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gecko-dev/image/encoders/png/nsPNGEncoder.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsCRT.h"
#include "nsPNGEncoder.h"
#include "prmem.h"
#include "prprf.h"
#include "nsString.h"
#include "nsStreamUtils.h"
using namespace mozilla;
NS_IMPL_THREADSAFE_ISUPPORTS3(nsPNGEncoder, imgIEncoder, nsIInputStream, nsIAsyncInputStream)
nsPNGEncoder::nsPNGEncoder() : mPNG(nsnull), mPNGinfo(nsnull),
mIsAnimation(false),
mFinished(false),
mImageBuffer(nsnull), mImageBufferSize(0),
mImageBufferUsed(0), mImageBufferReadPoint(0),
mCallback(nsnull),
mCallbackTarget(nsnull), mNotifyThreshold(0),
mReentrantMonitor("nsPNGEncoder.mReentrantMonitor")
{
}
nsPNGEncoder::~nsPNGEncoder()
{
if (mImageBuffer) {
PR_Free(mImageBuffer);
mImageBuffer = nsnull;
}
// don't leak if EndImageEncode wasn't called
if (mPNG)
png_destroy_write_struct(&mPNG, &mPNGinfo);
}
// nsPNGEncoder::InitFromData
//
// One output option is supported: "transparency=none" means that the
// output PNG will not have an alpha channel, even if the input does.
//
// Based partially on gfx/cairo/cairo/src/cairo-png.c
// See also modules/libimg/png/libpng.txt
NS_IMETHODIMP nsPNGEncoder::InitFromData(const PRUint8* aData,
PRUint32 aLength, // (unused,
// req'd by JS)
PRUint32 aWidth,
PRUint32 aHeight,
PRUint32 aStride,
PRUint32 aInputFormat,
const nsAString& aOutputOptions)
{
NS_ENSURE_ARG(aData);
nsresult rv;
rv = StartImageEncode(aWidth, aHeight, aInputFormat, aOutputOptions);
if (!NS_SUCCEEDED(rv))
return rv;
rv = AddImageFrame(aData, aLength, aWidth, aHeight, aStride,
aInputFormat, aOutputOptions);
if (!NS_SUCCEEDED(rv))
return rv;
rv = EndImageEncode();
return rv;
}
// nsPNGEncoder::StartImageEncode
//
//
// See ::InitFromData for other info.
NS_IMETHODIMP nsPNGEncoder::StartImageEncode(PRUint32 aWidth,
PRUint32 aHeight,
PRUint32 aInputFormat,
const nsAString& aOutputOptions)
{
bool useTransparency = true, skipFirstFrame = false;
PRUint32 numFrames = 1;
PRUint32 numPlays = 0; // For animations, 0 == forever
// can't initialize more than once
if (mImageBuffer != nsnull)
return NS_ERROR_ALREADY_INITIALIZED;
// validate input format
if (aInputFormat != INPUT_FORMAT_RGB &&
aInputFormat != INPUT_FORMAT_RGBA &&
aInputFormat != INPUT_FORMAT_HOSTARGB)
return NS_ERROR_INVALID_ARG;
// parse and check any provided output options
nsresult rv = ParseOptions(aOutputOptions, &useTransparency, &skipFirstFrame,
&numFrames, &numPlays, nsnull, nsnull,
nsnull, nsnull, nsnull);
if (rv != NS_OK)
return rv;
#ifdef PNG_APNG_SUPPORTED
if (numFrames > 1)
mIsAnimation = true;
#endif
// initialize
mPNG = png_create_write_struct(PNG_LIBPNG_VER_STRING,
nsnull,
ErrorCallback,
WarningCallback);
if (! mPNG)
return NS_ERROR_OUT_OF_MEMORY;
mPNGinfo = png_create_info_struct(mPNG);
if (! mPNGinfo) {
png_destroy_write_struct(&mPNG, nsnull);
return NS_ERROR_FAILURE;
}
// libpng's error handler jumps back here upon an error.
// Note: It's important that all png_* callers do this, or errors
// will result in a corrupt time-warped stack.
if (setjmp(png_jmpbuf(mPNG))) {
png_destroy_write_struct(&mPNG, &mPNGinfo);
return NS_ERROR_FAILURE;
}
// Set up to read the data into our image buffer, start out with an 8K
// estimated size. Note: we don't have to worry about freeing this data
// in this function. It will be freed on object destruction.
mImageBufferSize = 8192;
mImageBuffer = (PRUint8*)PR_Malloc(mImageBufferSize);
if (!mImageBuffer) {
png_destroy_write_struct(&mPNG, &mPNGinfo);
return NS_ERROR_OUT_OF_MEMORY;
}
mImageBufferUsed = 0;
// set our callback for libpng to give us the data
png_set_write_fn(mPNG, this, WriteCallback, nsnull);
// include alpha?
int colorType;
if ((aInputFormat == INPUT_FORMAT_HOSTARGB ||
aInputFormat == INPUT_FORMAT_RGBA) &&
useTransparency)
colorType = PNG_COLOR_TYPE_RGB_ALPHA;
else
colorType = PNG_COLOR_TYPE_RGB;
png_set_IHDR(mPNG, mPNGinfo, aWidth, aHeight, 8, colorType,
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
PNG_FILTER_TYPE_DEFAULT);
#ifdef PNG_APNG_SUPPORTED
if (mIsAnimation) {
png_set_first_frame_is_hidden(mPNG, mPNGinfo, skipFirstFrame);
png_set_acTL(mPNG, mPNGinfo, numFrames, numPlays);
}
#endif
// XXX: support PLTE, gAMA, tRNS, bKGD?
png_write_info(mPNG, mPNGinfo);
return NS_OK;
}
// Returns the number of bytes in the image buffer used.
NS_IMETHODIMP nsPNGEncoder::GetImageBufferUsed(PRUint32 *aOutputSize)
{
NS_ENSURE_ARG_POINTER(aOutputSize);
*aOutputSize = mImageBufferUsed;
return NS_OK;
}
// Returns a pointer to the start of the image buffer
NS_IMETHODIMP nsPNGEncoder::GetImageBuffer(char **aOutputBuffer)
{
NS_ENSURE_ARG_POINTER(aOutputBuffer);
*aOutputBuffer = reinterpret_cast<char*>(mImageBuffer);
return NS_OK;
}
NS_IMETHODIMP nsPNGEncoder::AddImageFrame(const PRUint8* aData,
PRUint32 aLength, // (unused,
// req'd by JS)
PRUint32 aWidth,
PRUint32 aHeight,
PRUint32 aStride,
PRUint32 aInputFormat,
const nsAString& aFrameOptions)
{
bool useTransparency= true;
PRUint32 delay_ms = 500;
#ifdef PNG_APNG_SUPPORTED
PRUint32 dispose_op = PNG_DISPOSE_OP_NONE;
PRUint32 blend_op = PNG_BLEND_OP_SOURCE;
#else
PRUint32 dispose_op;
PRUint32 blend_op;
#endif
PRUint32 x_offset = 0, y_offset = 0;
// must be initialized
if (mImageBuffer == nsnull)
return NS_ERROR_NOT_INITIALIZED;
// EndImageEncode was done, or some error occurred earlier
if (!mPNG)
return NS_BASE_STREAM_CLOSED;
// validate input format
if (aInputFormat != INPUT_FORMAT_RGB &&
aInputFormat != INPUT_FORMAT_RGBA &&
aInputFormat != INPUT_FORMAT_HOSTARGB)
return NS_ERROR_INVALID_ARG;
// libpng's error handler jumps back here upon an error.
if (setjmp(png_jmpbuf(mPNG))) {
png_destroy_write_struct(&mPNG, &mPNGinfo);
return NS_ERROR_FAILURE;
}
// parse and check any provided output options
nsresult rv = ParseOptions(aFrameOptions, &useTransparency, nsnull,
nsnull, nsnull, &dispose_op, &blend_op,
&delay_ms, &x_offset, &y_offset);
if (rv != NS_OK)
return rv;
#ifdef PNG_APNG_SUPPORTED
if (mIsAnimation) {
// XXX the row pointers arg (#3) is unused, can it be removed?
png_write_frame_head(mPNG, mPNGinfo, nsnull,
aWidth, aHeight, x_offset, y_offset,
delay_ms, 1000, dispose_op, blend_op);
}
#endif
// Stride is the padded width of each row, so it better be longer
// (I'm afraid people will not understand what stride means, so
// check it well)
if ((aInputFormat == INPUT_FORMAT_RGB &&
aStride < aWidth * 3) ||
((aInputFormat == INPUT_FORMAT_RGBA ||
aInputFormat == INPUT_FORMAT_HOSTARGB) &&
aStride < aWidth * 4)) {
NS_WARNING("Invalid stride for InitFromData/AddImageFrame");
return NS_ERROR_INVALID_ARG;
}
#ifdef PNG_WRITE_FILTER_SUPPORTED
png_set_filter(mPNG, PNG_FILTER_TYPE_BASE, PNG_FILTER_VALUE_NONE);
#endif
// write each row: if we add more input formats, we may want to
// generalize the conversions
if (aInputFormat == INPUT_FORMAT_HOSTARGB) {
// PNG requires RGBA with post-multiplied alpha, so we need to
// convert
PRUint8* row = new PRUint8[aWidth * 4];
for (PRUint32 y = 0; y < aHeight; y ++) {
ConvertHostARGBRow(&aData[y * aStride], row, aWidth, useTransparency);
png_write_row(mPNG, row);
}
delete[] row;
} else if (aInputFormat == INPUT_FORMAT_RGBA && ! useTransparency) {
// RBGA, but we need to strip the alpha
PRUint8* row = new PRUint8[aWidth * 4];
for (PRUint32 y = 0; y < aHeight; y ++) {
StripAlpha(&aData[y * aStride], row, aWidth);
png_write_row(mPNG, row);
}
delete[] row;
} else if (aInputFormat == INPUT_FORMAT_RGB ||
aInputFormat == INPUT_FORMAT_RGBA) {
// simple RBG(A), no conversion needed
for (PRUint32 y = 0; y < aHeight; y ++) {
png_write_row(mPNG, (PRUint8*)&aData[y * aStride]);
}
} else {
NS_NOTREACHED("Bad format type");
return NS_ERROR_INVALID_ARG;
}
#ifdef PNG_APNG_SUPPORTED
if (mIsAnimation) {
png_write_frame_tail(mPNG, mPNGinfo);
}
#endif
return NS_OK;
}
NS_IMETHODIMP nsPNGEncoder::EndImageEncode()
{
// must be initialized
if (mImageBuffer == nsnull)
return NS_ERROR_NOT_INITIALIZED;
// EndImageEncode has already been called, or some error
// occurred earlier
if (!mPNG)
return NS_BASE_STREAM_CLOSED;
// libpng's error handler jumps back here upon an error.
if (setjmp(png_jmpbuf(mPNG))) {
png_destroy_write_struct(&mPNG, &mPNGinfo);
return NS_ERROR_FAILURE;
}
png_write_end(mPNG, mPNGinfo);
png_destroy_write_struct(&mPNG, &mPNGinfo);
mFinished = true;
NotifyListener();
// if output callback can't get enough memory, it will free our buffer
if (!mImageBuffer)
return NS_ERROR_OUT_OF_MEMORY;
return NS_OK;
}
nsresult
nsPNGEncoder::ParseOptions(const nsAString& aOptions,
bool* useTransparency,
bool* skipFirstFrame,
PRUint32* numFrames,
PRUint32* numPlays,
PRUint32* frameDispose,
PRUint32* frameBlend,
PRUint32* frameDelay,
PRUint32* offsetX,
PRUint32* offsetY)
{
#ifdef PNG_APNG_SUPPORTED
// Make a copy of aOptions, because strtok() will modify it.
nsCAutoString optionsCopy;
optionsCopy.Assign(NS_ConvertUTF16toUTF8(aOptions));
char* options = optionsCopy.BeginWriting();
while (char* token = nsCRT::strtok(options, ";", &options)) {
// If there's an '=' character, split the token around it.
char* equals = token, *value = nsnull;
while(*equals != '=' && *equals) {
++equals;
}
if (*equals == '=')
value = equals + 1;
if (value)
*equals = '\0'; // temporary null
// transparency=[yes|no|none]
if (nsCRT::strcmp(token, "transparency") == 0 && useTransparency) {
if (!value)
return NS_ERROR_INVALID_ARG;
if (nsCRT::strcmp(value, "none") == 0 ||
nsCRT::strcmp(value, "no") == 0) {
*useTransparency = false;
} else if (nsCRT::strcmp(value, "yes") == 0) {
*useTransparency = true;
} else {
return NS_ERROR_INVALID_ARG;
}
// skipfirstframe=[yes|no]
} else if (nsCRT::strcmp(token, "skipfirstframe") == 0 &&
skipFirstFrame) {
if (!value)
return NS_ERROR_INVALID_ARG;
if (nsCRT::strcmp(value, "no") == 0) {
*skipFirstFrame = false;
} else if (nsCRT::strcmp(value, "yes") == 0) {
*skipFirstFrame = true;
} else {
return NS_ERROR_INVALID_ARG;
}
// frames=#
} else if (nsCRT::strcmp(token, "frames") == 0 && numFrames) {
if (!value)
return NS_ERROR_INVALID_ARG;
if (PR_sscanf(value, "%u", numFrames) != 1) {
return NS_ERROR_INVALID_ARG;
}
// frames=0 is nonsense.
if (*numFrames == 0)
return NS_ERROR_INVALID_ARG;
// plays=#
} else if (nsCRT::strcmp(token, "plays") == 0 && numPlays) {
if (!value)
return NS_ERROR_INVALID_ARG;
// plays=0 to loop forever, otherwise play sequence specified
// number of times
if (PR_sscanf(value, "%u", numPlays) != 1)
return NS_ERROR_INVALID_ARG;
// dispose=[none|background|previous]
} else if (nsCRT::strcmp(token, "dispose") == 0 && frameDispose) {
if (!value)
return NS_ERROR_INVALID_ARG;
if (nsCRT::strcmp(value, "none") == 0) {
*frameDispose = PNG_DISPOSE_OP_NONE;
} else if (nsCRT::strcmp(value, "background") == 0) {
*frameDispose = PNG_DISPOSE_OP_BACKGROUND;
} else if (nsCRT::strcmp(value, "previous") == 0) {
*frameDispose = PNG_DISPOSE_OP_PREVIOUS;
} else {
return NS_ERROR_INVALID_ARG;
}
// blend=[source|over]
} else if (nsCRT::strcmp(token, "blend") == 0 && frameBlend) {
if (!value)
return NS_ERROR_INVALID_ARG;
if (nsCRT::strcmp(value, "source") == 0) {
*frameBlend = PNG_BLEND_OP_SOURCE;
} else if (nsCRT::strcmp(value, "over") == 0) {
*frameBlend = PNG_BLEND_OP_OVER;
} else {
return NS_ERROR_INVALID_ARG;
}
// delay=# (in ms)
} else if (nsCRT::strcmp(token, "delay") == 0 && frameDelay) {
if (!value)
return NS_ERROR_INVALID_ARG;
if (PR_sscanf(value, "%u", frameDelay) != 1)
return NS_ERROR_INVALID_ARG;
// xoffset=#
} else if (nsCRT::strcmp(token, "xoffset") == 0 && offsetX) {
if (!value)
return NS_ERROR_INVALID_ARG;
if (PR_sscanf(value, "%u", offsetX) != 1)
return NS_ERROR_INVALID_ARG;
// yoffset=#
} else if (nsCRT::strcmp(token, "yoffset") == 0 && offsetY) {
if (!value)
return NS_ERROR_INVALID_ARG;
if (PR_sscanf(value, "%u", offsetY) != 1)
return NS_ERROR_INVALID_ARG;
// unknown token name
} else
return NS_ERROR_INVALID_ARG;
if (value)
*equals = '='; // restore '=' so strtok doesn't get lost
}
#endif
return NS_OK;
}
/* void close (); */
NS_IMETHODIMP nsPNGEncoder::Close()
{
if (mImageBuffer != nsnull) {
PR_Free(mImageBuffer);
mImageBuffer = nsnull;
mImageBufferSize = 0;
mImageBufferUsed = 0;
mImageBufferReadPoint = 0;
}
return NS_OK;
}
/* unsigned long available (); */
NS_IMETHODIMP nsPNGEncoder::Available(PRUint32 *_retval)
{
if (!mImageBuffer)
return NS_BASE_STREAM_CLOSED;
*_retval = mImageBufferUsed - mImageBufferReadPoint;
return NS_OK;
}
/* [noscript] unsigned long read (in charPtr aBuf,
in unsigned long aCount); */
NS_IMETHODIMP nsPNGEncoder::Read(char * aBuf, PRUint32 aCount,
PRUint32 *_retval)
{
return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, _retval);
}
/* [noscript] unsigned long readSegments (in nsWriteSegmentFun aWriter,
in voidPtr aClosure,
in unsigned long aCount); */
NS_IMETHODIMP nsPNGEncoder::ReadSegments(nsWriteSegmentFun aWriter,
void *aClosure, PRUint32 aCount,
PRUint32 *_retval)
{
// Avoid another thread reallocing the buffer underneath us
ReentrantMonitorAutoEnter autoEnter(mReentrantMonitor);
PRUint32 maxCount = mImageBufferUsed - mImageBufferReadPoint;
if (maxCount == 0) {
*_retval = 0;
return mFinished ? NS_OK : NS_BASE_STREAM_WOULD_BLOCK;
}
if (aCount > maxCount)
aCount = maxCount;
nsresult rv =
aWriter(this, aClosure,
reinterpret_cast<const char*>(mImageBuffer+mImageBufferReadPoint),
0, aCount, _retval);
if (NS_SUCCEEDED(rv)) {
NS_ASSERTION(*_retval <= aCount, "bad write count");
mImageBufferReadPoint += *_retval;
}
// errors returned from the writer end here!
return NS_OK;
}
/* boolean isNonBlocking (); */
NS_IMETHODIMP nsPNGEncoder::IsNonBlocking(bool *_retval)
{
*_retval = true;
return NS_OK;
}
NS_IMETHODIMP nsPNGEncoder::AsyncWait(nsIInputStreamCallback *aCallback,
PRUint32 aFlags,
PRUint32 aRequestedCount,
nsIEventTarget *aTarget)
{
if (aFlags != 0)
return NS_ERROR_NOT_IMPLEMENTED;
if (mCallback || mCallbackTarget)
return NS_ERROR_UNEXPECTED;
mCallbackTarget = aTarget;
// 0 means "any number of bytes except 0"
mNotifyThreshold = aRequestedCount;
if (!aRequestedCount)
mNotifyThreshold = 1024; // We don't want to notify incessantly
// We set the callback absolutely last, because NotifyListener uses it to
// determine if someone needs to be notified. If we don't set it last,
// NotifyListener might try to fire off a notification to a null target
// which will generally cause non-threadsafe objects to be used off the main thread
mCallback = aCallback;
// What we are being asked for may be present already
NotifyListener();
return NS_OK;
}
NS_IMETHODIMP nsPNGEncoder::CloseWithStatus(nsresult aStatus)
{
return Close();
}
// nsPNGEncoder::ConvertHostARGBRow
//
// Our colors are stored with premultiplied alphas, but PNGs use
// post-multiplied alpha. This swaps to PNG-style alpha.
//
// Copied from gfx/cairo/cairo/src/cairo-png.c
void
nsPNGEncoder::ConvertHostARGBRow(const PRUint8* aSrc, PRUint8* aDest,
PRUint32 aPixelWidth,
bool aUseTransparency)
{
PRUint32 pixelStride = aUseTransparency ? 4 : 3;
for (PRUint32 x = 0; x < aPixelWidth; x ++) {
const PRUint32& pixelIn = ((const PRUint32*)(aSrc))[x];
PRUint8 *pixelOut = &aDest[x * pixelStride];
PRUint8 alpha = (pixelIn & 0xff000000) >> 24;
if (alpha == 0) {
pixelOut[0] = pixelOut[1] = pixelOut[2] = pixelOut[3] = 0;
} else {
pixelOut[0] = (((pixelIn & 0xff0000) >> 16) * 255 + alpha / 2) / alpha;
pixelOut[1] = (((pixelIn & 0x00ff00) >> 8) * 255 + alpha / 2) / alpha;
pixelOut[2] = (((pixelIn & 0x0000ff) >> 0) * 255 + alpha / 2) / alpha;
if (aUseTransparency)
pixelOut[3] = alpha;
}
}
}
// nsPNGEncoder::StripAlpha
//
// Input is RGBA, output is RGB
void
nsPNGEncoder::StripAlpha(const PRUint8* aSrc, PRUint8* aDest,
PRUint32 aPixelWidth)
{
for (PRUint32 x = 0; x < aPixelWidth; x ++) {
const PRUint8* pixelIn = &aSrc[x * 4];
PRUint8* pixelOut = &aDest[x * 3];
pixelOut[0] = pixelIn[0];
pixelOut[1] = pixelIn[1];
pixelOut[2] = pixelIn[2];
}
}
// nsPNGEncoder::WarningCallback
void // static
nsPNGEncoder::WarningCallback(png_structp png_ptr,
png_const_charp warning_msg)
{
#ifdef DEBUG
// XXX: these messages are probably useful callers...
// use nsIConsoleService?
PR_fprintf(PR_STDERR, "PNG Encoder: %s\n", warning_msg);;
#endif
}
// nsPNGEncoder::ErrorCallback
void // static
nsPNGEncoder::ErrorCallback(png_structp png_ptr,
png_const_charp error_msg)
{
#ifdef DEBUG
// XXX: these messages are probably useful callers...
// use nsIConsoleService?
PR_fprintf(PR_STDERR, "PNG Encoder: %s\n", error_msg);;
#endif
#if PNG_LIBPNG_VER < 10500
longjmp(png_ptr->jmpbuf, 1);
#else
png_longjmp(png_ptr, 1);
#endif
}
// nsPNGEncoder::WriteCallback
void // static
nsPNGEncoder::WriteCallback(png_structp png, png_bytep data,
png_size_t size)
{
nsPNGEncoder* that = static_cast<nsPNGEncoder*>(png_get_io_ptr(png));
if (! that->mImageBuffer)
return;
if (that->mImageBufferUsed + size > that->mImageBufferSize) {
// When we're reallocing the buffer we need to take the lock to ensure
// that nobody is trying to read from the buffer we are destroying
ReentrantMonitorAutoEnter autoEnter(that->mReentrantMonitor);
// expand buffer, just double each time
that->mImageBufferSize *= 2;
PRUint8* newBuf = (PRUint8*)PR_Realloc(that->mImageBuffer,
that->mImageBufferSize);
if (! newBuf) {
// can't resize, just zero (this will keep us from writing more)
PR_Free(that->mImageBuffer);
that->mImageBuffer = nsnull;
that->mImageBufferSize = 0;
that->mImageBufferUsed = 0;
return;
}
that->mImageBuffer = newBuf;
}
memcpy(&that->mImageBuffer[that->mImageBufferUsed], data, size);
that->mImageBufferUsed += size;
that->NotifyListener();
}
void
nsPNGEncoder::NotifyListener()
{
// We might call this function on multiple threads (any threads that call
// AsyncWait and any that do encoding) so we lock to avoid notifying the
// listener twice about the same data (which generally leads to a truncated
// image).
ReentrantMonitorAutoEnter autoEnter(mReentrantMonitor);
if (mCallback &&
(mImageBufferUsed - mImageBufferReadPoint >= mNotifyThreshold ||
mFinished)) {
nsCOMPtr<nsIInputStreamCallback> callback;
if (mCallbackTarget) {
NS_NewInputStreamReadyEvent(getter_AddRefs(callback),
mCallback,
mCallbackTarget);
} else {
callback = mCallback;
}
NS_ASSERTION(callback, "Shouldn't fail to make the callback");
// Null the callback first because OnInputStreamReady could reenter
// AsyncWait
mCallback = nsnull;
mCallbackTarget = nsnull;
mNotifyThreshold = 0;
callback->OnInputStreamReady(this);
}
}
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