source/gif_engine.c file

gif_parse_result gif_parse(const void* buffer, size_t buffer_size, gif_details* details, gif_allocator allocator)

Parses the GIF file located at buffer.

This function will parse the contents of buffer in a way that makes OOB reads impossible, if the provided buffer and buffer_size arguments are valid. Because this function must allocate, the user can provide an allocator function using the allocator arguments, which is a pointer to a function with a signature matching that of realloc. The details argument is a pointer to a gif_details struct, which need not be zero initialized, because this function does zero initialization as its first step. Typical usage of this function looks as follows:

gif_details details;
gif_parse_result result = gif_parse(buffer, buffer_size, &details, &realloc);

The code member of the returned gif_parse_result object holds the result of the parsing process. If the code is GIF_SUCCESS, then the data member will hold the number of bytes remaining after the tail block in the buffer. Note that the number of bytes is a size_t value memcpy'd into this field, so you have to copy it out in a similar manner:

size_t leftover_bytes;
memcpy(&leftover_bytes, &result.data, sizeof(size_t));

If the code member is GIF_REALLOC_FAIL, then the pointer that caused the allocator function to fail in a realloc context (i.e. when the first argument isn't NULL) will be returned in the data member as is.

This function is thread-safe.

gif_decode_result gif_decode(gif_details* details, gif_allocator allocator)

Decodes the frame data parsed by gif_parse.

This function is not yet implemented.

void gif_free_details(const gif_details* details, gif_deallocator deallocator)

Frees the gif_details struct populated by gif_parse.

This function should be called even if the gif_parse function did not succeed.