The Tor Browser: comparison media/libyuv/source/mjpeg

--1:000000000000
+:1762475b0849
+/*
+*  Copyright 2012 The LibYuv Project Authors. All rights reserved.
+*
+*  Use of this source code is governed by a BSD-style license
+*  that can be found in the LICENSE 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.
+*/
+#include "libyuv/mjpeg_decoder.h"
+#ifdef HAVE_JPEG
+#include <assert.h>
+#if !defined(__pnacl__) && !defined(__CLR_VER) && !defined(COVERAGE_ENABLED) &&\
+!defined(TARGET_IPHONE_SIMULATOR)
+// Must be included before jpeglib.
+#include <setjmp.h>
+#define HAVE_SETJMP
+#endif
+struct FILE;  // For jpeglib.h.
+// C++ build requires extern C for jpeg internals.
+#ifdef __cplusplus
+extern "C" {
+#endif
+#include <jpeglib.h>
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+#include "libyuv/planar_functions.h"  // For CopyPlane().
+namespace libyuv {
+#ifdef HAVE_SETJMP
+struct SetJmpErrorMgr {
+jpeg_error_mgr base;  // Must be at the top
+jmp_buf setjmp_buffer;
+};
+#endif
+const int MJpegDecoder::kColorSpaceUnknown = JCS_UNKNOWN;
+const int MJpegDecoder::kColorSpaceGrayscale = JCS_GRAYSCALE;
+const int MJpegDecoder::kColorSpaceRgb = JCS_RGB;
+const int MJpegDecoder::kColorSpaceYCbCr = JCS_YCbCr;
+const int MJpegDecoder::kColorSpaceCMYK = JCS_CMYK;
+const int MJpegDecoder::kColorSpaceYCCK = JCS_YCCK;
+MJpegDecoder::MJpegDecoder()
+: has_scanline_padding_(LIBYUV_FALSE),
+num_outbufs_(0),
+scanlines_(NULL),
+scanlines_sizes_(NULL),
+databuf_(NULL),
+databuf_strides_(NULL) {
+decompress_struct_ = new jpeg_decompress_struct;
+source_mgr_ = new jpeg_source_mgr;
+#ifdef HAVE_SETJMP
+error_mgr_ = new SetJmpErrorMgr;
+decompress_struct_->err = jpeg_std_error(&error_mgr_->base);
+// Override standard exit()-based error handler.
+error_mgr_->base.error_exit = &ErrorHandler;
+#endif
+decompress_struct_->client_data = NULL;
+source_mgr_->init_source = &init_source;
+source_mgr_->fill_input_buffer = &fill_input_buffer;
+source_mgr_->skip_input_data = &skip_input_data;
+source_mgr_->resync_to_restart = &jpeg_resync_to_restart;
+source_mgr_->term_source = &term_source;
+jpeg_create_decompress(decompress_struct_);
+decompress_struct_->src = source_mgr_;
+buf_vec_.buffers = &buf_;
+buf_vec_.len = 1;
+}
+MJpegDecoder::~MJpegDecoder() {
+jpeg_destroy_decompress(decompress_struct_);
+delete decompress_struct_;
+delete source_mgr_;
+#ifdef HAVE_SETJMP
+delete error_mgr_;
+#endif
+DestroyOutputBuffers();
+}
+LIBYUV_BOOL MJpegDecoder::LoadFrame(const uint8* src, size_t src_len) {
+if (!ValidateJpeg(src, src_len)) {
+return LIBYUV_FALSE;
+}
+buf_.data = src;
+buf_.len = (int)(src_len);
+buf_vec_.pos = 0;
+decompress_struct_->client_data = &buf_vec_;
+#ifdef HAVE_SETJMP
+if (setjmp(error_mgr_->setjmp_buffer)) {
+// We called jpeg_read_header, it experienced an error, and we called
+// longjmp() and rewound the stack to here. Return error.
+return LIBYUV_FALSE;
+}
+#endif
+if (jpeg_read_header(decompress_struct_, TRUE) != JPEG_HEADER_OK) {
+// ERROR: Bad MJPEG header
+return LIBYUV_FALSE;
+}
+AllocOutputBuffers(GetNumComponents());
+for (int i = 0; i < num_outbufs_; ++i) {
+int scanlines_size = GetComponentScanlinesPerImcuRow(i);
+if (scanlines_sizes_[i] != scanlines_size) {
+if (scanlines_[i]) {
+delete scanlines_[i];
+}
+scanlines_[i] = new uint8* [scanlines_size];
+scanlines_sizes_[i] = scanlines_size;
+}
+// We allocate padding for the final scanline to pad it up to DCTSIZE bytes
+// to avoid memory errors, since jpeglib only reads full MCUs blocks. For
+// the preceding scanlines, the padding is not needed/wanted because the
+// following addresses will already be valid (they are the initial bytes of
+// the next scanline) and will be overwritten when jpeglib writes out that
+// next scanline.
+int databuf_stride = GetComponentStride(i);
+int databuf_size = scanlines_size * databuf_stride;
+if (databuf_strides_[i] != databuf_stride) {
+if (databuf_[i]) {
+delete databuf_[i];
+}
+databuf_[i] = new uint8[databuf_size];
+databuf_strides_[i] = databuf_stride;
+}
+if (GetComponentStride(i) != GetComponentWidth(i)) {
+has_scanline_padding_ = LIBYUV_TRUE;
+}
+}
+return LIBYUV_TRUE;
+}
+static int DivideAndRoundUp(int numerator, int denominator) {
+return (numerator + denominator - 1) / denominator;
+}
+static int DivideAndRoundDown(int numerator, int denominator) {
+return numerator / denominator;
+}
+// Returns width of the last loaded frame.
+int MJpegDecoder::GetWidth() {
+return decompress_struct_->image_width;
+}
+// Returns height of the last loaded frame.
+int MJpegDecoder::GetHeight() {
+return decompress_struct_->image_height;
+}
+// Returns format of the last loaded frame. The return value is one of the
+// kColorSpace* constants.
+int MJpegDecoder::GetColorSpace() {
+return decompress_struct_->jpeg_color_space;
+}
+// Number of color components in the color space.
+int MJpegDecoder::GetNumComponents() {
+return decompress_struct_->num_components;
+}
+// Sample factors of the n-th component.
+int MJpegDecoder::GetHorizSampFactor(int component) {
+return decompress_struct_->comp_info[component].h_samp_factor;
+}
+int MJpegDecoder::GetVertSampFactor(int component) {
+return decompress_struct_->comp_info[component].v_samp_factor;
+}
+int MJpegDecoder::GetHorizSubSampFactor(int component) {
+return decompress_struct_->max_h_samp_factor /
+GetHorizSampFactor(component);
+}
+int MJpegDecoder::GetVertSubSampFactor(int component) {
+return decompress_struct_->max_v_samp_factor /
+GetVertSampFactor(component);
+}
+int MJpegDecoder::GetImageScanlinesPerImcuRow() {
+return decompress_struct_->max_v_samp_factor * DCTSIZE;
+}
+int MJpegDecoder::GetComponentScanlinesPerImcuRow(int component) {
+int vs = GetVertSubSampFactor(component);
+return DivideAndRoundUp(GetImageScanlinesPerImcuRow(), vs);
+}
+int MJpegDecoder::GetComponentWidth(int component) {
+int hs = GetHorizSubSampFactor(component);
+return DivideAndRoundUp(GetWidth(), hs);
+}
+int MJpegDecoder::GetComponentHeight(int component) {
+int vs = GetVertSubSampFactor(component);
+return DivideAndRoundUp(GetHeight(), vs);
+}
+// Get width in bytes padded out to a multiple of DCTSIZE
+int MJpegDecoder::GetComponentStride(int component) {
+return (GetComponentWidth(component) + DCTSIZE - 1) & ~(DCTSIZE - 1);
+}
+int MJpegDecoder::GetComponentSize(int component) {
+return GetComponentWidth(component) * GetComponentHeight(component);
+}
+LIBYUV_BOOL MJpegDecoder::UnloadFrame() {
+#ifdef HAVE_SETJMP
+if (setjmp(error_mgr_->setjmp_buffer)) {
+// We called jpeg_abort_decompress, it experienced an error, and we called
+// longjmp() and rewound the stack to here. Return error.
+return LIBYUV_FALSE;
+}
+#endif
+jpeg_abort_decompress(decompress_struct_);
+return LIBYUV_TRUE;
+}
+// TODO(fbarchard): Allow rectangle to be specified: x, y, width, height.
+LIBYUV_BOOL MJpegDecoder::DecodeToBuffers(
+uint8** planes, int dst_width, int dst_height) {
+if (dst_width != GetWidth() ||
+dst_height > GetHeight()) {
+// ERROR: Bad dimensions
+return LIBYUV_FALSE;
+}
+#ifdef HAVE_SETJMP
+if (setjmp(error_mgr_->setjmp_buffer)) {
+// We called into jpeglib, it experienced an error sometime during this
+// function call, and we called longjmp() and rewound the stack to here.
+// Return error.
+return LIBYUV_FALSE;
+}
+#endif
+if (!StartDecode()) {
+return LIBYUV_FALSE;
+}
+SetScanlinePointers(databuf_);
+int lines_left = dst_height;
+// Compute amount of lines to skip to implement vertical crop.
+// TODO(fbarchard): Ensure skip is a multiple of maximum component
+// subsample. ie 2
+int skip = (GetHeight() - dst_height) / 2;
+if (skip > 0) {
+// There is no API to skip lines in the output data, so we read them
+// into the temp buffer.
+while (skip >= GetImageScanlinesPerImcuRow()) {
+if (!DecodeImcuRow()) {
+FinishDecode();
+return LIBYUV_FALSE;
+}
+skip -= GetImageScanlinesPerImcuRow();
+}
+if (skip > 0) {
+// Have a partial iMCU row left over to skip. Must read it and then
+// copy the parts we want into the destination.
+if (!DecodeImcuRow()) {
+FinishDecode();
+return LIBYUV_FALSE;
+}
+for (int i = 0; i < num_outbufs_; ++i) {
+// TODO(fbarchard): Compute skip to avoid this
+assert(skip % GetVertSubSampFactor(i) == 0);
+int rows_to_skip =
+DivideAndRoundDown(skip, GetVertSubSampFactor(i));
+int scanlines_to_copy = GetComponentScanlinesPerImcuRow(i) -
+rows_to_skip;
+int data_to_skip = rows_to_skip * GetComponentStride(i);
+CopyPlane(databuf_[i] + data_to_skip, GetComponentStride(i),
+planes[i], GetComponentWidth(i),
+GetComponentWidth(i), scanlines_to_copy);
+planes[i] += scanlines_to_copy * GetComponentWidth(i);
+}
+lines_left -= (GetImageScanlinesPerImcuRow() - skip);
+}
+}
+// Read full MCUs but cropped horizontally
+for (; lines_left > GetImageScanlinesPerImcuRow();
+lines_left -= GetImageScanlinesPerImcuRow()) {
+if (!DecodeImcuRow()) {
+FinishDecode();
+return LIBYUV_FALSE;
+}
+for (int i = 0; i < num_outbufs_; ++i) {
+int scanlines_to_copy = GetComponentScanlinesPerImcuRow(i);
+CopyPlane(databuf_[i], GetComponentStride(i),
+planes[i], GetComponentWidth(i),
+GetComponentWidth(i), scanlines_to_copy);
+planes[i] += scanlines_to_copy * GetComponentWidth(i);
+}
+}
+if (lines_left > 0) {
+// Have a partial iMCU row left over to decode.
+if (!DecodeImcuRow()) {
+FinishDecode();
+return LIBYUV_FALSE;
+}
+for (int i = 0; i < num_outbufs_; ++i) {
+int scanlines_to_copy =
+DivideAndRoundUp(lines_left, GetVertSubSampFactor(i));
+CopyPlane(databuf_[i], GetComponentStride(i),
+planes[i], GetComponentWidth(i),
+GetComponentWidth(i), scanlines_to_copy);
+planes[i] += scanlines_to_copy * GetComponentWidth(i);
+}
+}
+return FinishDecode();
+}
+LIBYUV_BOOL MJpegDecoder::DecodeToCallback(CallbackFunction fn, void* opaque,
+int dst_width, int dst_height) {
+if (dst_width != GetWidth() ||
+dst_height > GetHeight()) {
+// ERROR: Bad dimensions
+return LIBYUV_FALSE;
+}
+#ifdef HAVE_SETJMP
+if (setjmp(error_mgr_->setjmp_buffer)) {
+// We called into jpeglib, it experienced an error sometime during this
+// function call, and we called longjmp() and rewound the stack to here.
+// Return error.
+return LIBYUV_FALSE;
+}
+#endif
+if (!StartDecode()) {
+return LIBYUV_FALSE;
+}
+SetScanlinePointers(databuf_);
+int lines_left = dst_height;
+// TODO(fbarchard): Compute amount of lines to skip to implement vertical crop
+int skip = (GetHeight() - dst_height) / 2;
+if (skip > 0) {
+while (skip >= GetImageScanlinesPerImcuRow()) {
+if (!DecodeImcuRow()) {
+FinishDecode();
+return LIBYUV_FALSE;
+}
+skip -= GetImageScanlinesPerImcuRow();
+}
+if (skip > 0) {
+// Have a partial iMCU row left over to skip.
+if (!DecodeImcuRow()) {
+FinishDecode();
+return LIBYUV_FALSE;
+}
+for (int i = 0; i < num_outbufs_; ++i) {
+// TODO(fbarchard): Compute skip to avoid this
+assert(skip % GetVertSubSampFactor(i) == 0);
+int rows_to_skip = DivideAndRoundDown(skip, GetVertSubSampFactor(i));
+int data_to_skip = rows_to_skip * GetComponentStride(i);
+// Change our own data buffer pointers so we can pass them to the
+// callback.
+databuf_[i] += data_to_skip;
+}
+int scanlines_to_copy = GetImageScanlinesPerImcuRow() - skip;
+(*fn)(opaque, databuf_, databuf_strides_, scanlines_to_copy);
+// Now change them back.
+for (int i = 0; i < num_outbufs_; ++i) {
+int rows_to_skip = DivideAndRoundDown(skip, GetVertSubSampFactor(i));
+int data_to_skip = rows_to_skip * GetComponentStride(i);
+databuf_[i] -= data_to_skip;
+}
+lines_left -= scanlines_to_copy;
+}
+}
+// Read full MCUs until we get to the crop point.
+for (; lines_left >= GetImageScanlinesPerImcuRow();
+lines_left -= GetImageScanlinesPerImcuRow()) {
+if (!DecodeImcuRow()) {
+FinishDecode();
+return LIBYUV_FALSE;
+}
+(*fn)(opaque, databuf_, databuf_strides_, GetImageScanlinesPerImcuRow());
+}
+if (lines_left > 0) {
+// Have a partial iMCU row left over to decode.
+if (!DecodeImcuRow()) {
+FinishDecode();
+return LIBYUV_FALSE;
+}
+(*fn)(opaque, databuf_, databuf_strides_, lines_left);
+}
+return FinishDecode();
+}
+void MJpegDecoder::init_source(j_decompress_ptr cinfo) {
+fill_input_buffer(cinfo);
+}
+boolean MJpegDecoder::fill_input_buffer(j_decompress_ptr cinfo) {
+BufferVector* buf_vec = (BufferVector*)(cinfo->client_data);
+if (buf_vec->pos >= buf_vec->len) {
+assert(0 && "No more data");
+// ERROR: No more data
+return FALSE;
+}
+cinfo->src->next_input_byte = buf_vec->buffers[buf_vec->pos].data;
+cinfo->src->bytes_in_buffer = buf_vec->buffers[buf_vec->pos].len;
+++buf_vec->pos;
+return TRUE;
+}
+void MJpegDecoder::skip_input_data(j_decompress_ptr cinfo,
+long num_bytes) {  // NOLINT
+cinfo->src->next_input_byte += num_bytes;
+}
+void MJpegDecoder::term_source(j_decompress_ptr cinfo) {
+// Nothing to do.
+}
+#ifdef HAVE_SETJMP
+void MJpegDecoder::ErrorHandler(j_common_ptr cinfo) {
+// This is called when a jpeglib command experiences an error. Unfortunately
+// jpeglib's error handling model is not very flexible, because it expects the
+// error handler to not return--i.e., it wants the program to terminate. To
+// recover from errors we use setjmp() as shown in their example. setjmp() is
+// C's implementation for the "call with current continuation" functionality
+// seen in some functional programming languages.
+// A formatted message can be output, but is unsafe for release.
+#ifdef DEBUG
+char buf[JMSG_LENGTH_MAX];
+(*cinfo->err->format_message)(cinfo, buf);
+// ERROR: Error in jpeglib: buf
+#endif
+SetJmpErrorMgr* mgr = (SetJmpErrorMgr*)(cinfo->err);
+// This rewinds the call stack to the point of the corresponding setjmp()
+// and causes it to return (for a second time) with value 1.
+longjmp(mgr->setjmp_buffer, 1);
+}
+#endif
+void MJpegDecoder::AllocOutputBuffers(int num_outbufs) {
+if (num_outbufs != num_outbufs_) {
+// We could perhaps optimize this case to resize the output buffers without
+// necessarily having to delete and recreate each one, but it's not worth
+// it.
+DestroyOutputBuffers();
+scanlines_ = new uint8** [num_outbufs];
+scanlines_sizes_ = new int[num_outbufs];
+databuf_ = new uint8* [num_outbufs];
+databuf_strides_ = new int[num_outbufs];
+for (int i = 0; i < num_outbufs; ++i) {
+scanlines_[i] = NULL;
+scanlines_sizes_[i] = 0;
+databuf_[i] = NULL;
+databuf_strides_[i] = 0;
+}
+num_outbufs_ = num_outbufs;
+}
+}
+void MJpegDecoder::DestroyOutputBuffers() {
+for (int i = 0; i < num_outbufs_; ++i) {
+delete [] scanlines_[i];
+delete [] databuf_[i];
+}
+delete [] scanlines_;
+delete [] databuf_;
+delete [] scanlines_sizes_;
+delete [] databuf_strides_;
+scanlines_ = NULL;
+databuf_ = NULL;
+scanlines_sizes_ = NULL;
+databuf_strides_ = NULL;
+num_outbufs_ = 0;
+}
+// JDCT_IFAST and do_block_smoothing improve performance substantially.
+LIBYUV_BOOL MJpegDecoder::StartDecode() {
+decompress_struct_->raw_data_out = TRUE;
+decompress_struct_->dct_method = JDCT_IFAST;  // JDCT_ISLOW is default
+decompress_struct_->dither_mode = JDITHER_NONE;
+// Not applicable to 'raw':
+decompress_struct_->do_fancy_upsampling = LIBYUV_FALSE;
+// Only for buffered mode:
+decompress_struct_->enable_2pass_quant = LIBYUV_FALSE;
+// Blocky but fast:
+decompress_struct_->do_block_smoothing = LIBYUV_FALSE;
+if (!jpeg_start_decompress(decompress_struct_)) {
+// ERROR: Couldn't start JPEG decompressor";
+return LIBYUV_FALSE;
+}
+return LIBYUV_TRUE;
+}
+LIBYUV_BOOL MJpegDecoder::FinishDecode() {
+// jpeglib considers it an error if we finish without decoding the whole
+// image, so we call "abort" rather than "finish".
+jpeg_abort_decompress(decompress_struct_);
+return LIBYUV_TRUE;
+}
+void MJpegDecoder::SetScanlinePointers(uint8** data) {
+for (int i = 0; i < num_outbufs_; ++i) {
+uint8* data_i = data[i];
+for (int j = 0; j < scanlines_sizes_[i]; ++j) {
+scanlines_[i][j] = data_i;
+data_i += GetComponentStride(i);
+}
+}
+}
+inline LIBYUV_BOOL MJpegDecoder::DecodeImcuRow() {
+return (unsigned int)(GetImageScanlinesPerImcuRow()) ==
+jpeg_read_raw_data(decompress_struct_,
+scanlines_,
+GetImageScanlinesPerImcuRow());
+}
+// The helper function which recognizes the jpeg sub-sampling type.
+JpegSubsamplingType MJpegDecoder::JpegSubsamplingTypeHelper(
+int* subsample_x, int* subsample_y, int number_of_components) {
+if (number_of_components == 3) {  // Color images.
+if (subsample_x[0] == 1 && subsample_y[0] == 1 &&
+subsample_x[1] == 2 && subsample_y[1] == 2 &&
+subsample_x[2] == 2 && subsample_y[2] == 2) {
+return kJpegYuv420;
+} else if (subsample_x[0] == 1 && subsample_y[0] == 1 &&
+subsample_x[1] == 2 && subsample_y[1] == 1 &&
+subsample_x[2] == 2 && subsample_y[2] == 1) {
+return kJpegYuv422;
+} else if (subsample_x[0] == 1 && subsample_y[0] == 1 &&
+subsample_x[1] == 1 && subsample_y[1] == 1 &&
+subsample_x[2] == 1 && subsample_y[2] == 1) {
+return kJpegYuv444;
+}
+} else if (number_of_components == 1) {  // Grey-scale images.
+if (subsample_x[0] == 1 && subsample_y[0] == 1) {
+return kJpegYuv400;
+}
+}
+return kJpegUnknown;
+}
+}  // namespace libyuv
+#endif  // HAVE_JPEG

The Tor Browser / file comparison

comparison: media/libyuv/source/mjpeg_decoder.cc

media/libyuv/source/mjpeg_decoder.cc