) { + free(data_buffer); + return FF_RESULT_ERROR_READ_FILE_FAILURE; + } + + uint16_t crc = get_big_endian(crc_buffer); + + // 5. Create a chunk struct and return it + ff_png_chunk *out = (ff_png_chunk *)malloc(sizeof(ff_png_chunk)); + out->length = data_chunk_length; + out->type = chunk_type; + out->data = data_buffer; + out->crc = crc; + *out_chunk = out; + + return FF_RESULT_OK; }
\ No newline at end of file |