1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/image/encoders/png/nsPNGEncoder.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,726 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "nsCRT.h"
1.10 +#include "nsPNGEncoder.h"
1.11 +#include "prprf.h"
1.12 +#include "nsString.h"
1.13 +#include "nsStreamUtils.h"
1.14 +
1.15 +using namespace mozilla;
1.16 +
1.17 +NS_IMPL_ISUPPORTS(nsPNGEncoder, imgIEncoder, nsIInputStream, nsIAsyncInputStream)
1.18 +
1.19 +nsPNGEncoder::nsPNGEncoder() : mPNG(nullptr), mPNGinfo(nullptr),
1.20 + mIsAnimation(false),
1.21 + mFinished(false),
1.22 + mImageBuffer(nullptr), mImageBufferSize(0),
1.23 + mImageBufferUsed(0), mImageBufferReadPoint(0),
1.24 + mCallback(nullptr),
1.25 + mCallbackTarget(nullptr), mNotifyThreshold(0),
1.26 + mReentrantMonitor("nsPNGEncoder.mReentrantMonitor")
1.27 +{
1.28 +}
1.29 +
1.30 +nsPNGEncoder::~nsPNGEncoder()
1.31 +{
1.32 + if (mImageBuffer) {
1.33 + moz_free(mImageBuffer);
1.34 + mImageBuffer = nullptr;
1.35 + }
1.36 + // don't leak if EndImageEncode wasn't called
1.37 + if (mPNG)
1.38 + png_destroy_write_struct(&mPNG, &mPNGinfo);
1.39 +}
1.40 +
1.41 +// nsPNGEncoder::InitFromData
1.42 +//
1.43 +// One output option is supported: "transparency=none" means that the
1.44 +// output PNG will not have an alpha channel, even if the input does.
1.45 +//
1.46 +// Based partially on gfx/cairo/cairo/src/cairo-png.c
1.47 +// See also modules/libimg/png/libpng.txt
1.48 +
1.49 +NS_IMETHODIMP nsPNGEncoder::InitFromData(const uint8_t* aData,
1.50 + uint32_t aLength, // (unused,
1.51 + // req'd by JS)
1.52 + uint32_t aWidth,
1.53 + uint32_t aHeight,
1.54 + uint32_t aStride,
1.55 + uint32_t aInputFormat,
1.56 + const nsAString& aOutputOptions)
1.57 +{
1.58 + NS_ENSURE_ARG(aData);
1.59 + nsresult rv;
1.60 +
1.61 + rv = StartImageEncode(aWidth, aHeight, aInputFormat, aOutputOptions);
1.62 + if (!NS_SUCCEEDED(rv))
1.63 + return rv;
1.64 +
1.65 + rv = AddImageFrame(aData, aLength, aWidth, aHeight, aStride,
1.66 + aInputFormat, aOutputOptions);
1.67 + if (!NS_SUCCEEDED(rv))
1.68 + return rv;
1.69 +
1.70 + rv = EndImageEncode();
1.71 +
1.72 + return rv;
1.73 +}
1.74 +
1.75 +
1.76 +// nsPNGEncoder::StartImageEncode
1.77 +//
1.78 +//
1.79 +// See ::InitFromData for other info.
1.80 +NS_IMETHODIMP nsPNGEncoder::StartImageEncode(uint32_t aWidth,
1.81 + uint32_t aHeight,
1.82 + uint32_t aInputFormat,
1.83 + const nsAString& aOutputOptions)
1.84 +{
1.85 + bool useTransparency = true, skipFirstFrame = false;
1.86 + uint32_t numFrames = 1;
1.87 + uint32_t numPlays = 0; // For animations, 0 == forever
1.88 +
1.89 + // can't initialize more than once
1.90 + if (mImageBuffer != nullptr)
1.91 + return NS_ERROR_ALREADY_INITIALIZED;
1.92 +
1.93 + // validate input format
1.94 + if (aInputFormat != INPUT_FORMAT_RGB &&
1.95 + aInputFormat != INPUT_FORMAT_RGBA &&
1.96 + aInputFormat != INPUT_FORMAT_HOSTARGB)
1.97 + return NS_ERROR_INVALID_ARG;
1.98 +
1.99 + // parse and check any provided output options
1.100 + nsresult rv = ParseOptions(aOutputOptions, &useTransparency, &skipFirstFrame,
1.101 + &numFrames, &numPlays, nullptr, nullptr,
1.102 + nullptr, nullptr, nullptr);
1.103 + if (rv != NS_OK)
1.104 + return rv;
1.105 +
1.106 +#ifdef PNG_APNG_SUPPORTED
1.107 + if (numFrames > 1)
1.108 + mIsAnimation = true;
1.109 +
1.110 +#endif
1.111 +
1.112 + // initialize
1.113 + mPNG = png_create_write_struct(PNG_LIBPNG_VER_STRING,
1.114 + nullptr,
1.115 + ErrorCallback,
1.116 + WarningCallback);
1.117 + if (! mPNG)
1.118 + return NS_ERROR_OUT_OF_MEMORY;
1.119 +
1.120 + mPNGinfo = png_create_info_struct(mPNG);
1.121 + if (! mPNGinfo) {
1.122 + png_destroy_write_struct(&mPNG, nullptr);
1.123 + return NS_ERROR_FAILURE;
1.124 + }
1.125 +
1.126 + // libpng's error handler jumps back here upon an error.
1.127 + // Note: It's important that all png_* callers do this, or errors
1.128 + // will result in a corrupt time-warped stack.
1.129 + if (setjmp(png_jmpbuf(mPNG))) {
1.130 + png_destroy_write_struct(&mPNG, &mPNGinfo);
1.131 + return NS_ERROR_FAILURE;
1.132 + }
1.133 +
1.134 + // Set up to read the data into our image buffer, start out with an 8K
1.135 + // estimated size. Note: we don't have to worry about freeing this data
1.136 + // in this function. It will be freed on object destruction.
1.137 + mImageBufferSize = 8192;
1.138 + mImageBuffer = (uint8_t*)moz_malloc(mImageBufferSize);
1.139 + if (!mImageBuffer) {
1.140 + png_destroy_write_struct(&mPNG, &mPNGinfo);
1.141 + return NS_ERROR_OUT_OF_MEMORY;
1.142 + }
1.143 + mImageBufferUsed = 0;
1.144 +
1.145 + // set our callback for libpng to give us the data
1.146 + png_set_write_fn(mPNG, this, WriteCallback, nullptr);
1.147 +
1.148 + // include alpha?
1.149 + int colorType;
1.150 + if ((aInputFormat == INPUT_FORMAT_HOSTARGB ||
1.151 + aInputFormat == INPUT_FORMAT_RGBA) &&
1.152 + useTransparency)
1.153 + colorType = PNG_COLOR_TYPE_RGB_ALPHA;
1.154 + else
1.155 + colorType = PNG_COLOR_TYPE_RGB;
1.156 +
1.157 + png_set_IHDR(mPNG, mPNGinfo, aWidth, aHeight, 8, colorType,
1.158 + PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
1.159 + PNG_FILTER_TYPE_DEFAULT);
1.160 +
1.161 +#ifdef PNG_APNG_SUPPORTED
1.162 + if (mIsAnimation) {
1.163 + png_set_first_frame_is_hidden(mPNG, mPNGinfo, skipFirstFrame);
1.164 + png_set_acTL(mPNG, mPNGinfo, numFrames, numPlays);
1.165 + }
1.166 +#endif
1.167 +
1.168 + // XXX: support PLTE, gAMA, tRNS, bKGD?
1.169 +
1.170 + png_write_info(mPNG, mPNGinfo);
1.171 +
1.172 + return NS_OK;
1.173 +}
1.174 +
1.175 +// Returns the number of bytes in the image buffer used.
1.176 +NS_IMETHODIMP nsPNGEncoder::GetImageBufferUsed(uint32_t *aOutputSize)
1.177 +{
1.178 + NS_ENSURE_ARG_POINTER(aOutputSize);
1.179 + *aOutputSize = mImageBufferUsed;
1.180 + return NS_OK;
1.181 +}
1.182 +
1.183 +// Returns a pointer to the start of the image buffer
1.184 +NS_IMETHODIMP nsPNGEncoder::GetImageBuffer(char **aOutputBuffer)
1.185 +{
1.186 + NS_ENSURE_ARG_POINTER(aOutputBuffer);
1.187 + *aOutputBuffer = reinterpret_cast<char*>(mImageBuffer);
1.188 + return NS_OK;
1.189 +}
1.190 +
1.191 +NS_IMETHODIMP nsPNGEncoder::AddImageFrame(const uint8_t* aData,
1.192 + uint32_t aLength, // (unused,
1.193 + // req'd by JS)
1.194 + uint32_t aWidth,
1.195 + uint32_t aHeight,
1.196 + uint32_t aStride,
1.197 + uint32_t aInputFormat,
1.198 + const nsAString& aFrameOptions)
1.199 +{
1.200 + bool useTransparency= true;
1.201 + uint32_t delay_ms = 500;
1.202 +#ifdef PNG_APNG_SUPPORTED
1.203 + uint32_t dispose_op = PNG_DISPOSE_OP_NONE;
1.204 + uint32_t blend_op = PNG_BLEND_OP_SOURCE;
1.205 +#else
1.206 + uint32_t dispose_op;
1.207 + uint32_t blend_op;
1.208 +#endif
1.209 + uint32_t x_offset = 0, y_offset = 0;
1.210 +
1.211 + // must be initialized
1.212 + if (mImageBuffer == nullptr)
1.213 + return NS_ERROR_NOT_INITIALIZED;
1.214 +
1.215 + // EndImageEncode was done, or some error occurred earlier
1.216 + if (!mPNG)
1.217 + return NS_BASE_STREAM_CLOSED;
1.218 +
1.219 + // validate input format
1.220 + if (aInputFormat != INPUT_FORMAT_RGB &&
1.221 + aInputFormat != INPUT_FORMAT_RGBA &&
1.222 + aInputFormat != INPUT_FORMAT_HOSTARGB)
1.223 + return NS_ERROR_INVALID_ARG;
1.224 +
1.225 + // libpng's error handler jumps back here upon an error.
1.226 + if (setjmp(png_jmpbuf(mPNG))) {
1.227 + png_destroy_write_struct(&mPNG, &mPNGinfo);
1.228 + return NS_ERROR_FAILURE;
1.229 + }
1.230 +
1.231 + // parse and check any provided output options
1.232 + nsresult rv = ParseOptions(aFrameOptions, &useTransparency, nullptr,
1.233 + nullptr, nullptr, &dispose_op, &blend_op,
1.234 + &delay_ms, &x_offset, &y_offset);
1.235 + if (rv != NS_OK)
1.236 + return rv;
1.237 +
1.238 +#ifdef PNG_APNG_SUPPORTED
1.239 + if (mIsAnimation) {
1.240 + // XXX the row pointers arg (#3) is unused, can it be removed?
1.241 + png_write_frame_head(mPNG, mPNGinfo, nullptr,
1.242 + aWidth, aHeight, x_offset, y_offset,
1.243 + delay_ms, 1000, dispose_op, blend_op);
1.244 + }
1.245 +#endif
1.246 +
1.247 + // Stride is the padded width of each row, so it better be longer
1.248 + // (I'm afraid people will not understand what stride means, so
1.249 + // check it well)
1.250 + if ((aInputFormat == INPUT_FORMAT_RGB &&
1.251 + aStride < aWidth * 3) ||
1.252 + ((aInputFormat == INPUT_FORMAT_RGBA ||
1.253 + aInputFormat == INPUT_FORMAT_HOSTARGB) &&
1.254 + aStride < aWidth * 4)) {
1.255 + NS_WARNING("Invalid stride for InitFromData/AddImageFrame");
1.256 + return NS_ERROR_INVALID_ARG;
1.257 + }
1.258 +
1.259 +#ifdef PNG_WRITE_FILTER_SUPPORTED
1.260 + png_set_filter(mPNG, PNG_FILTER_TYPE_BASE, PNG_FILTER_VALUE_NONE);
1.261 +#endif
1.262 +
1.263 + // write each row: if we add more input formats, we may want to
1.264 + // generalize the conversions
1.265 + if (aInputFormat == INPUT_FORMAT_HOSTARGB) {
1.266 + // PNG requires RGBA with post-multiplied alpha, so we need to
1.267 + // convert
1.268 + uint8_t* row = new uint8_t[aWidth * 4];
1.269 + for (uint32_t y = 0; y < aHeight; y ++) {
1.270 + ConvertHostARGBRow(&aData[y * aStride], row, aWidth, useTransparency);
1.271 + png_write_row(mPNG, row);
1.272 + }
1.273 + delete[] row;
1.274 +
1.275 + } else if (aInputFormat == INPUT_FORMAT_RGBA && ! useTransparency) {
1.276 + // RBGA, but we need to strip the alpha
1.277 + uint8_t* row = new uint8_t[aWidth * 4];
1.278 + for (uint32_t y = 0; y < aHeight; y ++) {
1.279 + StripAlpha(&aData[y * aStride], row, aWidth);
1.280 + png_write_row(mPNG, row);
1.281 + }
1.282 + delete[] row;
1.283 +
1.284 + } else if (aInputFormat == INPUT_FORMAT_RGB ||
1.285 + aInputFormat == INPUT_FORMAT_RGBA) {
1.286 + // simple RBG(A), no conversion needed
1.287 + for (uint32_t y = 0; y < aHeight; y ++) {
1.288 + png_write_row(mPNG, (uint8_t*)&aData[y * aStride]);
1.289 + }
1.290 +
1.291 + } else {
1.292 + NS_NOTREACHED("Bad format type");
1.293 + return NS_ERROR_INVALID_ARG;
1.294 + }
1.295 +
1.296 +#ifdef PNG_APNG_SUPPORTED
1.297 + if (mIsAnimation) {
1.298 + png_write_frame_tail(mPNG, mPNGinfo);
1.299 + }
1.300 +#endif
1.301 +
1.302 + return NS_OK;
1.303 +}
1.304 +
1.305 +
1.306 +NS_IMETHODIMP nsPNGEncoder::EndImageEncode()
1.307 +{
1.308 + // must be initialized
1.309 + if (mImageBuffer == nullptr)
1.310 + return NS_ERROR_NOT_INITIALIZED;
1.311 +
1.312 + // EndImageEncode has already been called, or some error
1.313 + // occurred earlier
1.314 + if (!mPNG)
1.315 + return NS_BASE_STREAM_CLOSED;
1.316 +
1.317 + // libpng's error handler jumps back here upon an error.
1.318 + if (setjmp(png_jmpbuf(mPNG))) {
1.319 + png_destroy_write_struct(&mPNG, &mPNGinfo);
1.320 + return NS_ERROR_FAILURE;
1.321 + }
1.322 +
1.323 + png_write_end(mPNG, mPNGinfo);
1.324 + png_destroy_write_struct(&mPNG, &mPNGinfo);
1.325 +
1.326 + mFinished = true;
1.327 + NotifyListener();
1.328 +
1.329 + // if output callback can't get enough memory, it will free our buffer
1.330 + if (!mImageBuffer)
1.331 + return NS_ERROR_OUT_OF_MEMORY;
1.332 +
1.333 + return NS_OK;
1.334 +}
1.335 +
1.336 +
1.337 +nsresult
1.338 +nsPNGEncoder::ParseOptions(const nsAString& aOptions,
1.339 + bool* useTransparency,
1.340 + bool* skipFirstFrame,
1.341 + uint32_t* numFrames,
1.342 + uint32_t* numPlays,
1.343 + uint32_t* frameDispose,
1.344 + uint32_t* frameBlend,
1.345 + uint32_t* frameDelay,
1.346 + uint32_t* offsetX,
1.347 + uint32_t* offsetY)
1.348 +{
1.349 +#ifdef PNG_APNG_SUPPORTED
1.350 + // Make a copy of aOptions, because strtok() will modify it.
1.351 + nsAutoCString optionsCopy;
1.352 + optionsCopy.Assign(NS_ConvertUTF16toUTF8(aOptions));
1.353 + char* options = optionsCopy.BeginWriting();
1.354 +
1.355 + while (char* token = nsCRT::strtok(options, ";", &options)) {
1.356 + // If there's an '=' character, split the token around it.
1.357 + char* equals = token, *value = nullptr;
1.358 + while(*equals != '=' && *equals) {
1.359 + ++equals;
1.360 + }
1.361 + if (*equals == '=')
1.362 + value = equals + 1;
1.363 +
1.364 + if (value)
1.365 + *equals = '\0'; // temporary null
1.366 +
1.367 + // transparency=[yes|no|none]
1.368 + if (nsCRT::strcmp(token, "transparency") == 0 && useTransparency) {
1.369 + if (!value)
1.370 + return NS_ERROR_INVALID_ARG;
1.371 +
1.372 + if (nsCRT::strcmp(value, "none") == 0 ||
1.373 + nsCRT::strcmp(value, "no") == 0) {
1.374 + *useTransparency = false;
1.375 + } else if (nsCRT::strcmp(value, "yes") == 0) {
1.376 + *useTransparency = true;
1.377 + } else {
1.378 + return NS_ERROR_INVALID_ARG;
1.379 + }
1.380 +
1.381 + // skipfirstframe=[yes|no]
1.382 + } else if (nsCRT::strcmp(token, "skipfirstframe") == 0 &&
1.383 + skipFirstFrame) {
1.384 + if (!value)
1.385 + return NS_ERROR_INVALID_ARG;
1.386 +
1.387 + if (nsCRT::strcmp(value, "no") == 0) {
1.388 + *skipFirstFrame = false;
1.389 + } else if (nsCRT::strcmp(value, "yes") == 0) {
1.390 + *skipFirstFrame = true;
1.391 + } else {
1.392 + return NS_ERROR_INVALID_ARG;
1.393 + }
1.394 +
1.395 + // frames=#
1.396 + } else if (nsCRT::strcmp(token, "frames") == 0 && numFrames) {
1.397 + if (!value)
1.398 + return NS_ERROR_INVALID_ARG;
1.399 +
1.400 + if (PR_sscanf(value, "%u", numFrames) != 1) {
1.401 + return NS_ERROR_INVALID_ARG;
1.402 + }
1.403 +
1.404 + // frames=0 is nonsense.
1.405 + if (*numFrames == 0)
1.406 + return NS_ERROR_INVALID_ARG;
1.407 +
1.408 + // plays=#
1.409 + } else if (nsCRT::strcmp(token, "plays") == 0 && numPlays) {
1.410 + if (!value)
1.411 + return NS_ERROR_INVALID_ARG;
1.412 +
1.413 + // plays=0 to loop forever, otherwise play sequence specified
1.414 + // number of times
1.415 + if (PR_sscanf(value, "%u", numPlays) != 1)
1.416 + return NS_ERROR_INVALID_ARG;
1.417 +
1.418 + // dispose=[none|background|previous]
1.419 + } else if (nsCRT::strcmp(token, "dispose") == 0 && frameDispose) {
1.420 + if (!value)
1.421 + return NS_ERROR_INVALID_ARG;
1.422 +
1.423 + if (nsCRT::strcmp(value, "none") == 0) {
1.424 + *frameDispose = PNG_DISPOSE_OP_NONE;
1.425 + } else if (nsCRT::strcmp(value, "background") == 0) {
1.426 + *frameDispose = PNG_DISPOSE_OP_BACKGROUND;
1.427 + } else if (nsCRT::strcmp(value, "previous") == 0) {
1.428 + *frameDispose = PNG_DISPOSE_OP_PREVIOUS;
1.429 + } else {
1.430 + return NS_ERROR_INVALID_ARG;
1.431 + }
1.432 +
1.433 + // blend=[source|over]
1.434 + } else if (nsCRT::strcmp(token, "blend") == 0 && frameBlend) {
1.435 + if (!value)
1.436 + return NS_ERROR_INVALID_ARG;
1.437 +
1.438 + if (nsCRT::strcmp(value, "source") == 0) {
1.439 + *frameBlend = PNG_BLEND_OP_SOURCE;
1.440 + } else if (nsCRT::strcmp(value, "over") == 0) {
1.441 + *frameBlend = PNG_BLEND_OP_OVER;
1.442 + } else {
1.443 + return NS_ERROR_INVALID_ARG;
1.444 + }
1.445 +
1.446 + // delay=# (in ms)
1.447 + } else if (nsCRT::strcmp(token, "delay") == 0 && frameDelay) {
1.448 + if (!value)
1.449 + return NS_ERROR_INVALID_ARG;
1.450 +
1.451 + if (PR_sscanf(value, "%u", frameDelay) != 1)
1.452 + return NS_ERROR_INVALID_ARG;
1.453 +
1.454 + // xoffset=#
1.455 + } else if (nsCRT::strcmp(token, "xoffset") == 0 && offsetX) {
1.456 + if (!value)
1.457 + return NS_ERROR_INVALID_ARG;
1.458 +
1.459 + if (PR_sscanf(value, "%u", offsetX) != 1)
1.460 + return NS_ERROR_INVALID_ARG;
1.461 +
1.462 + // yoffset=#
1.463 + } else if (nsCRT::strcmp(token, "yoffset") == 0 && offsetY) {
1.464 + if (!value)
1.465 + return NS_ERROR_INVALID_ARG;
1.466 +
1.467 + if (PR_sscanf(value, "%u", offsetY) != 1)
1.468 + return NS_ERROR_INVALID_ARG;
1.469 +
1.470 + // unknown token name
1.471 + } else
1.472 + return NS_ERROR_INVALID_ARG;
1.473 +
1.474 + if (value)
1.475 + *equals = '='; // restore '=' so strtok doesn't get lost
1.476 + }
1.477 +
1.478 +#endif
1.479 + return NS_OK;
1.480 +}
1.481 +
1.482 +
1.483 +/* void close (); */
1.484 +NS_IMETHODIMP nsPNGEncoder::Close()
1.485 +{
1.486 + if (mImageBuffer != nullptr) {
1.487 + moz_free(mImageBuffer);
1.488 + mImageBuffer = nullptr;
1.489 + mImageBufferSize = 0;
1.490 + mImageBufferUsed = 0;
1.491 + mImageBufferReadPoint = 0;
1.492 + }
1.493 + return NS_OK;
1.494 +}
1.495 +
1.496 +/* unsigned long available (); */
1.497 +NS_IMETHODIMP nsPNGEncoder::Available(uint64_t *_retval)
1.498 +{
1.499 + if (!mImageBuffer)
1.500 + return NS_BASE_STREAM_CLOSED;
1.501 +
1.502 + *_retval = mImageBufferUsed - mImageBufferReadPoint;
1.503 + return NS_OK;
1.504 +}
1.505 +
1.506 +/* [noscript] unsigned long read (in charPtr aBuf,
1.507 + in unsigned long aCount); */
1.508 +NS_IMETHODIMP nsPNGEncoder::Read(char * aBuf, uint32_t aCount,
1.509 + uint32_t *_retval)
1.510 +{
1.511 + return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, _retval);
1.512 +}
1.513 +
1.514 +/* [noscript] unsigned long readSegments (in nsWriteSegmentFun aWriter,
1.515 + in voidPtr aClosure,
1.516 + in unsigned long aCount); */
1.517 +NS_IMETHODIMP nsPNGEncoder::ReadSegments(nsWriteSegmentFun aWriter,
1.518 + void *aClosure, uint32_t aCount,
1.519 + uint32_t *_retval)
1.520 +{
1.521 + // Avoid another thread reallocing the buffer underneath us
1.522 + ReentrantMonitorAutoEnter autoEnter(mReentrantMonitor);
1.523 +
1.524 + uint32_t maxCount = mImageBufferUsed - mImageBufferReadPoint;
1.525 + if (maxCount == 0) {
1.526 + *_retval = 0;
1.527 + return mFinished ? NS_OK : NS_BASE_STREAM_WOULD_BLOCK;
1.528 + }
1.529 +
1.530 + if (aCount > maxCount)
1.531 + aCount = maxCount;
1.532 + nsresult rv =
1.533 + aWriter(this, aClosure,
1.534 + reinterpret_cast<const char*>(mImageBuffer+mImageBufferReadPoint),
1.535 + 0, aCount, _retval);
1.536 + if (NS_SUCCEEDED(rv)) {
1.537 + NS_ASSERTION(*_retval <= aCount, "bad write count");
1.538 + mImageBufferReadPoint += *_retval;
1.539 + }
1.540 +
1.541 + // errors returned from the writer end here!
1.542 + return NS_OK;
1.543 +}
1.544 +
1.545 +/* boolean isNonBlocking (); */
1.546 +NS_IMETHODIMP nsPNGEncoder::IsNonBlocking(bool *_retval)
1.547 +{
1.548 + *_retval = true;
1.549 + return NS_OK;
1.550 +}
1.551 +
1.552 +NS_IMETHODIMP nsPNGEncoder::AsyncWait(nsIInputStreamCallback *aCallback,
1.553 + uint32_t aFlags,
1.554 + uint32_t aRequestedCount,
1.555 + nsIEventTarget *aTarget)
1.556 +{
1.557 + if (aFlags != 0)
1.558 + return NS_ERROR_NOT_IMPLEMENTED;
1.559 +
1.560 + if (mCallback || mCallbackTarget)
1.561 + return NS_ERROR_UNEXPECTED;
1.562 +
1.563 + mCallbackTarget = aTarget;
1.564 + // 0 means "any number of bytes except 0"
1.565 + mNotifyThreshold = aRequestedCount;
1.566 + if (!aRequestedCount)
1.567 + mNotifyThreshold = 1024; // We don't want to notify incessantly
1.568 +
1.569 + // We set the callback absolutely last, because NotifyListener uses it to
1.570 + // determine if someone needs to be notified. If we don't set it last,
1.571 + // NotifyListener might try to fire off a notification to a null target
1.572 + // which will generally cause non-threadsafe objects to be used off the main thread
1.573 + mCallback = aCallback;
1.574 +
1.575 + // What we are being asked for may be present already
1.576 + NotifyListener();
1.577 + return NS_OK;
1.578 +}
1.579 +
1.580 +NS_IMETHODIMP nsPNGEncoder::CloseWithStatus(nsresult aStatus)
1.581 +{
1.582 + return Close();
1.583 +}
1.584 +
1.585 +// nsPNGEncoder::ConvertHostARGBRow
1.586 +//
1.587 +// Our colors are stored with premultiplied alphas, but PNGs use
1.588 +// post-multiplied alpha. This swaps to PNG-style alpha.
1.589 +//
1.590 +// Copied from gfx/cairo/cairo/src/cairo-png.c
1.591 +
1.592 +void
1.593 +nsPNGEncoder::ConvertHostARGBRow(const uint8_t* aSrc, uint8_t* aDest,
1.594 + uint32_t aPixelWidth,
1.595 + bool aUseTransparency)
1.596 +{
1.597 + uint32_t pixelStride = aUseTransparency ? 4 : 3;
1.598 + for (uint32_t x = 0; x < aPixelWidth; x ++) {
1.599 + const uint32_t& pixelIn = ((const uint32_t*)(aSrc))[x];
1.600 + uint8_t *pixelOut = &aDest[x * pixelStride];
1.601 +
1.602 + uint8_t alpha = (pixelIn & 0xff000000) >> 24;
1.603 + if (alpha == 0) {
1.604 + pixelOut[0] = pixelOut[1] = pixelOut[2] = pixelOut[3] = 0;
1.605 + } else {
1.606 + pixelOut[0] = (((pixelIn & 0xff0000) >> 16) * 255 + alpha / 2) / alpha;
1.607 + pixelOut[1] = (((pixelIn & 0x00ff00) >> 8) * 255 + alpha / 2) / alpha;
1.608 + pixelOut[2] = (((pixelIn & 0x0000ff) >> 0) * 255 + alpha / 2) / alpha;
1.609 + if (aUseTransparency)
1.610 + pixelOut[3] = alpha;
1.611 + }
1.612 + }
1.613 +}
1.614 +
1.615 +
1.616 +// nsPNGEncoder::StripAlpha
1.617 +//
1.618 +// Input is RGBA, output is RGB
1.619 +
1.620 +void
1.621 +nsPNGEncoder::StripAlpha(const uint8_t* aSrc, uint8_t* aDest,
1.622 + uint32_t aPixelWidth)
1.623 +{
1.624 + for (uint32_t x = 0; x < aPixelWidth; x ++) {
1.625 + const uint8_t* pixelIn = &aSrc[x * 4];
1.626 + uint8_t* pixelOut = &aDest[x * 3];
1.627 + pixelOut[0] = pixelIn[0];
1.628 + pixelOut[1] = pixelIn[1];
1.629 + pixelOut[2] = pixelIn[2];
1.630 + }
1.631 +}
1.632 +
1.633 +
1.634 +// nsPNGEncoder::WarningCallback
1.635 +
1.636 +void // static
1.637 +nsPNGEncoder::WarningCallback(png_structp png_ptr,
1.638 + png_const_charp warning_msg)
1.639 +{
1.640 +#ifdef DEBUG
1.641 + // XXX: these messages are probably useful callers...
1.642 + // use nsIConsoleService?
1.643 + PR_fprintf(PR_STDERR, "PNG Encoder: %s\n", warning_msg);;
1.644 +#endif
1.645 +}
1.646 +
1.647 +
1.648 +// nsPNGEncoder::ErrorCallback
1.649 +
1.650 +void // static
1.651 +nsPNGEncoder::ErrorCallback(png_structp png_ptr,
1.652 + png_const_charp error_msg)
1.653 +{
1.654 +#ifdef DEBUG
1.655 + // XXX: these messages are probably useful callers...
1.656 + // use nsIConsoleService?
1.657 + PR_fprintf(PR_STDERR, "PNG Encoder: %s\n", error_msg);;
1.658 +#endif
1.659 +#if PNG_LIBPNG_VER < 10500
1.660 + longjmp(png_ptr->jmpbuf, 1);
1.661 +#else
1.662 + png_longjmp(png_ptr, 1);
1.663 +#endif
1.664 +}
1.665 +
1.666 +
1.667 +// nsPNGEncoder::WriteCallback
1.668 +
1.669 +void // static
1.670 +nsPNGEncoder::WriteCallback(png_structp png, png_bytep data,
1.671 + png_size_t size)
1.672 +{
1.673 + nsPNGEncoder* that = static_cast<nsPNGEncoder*>(png_get_io_ptr(png));
1.674 + if (! that->mImageBuffer)
1.675 + return;
1.676 +
1.677 + if (that->mImageBufferUsed + size > that->mImageBufferSize) {
1.678 + // When we're reallocing the buffer we need to take the lock to ensure
1.679 + // that nobody is trying to read from the buffer we are destroying
1.680 + ReentrantMonitorAutoEnter autoEnter(that->mReentrantMonitor);
1.681 +
1.682 + // expand buffer, just double each time
1.683 + that->mImageBufferSize *= 2;
1.684 + uint8_t* newBuf = (uint8_t*)moz_realloc(that->mImageBuffer,
1.685 + that->mImageBufferSize);
1.686 + if (! newBuf) {
1.687 + // can't resize, just zero (this will keep us from writing more)
1.688 + moz_free(that->mImageBuffer);
1.689 + that->mImageBuffer = nullptr;
1.690 + that->mImageBufferSize = 0;
1.691 + that->mImageBufferUsed = 0;
1.692 + return;
1.693 + }
1.694 + that->mImageBuffer = newBuf;
1.695 + }
1.696 + memcpy(&that->mImageBuffer[that->mImageBufferUsed], data, size);
1.697 + that->mImageBufferUsed += size;
1.698 + that->NotifyListener();
1.699 +}
1.700 +
1.701 +void
1.702 +nsPNGEncoder::NotifyListener()
1.703 +{
1.704 + // We might call this function on multiple threads (any threads that call
1.705 + // AsyncWait and any that do encoding) so we lock to avoid notifying the
1.706 + // listener twice about the same data (which generally leads to a truncated
1.707 + // image).
1.708 + ReentrantMonitorAutoEnter autoEnter(mReentrantMonitor);
1.709 +
1.710 + if (mCallback &&
1.711 + (mImageBufferUsed - mImageBufferReadPoint >= mNotifyThreshold ||
1.712 + mFinished)) {
1.713 + nsCOMPtr<nsIInputStreamCallback> callback;
1.714 + if (mCallbackTarget) {
1.715 + callback = NS_NewInputStreamReadyEvent(mCallback, mCallbackTarget);
1.716 + } else {
1.717 + callback = mCallback;
1.718 + }
1.719 +
1.720 + NS_ASSERTION(callback, "Shouldn't fail to make the callback");
1.721 + // Null the callback first because OnInputStreamReady could reenter
1.722 + // AsyncWait
1.723 + mCallback = nullptr;
1.724 + mCallbackTarget = nullptr;
1.725 + mNotifyThreshold = 0;
1.726 +
1.727 + callback->OnInputStreamReady(this);
1.728 + }
1.729 +}
