public ReadResult consume_data()
{
if (m_useDummyConsumeData)
return ReadResult.JPEG_SUSPENDED; /* Always indicate nothing was done */
JBLOCK[][][] buffer = new JBLOCK[JpegConstants.MAX_COMPS_IN_SCAN][][];
/* Align the virtual buffers for the components used in this scan. */
for (int ci = 0; ci < m_cinfo.m_comps_in_scan; ci++)
{
jpeg_component_info componentInfo = m_cinfo.Comp_info[m_cinfo.m_cur_comp_info[ci]];
buffer[ci] = m_whole_image[componentInfo.Component_index].Access(
m_cinfo.m_input_iMCU_row * componentInfo.V_samp_factor, componentInfo.V_samp_factor);
/* Note: entropy decoder expects buffer to be zeroed,
* but this is handled automatically by the memory manager
* because we requested a pre-zeroed array.
*/
}
/* Loop to process one whole iMCU row */
for (int yoffset = m_MCU_vert_offset; yoffset < m_MCU_rows_per_iMCU_row; yoffset++)
{
for (int MCU_col_num = m_MCU_ctr; MCU_col_num < m_cinfo.m_MCUs_per_row; MCU_col_num++)
{
/* Construct list of pointers to DCT blocks belonging to this MCU */
int blkn = 0; /* index of current DCT block within MCU */
for (int ci = 0; ci < m_cinfo.m_comps_in_scan; ci++)
{
jpeg_component_info componentInfo = m_cinfo.Comp_info[m_cinfo.m_cur_comp_info[ci]];
int start_col = MCU_col_num * componentInfo.MCU_width;
for (int yindex = 0; yindex < componentInfo.MCU_height; yindex++)
{
for (int xindex = 0; xindex < componentInfo.MCU_width; xindex++)
{
m_MCU_buffer[blkn] = buffer[ci][yindex + yoffset][start_col + xindex];
blkn++;
}
}
}
/* Try to fetch the MCU. */
if (!m_cinfo.m_entropy.decode_mcu(m_MCU_buffer))
{
/* Suspension forced; update state counters and exit */
m_MCU_vert_offset = yoffset;
m_MCU_ctr = MCU_col_num;
return ReadResult.JPEG_SUSPENDED;
}
}
/* Completed an MCU row, but perhaps not an iMCU row */
m_MCU_ctr = 0;
}
/* Completed the iMCU row, advance counters for next one */
m_cinfo.m_input_iMCU_row++;
if (m_cinfo.m_input_iMCU_row < m_cinfo.m_total_iMCU_rows)
{
start_iMCU_row();
return ReadResult.JPEG_ROW_COMPLETED;
}
/* Completed the scan */
m_cinfo.m_inputctl.finish_input_pass();
return ReadResult.JPEG_SCAN_COMPLETED;
}
