libwebp/imageio/image_enc.c
Pascal Massimino 827a307fec BMP enc: fix the transparency case
When transparency is present, it's not enough to just write 32bpp samples.
One need to use the full BITMAPV3INFOHEADER syntax and specify the
masks for BGRA.

 see https://en.wikipedia.org/wiki/BMP_file_format#Pixel_storage

Also remove the height-flip trick and write samples bottom-to-top instead.

Change-Id: If5d92c11453b96764b5bfbf19e9678e632bc911f
(cherry picked from commit 480cd51de6)
2022-01-19 18:07:17 +00:00

616 lines
21 KiB
C

// Copyright 2016 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
// -----------------------------------------------------------------------------
//
// Save image
#include "./image_enc.h"
#include <assert.h>
#include <string.h>
#ifdef WEBP_HAVE_PNG
#include <png.h>
#include <setjmp.h> // note: this must be included *after* png.h
#endif
#ifdef HAVE_WINCODEC_H
#ifdef __MINGW32__
#define INITGUID // Without this GUIDs are declared extern and fail to link
#endif
#define CINTERFACE
#define COBJMACROS
#define _WIN32_IE 0x500 // Workaround bug in shlwapi.h when compiling C++
// code with COBJMACROS.
#include <ole2.h> // CreateStreamOnHGlobal()
#include <shlwapi.h>
#include <tchar.h>
#include <windows.h>
#include <wincodec.h>
#endif
#include "./imageio_util.h"
#include "../examples/unicode.h"
//------------------------------------------------------------------------------
// PNG
#ifdef HAVE_WINCODEC_H
#define IFS(fn) \
do { \
if (SUCCEEDED(hr)) { \
hr = (fn); \
if (FAILED(hr)) fprintf(stderr, #fn " failed %08lx\n", hr); \
} \
} while (0)
#ifdef __cplusplus
#define MAKE_REFGUID(x) (x)
#else
#define MAKE_REFGUID(x) &(x)
#endif
static HRESULT CreateOutputStream(const char* out_file_name,
int write_to_mem, IStream** stream) {
HRESULT hr = S_OK;
if (write_to_mem) {
// Output to a memory buffer. This is freed when 'stream' is released.
IFS(CreateStreamOnHGlobal(NULL, TRUE, stream));
} else {
IFS(SHCreateStreamOnFile((const LPTSTR)out_file_name,
STGM_WRITE | STGM_CREATE, stream));
}
if (FAILED(hr)) {
_ftprintf(stderr, _T("Error opening output file %s (%08lx)\n"),
(const LPTSTR)out_file_name, hr);
}
return hr;
}
static HRESULT WriteUsingWIC(const char* out_file_name, int use_stdout,
REFGUID container_guid,
uint8_t* rgb, int stride,
uint32_t width, uint32_t height, int has_alpha) {
HRESULT hr = S_OK;
IWICImagingFactory* factory = NULL;
IWICBitmapFrameEncode* frame = NULL;
IWICBitmapEncoder* encoder = NULL;
IStream* stream = NULL;
WICPixelFormatGUID pixel_format = has_alpha ? GUID_WICPixelFormat32bppBGRA
: GUID_WICPixelFormat24bppBGR;
if (out_file_name == NULL || rgb == NULL) return E_INVALIDARG;
IFS(CoInitialize(NULL));
IFS(CoCreateInstance(MAKE_REFGUID(CLSID_WICImagingFactory), NULL,
CLSCTX_INPROC_SERVER,
MAKE_REFGUID(IID_IWICImagingFactory),
(LPVOID*)&factory));
if (hr == REGDB_E_CLASSNOTREG) {
fprintf(stderr,
"Couldn't access Windows Imaging Component (are you running "
"Windows XP SP3 or newer?). PNG support not available. "
"Use -ppm or -pgm for available PPM and PGM formats.\n");
}
IFS(CreateOutputStream(out_file_name, use_stdout, &stream));
IFS(IWICImagingFactory_CreateEncoder(factory, container_guid, NULL,
&encoder));
IFS(IWICBitmapEncoder_Initialize(encoder, stream,
WICBitmapEncoderNoCache));
IFS(IWICBitmapEncoder_CreateNewFrame(encoder, &frame, NULL));
IFS(IWICBitmapFrameEncode_Initialize(frame, NULL));
IFS(IWICBitmapFrameEncode_SetSize(frame, width, height));
IFS(IWICBitmapFrameEncode_SetPixelFormat(frame, &pixel_format));
IFS(IWICBitmapFrameEncode_WritePixels(frame, height, stride,
height * stride, rgb));
IFS(IWICBitmapFrameEncode_Commit(frame));
IFS(IWICBitmapEncoder_Commit(encoder));
if (SUCCEEDED(hr) && use_stdout) {
HGLOBAL image;
IFS(GetHGlobalFromStream(stream, &image));
if (SUCCEEDED(hr)) {
HANDLE std_output = GetStdHandle(STD_OUTPUT_HANDLE);
DWORD mode;
const BOOL update_mode = GetConsoleMode(std_output, &mode);
const void* const image_mem = GlobalLock(image);
DWORD bytes_written = 0;
// Clear output processing if necessary, then output the image.
if (update_mode) SetConsoleMode(std_output, 0);
if (!WriteFile(std_output, image_mem, (DWORD)GlobalSize(image),
&bytes_written, NULL) ||
bytes_written != GlobalSize(image)) {
hr = E_FAIL;
}
if (update_mode) SetConsoleMode(std_output, mode);
GlobalUnlock(image);
}
}
if (frame != NULL) IUnknown_Release(frame);
if (encoder != NULL) IUnknown_Release(encoder);
if (factory != NULL) IUnknown_Release(factory);
if (stream != NULL) IUnknown_Release(stream);
return hr;
}
int WebPWritePNG(const char* out_file_name, int use_stdout,
const WebPDecBuffer* const buffer) {
const uint32_t width = buffer->width;
const uint32_t height = buffer->height;
uint8_t* const rgb = buffer->u.RGBA.rgba;
const int stride = buffer->u.RGBA.stride;
const int has_alpha = WebPIsAlphaMode(buffer->colorspace);
return SUCCEEDED(WriteUsingWIC(out_file_name, use_stdout,
MAKE_REFGUID(GUID_ContainerFormatPng),
rgb, stride, width, height, has_alpha));
}
#elif defined(WEBP_HAVE_PNG) // !HAVE_WINCODEC_H
static void PNGAPI PNGErrorFunction(png_structp png, png_const_charp unused) {
(void)unused; // remove variable-unused warning
longjmp(png_jmpbuf(png), 1);
}
int WebPWritePNG(FILE* out_file, const WebPDecBuffer* const buffer) {
volatile png_structp png;
volatile png_infop info;
if (out_file == NULL || buffer == NULL) return 0;
png = png_create_write_struct(PNG_LIBPNG_VER_STRING,
NULL, PNGErrorFunction, NULL);
if (png == NULL) {
return 0;
}
info = png_create_info_struct(png);
if (info == NULL) {
png_destroy_write_struct((png_structpp)&png, NULL);
return 0;
}
if (setjmp(png_jmpbuf(png))) {
png_destroy_write_struct((png_structpp)&png, (png_infopp)&info);
return 0;
}
png_init_io(png, out_file);
{
const uint32_t width = buffer->width;
const uint32_t height = buffer->height;
png_bytep row = buffer->u.RGBA.rgba;
const int stride = buffer->u.RGBA.stride;
const int has_alpha = WebPIsAlphaMode(buffer->colorspace);
uint32_t y;
png_set_IHDR(png, info, width, height, 8,
has_alpha ? PNG_COLOR_TYPE_RGBA : PNG_COLOR_TYPE_RGB,
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
PNG_FILTER_TYPE_DEFAULT);
png_write_info(png, info);
for (y = 0; y < height; ++y) {
png_write_rows(png, &row, 1);
row += stride;
}
}
png_write_end(png, info);
png_destroy_write_struct((png_structpp)&png, (png_infopp)&info);
return 1;
}
#else // !HAVE_WINCODEC_H && !WEBP_HAVE_PNG
int WebPWritePNG(FILE* fout, const WebPDecBuffer* const buffer) {
if (fout == NULL || buffer == NULL) return 0;
fprintf(stderr, "PNG support not compiled. Please install the libpng "
"development package before building.\n");
fprintf(stderr, "You can run with -ppm flag to decode in PPM format.\n");
return 0;
}
#endif
//------------------------------------------------------------------------------
// PPM / PAM
static int WritePPMPAM(FILE* fout, const WebPDecBuffer* const buffer,
int alpha) {
if (fout == NULL || buffer == NULL) {
return 0;
} else {
const uint32_t width = buffer->width;
const uint32_t height = buffer->height;
const uint8_t* row = buffer->u.RGBA.rgba;
const int stride = buffer->u.RGBA.stride;
const size_t bytes_per_px = alpha ? 4 : 3;
uint32_t y;
if (row == NULL) return 0;
if (alpha) {
fprintf(fout, "P7\nWIDTH %u\nHEIGHT %u\nDEPTH 4\nMAXVAL 255\n"
"TUPLTYPE RGB_ALPHA\nENDHDR\n", width, height);
} else {
fprintf(fout, "P6\n%u %u\n255\n", width, height);
}
for (y = 0; y < height; ++y) {
if (fwrite(row, width, bytes_per_px, fout) != bytes_per_px) {
return 0;
}
row += stride;
}
}
return 1;
}
int WebPWritePPM(FILE* fout, const WebPDecBuffer* const buffer) {
return WritePPMPAM(fout, buffer, 0);
}
int WebPWritePAM(FILE* fout, const WebPDecBuffer* const buffer) {
return WritePPMPAM(fout, buffer, 1);
}
//------------------------------------------------------------------------------
// Raw PGM
// Save 16b mode (RGBA4444, RGB565, ...) for debugging purpose.
int WebPWrite16bAsPGM(FILE* fout, const WebPDecBuffer* const buffer) {
const uint32_t width = buffer->width;
const uint32_t height = buffer->height;
const uint8_t* rgba = buffer->u.RGBA.rgba;
const int stride = buffer->u.RGBA.stride;
const uint32_t bytes_per_px = 2;
uint32_t y;
if (fout == NULL || buffer == NULL || rgba == NULL) return 0;
fprintf(fout, "P5\n%u %u\n255\n", width * bytes_per_px, height);
for (y = 0; y < height; ++y) {
if (fwrite(rgba, width, bytes_per_px, fout) != bytes_per_px) {
return 0;
}
rgba += stride;
}
return 1;
}
//------------------------------------------------------------------------------
// BMP (see https://en.wikipedia.org/wiki/BMP_file_format#Pixel_storage)
static void PutLE16(uint8_t* const dst, uint32_t value) {
dst[0] = (value >> 0) & 0xff;
dst[1] = (value >> 8) & 0xff;
}
static void PutLE32(uint8_t* const dst, uint32_t value) {
PutLE16(dst + 0, (value >> 0) & 0xffff);
PutLE16(dst + 2, (value >> 16) & 0xffff);
}
#define BMP_HEADER_SIZE 54
#define BMP_HEADER_ALPHA_EXTRA_SIZE 16 // for alpha info
int WebPWriteBMP(FILE* fout, const WebPDecBuffer* const buffer) {
const int has_alpha = WebPIsAlphaMode(buffer->colorspace);
const int header_size =
BMP_HEADER_SIZE + (has_alpha ? BMP_HEADER_ALPHA_EXTRA_SIZE : 0);
const uint32_t width = buffer->width;
const uint32_t height = buffer->height;
const uint8_t* rgba = buffer->u.RGBA.rgba;
const int stride = buffer->u.RGBA.stride;
const uint32_t bytes_per_px = has_alpha ? 4 : 3;
uint32_t y;
const uint32_t line_size = bytes_per_px * width;
const uint32_t bmp_stride = (line_size + 3) & ~3; // pad to 4
const uint32_t image_size = bmp_stride * height;
const uint32_t total_size = image_size + header_size;
uint8_t bmp_header[BMP_HEADER_SIZE + BMP_HEADER_ALPHA_EXTRA_SIZE] = { 0 };
if (fout == NULL || buffer == NULL || rgba == NULL) return 0;
// bitmap file header
PutLE16(bmp_header + 0, 0x4d42); // signature 'BM'
PutLE32(bmp_header + 2, total_size); // size including header
PutLE32(bmp_header + 6, 0); // reserved
PutLE32(bmp_header + 10, header_size); // offset to pixel array
// bitmap info header
PutLE32(bmp_header + 14, header_size - 14); // DIB header size
PutLE32(bmp_header + 18, width); // dimensions
PutLE32(bmp_header + 22, height); // no vertical flip
PutLE16(bmp_header + 26, 1); // number of planes
PutLE16(bmp_header + 28, bytes_per_px * 8); // bits per pixel
PutLE32(bmp_header + 30, has_alpha ? 3 : 0); // BI_BITFIELDS or BI_RGB
PutLE32(bmp_header + 34, image_size);
PutLE32(bmp_header + 38, 2400); // x pixels/meter
PutLE32(bmp_header + 42, 2400); // y pixels/meter
PutLE32(bmp_header + 46, 0); // number of palette colors
PutLE32(bmp_header + 50, 0); // important color count
if (has_alpha) { // BITMAPV3INFOHEADER complement
PutLE32(bmp_header + 54, 0x00ff0000); // red mask
PutLE32(bmp_header + 58, 0x0000ff00); // green mask
PutLE32(bmp_header + 62, 0x000000ff); // blue mask
PutLE32(bmp_header + 66, 0xff000000); // alpha mask
}
// TODO(skal): color profile
// write header
if (fwrite(bmp_header, header_size, 1, fout) != 1) {
return 0;
}
// write pixel array, bottom to top
for (y = 0; y < height; ++y) {
const uint8_t* const src = &rgba[(uint64_t)(height - 1 - y) * stride];
if (fwrite(src, line_size, 1, fout) != 1) {
return 0;
}
// write padding zeroes
if (bmp_stride != line_size) {
const uint8_t zeroes[3] = { 0 };
if (fwrite(zeroes, bmp_stride - line_size, 1, fout) != 1) {
return 0;
}
}
}
return 1;
}
#undef BMP_HEADER_SIZE
#undef BMP_HEADER_ALPHA_EXTRA_SIZE
//------------------------------------------------------------------------------
// TIFF
#define NUM_IFD_ENTRIES 15
#define EXTRA_DATA_SIZE 16
// 10b for signature/header + n * 12b entries + 4b for IFD terminator:
#define EXTRA_DATA_OFFSET (10 + 12 * NUM_IFD_ENTRIES + 4)
#define TIFF_HEADER_SIZE (EXTRA_DATA_OFFSET + EXTRA_DATA_SIZE)
int WebPWriteTIFF(FILE* fout, const WebPDecBuffer* const buffer) {
const int has_alpha = WebPIsAlphaMode(buffer->colorspace);
const uint32_t width = buffer->width;
const uint32_t height = buffer->height;
const uint8_t* rgba = buffer->u.RGBA.rgba;
const int stride = buffer->u.RGBA.stride;
const uint8_t bytes_per_px = has_alpha ? 4 : 3;
const uint8_t assoc_alpha =
WebPIsPremultipliedMode(buffer->colorspace) ? 1 : 2;
// For non-alpha case, we omit tag 0x152 (ExtraSamples).
const uint8_t num_ifd_entries = has_alpha ? NUM_IFD_ENTRIES
: NUM_IFD_ENTRIES - 1;
uint8_t tiff_header[TIFF_HEADER_SIZE] = {
0x49, 0x49, 0x2a, 0x00, // little endian signature
8, 0, 0, 0, // offset to the unique IFD that follows
// IFD (offset = 8). Entries must be written in increasing tag order.
num_ifd_entries, 0, // Number of entries in the IFD (12 bytes each).
0x00, 0x01, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, // 10: Width (TBD)
0x01, 0x01, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, // 22: Height (TBD)
0x02, 0x01, 3, 0, bytes_per_px, 0, 0, 0, // 34: BitsPerSample: 8888
EXTRA_DATA_OFFSET + 0, 0, 0, 0,
0x03, 0x01, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, // 46: Compression: none
0x06, 0x01, 3, 0, 1, 0, 0, 0, 2, 0, 0, 0, // 58: Photometric: RGB
0x11, 0x01, 4, 0, 1, 0, 0, 0, // 70: Strips offset:
TIFF_HEADER_SIZE, 0, 0, 0, // data follows header
0x12, 0x01, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, // 82: Orientation: topleft
0x15, 0x01, 3, 0, 1, 0, 0, 0, // 94: SamplesPerPixels
bytes_per_px, 0, 0, 0,
0x16, 0x01, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, // 106: Rows per strip (TBD)
0x17, 0x01, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0, // 118: StripByteCount (TBD)
0x1a, 0x01, 5, 0, 1, 0, 0, 0, // 130: X-resolution
EXTRA_DATA_OFFSET + 8, 0, 0, 0,
0x1b, 0x01, 5, 0, 1, 0, 0, 0, // 142: Y-resolution
EXTRA_DATA_OFFSET + 8, 0, 0, 0,
0x1c, 0x01, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, // 154: PlanarConfiguration
0x28, 0x01, 3, 0, 1, 0, 0, 0, 2, 0, 0, 0, // 166: ResolutionUnit (inch)
0x52, 0x01, 3, 0, 1, 0, 0, 0,
assoc_alpha, 0, 0, 0, // 178: ExtraSamples: rgbA/RGBA
0, 0, 0, 0, // 190: IFD terminator
// EXTRA_DATA_OFFSET:
8, 0, 8, 0, 8, 0, 8, 0, // BitsPerSample
72, 0, 0, 0, 1, 0, 0, 0 // 72 pixels/inch, for X/Y-resolution
};
uint32_t y;
if (fout == NULL || buffer == NULL || rgba == NULL) return 0;
// Fill placeholders in IFD:
PutLE32(tiff_header + 10 + 8, width);
PutLE32(tiff_header + 22 + 8, height);
PutLE32(tiff_header + 106 + 8, height);
PutLE32(tiff_header + 118 + 8, width * bytes_per_px * height);
if (!has_alpha) PutLE32(tiff_header + 178, 0); // IFD terminator
// write header
if (fwrite(tiff_header, sizeof(tiff_header), 1, fout) != 1) {
return 0;
}
// write pixel values
for (y = 0; y < height; ++y) {
if (fwrite(rgba, bytes_per_px, width, fout) != width) {
return 0;
}
rgba += stride;
}
return 1;
}
#undef TIFF_HEADER_SIZE
#undef EXTRA_DATA_OFFSET
#undef EXTRA_DATA_SIZE
#undef NUM_IFD_ENTRIES
//------------------------------------------------------------------------------
// Raw Alpha
int WebPWriteAlphaPlane(FILE* fout, const WebPDecBuffer* const buffer) {
if (fout == NULL || buffer == NULL) {
return 0;
} else {
const uint32_t width = buffer->width;
const uint32_t height = buffer->height;
const uint8_t* a = buffer->u.YUVA.a;
const int a_stride = buffer->u.YUVA.a_stride;
uint32_t y;
if (a == NULL) return 0;
fprintf(fout, "P5\n%u %u\n255\n", width, height);
for (y = 0; y < height; ++y) {
if (fwrite(a, width, 1, fout) != 1) return 0;
a += a_stride;
}
return 1;
}
}
//------------------------------------------------------------------------------
// PGM with IMC4 layout
int WebPWritePGM(FILE* fout, const WebPDecBuffer* const buffer) {
if (fout == NULL || buffer == NULL) {
return 0;
} else {
const int width = buffer->width;
const int height = buffer->height;
const WebPYUVABuffer* const yuv = &buffer->u.YUVA;
const uint8_t* src_y = yuv->y;
const uint8_t* src_u = yuv->u;
const uint8_t* src_v = yuv->v;
const uint8_t* src_a = yuv->a;
const int uv_width = (width + 1) / 2;
const int uv_height = (height + 1) / 2;
const int a_height = (src_a != NULL) ? height : 0;
int ok = 1;
int y;
if (src_y == NULL || src_u == NULL || src_v == NULL) return 0;
fprintf(fout, "P5\n%d %d\n255\n",
(width + 1) & ~1, height + uv_height + a_height);
for (y = 0; ok && y < height; ++y) {
ok &= (fwrite(src_y, width, 1, fout) == 1);
if (width & 1) fputc(0, fout); // padding byte
src_y += yuv->y_stride;
}
for (y = 0; ok && y < uv_height; ++y) {
ok &= (fwrite(src_u, uv_width, 1, fout) == 1);
ok &= (fwrite(src_v, uv_width, 1, fout) == 1);
src_u += yuv->u_stride;
src_v += yuv->v_stride;
}
for (y = 0; ok && y < a_height; ++y) {
ok &= (fwrite(src_a, width, 1, fout) == 1);
if (width & 1) fputc(0, fout); // padding byte
src_a += yuv->a_stride;
}
return ok;
}
}
//------------------------------------------------------------------------------
// Raw YUV(A) planes
int WebPWriteYUV(FILE* fout, const WebPDecBuffer* const buffer) {
if (fout == NULL || buffer == NULL) {
return 0;
} else {
const int width = buffer->width;
const int height = buffer->height;
const WebPYUVABuffer* const yuv = &buffer->u.YUVA;
const uint8_t* src_y = yuv->y;
const uint8_t* src_u = yuv->u;
const uint8_t* src_v = yuv->v;
const uint8_t* src_a = yuv->a;
const int uv_width = (width + 1) / 2;
const int uv_height = (height + 1) / 2;
const int a_height = (src_a != NULL) ? height : 0;
int ok = 1;
int y;
if (src_y == NULL || src_u == NULL || src_v == NULL) return 0;
for (y = 0; ok && y < height; ++y) {
ok &= (fwrite(src_y, width, 1, fout) == 1);
src_y += yuv->y_stride;
}
for (y = 0; ok && y < uv_height; ++y) {
ok &= (fwrite(src_u, uv_width, 1, fout) == 1);
src_u += yuv->u_stride;
}
for (y = 0; ok && y < uv_height; ++y) {
ok &= (fwrite(src_v, uv_width, 1, fout) == 1);
src_v += yuv->v_stride;
}
for (y = 0; ok && y < a_height; ++y) {
ok &= (fwrite(src_a, width, 1, fout) == 1);
src_a += yuv->a_stride;
}
return ok;
}
}
//------------------------------------------------------------------------------
// Generic top-level call
int WebPSaveImage(const WebPDecBuffer* const buffer,
WebPOutputFileFormat format,
const char* const out_file_name) {
FILE* fout = NULL;
int needs_open_file = 1;
const int use_stdout =
(out_file_name != NULL) && !WSTRCMP(out_file_name, "-");
int ok = 1;
if (buffer == NULL || out_file_name == NULL) return 0;
#ifdef HAVE_WINCODEC_H
needs_open_file = (format != PNG);
#endif
if (needs_open_file) {
fout = use_stdout ? ImgIoUtilSetBinaryMode(stdout)
: WFOPEN(out_file_name, "wb");
if (fout == NULL) {
WFPRINTF(stderr, "Error opening output file %s\n",
(const W_CHAR*)out_file_name);
return 0;
}
}
if (format == PNG ||
format == RGBA || format == BGRA || format == ARGB ||
format == rgbA || format == bgrA || format == Argb) {
#ifdef HAVE_WINCODEC_H
ok &= WebPWritePNG(out_file_name, use_stdout, buffer);
#else
ok &= WebPWritePNG(fout, buffer);
#endif
} else if (format == PAM) {
ok &= WebPWritePAM(fout, buffer);
} else if (format == PPM || format == RGB || format == BGR) {
ok &= WebPWritePPM(fout, buffer);
} else if (format == RGBA_4444 || format == RGB_565 || format == rgbA_4444) {
ok &= WebPWrite16bAsPGM(fout, buffer);
} else if (format == BMP) {
ok &= WebPWriteBMP(fout, buffer);
} else if (format == TIFF) {
ok &= WebPWriteTIFF(fout, buffer);
} else if (format == RAW_YUV) {
ok &= WebPWriteYUV(fout, buffer);
} else if (format == PGM || format == YUV || format == YUVA) {
ok &= WebPWritePGM(fout, buffer);
} else if (format == ALPHA_PLANE_ONLY) {
ok &= WebPWriteAlphaPlane(fout, buffer);
}
if (fout != NULL && fout != stdout) {
fclose(fout);
}
return ok;
}