summaryrefslogtreecommitdiff
path: root/core/fxcodec/lgif/cgifcontext.cpp
diff options
context:
space:
mode:
authorRyan Harrison <rharrison@chromium.org>2017-09-27 15:39:26 -0400
committerChromium commit bot <commit-bot@chromium.org>2017-09-27 19:56:53 +0000
commit36a155d1f3a9d9f315655a20d583c13644ef1f3e (patch)
tree66e8a87c0b35f3d6c71460f3a0c4ce68a15b51f0 /core/fxcodec/lgif/cgifcontext.cpp
parentdd17a14f060c39f50ca24522b202ffef5436dd43 (diff)
downloadpdfium-36a155d1f3a9d9f315655a20d583c13644ef1f3e.tar.xz
Cleaning up naming of GIF files/classes/variables
Moved everything from core/fxcodec/lgif to core/fxcodec/gif Converted CGifContext -> CFX_GifContext Removed _ptr suffixes from CXF_GifContext Movef fx_gif.* -> cfx_gif.* Renamed structs in cfx_gif.h Renamed members of CFX_GifImage Renamed members of CFX_GifContext Renamed CFX_LZWDecoder -> CFX_LZWDecompressor BUG=pdfium:903 Change-Id: I537e905e935da26832e6bbdc03e0373ed5500bcb Reviewed-on: https://pdfium-review.googlesource.com/14990 Commit-Queue: Ryan Harrison <rharrison@chromium.org> Reviewed-by: dsinclair <dsinclair@chromium.org>
Diffstat (limited to 'core/fxcodec/lgif/cgifcontext.cpp')
-rw-r--r--core/fxcodec/lgif/cgifcontext.cpp549
1 files changed, 0 insertions, 549 deletions
diff --git a/core/fxcodec/lgif/cgifcontext.cpp b/core/fxcodec/lgif/cgifcontext.cpp
deleted file mode 100644
index af1895316f..0000000000
--- a/core/fxcodec/lgif/cgifcontext.cpp
+++ /dev/null
@@ -1,549 +0,0 @@
-// Copyright 2017 PDFium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
-
-#include "core/fxcodec/lgif/cgifcontext.h"
-
-#include <algorithm>
-#include <utility>
-
-#include "core/fxcodec/codec/ccodec_gifmodule.h"
-#include "core/fxcodec/lbmp/fx_bmp.h"
-#include "core/fxcodec/lgif/fx_gif.h"
-#include "third_party/base/ptr_util.h"
-#include "third_party/base/stl_util.h"
-
-namespace {
-
-const int32_t s_gif_interlace_step[4] = {8, 8, 4, 2};
-
-} // namespace
-
-CGifContext::CGifContext(CCodec_GifModule* gif_module,
- CCodec_GifModule::Delegate* pDelegate)
- : m_pModule(gif_module),
- m_pDelegate(pDelegate),
- global_pal_exp(0),
- img_row_offset(0),
- img_row_avail_size(0),
- avail_in(0),
- decode_status(GIF_D_STATUS_SIG),
- skip_size(0),
- next_in(nullptr),
- width(0),
- height(0),
- bc_index(0),
- pixel_aspect(0),
- global_sort_flag(0),
- global_color_resolution(0),
- img_pass_num(0) {
-}
-
-CGifContext::~CGifContext() {}
-
-void CGifContext::RecordCurrentPosition(uint32_t* cur_pos_ptr) {
- m_pDelegate->GifRecordCurrentPosition(*cur_pos_ptr);
-}
-
-void CGifContext::ReadScanline(int32_t row_num, uint8_t* row_buf) {
- m_pDelegate->GifReadScanline(row_num, row_buf);
-}
-
-bool CGifContext::GetRecordPosition(uint32_t cur_pos,
- int32_t left,
- int32_t top,
- int32_t width,
- int32_t height,
- int32_t pal_num,
- GifPalette* pal_ptr,
- int32_t delay_time,
- bool user_input,
- int32_t trans_index,
- int32_t disposal_method,
- bool interlace) {
- return m_pDelegate->GifInputRecordPositionBuf(
- cur_pos, FX_RECT(left, top, left + width, top + height), pal_num, pal_ptr,
- delay_time, user_input, trans_index, disposal_method, interlace);
-}
-
-GifDecodeStatus CGifContext::ReadHeader() {
- uint32_t skip_size_org = skip_size;
- GifHeader* gif_header_ptr = nullptr;
- if (!ReadData(reinterpret_cast<uint8_t**>(&gif_header_ptr), 6))
- return GifDecodeStatus::Unfinished;
-
- if (strncmp(gif_header_ptr->signature, GIF_SIGNATURE, 3) != 0 ||
- gif_header_ptr->version[0] != '8' || gif_header_ptr->version[2] != 'a')
- return GifDecodeStatus::Error;
-
- GifLocalScreenDescriptor* gif_lsd_ptr = nullptr;
- if (!ReadData(reinterpret_cast<uint8_t**>(&gif_lsd_ptr), 7)) {
- skip_size = skip_size_org;
- return GifDecodeStatus::Unfinished;
- }
-
- if (gif_lsd_ptr->global_flags.global_pal) {
- global_pal_exp = gif_lsd_ptr->global_flags.pal_bits;
- uint32_t global_pal_size = unsigned(2 << global_pal_exp) * 3u;
- uint8_t* global_pal_ptr = nullptr;
- if (!ReadData(&global_pal_ptr, global_pal_size)) {
- skip_size = skip_size_org;
- return GifDecodeStatus::Unfinished;
- }
-
- global_sort_flag = gif_lsd_ptr->global_flags.sort_flag;
- global_color_resolution = gif_lsd_ptr->global_flags.color_resolution;
- m_GlobalPalette.resize(global_pal_size / 3);
- memcpy(m_GlobalPalette.data(), global_pal_ptr, global_pal_size);
- }
-
- width = static_cast<int>(
- GetWord_LSBFirst(reinterpret_cast<uint8_t*>(&gif_lsd_ptr->width)));
- height = static_cast<int>(
- GetWord_LSBFirst(reinterpret_cast<uint8_t*>(&gif_lsd_ptr->height)));
- bc_index = gif_lsd_ptr->bc_index;
- pixel_aspect = gif_lsd_ptr->pixel_aspect;
- return GifDecodeStatus::Success;
-}
-
-GifDecodeStatus CGifContext::GetFrame() {
- GifDecodeStatus ret = GifDecodeStatus::Success;
- while (true) {
- switch (decode_status) {
- case GIF_D_STATUS_TAIL:
- return GifDecodeStatus::Success;
- case GIF_D_STATUS_SIG: {
- uint8_t* sig_ptr = nullptr;
- if (!ReadData(&sig_ptr, 1))
- return GifDecodeStatus::Unfinished;
-
- switch (*sig_ptr) {
- case GIF_SIG_EXTENSION:
- SaveDecodingStatus(GIF_D_STATUS_EXT);
- continue;
- case GIF_SIG_IMAGE:
- SaveDecodingStatus(GIF_D_STATUS_IMG_INFO);
- continue;
- case GIF_SIG_TRAILER:
- SaveDecodingStatus(GIF_D_STATUS_TAIL);
- return GifDecodeStatus::Success;
- default:
- if (avail_in) {
- // The Gif File has non_standard Tag!
- SaveDecodingStatus(GIF_D_STATUS_SIG);
- continue;
- }
- // The Gif File Doesn't have Trailer Tag!
- return GifDecodeStatus::Success;
- }
- }
- case GIF_D_STATUS_EXT: {
- uint8_t* ext_ptr = nullptr;
- if (!ReadData(&ext_ptr, 1))
- return GifDecodeStatus::Unfinished;
-
- switch (*ext_ptr) {
- case GIF_BLOCK_CE:
- SaveDecodingStatus(GIF_D_STATUS_EXT_CE);
- continue;
- case GIF_BLOCK_GCE:
- SaveDecodingStatus(GIF_D_STATUS_EXT_GCE);
- continue;
- case GIF_BLOCK_PTE:
- SaveDecodingStatus(GIF_D_STATUS_EXT_PTE);
- continue;
- default: {
- int32_t status = GIF_D_STATUS_EXT_UNE;
- if (*ext_ptr == GIF_BLOCK_PTE) {
- status = GIF_D_STATUS_EXT_PTE;
- }
- SaveDecodingStatus(status);
- continue;
- }
- }
- }
- case GIF_D_STATUS_IMG_INFO: {
- ret = DecodeImageInfo();
- if (ret != GifDecodeStatus::Success)
- return ret;
-
- continue;
- }
- case GIF_D_STATUS_IMG_DATA: {
- uint8_t* data_size_ptr = nullptr;
- uint8_t* data_ptr = nullptr;
- uint32_t skip_size_org = skip_size;
- if (!ReadData(&data_size_ptr, 1))
- return GifDecodeStatus::Unfinished;
-
- while (*data_size_ptr != GIF_BLOCK_TERMINAL) {
- if (!ReadData(&data_ptr, *data_size_ptr)) {
- skip_size = skip_size_org;
- return GifDecodeStatus::Unfinished;
- }
-
- SaveDecodingStatus(GIF_D_STATUS_IMG_DATA);
- skip_size_org = skip_size;
- if (!ReadData(&data_size_ptr, 1))
- return GifDecodeStatus::Unfinished;
- }
- SaveDecodingStatus(GIF_D_STATUS_SIG);
- continue;
- }
- default: {
- ret = DecodeExtension();
- if (ret != GifDecodeStatus::Success)
- return ret;
- break;
- }
- }
- }
- return GifDecodeStatus::Success;
-}
-
-GifDecodeStatus CGifContext::LoadFrame(int32_t frame_num) {
- if (!pdfium::IndexInBounds(m_Images, frame_num))
- return GifDecodeStatus::Error;
-
- uint8_t* data_size_ptr = nullptr;
- uint8_t* data_ptr = nullptr;
- uint32_t skip_size_org = skip_size;
- GifImage* gif_image_ptr = m_Images[frame_num].get();
- uint32_t gif_img_row_bytes = gif_image_ptr->m_ImageInfo.width;
- if (gif_img_row_bytes == 0)
- return GifDecodeStatus::Error;
-
- if (decode_status == GIF_D_STATUS_TAIL) {
- gif_image_ptr->m_ImageRowBuf.resize(gif_img_row_bytes);
- GifGraphicControlExtension* gif_img_gce_ptr =
- gif_image_ptr->m_ImageGCE.get();
- int32_t loc_pal_num =
- gif_image_ptr->m_ImageInfo.local_flags.local_pal
- ? (2 << gif_image_ptr->m_ImageInfo.local_flags.pal_bits)
- : 0;
- avail_in = 0;
- GifPalette* pLocalPalette = gif_image_ptr->m_LocalPalettes.empty()
- ? nullptr
- : gif_image_ptr->m_LocalPalettes.data();
- if (!gif_img_gce_ptr) {
- bool bRes = GetRecordPosition(
- gif_image_ptr->image_data_pos, gif_image_ptr->m_ImageInfo.left,
- gif_image_ptr->m_ImageInfo.top, gif_image_ptr->m_ImageInfo.width,
- gif_image_ptr->m_ImageInfo.height, loc_pal_num, pLocalPalette, 0, 0,
- -1, 0, gif_image_ptr->m_ImageInfo.local_flags.interlace);
- if (!bRes) {
- gif_image_ptr->m_ImageRowBuf.clear();
- return GifDecodeStatus::Error;
- }
- } else {
- bool bRes = GetRecordPosition(
- gif_image_ptr->image_data_pos, gif_image_ptr->m_ImageInfo.left,
- gif_image_ptr->m_ImageInfo.top, gif_image_ptr->m_ImageInfo.width,
- gif_image_ptr->m_ImageInfo.height, loc_pal_num, pLocalPalette,
- static_cast<int32_t>(gif_image_ptr->m_ImageGCE->delay_time),
- gif_image_ptr->m_ImageGCE->gce_flags.user_input,
- gif_image_ptr->m_ImageGCE->gce_flags.transparency
- ? static_cast<int32_t>(gif_image_ptr->m_ImageGCE->trans_index)
- : -1,
- static_cast<int32_t>(
- gif_image_ptr->m_ImageGCE->gce_flags.disposal_method),
- gif_image_ptr->m_ImageInfo.local_flags.interlace);
- if (!bRes) {
- gif_image_ptr->m_ImageRowBuf.clear();
- return GifDecodeStatus::Error;
- }
- }
-
- if (gif_image_ptr->image_code_exp > GIF_MAX_LZW_EXP) {
- gif_image_ptr->m_ImageRowBuf.clear();
- return GifDecodeStatus::Error;
- }
-
- img_row_offset = 0;
- img_row_avail_size = 0;
- img_pass_num = 0;
- gif_image_ptr->image_row_num = 0;
- SaveDecodingStatus(GIF_D_STATUS_IMG_DATA);
- }
-
- if (decode_status == GIF_D_STATUS_IMG_DATA) {
- if (!ReadData(&data_size_ptr, 1))
- return GifDecodeStatus::Unfinished;
-
- if (*data_size_ptr != GIF_BLOCK_TERMINAL) {
- if (!ReadData(&data_ptr, *data_size_ptr)) {
- skip_size = skip_size_org;
- return GifDecodeStatus::Unfinished;
- }
-
- if (!m_ImgDecoder.get())
- m_ImgDecoder =
- CFX_LZWDecoder::Create(!gif_image_ptr->m_LocalPalettes.empty()
- ? gif_image_ptr->local_pallette_exp
- : global_pal_exp,
- gif_image_ptr->image_code_exp);
- SaveDecodingStatus(GIF_D_STATUS_IMG_DATA);
- img_row_offset += img_row_avail_size;
- img_row_avail_size = gif_img_row_bytes - img_row_offset;
- GifDecodeStatus ret =
- m_ImgDecoder.get()
- ? m_ImgDecoder->Decode(
- data_ptr, *data_size_ptr,
- gif_image_ptr->m_ImageRowBuf.data() + img_row_offset,
- &img_row_avail_size)
- : GifDecodeStatus::Error;
- if (ret == GifDecodeStatus::Error) {
- DecodingFailureAtTailCleanup(gif_image_ptr);
- return GifDecodeStatus::Error;
- }
- while (ret != GifDecodeStatus::Error) {
- if (ret == GifDecodeStatus::Success) {
- ReadScanline(gif_image_ptr->image_row_num,
- gif_image_ptr->m_ImageRowBuf.data());
- gif_image_ptr->m_ImageRowBuf.clear();
- SaveDecodingStatus(GIF_D_STATUS_TAIL);
- return GifDecodeStatus::Success;
- }
- if (ret == GifDecodeStatus::Unfinished) {
- skip_size_org = skip_size;
- if (!ReadData(&data_size_ptr, 1))
- return GifDecodeStatus::Unfinished;
-
- if (*data_size_ptr != GIF_BLOCK_TERMINAL) {
- if (!ReadData(&data_ptr, *data_size_ptr)) {
- skip_size = skip_size_org;
- return GifDecodeStatus::Unfinished;
- }
- if (!m_ImgDecoder.get())
- m_ImgDecoder =
- CFX_LZWDecoder::Create(!gif_image_ptr->m_LocalPalettes.empty()
- ? gif_image_ptr->local_pallette_exp
- : global_pal_exp,
- gif_image_ptr->image_code_exp);
- SaveDecodingStatus(GIF_D_STATUS_IMG_DATA);
- img_row_offset += img_row_avail_size;
- img_row_avail_size = gif_img_row_bytes - img_row_offset;
- ret =
- m_ImgDecoder.get()
- ? m_ImgDecoder->Decode(
- data_ptr, *data_size_ptr,
- gif_image_ptr->m_ImageRowBuf.data() + img_row_offset,
- &img_row_avail_size)
- : GifDecodeStatus::Error;
- }
- }
- if (ret == GifDecodeStatus::InsufficientDestSize) {
- if (gif_image_ptr->m_ImageInfo.local_flags.interlace) {
- ReadScanline(gif_image_ptr->image_row_num,
- gif_image_ptr->m_ImageRowBuf.data());
- gif_image_ptr->image_row_num += s_gif_interlace_step[img_pass_num];
- if (gif_image_ptr->image_row_num >=
- static_cast<int32_t>(gif_image_ptr->m_ImageInfo.height)) {
- img_pass_num++;
- if (img_pass_num == FX_ArraySize(s_gif_interlace_step)) {
- DecodingFailureAtTailCleanup(gif_image_ptr);
- return GifDecodeStatus::Error;
- }
- gif_image_ptr->image_row_num =
- s_gif_interlace_step[img_pass_num] / 2;
- }
- } else {
- ReadScanline(gif_image_ptr->image_row_num++,
- gif_image_ptr->m_ImageRowBuf.data());
- }
- img_row_offset = 0;
- img_row_avail_size = gif_img_row_bytes;
- ret = m_ImgDecoder.get()
- ? m_ImgDecoder->Decode(
- data_ptr, *data_size_ptr,
- gif_image_ptr->m_ImageRowBuf.data() + img_row_offset,
- &img_row_avail_size)
- : GifDecodeStatus::Error;
- }
- if (ret == GifDecodeStatus::Error) {
- DecodingFailureAtTailCleanup(gif_image_ptr);
- return GifDecodeStatus::Error;
- }
- }
- }
- SaveDecodingStatus(GIF_D_STATUS_TAIL);
- }
- return GifDecodeStatus::Error;
-}
-
-void CGifContext::SetInputBuffer(uint8_t* src_buf, uint32_t src_size) {
- next_in = src_buf;
- avail_in = src_size;
- skip_size = 0;
-}
-
-uint32_t CGifContext::GetAvailInput(uint8_t** avail_buf_ptr) const {
- if (avail_buf_ptr) {
- *avail_buf_ptr = nullptr;
- if (avail_in > 0)
- *avail_buf_ptr = next_in;
- }
- return avail_in;
-}
-
-int32_t CGifContext::GetFrameNum() const {
- return pdfium::CollectionSize<int32_t>(m_Images);
-}
-
-uint8_t* CGifContext::ReadData(uint8_t** des_buf_pp, uint32_t data_size) {
- if (avail_in < skip_size + data_size)
- return nullptr;
-
- *des_buf_pp = next_in + skip_size;
- skip_size += data_size;
- return *des_buf_pp;
-}
-
-void CGifContext::SaveDecodingStatus(int32_t status) {
- decode_status = status;
- next_in += skip_size;
- avail_in -= skip_size;
- skip_size = 0;
-}
-
-GifDecodeStatus CGifContext::DecodeExtension() {
- uint8_t* data_size_ptr = nullptr;
- uint8_t* data_ptr = nullptr;
- uint32_t skip_size_org = skip_size;
- switch (decode_status) {
- case GIF_D_STATUS_EXT_CE: {
- if (!ReadData(&data_size_ptr, 1)) {
- skip_size = skip_size_org;
- return GifDecodeStatus::Unfinished;
- }
-
- cmt_data.clear();
- while (*data_size_ptr != GIF_BLOCK_TERMINAL) {
- uint8_t data_size = *data_size_ptr;
- if (!ReadData(&data_ptr, *data_size_ptr) ||
- !ReadData(&data_size_ptr, 1)) {
- skip_size = skip_size_org;
- return GifDecodeStatus::Unfinished;
- }
-
- cmt_data += ByteString(data_ptr, data_size);
- }
- break;
- }
- case GIF_D_STATUS_EXT_PTE: {
- GifPlainTextExtension* gif_pte = nullptr;
- if (!ReadData(reinterpret_cast<uint8_t**>(&gif_pte), 13))
- return GifDecodeStatus::Unfinished;
-
- m_GraphicControlExtension = nullptr;
- if (!ReadData(&data_size_ptr, 1)) {
- skip_size = skip_size_org;
- return GifDecodeStatus::Unfinished;
- }
-
- while (*data_size_ptr != GIF_BLOCK_TERMINAL) {
- if (!ReadData(&data_ptr, *data_size_ptr) ||
- !ReadData(&data_size_ptr, 1)) {
- skip_size = skip_size_org;
- return GifDecodeStatus::Unfinished;
- }
- }
- break;
- }
- case GIF_D_STATUS_EXT_GCE: {
- GifGraphicControlExtension* gif_gce_ptr = nullptr;
- if (!ReadData(reinterpret_cast<uint8_t**>(&gif_gce_ptr), 6))
- return GifDecodeStatus::Unfinished;
-
- if (!m_GraphicControlExtension.get())
- m_GraphicControlExtension =
- pdfium::MakeUnique<GifGraphicControlExtension>();
- m_GraphicControlExtension->block_size = gif_gce_ptr->block_size;
- m_GraphicControlExtension->gce_flags = gif_gce_ptr->gce_flags;
- m_GraphicControlExtension->delay_time = GetWord_LSBFirst(
- reinterpret_cast<uint8_t*>(&gif_gce_ptr->delay_time));
- m_GraphicControlExtension->trans_index = gif_gce_ptr->trans_index;
- break;
- }
- default: {
- if (decode_status == GIF_D_STATUS_EXT_PTE)
- m_GraphicControlExtension = nullptr;
- if (!ReadData(&data_size_ptr, 1))
- return GifDecodeStatus::Unfinished;
-
- while (*data_size_ptr != GIF_BLOCK_TERMINAL) {
- if (!ReadData(&data_ptr, *data_size_ptr) ||
- !ReadData(&data_size_ptr, 1)) {
- skip_size = skip_size_org;
- return GifDecodeStatus::Unfinished;
- }
- }
- }
- }
- SaveDecodingStatus(GIF_D_STATUS_SIG);
- return GifDecodeStatus::Success;
-}
-
-GifDecodeStatus CGifContext::DecodeImageInfo() {
- if (width == 0 || height == 0)
- return GifDecodeStatus::Error;
-
- uint32_t skip_size_org = skip_size;
- GifImageInfo* gif_img_info_ptr = nullptr;
- if (!ReadData(reinterpret_cast<uint8_t**>(&gif_img_info_ptr), 9))
- return GifDecodeStatus::Unfinished;
-
- auto gif_image = pdfium::MakeUnique<GifImage>();
- gif_image->m_ImageInfo.left =
- GetWord_LSBFirst(reinterpret_cast<uint8_t*>(&gif_img_info_ptr->left));
- gif_image->m_ImageInfo.top =
- GetWord_LSBFirst(reinterpret_cast<uint8_t*>(&gif_img_info_ptr->top));
- gif_image->m_ImageInfo.width =
- GetWord_LSBFirst(reinterpret_cast<uint8_t*>(&gif_img_info_ptr->width));
- gif_image->m_ImageInfo.height =
- GetWord_LSBFirst(reinterpret_cast<uint8_t*>(&gif_img_info_ptr->height));
- gif_image->m_ImageInfo.local_flags = gif_img_info_ptr->local_flags;
- if (gif_image->m_ImageInfo.left + gif_image->m_ImageInfo.width > width ||
- gif_image->m_ImageInfo.top + gif_image->m_ImageInfo.height > height)
- return GifDecodeStatus::Error;
-
- GifLocalFlags* gif_img_info_lf_ptr = &gif_img_info_ptr->local_flags;
- if (gif_img_info_lf_ptr->local_pal) {
- gif_image->local_pallette_exp = gif_img_info_lf_ptr->pal_bits;
- uint32_t loc_pal_size = unsigned(2 << gif_img_info_lf_ptr->pal_bits) * 3u;
- uint8_t* loc_pal_ptr = nullptr;
- if (!ReadData(&loc_pal_ptr, loc_pal_size)) {
- skip_size = skip_size_org;
- return GifDecodeStatus::Unfinished;
- }
-
- gif_image->m_LocalPalettes = std::vector<GifPalette>(loc_pal_size / 3);
- std::copy(loc_pal_ptr, loc_pal_ptr + loc_pal_size,
- reinterpret_cast<uint8_t*>(gif_image->m_LocalPalettes.data()));
- }
-
- uint8_t* code_size_ptr = nullptr;
- if (!ReadData(&code_size_ptr, 1)) {
- skip_size = skip_size_org;
- return GifDecodeStatus::Unfinished;
- }
-
- gif_image->image_code_exp = *code_size_ptr;
- RecordCurrentPosition(&gif_image->image_data_pos);
- gif_image->image_data_pos += skip_size;
- gif_image->m_ImageGCE = nullptr;
- if (m_GraphicControlExtension.get()) {
- gif_image->m_ImageGCE = std::move(m_GraphicControlExtension);
- m_GraphicControlExtension = nullptr;
- }
- m_Images.push_back(std::move(gif_image));
- SaveDecodingStatus(GIF_D_STATUS_IMG_DATA);
- return GifDecodeStatus::Success;
-}
-
-void CGifContext::DecodingFailureAtTailCleanup(GifImage* gif_image_ptr) {
- gif_image_ptr->m_ImageRowBuf.clear();
- SaveDecodingStatus(GIF_D_STATUS_TAIL);
-}