static CONSUME_INPUT decompress_data_d_diff(jpeg_decompress cinfo, byte[][][] output_buf, int[] output_buf_ind)
{
jpeg_lossless_d_codec losslsd = (jpeg_lossless_d_codec)cinfo.coef;
d_diff_controller diff = (d_diff_controller)losslsd.diff_private;
// Loop to process as much as one whole iMCU row
for (uint yoffset = diff.MCU_vert_offset; yoffset < diff.MCU_rows_per_iMCU_row; yoffset++)
{
// Process restart marker if needed; may have to suspend
if (cinfo.restart_interval != 0)
{
if (diff.restart_rows_to_go == 0)
{
if (!process_restart_d_diff(cinfo))
{
return(CONSUME_INPUT.JPEG_SUSPENDED);
}
}
}
uint MCU_col_num = diff.MCU_ctr; // index of current MCU within row
// Try to fetch an MCU-row (or remaining portion of suspended MCU-row).
uint MCU_count = losslsd.entropy_decode_mcus(cinfo, diff.diff_buf, yoffset, MCU_col_num, cinfo.MCUs_per_row - MCU_col_num);
if (MCU_count != cinfo.MCUs_per_row - MCU_col_num)
{
// Suspension forced; update state counters and exit
diff.MCU_vert_offset = yoffset;
diff.MCU_ctr += MCU_count;
return(CONSUME_INPUT.JPEG_SUSPENDED);
}
// Account for restart interval (no-op if not using restarts)
diff.restart_rows_to_go--;
// Completed an MCU row, but perhaps not an iMCU row
diff.MCU_ctr = 0;
}
uint last_iMCU_row = cinfo.total_iMCU_rows - 1;
// Undifference and scale each scanline of the disassembled MCU-row
// separately. We do not process dummy samples at the end of a scanline
// or dummy rows at the end of the image.
for (int comp = 0; comp < cinfo.comps_in_scan; comp++)
{
jpeg_component_info compptr = cinfo.cur_comp_info[comp];
int ci = compptr.component_index;
int stop = cinfo.input_iMCU_row == last_iMCU_row?compptr.last_row_height:compptr.v_samp_factor;
for (int row = 0, prev_row = compptr.v_samp_factor - 1; row < stop; prev_row = row, row++)
{
losslsd.predict_undifference[ci](cinfo, ci, diff.diff_buf[ci][row], diff.undiff_buf[ci][prev_row], diff.undiff_buf[ci][row], compptr.width_in_blocks);
losslsd.scaler_scale(cinfo, diff.undiff_buf[ci][row], output_buf[ci][output_buf_ind[ci] + row], compptr.width_in_blocks);
}
}
// Completed the iMCU row, advance counters for next one.
//
// NB: output_data will increment output_iMCU_row.
// This counter is not needed for the single-pass case
// or the input side of the multi-pass case.
if (++(cinfo.input_iMCU_row) < cinfo.total_iMCU_rows)
{
start_iMCU_row_d_diff(cinfo);
return(CONSUME_INPUT.JPEG_ROW_COMPLETED);
}
// Completed the scan
cinfo.inputctl.finish_input_pass(cinfo);
return(CONSUME_INPUT.JPEG_SCAN_COMPLETED);
}
