From ff542c2ae656c574ffe7bfaec9967146e8f96d2a Mon Sep 17 00:00:00 2001 From: Dominic Szablewski Date: Sat, 27 Nov 2021 18:36:17 +0100 Subject: [PATCH] Change the API to supply/return channel count and colorspace info --- README.md | 7 ++- qoi.h | 154 ++++++++++++++++++++++++++++++++++------------------- qoibench.c | 18 +++++-- qoiconv.c | 26 ++++++--- 4 files changed, 137 insertions(+), 68 deletions(-) diff --git a/README.md b/README.md index 1015c813..6ea62a76 100644 --- a/README.md +++ b/README.md @@ -10,11 +10,14 @@ More info at https://phoboslab.org/log/2021/11/qoi-fast-lossless-image-compressi ⚠️ Please note that this library is not yet ready to deal with untrusted input. ⚠️ 2021.11.27 – the specification for QOI has changed to accomodate some -concerns with the format. These specification changes are **not yet reflected in -the code here**. If you are working on a QOI implementation, please refer to +concerns with the format. If you are working on a QOI implementation, please +refer to [#37 The QOI File Format Specification](https://github.com/phoboslab/qoi/issues/37) for the details. +These specification changes are ~~not yet reflected in the code here~~ +reflected in qoi.h now. + ## Why? diff --git a/qoi.h b/qoi.h index 6dd232d2..23e54732 100644 --- a/qoi.h +++ b/qoi.h @@ -45,12 +45,21 @@ than stbi_image or libpng. #define QOI_IMPLEMENTATION #include "qoi.h" -// Load and decode a QOI image from the file system into a 32bbp RGBA buffer -int width, height; -void *rgba_pixels = qoi_read("image.qoi", &width, &height, 4); +// Encode and store an RGBA buffer to the file system. The qoi_desc describes +// the input pixel data. +qoi_write("image_new.qoi", rgba_pixels, &(qoi_desc){ + .width = 1920, + .height = 1080, + .channels = 4, + .colorspace = QOI_SRGB +}); + +// Load and decode a QOI image from the file system into a 32bbp RGBA buffer. +// The qoi_desc struct will be filled with the width, height, number of channels +// and colorspace read from the file header. +qoi_desc desc; +void *rgba_pixels = qoi_read("image.qoi", &desc, 4); -// Encode and store an RGBA buffer to the file system -qoi_write("image_new.qoi", rgba_pixels, width, height, 4); -- Documentation @@ -166,48 +175,75 @@ to check for an overrun once per decode loop iteration. extern "C" { #endif +// A pointer to qoi_desc struct has to be supplied to all of qoi's functions. It +// describes either the input format (for qoi_write, qoi_encode), or is filled +// with the description read from the file header (for qoi_read, qoi_decode). + +// The colorspace in this qoi_desc is a bitmap with 0000rgba where a 0-bit +// indicates sRGB and a 1-bit indicates linear colorspace for each channel. You +// may use one of the predefined constants: QOI_SRGB, QOI_SRGB_LINEAR_ALPHA or +// QOI_LINEAR. The colorspace is purely informative. It will be saved to the +// file header, but does not affect en-/decoding in any way. + +#define QOI_SRGB 0x00 +#define QOI_SRGB_LINEAR_ALPHA 0x01 +#define QOI_LINEAR 0x0f + +typedef struct { + unsigned int width; + unsigned int height; + unsigned char channels; + unsigned char colorspace; +} qoi_desc; + #ifndef QOI_NO_STDIO -// Encode raw RGB or RGBA pixels into a QOI image write it to the file system. -// w and h denote the the width and height of the pixel data. channels must be -// either 3 for RGB data or 4 for RGBA. +// Encode raw RGB or RGBA pixels into a QOI image and write it to the file +// system. The qoi_desc struct must be filled with the image width, height, +// number of channels (3 = RGB, 4 = RGBA) and the colorspace. + // The function returns 0 on failure (invalid parameters, or fopen or malloc // failed) or the number of bytes written on success. -int qoi_write(const char *filename, const void *data, int w, int h, int channels); +int qoi_write(const char *filename, const void *data, const qoi_desc *desc); -// Read and decode a QOI image from the file system into either raw RGB -// (channels=3) or RGBA (channels=4) pixel data. +// Read and decode a QOI image from the file system. If channels is 0, the +// number of channels from the file header is used. If channels is 3 or 4 the +// output format will be forced into this number of channels. + // The function either returns NULL on failure (invalid data, or malloc or fopen -// failed) or a pointer to the decoded pixels. On success out_w and out_h will -// be set to the width and height of the decoded image. +// failed) or a pointer to the decoded pixels. On success, the qoi_desc struct +// will be filled with the description from the file header. + // The returned pixel data should be free()d after use. -void *qoi_read(const char *filename, int *out_w, int *out_h, int channels); +void *qoi_read(const char *filename, qoi_desc *desc, int channels); #endif // QOI_NO_STDIO -// Encode raw RGB or RGBA pixels into a QOI image in memory. w and h denote the -// width and height of the pixel data. channels must be either 3 for RGB data -// or 4 for RGBA. +// Encode raw RGB or RGBA pixels into a QOI image in memory. + // The function either returns NULL on failure (invalid parameters or malloc -// failed) or a pointer to the encoded data on success. On success the out_len +// failed) or a pointer to the encoded data on success. On success the out_len // is set to the size in bytes of the encoded data. + // The returned qoi data should be free()d after user. -void *qoi_encode(const void *data, int w, int h, int channels, int *out_len); +void *qoi_encode(const void *data, const qoi_desc *desc, int *out_len); -// Decode a QOI image from memory into either raw RGB (channels=3) or RGBA -// (channels=4) pixel data. +// Decode a QOI image from memory. + // The function either returns NULL on failure (invalid parameters or malloc -// failed) or a pointer to the decoded pixels. On success out_w and out_h will -// be set to the width and height of the decoded image. +// failed) or a pointer to the decoded pixels. On success, the qoi_desc struct +// is filled with the description from the file header. + // The returned pixel data should be free()d after use. -void *qoi_decode(const void *data, int size, int *out_w, int *out_h, int channels); +void *qoi_decode(const void *data, int size, qoi_desc *desc, int channels); + #ifdef __cplusplus } @@ -265,17 +301,20 @@ unsigned int qoi_read_32(const unsigned char *bytes, int *p) { return (a << 24) | (b << 16) | (c << 8) | d; } -void *qoi_encode(const void *data, int w, int h, int channels, int *out_len) { +void *qoi_encode(const void *data, const qoi_desc *desc, int *out_len) { if ( - data == NULL || out_len == NULL || - w <= 0 || w >= (1 << 16) || - h <= 0 || h >= (1 << 16) || - channels < 3 || channels > 4 + data == NULL || out_len == NULL || desc == NULL || + desc->width == 0 || desc->height == 0 || + desc->channels < 3 || desc->channels > 4 || + (desc->colorspace & 0xf0) != 0 ) { return NULL; } - int max_size = w * h * (channels + 1) + QOI_HEADER_SIZE + QOI_PADDING; + int max_size = + desc->width * desc->height * (desc->channels + 1) + + QOI_HEADER_SIZE + QOI_PADDING; + int p = 0; unsigned char *bytes = QOI_MALLOC(max_size); if (!bytes) { @@ -283,10 +322,11 @@ void *qoi_encode(const void *data, int w, int h, int channels, int *out_len) { } qoi_write_32(bytes, &p, QOI_MAGIC); - qoi_write_32(bytes, &p, w); - qoi_write_32(bytes, &p, h); - bytes[p++] = channels; - bytes[p++] = 0; // TODO: accept a colorspace as a parameter to this function + qoi_write_32(bytes, &p, desc->width); + qoi_write_32(bytes, &p, desc->height); + bytes[p++] = desc->channels; + bytes[p++] = desc->colorspace; + const unsigned char *pixels = (const unsigned char *)data; @@ -295,11 +335,11 @@ void *qoi_encode(const void *data, int w, int h, int channels, int *out_len) { int run = 0; qoi_rgba_t px_prev = {.rgba = {.r = 0, .g = 0, .b = 0, .a = 255}}; qoi_rgba_t px = px_prev; - - int px_len = w * h * channels; - int px_end = px_len - channels; - for (int px_pos = 0; px_pos < px_len; px_pos += channels) { - if (channels == 4) { + + int px_len = desc->width * desc->height * desc->channels; + int px_end = px_len - desc->channels; + for (int px_pos = 0; px_pos < px_len; px_pos += desc->channels) { + if (desc->channels == 4) { px = *(qoi_rgba_t *)(pixels + px_pos); } else { @@ -382,8 +422,12 @@ void *qoi_encode(const void *data, int w, int h, int channels, int *out_len) { return bytes; } -void *qoi_decode(const void *data, int size, int *out_w, int *out_h, int channels) { - if (channels < 3 || channels > 4 || size < QOI_HEADER_SIZE + QOI_PADDING) { +void *qoi_decode(const void *data, int size, qoi_desc *desc, int channels) { + if ( + data == NULL || desc == NULL || + (channels != 0 && channels != 3 && channels != 4) || + size < QOI_HEADER_SIZE + QOI_PADDING + ) { return NULL; } @@ -391,20 +435,24 @@ void *qoi_decode(const void *data, int size, int *out_w, int *out_h, int channel int p = 0; unsigned int header_magic = qoi_read_32(bytes, &p); - unsigned int header_w = qoi_read_32(bytes, &p); - unsigned int header_h = qoi_read_32(bytes, &p); - unsigned int header_channels = bytes[p++]; - unsigned int header_colorspace = bytes[p++]; + desc->width = qoi_read_32(bytes, &p); + desc->height = qoi_read_32(bytes, &p); + desc->channels = bytes[p++]; + desc->colorspace = bytes[p++]; if ( - header_w == 0 || header_h == 0 || - header_channels < 3 || header_channels > 4 || + desc->width == 0 || desc->height == 0 || + desc->channels < 3 || desc->channels > 4 || header_magic != QOI_MAGIC ) { return NULL; } - int px_len = header_w * header_h * channels; + if (channels == 0) { + channels = desc->channels; + } + + int px_len = desc->width * desc->height * channels; unsigned char *pixels = QOI_MALLOC(px_len); if (!pixels) { return NULL; @@ -471,17 +519,15 @@ void *qoi_decode(const void *data, int size, int *out_w, int *out_h, int channel } } - *out_w = header_w; - *out_h = header_h; return pixels; } #ifndef QOI_NO_STDIO #include -int qoi_write(const char *filename, const void *data, int w, int h, int channels) { +int qoi_write(const char *filename, const void *data, const qoi_desc *desc) { int size; - void *encoded = qoi_encode(data, w, h, channels, &size); + void *encoded = qoi_encode(data, desc, &size); if (!encoded) { return 0; } @@ -498,7 +544,7 @@ int qoi_write(const char *filename, const void *data, int w, int h, int channels return size; } -void *qoi_read(const char *filename, int *out_w, int *out_h, int channels) { +void *qoi_read(const char *filename, qoi_desc *desc, int channels) { FILE *f = fopen(filename, "rb"); if (!f) { return NULL; @@ -516,7 +562,7 @@ void *qoi_read(const char *filename, int *out_w, int *out_h, int channels) { int bytes_read = fread(data, 1, size, f); fclose(f); - void *pixels = qoi_decode(data, bytes_read, out_w, out_h, channels); + void *pixels = qoi_decode(data, bytes_read, desc, channels); QOI_FREE(data); return pixels; } diff --git a/qoibench.c b/qoibench.c index cb4d1e87..f48e2361 100644 --- a/qoibench.c +++ b/qoibench.c @@ -350,7 +350,12 @@ benchmark_result_t benchmark_image(const char *path, int runs) { // Load the encoded PNG, encoded QOI and raw pixels into memory void *pixels = (void *)stbi_load(path, &w, &h, NULL, 4); void *encoded_png = fload(path, &encoded_png_size); - void *encoded_qoi = qoi_encode(pixels, w, h, 4, &encoded_qoi_size); + void *encoded_qoi = qoi_encode(pixels, &(qoi_desc){ + .width = w, + .height = h, + .channels = 4, + .colorspace = QOI_SRGB + }, &encoded_qoi_size); if (!pixels || !encoded_qoi || !encoded_png) { ERROR("Error decoding %s\n", path); @@ -377,8 +382,8 @@ benchmark_result_t benchmark_image(const char *path, int runs) { }); BENCHMARK_FN(runs, res.qoi.decode_time, { - int dec_w, dec_h; - void *dec_p = qoi_decode(encoded_qoi, encoded_qoi_size, &dec_w, &dec_h, 4); + qoi_desc desc; + void *dec_p = qoi_decode(encoded_qoi, encoded_qoi_size, &desc, 4); free(dec_p); }); @@ -400,7 +405,12 @@ benchmark_result_t benchmark_image(const char *path, int runs) { BENCHMARK_FN(runs, res.qoi.encode_time, { int enc_size; - void *enc_p = qoi_encode(pixels, w, h, 4, &enc_size); + void *enc_p = qoi_encode(pixels, &(qoi_desc){ + .width = w, + .height = h, + .channels = 4, + .colorspace = QOI_SRGB + }, &enc_size); res.qoi.size = enc_size; free(enc_p); }); diff --git a/qoiconv.c b/qoiconv.c index a66f481a..6e7ad36c 100644 --- a/qoiconv.c +++ b/qoiconv.c @@ -48,20 +48,24 @@ SOFTWARE. int main(int argc, char **argv) { if (argc < 3) { - printf("Usage: qoiconv infile outfile\n"); + printf("Usage: qoiconv \n"); printf("Examples:\n"); - printf(" qoiconv image.png image.qoi\n"); - printf(" qoiconv image.qoi image.png\n"); + printf(" qoiconv input.png output.qoi\n"); + printf(" qoiconv input.qoi output.png\n"); exit(1); } void *pixels = NULL; - int w, h; + int w, h, channels; if (STR_ENDS_WITH(argv[1], ".png")) { - pixels = (void *)stbi_load(argv[1], &w, &h, NULL, 4); + pixels = (void *)stbi_load(argv[1], &w, &h, &channels, 0); } else if (STR_ENDS_WITH(argv[1], ".qoi")) { - pixels = qoi_read(argv[1], &w, &h, 4); + qoi_desc desc; + pixels = qoi_read(argv[1], &desc, 0); + channels = desc.channels; + w = desc.width; + h = desc.height; } if (pixels == NULL) { @@ -71,10 +75,15 @@ int main(int argc, char **argv) { int encoded = 0; if (STR_ENDS_WITH(argv[2], ".png")) { - encoded = stbi_write_png(argv[2], w, h, 4, pixels, 0); + encoded = stbi_write_png(argv[2], w, h, channels, pixels, 0); } else if (STR_ENDS_WITH(argv[2], ".qoi")) { - encoded = qoi_write(argv[2], pixels, w, h, 4); + encoded = qoi_write(argv[2], pixels, &(qoi_desc){ + .width = w, + .height = h, + .channels = channels, + .colorspace = QOI_SRGB + }); } if (!encoded) { @@ -82,5 +91,6 @@ int main(int argc, char **argv) { exit(1); } + free(pixels); return 0; }