diff options
Diffstat (limited to 'WebCore/platform/image-decoders/jpeg/JPEGImageDecoder.cpp')
| -rw-r--r-- | WebCore/platform/image-decoders/jpeg/JPEGImageDecoder.cpp | 368 |
1 files changed, 168 insertions, 200 deletions
diff --git a/WebCore/platform/image-decoders/jpeg/JPEGImageDecoder.cpp b/WebCore/platform/image-decoders/jpeg/JPEGImageDecoder.cpp index aaa9047..9ed20b6 100644 --- a/WebCore/platform/image-decoders/jpeg/JPEGImageDecoder.cpp +++ b/WebCore/platform/image-decoders/jpeg/JPEGImageDecoder.cpp @@ -59,18 +59,17 @@ extern "C" { namespace WebCore { struct decoder_error_mgr { - struct jpeg_error_mgr pub; /* "public" fields for IJG library*/ - jmp_buf setjmp_buffer; /* For handling catastropic errors */ + struct jpeg_error_mgr pub; // "public" fields for IJG library + jmp_buf setjmp_buffer; // For handling catastropic errors }; enum jstate { - JPEG_HEADER, /* Reading JFIF headers */ + JPEG_HEADER, // Reading JFIF headers JPEG_START_DECOMPRESS, - JPEG_DECOMPRESS_PROGRESSIVE, /* Output progressive pixels */ - JPEG_DECOMPRESS_SEQUENTIAL, /* Output sequential pixels */ + JPEG_DECOMPRESS_PROGRESSIVE, // Output progressive pixels + JPEG_DECOMPRESS_SEQUENTIAL, // Output sequential pixels JPEG_DONE, - JPEG_SINK_NON_JPEG_TRAILER, /* Some image files have a */ - /* non-JPEG trailer */ + JPEG_SINK_NON_JPEG_TRAILER, // Some image files have a non-JPEG trailer JPEG_ERROR }; @@ -80,14 +79,12 @@ 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); -/* - * Implementation of a JPEG src object that understands our state machine - */ +// Implementation of a JPEG src object that understands our state machine struct decoder_source_mgr { - /* public fields; must be first in this struct! */ - struct jpeg_source_mgr pub; + // public fields; must be first in this struct! + struct jpeg_source_mgr pub; - JPEGImageReader *decoder; + JPEGImageReader* decoder; }; class JPEGImageReader @@ -102,11 +99,11 @@ public: { memset(&m_info, 0, sizeof(jpeg_decompress_struct)); - /* We set up the normal JPEG error routines, then override error_exit. */ + // We set up the normal JPEG error routines, then override error_exit. m_info.err = jpeg_std_error(&m_err.pub); m_err.pub.error_exit = error_exit; - /* Allocate and initialize JPEG decompression object */ + // Allocate and initialize JPEG decompression object. jpeg_create_decompress(&m_info); decoder_source_mgr* src = 0; @@ -120,7 +117,7 @@ public: m_info.src = (jpeg_source_mgr*)src; - /* Set up callback functions. */ + // Set up callback functions. src->pub.init_source = init_source; src->pub.fill_input_buffer = fill_input_buffer; src->pub.skip_input_data = skip_input_data; @@ -148,22 +145,20 @@ public: long bytesToSkip = std::min(num_bytes, (long)src->pub.bytes_in_buffer); src->pub.bytes_in_buffer -= (size_t)bytesToSkip; src->pub.next_input_byte += bytesToSkip; - - if (num_bytes > bytesToSkip) - m_bytesToSkip = (size_t)(num_bytes - bytesToSkip); - else - m_bytesToSkip = 0; + + m_bytesToSkip = std::max(num_bytes - bytesToSkip, static_cast<long>(0)); } - bool decode(const Vector<char>& data, bool sizeOnly) { - m_decodingSizeOnly = sizeOnly; - + 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 we still have bytes to skip, try to skip those now. if (m_bytesToSkip) skipBytes(m_bytesToSkip); @@ -178,172 +173,150 @@ public: } switch (m_state) { - case JPEG_HEADER: - { - /* Read file parameters with jpeg_read_header() */ - if (jpeg_read_header(&m_info, true) == JPEG_SUSPENDED) - return true; /* I/O suspension */ - - /* let libjpeg take care of gray->RGB and YCbCr->RGB conversions */ - 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: - // jpeglib cannot convert these to rgb, but it can - // convert ycck to cmyk - m_info.out_color_space = JCS_CMYK; - break; - default: - m_state = JPEG_ERROR; - return false; - } - - /* - * Don't allocate a giant and superfluous memory buffer - * when the image is a sequential JPEG. - */ - m_info.buffered_image = jpeg_has_multiple_scans(&m_info); - - /* Used to set up image size so arrays can be allocated */ - jpeg_calc_output_dimensions(&m_info); - - /* - * Make a one-row-high sample array that will go away - * when done with image. Always make it big enough to - * hold an RGB row. Since this uses the IJG memory - * manager, it must be allocated before the call to - * jpeg_start_compress(). - */ - int row_stride = m_info.output_width * 4; // RGBA buffer + case JPEG_HEADER: + // Read file parameters with jpeg_read_header(). + if (jpeg_read_header(&m_info, true) == JPEG_SUSPENDED) + return true; // I/O suspension. + + // Let libjpeg take care of gray->RGB and YCbCr->RGB conversions. + 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: + // jpeglib cannot convert these to rgb, but it can convert ycck + // to cmyk. + m_info.out_color_space = JCS_CMYK; + break; + default: + m_state = JPEG_ERROR; + return false; + } + // Don't allocate a giant and superfluous memory buffer when the + // image is a sequential JPEG. + m_info.buffered_image = jpeg_has_multiple_scans(&m_info); - m_samples = (*m_info.mem->alloc_sarray)((j_common_ptr) &m_info, - JPOOL_IMAGE, - row_stride, 1); + // Used to set up image size so arrays can be allocated. + jpeg_calc_output_dimensions(&m_info); - m_state = JPEG_START_DECOMPRESS; + // Make a one-row-high sample array that will go away when done with + // image. Always make it big enough to hold an RGB row. Since this + // uses the IJG memory manager, it must be allocated before the call + // to jpeg_start_compress(). + m_samples = (*m_info.mem->alloc_sarray)((j_common_ptr) &m_info, JPOOL_IMAGE, m_info.output_width * 4, 1); - // We can fill in the size now that the header is available. - if (!m_decoder->setSize(m_info.image_width, m_info.image_height)) { - m_state = JPEG_ERROR; - return false; - } + m_state = JPEG_START_DECOMPRESS; - if (m_decodingSizeOnly) { - // We can stop here. - // Reduce our buffer length and available data. - m_bufferLength -= m_info.src->bytes_in_buffer; - m_info.src->bytes_in_buffer = 0; - return true; - } + // We can fill in the size now that the header is available. + if (!m_decoder->setSize(m_info.image_width, m_info.image_height)) { + m_state = JPEG_ERROR; + return false; } - case JPEG_START_DECOMPRESS: - { - /* Set parameters for decompression */ - /* FIXME -- Should reset dct_method and dither mode - * for final pass of progressive JPEG - */ - 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; - - /* Start decompressor */ - if (!jpeg_start_decompress(&m_info)) - return true; /* I/O suspension */ - - /* If this is a progressive JPEG ... */ - m_state = (m_info.buffered_image) ? JPEG_DECOMPRESS_PROGRESSIVE : JPEG_DECOMPRESS_SEQUENTIAL; + if (m_decodingSizeOnly) { + // We can stop here. Reduce our buffer length and available + // data. + m_bufferLength -= m_info.src->bytes_in_buffer; + m_info.src->bytes_in_buffer = 0; + return true; } - - case JPEG_DECOMPRESS_SEQUENTIAL: - { - if (m_state == JPEG_DECOMPRESS_SEQUENTIAL) { - - if (!m_decoder->outputScanlines()) - return true; /* I/O suspension */ - - /* If we've completed image output ... */ - ASSERT(m_info.output_scanline == m_info.output_height); - m_state = JPEG_DONE; - } + // FALL THROUGH + + case JPEG_START_DECOMPRESS: + // Set parameters for decompression. + // FIXME -- Should reset dct_method and dither mode for final pass + // of progressive JPEG. + 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; + + // Start decompressor. + if (!jpeg_start_decompress(&m_info)) + return true; // I/O suspension. + + // If this is a progressive JPEG ... + m_state = (m_info.buffered_image) ? JPEG_DECOMPRESS_PROGRESSIVE : JPEG_DECOMPRESS_SEQUENTIAL; + // FALL THROUGH + + case JPEG_DECOMPRESS_SEQUENTIAL: + if (m_state == JPEG_DECOMPRESS_SEQUENTIAL) { + + if (!m_decoder->outputScanlines()) + return true; // I/O suspension. + + // If we've completed image output... + ASSERT(m_info.output_scanline == m_info.output_height); + m_state = JPEG_DONE; } + // FALL THROUGH + + 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 we haven't displayed anything yet + // (output_scan_number == 0) and we have enough data for + // a complete scan, force output of the last full scan. + if (!m_info.output_scan_number && (scan > 1) && (status != JPEG_REACHED_EOI)) + --scan; + + if (!jpeg_start_output(&m_info, scan)) + return true; // I/O suspension. + } + + if (m_info.output_scanline == 0xffffff) + m_info.output_scanline = 0; - 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 == 0) { - int scan = m_info.input_scan_number; - - /* if we haven't displayed anything yet (output_scan_number==0) - and we have enough data for a complete scan, force output - of the last full scan */ - if ((m_info.output_scan_number == 0) && - (scan > 1) && - (status != JPEG_REACHED_EOI)) - scan--; - - if (!jpeg_start_output(&m_info, scan)) - return true; /* I/O suspension */ - } - - if (m_info.output_scanline == 0xffffff) - m_info.output_scanline = 0; - - if (!m_decoder->outputScanlines()) { - if (m_info.output_scanline == 0) - /* didn't manage to read any lines - flag so we don't call - jpeg_start_output() multiple times for the same scan */ - m_info.output_scanline = 0xffffff; - return true; /* I/O suspension */ - } - - if (m_info.output_scanline == m_info.output_height) { - if (!jpeg_finish_output(&m_info)) - return true; /* I/O suspension */ - - if (jpeg_input_complete(&m_info) && - (m_info.input_scan_number == m_info.output_scan_number)) - break; - - m_info.output_scanline = 0; - } + if (!m_decoder->outputScanlines()) { + if (!m_info.output_scanline) + // Didn't manage to read any lines - flag so we + // don't call jpeg_start_output() multiple times for + // the same scan. + m_info.output_scanline = 0xffffff; + return true; // I/O suspension. } - m_state = JPEG_DONE; - } - } + if (m_info.output_scanline == m_info.output_height) { + if (!jpeg_finish_output(&m_info)) + return true; // I/O suspension. - case JPEG_DONE: - { - /* Finish decompression */ - if (!jpeg_finish_decompress(&m_info)) - return true; /* I/O suspension */ + if (jpeg_input_complete(&m_info) && (m_info.input_scan_number == m_info.output_scan_number)) + break; - m_state = JPEG_SINK_NON_JPEG_TRAILER; + m_info.output_scanline = 0; + } + } - /* we're done */ - break; + m_state = JPEG_DONE; } - - case JPEG_SINK_NON_JPEG_TRAILER: - break; + // FALL THROUGH - case JPEG_ERROR: - break; + case JPEG_DONE: + // Finish decompression. + if (!jpeg_finish_decompress(&m_info)) + return true; // I/O suspension. + + m_state = JPEG_SINK_NON_JPEG_TRAILER; + break; + + case JPEG_SINK_NON_JPEG_TRAILER: + break; + + case JPEG_ERROR: + break; } return true; @@ -367,10 +340,10 @@ private: JSAMPARRAY m_samples; }; -/* Override the standard error method in the IJG JPEG decoder code. */ +// Override the standard error method in the IJG JPEG decoder code. void error_exit(j_common_ptr cinfo) { - /* Return control to the setjmp point. */ + // Return control to the setjmp point. decoder_error_mgr *err = (decoder_error_mgr *) cinfo->err; longjmp(err->setjmp_buffer, -1); } @@ -388,12 +361,12 @@ void skip_input_data(j_decompress_ptr jd, long num_bytes) boolean fill_input_buffer(j_decompress_ptr jd) { // Our decode step always sets things up properly, so if this method is ever - // called, then we have hit the end of the buffer. A return value of FALSE indicates - // that we have no data to supply yet. + // called, then we have hit the end of the buffer. A return value of false + // indicates that we have no data to supply yet. return false; } -void term_source (j_decompress_ptr jd) +void term_source(j_decompress_ptr jd) { decoder_source_mgr *src = (decoder_source_mgr *)jd->src; src->decoder->decoder()->jpegComplete(); @@ -407,21 +380,17 @@ JPEGImageDecoder::~JPEGImageDecoder() { } -// Take the data and store it. void JPEGImageDecoder::setData(SharedBuffer* data, bool allDataReceived) { if (m_failed) return; - // Cache our new data. ImageDecoder::setData(data, allDataReceived); - // Create the JPEG reader. if (!m_reader && !m_failed) m_reader.set(new JPEGImageReader(this)); } -// Whether or not the size information has been decoded yet. bool JPEGImageDecoder::isSizeAvailable() { if (!ImageDecoder::isSizeAvailable() && !failed() && m_reader) @@ -434,6 +403,7 @@ bool JPEGImageDecoder::setSize(unsigned width, unsigned height) { if (!ImageDecoder::setSize(width, height)) return false; + prepareScaleDataIfNecessary(); return true; } @@ -448,23 +418,10 @@ RGBA32Buffer* JPEGImageDecoder::frameBufferAtIndex(size_t index) RGBA32Buffer& frame = m_frameBufferCache[0]; if (frame.status() != RGBA32Buffer::FrameComplete && m_reader) - // Decode this frame. - decode(); + decode(false); return &frame; } -// Feed data to the JPEG reader. -void JPEGImageDecoder::decode(bool sizeOnly) -{ - if (m_failed) - return; - - m_failed = !m_reader->decode(m_data->buffer(), sizeOnly); - - if (m_failed || (!m_frameBufferCache.isEmpty() && m_frameBufferCache[0].status() == RGBA32Buffer::FrameComplete)) - m_reader.clear(); -} - bool JPEGImageDecoder::outputScanlines() { if (m_frameBufferCache.isEmpty()) @@ -531,9 +488,20 @@ void JPEGImageDecoder::jpegComplete() if (m_frameBufferCache.isEmpty()) return; - // Hand back an appropriately sized buffer, even if the image ended up being empty. - RGBA32Buffer& buffer = m_frameBufferCache[0]; - buffer.setStatus(RGBA32Buffer::FrameComplete); + // Hand back an appropriately sized buffer, even if the image ended up being + // empty. + m_frameBufferCache[0].setStatus(RGBA32Buffer::FrameComplete); +} + +void JPEGImageDecoder::decode(bool onlySize) +{ + if (m_failed) + return; + + m_failed = !m_reader->decode(m_data->buffer(), onlySize); + + if (m_failed || (!m_frameBufferCache.isEmpty() && m_frameBufferCache[0].status() == RGBA32Buffer::FrameComplete)) + m_reader.clear(); } } |