JPEG support: introducing jpeg encoding for spice bitmaps

1 files changed, 147 insertions, 0 deletions

diff --git a/client/jpeg_decoder.cpp b/client/jpeg_decoder.cpp
new file mode 100644
index 00000000..a7824a9d
--- /dev/null
+++ b/client/jpeg_decoder.cpp
@@ -0,0 +1,147 @@
+/*
+   Copyright (C) 2009 Red Hat, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "common.h"
+#include "jpeg_decoder.h"
+#include "debug.h"
+#include "utils.h"
+
+static void op_begin_decode(SpiceJpegDecoder *decoder,
+                            uint8_t* data,
+                            int data_size,
+                            int* out_width,
+                            int* out_height)
+{
+    JpegDecoder* _decoder = static_cast<JpegDecoder*>(decoder);
+    _decoder->begin_decode(data, data_size, *out_width, *out_height);
+}
+
+static void op_decode(SpiceJpegDecoder *decoder,
+                      uint8_t* dest,
+                      int stride,
+                      int format)
+{
+    JpegDecoder* _decoder = static_cast<JpegDecoder*>(decoder);
+    _decoder->decode(dest, stride, format);
+}
+
+extern "C" {
+
+    void jpeg_decoder_init_source(j_decompress_ptr cinfo)
+    {
+    }
+
+    static boolean jpeg_decoder_fill_input_buffer(j_decompress_ptr cinfo)
+    {
+        PANIC("no more data for jpeg");
+        return FALSE;
+    }
+
+    static void jpeg_decoder_skip_input_data(j_decompress_ptr cinfo, long num_bytes)
+    {
+        ASSERT(num_bytes < (long)cinfo->src->bytes_in_buffer);
+        cinfo->src->next_input_byte += num_bytes;
+        cinfo->src->bytes_in_buffer -= num_bytes;
+    }
+
+    static void jpeg_decoder_term_source (j_decompress_ptr cinfo)
+    {
+        return;
+    }
+}
+
+
+JpegDecoder::JpegDecoder()
+    : _data (NULL)
+    , _data_size (0)
+{
+    _cinfo.err = jpeg_std_error(&_jerr);
+    jpeg_create_decompress(&_cinfo);
+
+    _cinfo.src = &_jsrc;
+    _cinfo.src->init_source = jpeg_decoder_init_source;
+    _cinfo.src->fill_input_buffer = jpeg_decoder_fill_input_buffer;
+    _cinfo.src->skip_input_data = jpeg_decoder_skip_input_data;
+    _cinfo.src->resync_to_restart = jpeg_resync_to_restart;
+    _cinfo.src->term_source = jpeg_decoder_term_source;
+    
+    static SpiceJpegDecoderOps decoder_ops = {
+        op_begin_decode,
+        op_decode,
+    };
+
+    ops = &decoder_ops;
+}
+
+JpegDecoder::~JpegDecoder()
+{
+    jpeg_destroy_decompress(&_cinfo);
+}
+
+void JpegDecoder::begin_decode(uint8_t* data, int data_size, int& out_width, int& out_height)
+{
+    ASSERT(data);
+    ASSERT(data_size);
+
+    if (_data) {
+        jpeg_abort_decompress(&_cinfo);
+    }
+
+    _data = data;
+    _data_size = data_size;
+
+    _cinfo.src->next_input_byte = _data;
+    _cinfo.src->bytes_in_buffer = _data_size;
+
+    jpeg_read_header(&_cinfo, TRUE);
+
+    _cinfo.out_color_space = JCS_RGB;
+    _width = _cinfo.image_width;
+    _height = _cinfo.image_height;
+
+    out_width = _width;
+    out_height = _height;
+}
+
+void JpegDecoder::decode(uint8_t *dest, int stride, int format)
+{
+    uint8_t* scan_line = new uint8_t[_width*3];
+    RGBConverter* rgb_converter;
+
+    switch (format) {
+    case SPICE_BITMAP_FMT_24BIT:
+        rgb_converter = &_rgb2bgr;
+        break;
+    case SPICE_BITMAP_FMT_32BIT:
+        rgb_converter = &_rgb2bgrx;
+        break;
+    default:
+        THROW("bad bitmap format, %d", format);
+    }
+
+    jpeg_start_decompress(&_cinfo);
+
+    for (int row = 0; row < _height; row++) {
+        jpeg_read_scanlines(&_cinfo, &scan_line, 1);
+        rgb_converter->convert(scan_line, dest, _width);
+        dest += stride;
+    }
+
+    delete [] scan_line;
+
+    jpeg_finish_decompress(&_cinfo);
+}