JPEGImageDecoder.cpp [plain text]
#include "config.h"
#include "JPEGImageDecoder.h"
#include <stdio.h> // Needed by jpeglib.h for FILE.
#if OS(WINCE) || PLATFORM(BREWMP_SIMULATOR)
#undef FAR
#define XMD_H
#endif
extern "C" {
#include "jpeglib.h"
}
#include <setjmp.h>
namespace WebCore {
struct decoder_error_mgr {
struct jpeg_error_mgr pub; jmp_buf setjmp_buffer; };
enum jstate {
JPEG_HEADER, JPEG_START_DECOMPRESS,
JPEG_DECOMPRESS_PROGRESSIVE, JPEG_DECOMPRESS_SEQUENTIAL, JPEG_DONE,
JPEG_ERROR
};
void init_source(j_decompress_ptr jd);
boolean fill_input_buffer(j_decompress_ptr jd);
void skip_input_data(j_decompress_ptr jd, long num_bytes);
void term_source(j_decompress_ptr jd);
void error_exit(j_common_ptr cinfo);
struct decoder_source_mgr {
struct jpeg_source_mgr pub;
JPEGImageReader* decoder;
};
class JPEGImageReader
{
public:
JPEGImageReader(JPEGImageDecoder* decoder)
: m_decoder(decoder)
, m_bufferLength(0)
, m_bytesToSkip(0)
, m_state(JPEG_HEADER)
, m_samples(0)
{
memset(&m_info, 0, sizeof(jpeg_decompress_struct));
m_info.err = jpeg_std_error(&m_err.pub);
m_err.pub.error_exit = error_exit;
jpeg_create_decompress(&m_info);
decoder_source_mgr* src = 0;
if (!m_info.src) {
src = (decoder_source_mgr*)fastCalloc(sizeof(decoder_source_mgr), 1);
if (!src) {
m_state = JPEG_ERROR;
return;
}
}
m_info.src = (jpeg_source_mgr*)src;
src->pub.init_source = init_source;
src->pub.fill_input_buffer = fill_input_buffer;
src->pub.skip_input_data = skip_input_data;
src->pub.resync_to_restart = jpeg_resync_to_restart;
src->pub.term_source = term_source;
src->decoder = this;
}
~JPEGImageReader()
{
close();
}
void close()
{
decoder_source_mgr* src = (decoder_source_mgr*)m_info.src;
if (src)
fastFree(src);
m_info.src = 0;
jpeg_destroy_decompress(&m_info);
}
void skipBytes(long numBytes)
{
decoder_source_mgr* src = (decoder_source_mgr*)m_info.src;
long bytesToSkip = std::min(numBytes, (long)src->pub.bytes_in_buffer);
src->pub.bytes_in_buffer -= (size_t)bytesToSkip;
src->pub.next_input_byte += bytesToSkip;
m_bytesToSkip = std::max(numBytes - bytesToSkip, static_cast<long>(0));
}
bool decode(const Vector<char>& data, bool onlySize)
{
m_decodingSizeOnly = onlySize;
unsigned newByteCount = data.size() - m_bufferLength;
unsigned readOffset = m_bufferLength - m_info.src->bytes_in_buffer;
m_info.src->bytes_in_buffer += newByteCount;
m_info.src->next_input_byte = (JOCTET*)(data.data()) + readOffset;
if (m_bytesToSkip)
skipBytes(m_bytesToSkip);
m_bufferLength = data.size();
if (setjmp(m_err.setjmp_buffer)) {
close();
return m_decoder->setFailed();
}
switch (m_state) {
case JPEG_HEADER:
if (jpeg_read_header(&m_info, true) == JPEG_SUSPENDED)
return false;
switch (m_info.jpeg_color_space) {
case JCS_GRAYSCALE:
case JCS_RGB:
case JCS_YCbCr:
m_info.out_color_space = JCS_RGB;
break;
case JCS_CMYK:
case JCS_YCCK:
m_info.out_color_space = JCS_CMYK;
break;
default:
return m_decoder->setFailed();
}
m_info.buffered_image = jpeg_has_multiple_scans(&m_info);
jpeg_calc_output_dimensions(&m_info);
m_samples = (*m_info.mem->alloc_sarray)((j_common_ptr) &m_info, JPOOL_IMAGE, m_info.output_width * 4, 1);
m_state = JPEG_START_DECOMPRESS;
if (!m_decoder->setSize(m_info.image_width, m_info.image_height))
return m_decoder->setFailed();
if (m_decodingSizeOnly) {
m_bufferLength -= m_info.src->bytes_in_buffer;
m_info.src->bytes_in_buffer = 0;
return true;
}
case JPEG_START_DECOMPRESS:
m_info.dct_method = JDCT_ISLOW;
m_info.dither_mode = JDITHER_FS;
m_info.do_fancy_upsampling = true;
m_info.enable_2pass_quant = false;
m_info.do_block_smoothing = true;
if (!jpeg_start_decompress(&m_info))
return false;
m_state = (m_info.buffered_image) ? JPEG_DECOMPRESS_PROGRESSIVE : JPEG_DECOMPRESS_SEQUENTIAL;
case JPEG_DECOMPRESS_SEQUENTIAL:
if (m_state == JPEG_DECOMPRESS_SEQUENTIAL) {
if (!m_decoder->outputScanlines())
return false;
ASSERT(m_info.output_scanline == m_info.output_height);
m_state = JPEG_DONE;
}
case JPEG_DECOMPRESS_PROGRESSIVE:
if (m_state == JPEG_DECOMPRESS_PROGRESSIVE) {
int status;
do {
status = jpeg_consume_input(&m_info);
} while ((status != JPEG_SUSPENDED) && (status != JPEG_REACHED_EOI));
for (;;) {
if (!m_info.output_scanline) {
int scan = m_info.input_scan_number;
if (!m_info.output_scan_number && (scan > 1) && (status != JPEG_REACHED_EOI))
--scan;
if (!jpeg_start_output(&m_info, scan))
return false; }
if (m_info.output_scanline == 0xffffff)
m_info.output_scanline = 0;
if (!m_decoder->outputScanlines()) {
if (!m_info.output_scanline)
m_info.output_scanline = 0xffffff;
return false; }
if (m_info.output_scanline == m_info.output_height) {
if (!jpeg_finish_output(&m_info))
return false;
if (jpeg_input_complete(&m_info) && (m_info.input_scan_number == m_info.output_scan_number))
break;
m_info.output_scanline = 0;
}
}
m_state = JPEG_DONE;
}
case JPEG_DONE:
return jpeg_finish_decompress(&m_info);
case JPEG_ERROR:
return m_decoder->setFailed();
}
return true;
}
jpeg_decompress_struct* info() { return &m_info; }
JSAMPARRAY samples() const { return m_samples; }
JPEGImageDecoder* decoder() { return m_decoder; }
private:
JPEGImageDecoder* m_decoder;
unsigned m_bufferLength;
int m_bytesToSkip;
bool m_decodingSizeOnly;
bool m_initialized;
jpeg_decompress_struct m_info;
decoder_error_mgr m_err;
jstate m_state;
JSAMPARRAY m_samples;
};
void error_exit(j_common_ptr cinfo)
{
decoder_error_mgr *err = (decoder_error_mgr *) cinfo->err;
longjmp(err->setjmp_buffer, -1);
}
void init_source(j_decompress_ptr jd)
{
}
void skip_input_data(j_decompress_ptr jd, long num_bytes)
{
decoder_source_mgr *src = (decoder_source_mgr *)jd->src;
src->decoder->skipBytes(num_bytes);
}
boolean fill_input_buffer(j_decompress_ptr jd)
{
return false;
}
void term_source(j_decompress_ptr jd)
{
decoder_source_mgr *src = (decoder_source_mgr *)jd->src;
src->decoder->decoder()->jpegComplete();
}
JPEGImageDecoder::JPEGImageDecoder()
{
}
JPEGImageDecoder::~JPEGImageDecoder()
{
}
bool JPEGImageDecoder::isSizeAvailable()
{
if (!ImageDecoder::isSizeAvailable())
decode(true);
return ImageDecoder::isSizeAvailable();
}
bool JPEGImageDecoder::setSize(unsigned width, unsigned height)
{
if (!ImageDecoder::setSize(width, height))
return false;
prepareScaleDataIfNecessary();
return true;
}
RGBA32Buffer* JPEGImageDecoder::frameBufferAtIndex(size_t index)
{
if (index)
return 0;
if (m_frameBufferCache.isEmpty())
m_frameBufferCache.resize(1);
RGBA32Buffer& frame = m_frameBufferCache[0];
if (frame.status() != RGBA32Buffer::FrameComplete)
decode(false);
return &frame;
}
bool JPEGImageDecoder::outputScanlines()
{
if (m_frameBufferCache.isEmpty())
return false;
RGBA32Buffer& buffer = m_frameBufferCache[0];
if (buffer.status() == RGBA32Buffer::FrameEmpty) {
if (!buffer.setSize(scaledSize().width(), scaledSize().height()))
return setFailed();
buffer.setStatus(RGBA32Buffer::FramePartial);
buffer.setHasAlpha(false);
buffer.setRect(IntRect(IntPoint(), size()));
}
jpeg_decompress_struct* info = m_reader->info();
JSAMPARRAY samples = m_reader->samples();
while (info->output_scanline < info->output_height) {
int sourceY = info->output_scanline;
if (jpeg_read_scanlines(info, samples, 1) != 1)
return false;
int destY = scaledY(sourceY);
if (destY < 0)
continue;
int width = m_scaled ? m_scaledColumns.size() : info->output_width;
for (int x = 0; x < width; ++x) {
JSAMPLE* jsample = *samples + (m_scaled ? m_scaledColumns[x] : x) * ((info->out_color_space == JCS_RGB) ? 3 : 4);
if (info->out_color_space == JCS_RGB)
buffer.setRGBA(x, destY, jsample[0], jsample[1], jsample[2], 0xFF);
else if (info->out_color_space == JCS_CMYK) {
unsigned k = jsample[3];
buffer.setRGBA(x, destY, jsample[0] * k / 255, jsample[1] * k / 255, jsample[2] * k / 255, 0xFF);
} else {
ASSERT_NOT_REACHED();
return setFailed();
}
}
}
return true;
}
void JPEGImageDecoder::jpegComplete()
{
if (m_frameBufferCache.isEmpty())
return;
m_frameBufferCache[0].setStatus(RGBA32Buffer::FrameComplete);
}
void JPEGImageDecoder::decode(bool onlySize)
{
if (failed())
return;
if (!m_reader)
m_reader.set(new JPEGImageReader(this));
if (!m_reader->decode(m_data->buffer(), onlySize) && isAllDataReceived())
setFailed();
if (failed() || (!m_frameBufferCache.isEmpty() && m_frameBufferCache[0].status() == RGBA32Buffer::FrameComplete))
m_reader.clear();
}
}