| public static jround_up ( int a, int b ) : int | ||
| a | int | |
| b | int | |
| return | int | |
private int m_next_row; /* index of next row to fill/empty in strip */
/// <summary>
/// Initialize postprocessing controller.
/// </summary>
public jpeg_d_post_controller(jpeg_decompress_struct cinfo, bool need_full_buffer)
{
m_cinfo = cinfo;
/* Create the quantization buffer, if needed */
if (cinfo.m_quantize_colors)
{
/* The buffer strip height is max_v_samp_factor, which is typically
* an efficient number of rows for upsampling to return.
* (In the presence of output rescaling, we might want to be smarter?)
*/
m_strip_height = cinfo.m_max_v_samp_factor;
if (need_full_buffer)
{
/* Two-pass color quantization: need full-image storage. */
/* We round up the number of rows to a multiple of the strip height. */
m_whole_image = jpeg_common_struct.CreateSamplesArray(
cinfo.m_output_width * cinfo.m_out_color_components,
JpegUtils.jround_up(cinfo.m_output_height, m_strip_height));
m_whole_image.ErrorProcessor = cinfo;
}
else
{
/* One-pass color quantization: just make a strip buffer. */
m_buffer = jpeg_common_struct.AllocJpegSamples(
cinfo.m_output_width * cinfo.m_out_color_components, m_strip_height);
}
}
}
public jpeg_d_coef_controller(jpeg_decompress_struct cinfo, bool need_full_buffer)
{
m_cinfo = cinfo;
/* Create the coefficient buffer. */
if (need_full_buffer)
{
/* Allocate a full-image virtual array for each component, */
/* padded to a multiple of samp_factor DCT blocks in each direction. */
/* Note we ask for a pre-zeroed array. */
for (int ci = 0; ci < cinfo.m_num_components; ci++)
{
m_whole_image[ci] = jpeg_common_struct.CreateBlocksArray(
JpegUtils.jround_up(cinfo.Comp_info[ci].Width_in_blocks, cinfo.Comp_info[ci].H_samp_factor),
JpegUtils.jround_up(cinfo.Comp_info[ci].height_in_blocks, cinfo.Comp_info[ci].V_samp_factor));
m_whole_image[ci].ErrorProcessor = cinfo;
}
m_useDummyConsumeData = false;
m_decompressor = DecompressorType.Ordinary;
m_coef_arrays = m_whole_image; /* link to virtual arrays */
}
else
{
/* We only need a single-MCU buffer. */
for (int i = 0; i < JpegConstants.D_MAX_BLOCKS_IN_MCU; i++)
{
m_MCU_buffer[i] = new JBLOCK();
}
m_useDummyConsumeData = true;
m_decompressor = DecompressorType.OnePass;
m_coef_arrays = null; /* flag for no virtual arrays */
}
}
public my_c_coef_controller(jpeg_compress_struct cinfo, bool need_full_buffer)
{
m_cinfo = cinfo;
/* Create the coefficient buffer. */
if (need_full_buffer)
{
/* Allocate a full-image virtual array for each component, */
/* padded to a multiple of samp_factor DCT blocks in each direction. */
for (int ci = 0; ci < cinfo.m_num_components; ci++)
{
m_whole_image[ci] = jpeg_common_struct.CreateBlocksArray(
JpegUtils.jround_up(cinfo.Component_info[ci].Width_in_blocks, cinfo.Component_info[ci].H_samp_factor),
JpegUtils.jround_up(cinfo.Component_info[ci].height_in_blocks, cinfo.Component_info[ci].V_samp_factor));
m_whole_image[ci].ErrorProcessor = cinfo;
}
}
else
{
/* We only need a single-MCU buffer. */
JBLOCK[] buffer = new JBLOCK[JpegConstants.C_MAX_BLOCKS_IN_MCU];
for (int i = 0; i < JpegConstants.C_MAX_BLOCKS_IN_MCU; i++)
{
buffer[i] = new JBLOCK();
}
for (int i = 0; i < JpegConstants.C_MAX_BLOCKS_IN_MCU; i++)
{
m_MCU_buffer[i] = new JBLOCK[JpegConstants.C_MAX_BLOCKS_IN_MCU - i];
for (int j = i; j < JpegConstants.C_MAX_BLOCKS_IN_MCU; j++)
{
m_MCU_buffer[i][j - i] = buffer[j];
}
}
/* flag for no virtual arrays */
m_whole_image[0] = null;
}
}
public my_upsampler(jpeg_decompress_struct cinfo)
{
m_cinfo = cinfo;
m_need_context_rows = false; /* until we find out differently */
if (cinfo.m_CCIR601_sampling) /* this isn't supported */
{
cinfo.ERREXIT(J_MESSAGE_CODE.JERR_CCIR601_NOTIMPL);
}
/* jpeg_d_main_controller doesn't support context rows when min_DCT_scaled_size = 1,
* so don't ask for it.
*/
bool do_fancy = cinfo.m_do_fancy_upsampling && cinfo.m_min_DCT_scaled_size > 1;
/* Verify we can handle the sampling factors, select per-component methods,
* and create storage as needed.
*/
for (int ci = 0; ci < cinfo.m_num_components; ci++)
{
jpeg_component_info componentInfo = cinfo.Comp_info[ci];
/* Compute size of an "input group" after IDCT scaling. This many samples
* are to be converted to max_h_samp_factor * max_v_samp_factor pixels.
*/
int h_in_group = (componentInfo.H_samp_factor * componentInfo.DCT_scaled_size) / cinfo.m_min_DCT_scaled_size;
int v_in_group = (componentInfo.V_samp_factor * componentInfo.DCT_scaled_size) / cinfo.m_min_DCT_scaled_size;
int h_out_group = cinfo.m_max_h_samp_factor;
int v_out_group = cinfo.m_max_v_samp_factor;
/* save for use later */
m_rowgroup_height[ci] = v_in_group;
bool need_buffer = true;
if (!componentInfo.component_needed)
{
/* Don't bother to upsample an uninteresting component. */
m_upsampleMethods[ci] = ComponentUpsampler.noop_upsampler;
need_buffer = false;
}
else if (h_in_group == h_out_group && v_in_group == v_out_group)
{
/* Fullsize components can be processed without any work. */
m_upsampleMethods[ci] = ComponentUpsampler.fullsize_upsampler;
need_buffer = false;
}
else if (h_in_group * 2 == h_out_group && v_in_group == v_out_group)
{
/* Special cases for 2h1v upsampling */
if (do_fancy && componentInfo.downsampled_width > 2)
{
m_upsampleMethods[ci] = ComponentUpsampler.h2v1_fancy_upsampler;
}
else
{
m_upsampleMethods[ci] = ComponentUpsampler.h2v1_upsampler;
}
}
else if (h_in_group * 2 == h_out_group && v_in_group * 2 == v_out_group)
{
/* Special cases for 2h2v upsampling */
if (do_fancy && componentInfo.downsampled_width > 2)
{
m_upsampleMethods[ci] = ComponentUpsampler.h2v2_fancy_upsampler;
m_need_context_rows = true;
}
else
{
m_upsampleMethods[ci] = ComponentUpsampler.h2v2_upsampler;
}
}
else if ((h_out_group % h_in_group) == 0 && (v_out_group % v_in_group) == 0)
{
/* Generic integral-factors upsampling method */
m_upsampleMethods[ci] = ComponentUpsampler.int_upsampler;
m_h_expand[ci] = (byte)(h_out_group / h_in_group);
m_v_expand[ci] = (byte)(v_out_group / v_in_group);
}
else
{
cinfo.ERREXIT(J_MESSAGE_CODE.JERR_FRACT_SAMPLE_NOTIMPL);
}
if (need_buffer)
{
ComponentBuffer cb = new ComponentBuffer();
cb.SetBuffer(jpeg_common_struct.AllocJpegSamples(JpegUtils.jround_up(cinfo.m_output_width,
cinfo.m_max_h_samp_factor), cinfo.m_max_v_samp_factor), null, 0);
m_color_buf[ci] = cb;
}
}
}
