public override bool encode_mcu(JBLOCK[][] MCU_data)
{
if (m_gather_statistics)
return encode_mcu_gather(MCU_data);
return encode_mcu_huff(MCU_data);
}
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;
}
}
/// <summary>
/// Process some data in subsequent passes of a multi-pass case.
/// We process the equivalent of one fully interleaved MCU row ("iMCU" row)
/// per call, ie, v_samp_factor block rows for each component in the scan.
/// The data is obtained from the virtual arrays and fed to the entropy coder.
/// Returns true if the iMCU row is completed, false if suspended.
/// </summary>
private bool compressOutput()
{
/* Align the virtual buffers for the components used in this scan.
*/
JBLOCK[][][] buffer = new JBLOCK[JpegConstants.MAX_COMPS_IN_SCAN][][];
for (int ci = 0; ci < m_cinfo.m_comps_in_scan; ci++)
{
jpeg_component_info componentInfo = m_cinfo.Component_info[m_cinfo.m_cur_comp_info[ci]];
buffer[ci] = m_whole_image[componentInfo.Component_index].Access(
m_iMCU_row_num * componentInfo.V_samp_factor, componentInfo.V_samp_factor);
}
/* 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.Component_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++)
{
int bufLength = buffer[ci][yindex + yoffset].Length;
int start = start_col + xindex;
m_MCU_buffer[blkn] = new JBLOCK[bufLength - start];
for (int j = start; j < bufLength; j++)
{
m_MCU_buffer[blkn][j - start] = buffer[ci][yindex + yoffset][j];
}
blkn++;
}
}
}
/* Try to write the MCU. */
if (!m_cinfo.m_entropy.encode_mcu(m_MCU_buffer))
{
/* Suspension forced; update state counters and exit */
m_MCU_vert_offset = yoffset;
m_mcu_ctr = MCU_col_num;
return(false);
}
}
/* Completed an MCU row, but perhaps not an iMCU row */
m_mcu_ctr = 0;
}
/* Completed the iMCU row, advance counters for next one */
m_iMCU_row_num++;
start_iMCU_row();
return(true);
}
private byte[] Hash(JBLOCK block, int[] group)
{
using (var ms = new MemoryStream())
using (var sw = new BinaryWriter(ms))
{
group.Select(i => block[i]).ToList().ForEach(sw.Write);
sw.Flush();
ms.Seek(0, SeekOrigin.Begin);
return(_md5.ComputeHash(ms).Take(BytesPerGroup).ToArray());
}
}
private void EncodeGroup(JBLOCK block, int[] @group, byte[] data)
{
var deviation = 1;
while (!Go(block, @group, data, 0, deviation))
{
deviation++;
Console.Out.WriteLine("deviation = {0}", deviation);
}
Console.Out.WriteLine("block encrypted");
}
private byte[] DecodeBlock(JBLOCK block)
{
using (var ms = new MemoryStream())
{
foreach (var @group in Groups)
{
var h = DecodeGroup(block, @group);
ms.Write(h, 0, h.Length);
}
return(ms.GetBuffer().Take(BytesPerBlock).ToArray());
}
}
private void EncodeBlock(JBLOCK block, byte[] data)
{
for (var i = 0; i < Groups.Length; i++)
{
var currentGroupData = data.Skip(i * BytesPerGroup).Take(BytesPerGroup).ToArray();
if (UseOldEncoder)
{
EncodeGroupOld(block, Groups[i], currentGroupData);
}
else
{
EncodeGroup(block, Groups[i], currentGroupData);
}
}
}
private void EncodeGroupOld(JBLOCK block, int[] @group, byte[] data)
{
var tries = 0;
while (!Hash(block, group).SequenceEqual(data))
{
var index = @group[_random.Next(@group.Length)];
block[index] += _random.Next(2) == 0 ? (short)1 : (short)-1;
if (tries++ > 10000000)
{
throw new Exception("Max tries reached");
}
}
Console.Out.WriteLine("block encrypted");
}
/// <summary>
/// Initialize coefficient buffer controller.
///
/// Each passed coefficient array must be the right size for that
/// coefficient: width_in_blocks wide and height_in_blocks high,
/// with unit height at least v_samp_factor.
/// </summary>
public my_trans_c_coef_controller(jpeg_compress_struct cinfo, jvirt_array<JBLOCK>[] coef_arrays)
{
m_cinfo = cinfo;
/* Save pointer to virtual arrays */
m_whole_image = coef_arrays;
/* Allocate and pre-zero space for dummy DCT blocks. */
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_dummy_buffer[i] = new JBLOCK[JpegConstants.C_MAX_BLOCKS_IN_MCU - i];
for (int j = i; j < JpegConstants.C_MAX_BLOCKS_IN_MCU; j++)
m_dummy_buffer[i][j - i] = buffer[j];
}
}
private bool Go(JBLOCK block, int[] @group, byte[] target, int pos, int deviation)
{
if (pos == @group.Length)
{
return(Hash(block, @group).SequenceEqual(target));
}
for (var i = -deviation; i <= deviation; i++)
{
block[@group[pos]] += (short)i;
if (Go(block, @group, target, pos + 1, deviation - Math.Abs(i)))
{
return(true);
}
block[@group[pos]] -= (short)i;
}
return(false);
}
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;
}
}
/// <summary>
/// Initialize coefficient buffer controller.
///
/// Each passed coefficient array must be the right size for that
/// coefficient: width_in_blocks wide and height_in_blocks high,
/// with unit height at least v_samp_factor.
/// </summary>
public my_trans_c_coef_controller(jpeg_compress_struct cinfo, jvirt_array <JBLOCK>[] coef_arrays)
{
m_cinfo = cinfo;
/* Save pointer to virtual arrays */
m_whole_image = coef_arrays;
/* Allocate and pre-zero space for dummy DCT blocks. */
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_dummy_buffer[i] = new JBLOCK[JpegConstants.C_MAX_BLOCKS_IN_MCU - i];
for (int j = i; j < JpegConstants.C_MAX_BLOCKS_IN_MCU; j++)
{
m_dummy_buffer[i][j - i] = buffer[j];
}
}
}
/// <summary>
/// Decode and return one MCU's worth of Huffman-compressed coefficients.
/// The coefficients are reordered from zigzag order into natural array order,
/// but are not dequantized.
///
/// The i'th block of the MCU is stored into the block pointed to by
/// MCU_data[i]. WE ASSUME THIS AREA HAS BEEN ZEROED BY THE CALLER.
/// (Wholesale zeroing is usually a little faster than retail...)
///
/// Returns false if data source requested suspension. In that case no
/// changes have been made to permanent state. (Exception: some output
/// coefficients may already have been assigned. This is harmless for
/// this module, since we'll just re-assign them on the next call.)
/// </summary>
public override bool decode_mcu(JBLOCK[] MCU_data)
{
/* Process restart marker if needed; may have to suspend */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
{
if (!process_restart())
return false;
}
}
/* If we've run out of data, just leave the MCU set to zeroes.
* This way, we return uniform gray for the remainder of the segment.
*/
if (!m_insufficient_data)
{
/* Load up working state */
int get_buffer;
int bits_left;
bitread_working_state br_state = new bitread_working_state();
BITREAD_LOAD_STATE(m_bitstate, out get_buffer, out bits_left, ref br_state);
savable_state state = new savable_state();
state.Assign(m_saved);
/* Outer loop handles each block in the MCU */
for (int blkn = 0; blkn < m_cinfo.m_blocks_in_MCU; blkn++)
{
/* Decode a single block's worth of coefficients */
/* Section F.2.2.1: decode the DC coefficient difference */
int s;
if (!HUFF_DECODE(out s, ref br_state, m_dc_cur_tbls[blkn], ref get_buffer, ref bits_left))
return false;
if (s != 0)
{
if (!CHECK_BIT_BUFFER(ref br_state, s, ref get_buffer, ref bits_left))
return false;
int r = GET_BITS(s, get_buffer, ref bits_left);
s = HUFF_EXTEND(r, s);
}
if (m_dc_needed[blkn])
{
/* Convert DC difference to actual value, update last_dc_val */
int ci = m_cinfo.m_MCU_membership[blkn];
s += state.last_dc_val[ci];
state.last_dc_val[ci] = s;
/* Output the DC coefficient (assumes jpeg_natural_order[0] = 0) */
MCU_data[blkn][0] = (short) s;
}
if (m_ac_needed[blkn])
{
/* Section F.2.2.2: decode the AC coefficients */
/* Since zeroes are skipped, output area must be cleared beforehand */
for (int k = 1; k < JpegConstants.DCTSIZE2; k++)
{
if (!HUFF_DECODE(out s, ref br_state, m_ac_cur_tbls[blkn], ref get_buffer, ref bits_left))
return false;
int r = s >> 4;
s &= 15;
if (s != 0)
{
k += r;
if (!CHECK_BIT_BUFFER(ref br_state, s, ref get_buffer, ref bits_left))
return false;
r = GET_BITS(s, get_buffer, ref bits_left);
s = HUFF_EXTEND(r, s);
/* Output coefficient in natural (dezigzagged) order.
* Note: the extra entries in jpeg_natural_order[] will save us
* if k >= DCTSIZE2, which could happen if the data is corrupted.
*/
MCU_data[blkn][JpegUtils.jpeg_natural_order[k]] = (short) s;
}
else
{
if (r != 15)
break;
k += 15;
}
}
}
else
{
/* Section F.2.2.2: decode the AC coefficients */
/* In this path we just discard the values */
for (int k = 1; k < JpegConstants.DCTSIZE2; k++)
{
if (!HUFF_DECODE(out s, ref br_state, m_ac_cur_tbls[blkn], ref get_buffer, ref bits_left))
return false;
int r = s >> 4;
s &= 15;
if (s != 0)
{
k += r;
if (!CHECK_BIT_BUFFER(ref br_state, s, ref get_buffer, ref bits_left))
return false;
DROP_BITS(s, ref bits_left);
}
else
{
if (r != 15)
break;
k += 15;
}
}
}
}
/* Completed MCU, so update state */
BITREAD_SAVE_STATE(ref m_bitstate, get_buffer, bits_left);
m_saved.Assign(state);
}
/* Account for restart interval (no-op if not using restarts) */
m_restarts_to_go--;
return true;
}
/// <summary>
/// Trial-encode one MCU's worth of Huffman-compressed coefficients.
/// No data is actually output, so no suspension return is possible.
/// </summary>
private bool encode_mcu_gather(JBLOCK[][] MCU_data)
{
/* Take care of restart intervals if needed */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
{
/* Re-initialize DC predictions to 0 */
for (int ci = 0; ci < m_cinfo.m_comps_in_scan; ci++)
m_saved.last_dc_val[ci] = 0;
/* Update restart state */
m_restarts_to_go = m_cinfo.m_restart_interval;
}
m_restarts_to_go--;
}
for (int blkn = 0; blkn < m_cinfo.m_blocks_in_MCU; blkn++)
{
int ci = m_cinfo.m_MCU_membership[blkn];
htest_one_block(MCU_data[blkn][0].data, m_saved.last_dc_val[ci],
m_dc_count_ptrs[m_cinfo.Component_info[m_cinfo.m_cur_comp_info[ci]].Dc_tbl_no],
m_ac_count_ptrs[m_cinfo.Component_info[m_cinfo.m_cur_comp_info[ci]].Ac_tbl_no]);
m_saved.last_dc_val[ci] = MCU_data[blkn][0][0];
}
return true;
}
/// <summary>
/// MCU decoding for AC successive approximation refinement scan.
/// </summary>
private static void undo_decode_mcu_AC_refine(JBLOCK[] block, int[] newnz_pos, int num_newnz)
{
/* Re-zero any output coefficients that we made newly nonzero */
while (num_newnz > 0)
block[0][newnz_pos[--num_newnz]] = 0;
}
/// <summary>
/// Variant of decompress_data for use when doing block smoothing.
/// </summary>
private ReadResult decompress_smooth_data(ComponentBuffer[] output_buf)
{
/* Force some input to be done if we are getting ahead of the input. */
while (m_cinfo.m_input_scan_number <= m_cinfo.m_output_scan_number && !m_cinfo.m_inputctl.EOIReached())
{
if (m_cinfo.m_input_scan_number == m_cinfo.m_output_scan_number)
{
/* If input is working on current scan, we ordinarily want it to
* have completed the current row. But if input scan is DC,
* we want it to keep one row ahead so that next block row's DC
* values are up to date.
*/
int delta = (m_cinfo.m_Ss == 0) ? 1 : 0;
if (m_cinfo.m_input_iMCU_row > m_cinfo.m_output_iMCU_row + delta)
break;
}
if (m_cinfo.m_inputctl.consume_input() == ReadResult.JPEG_SUSPENDED)
return ReadResult.JPEG_SUSPENDED;
}
int last_iMCU_row = m_cinfo.m_total_iMCU_rows - 1;
/* OK, output from the virtual arrays. */
for (int ci = 0; ci < m_cinfo.m_num_components; ci++)
{
jpeg_component_info componentInfo = m_cinfo.Comp_info[ci];
/* Don't bother to IDCT an uninteresting component. */
if (!componentInfo.component_needed)
continue;
int block_rows;
int access_rows;
bool last_row;
/* Count non-dummy DCT block rows in this iMCU row. */
if (m_cinfo.m_output_iMCU_row < last_iMCU_row)
{
block_rows = componentInfo.V_samp_factor;
access_rows = block_rows * 2; /* this and next iMCU row */
last_row = false;
}
else
{
/* NB: can't use last_row_height here; it is input-side-dependent! */
block_rows = componentInfo.height_in_blocks % componentInfo.V_samp_factor;
if (block_rows == 0)
block_rows = componentInfo.V_samp_factor;
access_rows = block_rows; /* this iMCU row only */
last_row = true;
}
/* Align the virtual buffer for this component. */
JBLOCK[][] buffer = null;
bool first_row;
int bufferRowOffset = 0;
if (m_cinfo.m_output_iMCU_row > 0)
{
access_rows += componentInfo.V_samp_factor; /* prior iMCU row too */
buffer = m_whole_image[ci].Access((m_cinfo.m_output_iMCU_row - 1) * componentInfo.V_samp_factor, access_rows);
bufferRowOffset = componentInfo.V_samp_factor; /* point to current iMCU row */
first_row = false;
}
else
{
buffer = m_whole_image[ci].Access(0, access_rows);
first_row = true;
}
/* Fetch component-dependent info */
int coefBitsOffset = ci * SAVED_COEFS;
int Q00 = componentInfo.quant_table.quantval[0];
int Q01 = componentInfo.quant_table.quantval[Q01_POS];
int Q10 = componentInfo.quant_table.quantval[Q10_POS];
int Q20 = componentInfo.quant_table.quantval[Q20_POS];
int Q11 = componentInfo.quant_table.quantval[Q11_POS];
int Q02 = componentInfo.quant_table.quantval[Q02_POS];
int outputIndex = ci;
/* Loop over all DCT blocks to be processed. */
for (int block_row = 0; block_row < block_rows; block_row++)
{
int bufferIndex = bufferRowOffset + block_row;
int prev_block_row = 0;
if (first_row && block_row == 0)
prev_block_row = bufferIndex;
else
prev_block_row = bufferIndex - 1;
int next_block_row = 0;
if (last_row && block_row == block_rows - 1)
next_block_row = bufferIndex;
else
next_block_row = bufferIndex + 1;
/* We fetch the surrounding DC values using a sliding-register approach.
* Initialize all nine here so as to do the right thing on narrow pics.
*/
int DC1 = buffer[prev_block_row][0][0];
int DC2 = DC1;
int DC3 = DC1;
int DC4 = buffer[bufferIndex][0][0];
int DC5 = DC4;
int DC6 = DC4;
int DC7 = buffer[next_block_row][0][0];
int DC8 = DC7;
int DC9 = DC7;
int output_col = 0;
int last_block_column = componentInfo.Width_in_blocks - 1;
for (int block_num = 0; block_num <= last_block_column; block_num++)
{
/* Fetch current DCT block into workspace so we can modify it. */
JBLOCK workspace = new JBLOCK();
Buffer.BlockCopy(buffer[bufferIndex][0].data, 0, workspace.data, 0, workspace.data.Length * sizeof(short));
/* Update DC values */
if (block_num < last_block_column)
{
DC3 = buffer[prev_block_row][1][0];
DC6 = buffer[bufferIndex][1][0];
DC9 = buffer[next_block_row][1][0];
}
/* Compute coefficient estimates per K.8.
* An estimate is applied only if coefficient is still zero,
* and is not known to be fully accurate.
*/
/* AC01 */
int Al = m_coef_bits_latch[m_coef_bits_savedOffset + coefBitsOffset + 1];
if (Al != 0 && workspace[1] == 0)
{
int pred;
int num = 36 * Q00 * (DC4 - DC6);
if (num >= 0)
{
pred = ((Q01 << 7) + num) / (Q01 << 8);
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
}
else
{
pred = ((Q01 << 7) - num) / (Q01 << 8);
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
pred = -pred;
}
workspace[1] = (short) pred;
}
/* AC10 */
Al = m_coef_bits_latch[m_coef_bits_savedOffset + coefBitsOffset + 2];
if (Al != 0 && workspace[8] == 0)
{
int pred;
int num = 36 * Q00 * (DC2 - DC8);
if (num >= 0)
{
pred = ((Q10 << 7) + num) / (Q10 << 8);
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
}
else
{
pred = ((Q10 << 7) - num) / (Q10 << 8);
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
pred = -pred;
}
workspace[8] = (short) pred;
}
/* AC20 */
Al = m_coef_bits_latch[m_coef_bits_savedOffset + coefBitsOffset + 3];
if (Al != 0 && workspace[16] == 0)
{
int pred;
int num = 9 * Q00 * (DC2 + DC8 - 2 * DC5);
if (num >= 0)
{
pred = ((Q20 << 7) + num) / (Q20 << 8);
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
}
else
{
pred = ((Q20 << 7) - num) / (Q20 << 8);
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
pred = -pred;
}
workspace[16] = (short) pred;
}
/* AC11 */
Al = m_coef_bits_latch[m_coef_bits_savedOffset + coefBitsOffset + 4];
if (Al != 0 && workspace[9] == 0)
{
int pred;
int num = 5 * Q00 * (DC1 - DC3 - DC7 + DC9);
if (num >= 0)
{
pred = ((Q11 << 7) + num) / (Q11 << 8);
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
}
else
{
pred = ((Q11 << 7) - num) / (Q11 << 8);
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
pred = -pred;
}
workspace[9] = (short) pred;
}
/* AC02 */
Al = m_coef_bits_latch[m_coef_bits_savedOffset + coefBitsOffset + 5];
if (Al != 0 && workspace[2] == 0)
{
int pred;
int num = 9 * Q00 * (DC4 + DC6 - 2 * DC5);
if (num >= 0)
{
pred = ((Q02 << 7) + num) / (Q02 << 8);
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
}
else
{
pred = ((Q02 << 7) - num) / (Q02 << 8);
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
pred = -pred;
}
workspace[2] = (short) pred;
}
/* OK, do the IDCT */
m_cinfo.m_idct.inverse(componentInfo.Component_index, workspace.data, output_buf[outputIndex], 0, output_col);
/* Advance for next column */
DC1 = DC2;
DC2 = DC3;
DC4 = DC5;
DC5 = DC6;
DC7 = DC8;
DC8 = DC9;
bufferIndex++;
prev_block_row++;
next_block_row++;
output_col += componentInfo.DCT_scaled_size;
}
outputIndex += componentInfo.DCT_scaled_size;
}
}
m_cinfo.m_output_iMCU_row++;
if (m_cinfo.m_output_iMCU_row < m_cinfo.m_total_iMCU_rows)
return ReadResult.JPEG_ROW_COMPLETED;
return ReadResult.JPEG_SCAN_COMPLETED;
}
// This version is used for integer DCT implementations.
private void forwardDCTImpl(int quant_tbl_no, byte[][] sample_data, JBLOCK[] coef_blocks, int start_row, int start_col, int num_blocks)
{
/* This routine is heavily used, so it's worth coding it tightly. */
int[] workspace = new int [JpegConstants.DCTSIZE2]; /* work area for FDCT subroutine */
for (int bi = 0; bi < num_blocks; bi++, start_col += JpegConstants.DCTSIZE)
{
/* Load data into workspace, applying unsigned->signed conversion */
int workspaceIndex = 0;
for (int elemr = 0; elemr < JpegConstants.DCTSIZE; elemr++)
{
for (int column = 0; column < JpegConstants.DCTSIZE; column++)
{
workspace[workspaceIndex] = (int)sample_data[start_row + elemr][start_col + column] - JpegConstants.CENTERJSAMPLE;
workspaceIndex++;
}
}
/* Perform the DCT */
if (m_useSlowMethod)
jpeg_fdct_islow(workspace);
else
jpeg_fdct_ifast(workspace);
/* Quantize/descale the coefficients, and store into coef_blocks[] */
for (int i = 0; i < JpegConstants.DCTSIZE2; i++)
{
int qval = m_divisors[quant_tbl_no][i];
int temp = workspace[i];
if (temp < 0)
{
temp = -temp;
temp += qval >> 1; /* for rounding */
if (temp >= qval)
temp /= qval;
else
temp = 0;
temp = -temp;
}
else
{
temp += qval >> 1; /* for rounding */
if (temp >= qval)
temp /= qval;
else
temp = 0;
}
coef_blocks[bi][i] = (short) temp;
}
}
}
/// <summary>
/// Perform forward DCT on one or more blocks of a component.
///
/// The input samples are taken from the sample_data[] array starting at
/// position start_row/start_col, and moving to the right for any additional
/// blocks. The quantized coefficients are returned in coef_blocks[].
/// </summary>
public virtual void forward_DCT(int quant_tbl_no, byte[][] sample_data, JBLOCK[] coef_blocks, int start_row, int start_col, int num_blocks)
{
if (m_useFloatMethod)
forwardDCTFloatImpl(quant_tbl_no, sample_data, coef_blocks, start_row, start_col, num_blocks);
else
forwardDCTImpl(quant_tbl_no, sample_data, coef_blocks, start_row, start_col, num_blocks);
}
/// <summary>
/// MCU decoding for DC successive approximation refinement scan.
/// Note: we assume such scans can be multi-component, although the spec
/// is not very clear on the point.
/// </summary>
private bool decode_mcu_DC_refine(JBLOCK[] MCU_data)
{
/* Process restart marker if needed; may have to suspend */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
{
if (!process_restart())
return false;
}
}
/* Not worth the cycles to check insufficient_data here,
* since we will not change the data anyway if we read zeroes.
*/
/* Load up working state */
int get_buffer;
int bits_left;
bitread_working_state br_state = new bitread_working_state();
BITREAD_LOAD_STATE(m_bitstate, out get_buffer, out bits_left, ref br_state);
/* Outer loop handles each block in the MCU */
for (int blkn = 0; blkn < m_cinfo.m_blocks_in_MCU; blkn++)
{
/* Encoded data is simply the next bit of the two's-complement DC value */
if (!CHECK_BIT_BUFFER(ref br_state, 1, ref get_buffer, ref bits_left))
return false;
if (GET_BITS(1, get_buffer, ref bits_left) != 0)
{
/* 1 in the bit position being coded */
MCU_data[blkn][0] = (short)((ushort)MCU_data[blkn][0] | (ushort)(1 << m_cinfo.m_Al));
}
/* Note: since we use |=, repeating the assignment later is safe */
}
/* Completed MCU, so update state */
BITREAD_SAVE_STATE(ref m_bitstate, get_buffer, bits_left);
/* Account for restart interval (no-op if not using restarts) */
m_restarts_to_go--;
return true;
}
/// <summary>
/// MCU encoding for AC successive approximation refinement scan.
/// </summary>
private bool encode_mcu_AC_refine(JBLOCK[][] MCU_data)
{
/* Emit restart marker if needed */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
emit_restart(m_next_restart_num);
}
/* Encode the MCU data block */
/* It is convenient to make a pre-pass to determine the transformed
* coefficients' absolute values and the EOB position.
*/
int EOB = 0;
int[] absvalues = new int[JpegConstants.DCTSIZE2];
for (int k = m_cinfo.m_Ss; k <= m_cinfo.m_Se; k++)
{
int temp = MCU_data[0][0][JpegUtils.jpeg_natural_order[k]];
/* We must apply the point transform by Al. For AC coefficients this
* is an integer division with rounding towards 0. To do this portably
* in C, we shift after obtaining the absolute value.
*/
if (temp < 0)
temp = -temp; /* temp is abs value of input */
temp >>= m_cinfo.m_Al; /* apply the point transform */
absvalues[k] = temp; /* save abs value for main pass */
if (temp == 1)
{
/* EOB = index of last newly-nonzero coef */
EOB = k;
}
}
/* Encode the AC coefficients per section G.1.2.3, fig. G.7 */
int r = 0; /* r = run length of zeros */
int BR = 0; /* BR = count of buffered bits added now */
int bitBufferOffset = m_BE; /* Append bits to buffer */
for (int k = m_cinfo.m_Ss; k <= m_cinfo.m_Se; k++)
{
int temp = absvalues[k];
if (temp == 0)
{
r++;
continue;
}
/* Emit any required ZRLs, but not if they can be folded into EOB */
while (r > 15 && k <= EOB)
{
/* emit any pending EOBRUN and the BE correction bits */
emit_eobrun();
/* Emit ZRL */
emit_symbol(m_ac_tbl_no, 0xF0);
r -= 16;
/* Emit buffered correction bits that must be associated with ZRL */
emit_buffered_bits(bitBufferOffset, BR);
bitBufferOffset = 0;/* BE bits are gone now */
BR = 0;
}
/* If the coef was previously nonzero, it only needs a correction bit.
* NOTE: a straight translation of the spec's figure G.7 would suggest
* that we also need to test r > 15. But if r > 15, we can only get here
* if k > EOB, which implies that this coefficient is not 1.
*/
if (temp > 1)
{
/* The correction bit is the next bit of the absolute value. */
m_bit_buffer[bitBufferOffset + BR] = (char) (temp & 1);
BR++;
continue;
}
/* Emit any pending EOBRUN and the BE correction bits */
emit_eobrun();
/* Count/emit Huffman symbol for run length / number of bits */
emit_symbol(m_ac_tbl_no, (r << 4) + 1);
/* Emit output bit for newly-nonzero coef */
temp = (MCU_data[0][0][JpegUtils.jpeg_natural_order[k]] < 0) ? 0 : 1;
emit_bits(temp, 1);
/* Emit buffered correction bits that must be associated with this code */
emit_buffered_bits(bitBufferOffset, BR);
bitBufferOffset = 0;/* BE bits are gone now */
BR = 0;
r = 0; /* reset zero run length */
}
if (r > 0 || BR > 0)
{
/* If there are trailing zeroes, */
m_EOBRUN++; /* count an EOB */
m_BE += BR; /* concat my correction bits to older ones */
/* We force out the EOB if we risk either:
* 1. overflow of the EOB counter;
* 2. overflow of the correction bit buffer during the next MCU.
*/
if (m_EOBRUN == 0x7FFF || m_BE > (MAX_CORR_BITS - JpegConstants.DCTSIZE2 + 1))
emit_eobrun();
}
/* Update restart-interval state too */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
{
m_restarts_to_go = m_cinfo.m_restart_interval;
m_next_restart_num++;
m_next_restart_num &= 7;
}
m_restarts_to_go--;
}
return true;
}
public override bool encode_mcu(JBLOCK[][] MCU_data)
{
switch (m_MCUEncoder)
{
case MCUEncoder.mcu_DC_first_encoder:
return encode_mcu_DC_first(MCU_data);
case MCUEncoder.mcu_AC_first_encoder:
return encode_mcu_AC_first(MCU_data);
case MCUEncoder.mcu_DC_refine_encoder:
return encode_mcu_DC_refine(MCU_data);
case MCUEncoder.mcu_AC_refine_encoder:
return encode_mcu_AC_refine(MCU_data);
}
m_cinfo.ERREXIT(J_MESSAGE_CODE.JERR_NOTIMPL);
return false;
}
// This version is used for floating-point DCT implementations.
private void forwardDCTFloatImpl(jpeg_component_info compptr, byte[][] sample_data, JBLOCK[] coef_blocks, int start_row, int start_col, int num_blocks)
{
/* This routine is heavily used, so it's worth coding it tightly. */
float_DCT_method_ptr do_dct = do_float_dct[compptr.Component_index];
float[] divisors = m_dctTables[compptr.Component_index].float_array;
float[] workspace = new float[JpegConstants.DCTSIZE2]; /* work area for FDCT subroutine */
for (int bi = 0; bi < num_blocks; bi++, start_col += compptr.DCT_h_scaled_size)
{
/* Perform the DCT */
do_dct(workspace, sample_data, start_row, start_col);
/* Quantize/descale the coefficients, and store into coef_blocks[] */
for (int i = 0; i < JpegConstants.DCTSIZE2; i++)
{
/* Apply the quantization and scaling factor */
float temp = workspace[i] * divisors[i];
/* Round to nearest integer.
* Since C does not specify the direction of rounding for negative
* quotients, we have to force the dividend positive for portability.
* The maximum coefficient size is +-16K (for 12-bit data), so this
* code should work for either 16-bit or 32-bit ints.
*/
coef_blocks[bi][i] = (short)((int)(temp + (float)16384.5) - 16384);
}
}
}
// This version is used for integer DCT implementations.
private void forwardDCTImpl(jpeg_component_info compptr, byte[][] sample_data, JBLOCK[] coef_blocks, int start_row, int start_col, int num_blocks)
{
/* This routine is heavily used, so it's worth coding it tightly. */
forward_DCT_method_ptr do_dct = this.do_dct[compptr.Component_index];
int[] divisors = m_dctTables[compptr.Component_index].int_array;
int[] workspace = new int[JpegConstants.DCTSIZE2]; /* work area for FDCT subroutine */
for (int bi = 0; bi < num_blocks; bi++, start_col += compptr.DCT_h_scaled_size)
{
/* Perform the DCT */
do_dct(workspace, sample_data, start_row, start_col);
/* Quantize/descale the coefficients, and store into coef_blocks[] */
for (int i = 0; i < JpegConstants.DCTSIZE2; i++)
{
int qval = divisors[i];
int temp = workspace[i];
if (temp < 0)
{
temp = -temp;
temp += qval >> 1; /* for rounding */
if (temp >= qval)
temp /= qval;
else
temp = 0;
temp = -temp;
}
else
{
temp += qval >> 1; /* for rounding */
if (temp >= qval)
temp /= qval;
else
temp = 0;
}
coef_blocks[bi][i] = (short)temp;
}
}
}
/// <summary>
/// Process some data.
/// We process the equivalent of one fully interleaved MCU row ("iMCU" row)
/// per call, ie, v_samp_factor block rows for each component in the scan.
/// The data is obtained from the virtual arrays and fed to the entropy coder.
/// Returns true if the iMCU row is completed, false if suspended.
///
/// NB: input_buf is ignored; it is likely to be a null pointer.
/// </summary>
public virtual bool compress_data(byte[][][] input_buf)
{
/* Align the virtual buffers for the components used in this scan. */
JBLOCK[][][] buffer = new JBLOCK[JpegConstants.MAX_COMPS_IN_SCAN][][];
for (int ci = 0; ci < m_cinfo.m_comps_in_scan; ci++)
{
jpeg_component_info componentInfo = m_cinfo.Component_info[m_cinfo.m_cur_comp_info[ci]];
buffer[ci] = m_whole_image[componentInfo.Component_index].Access(
m_iMCU_row_num * componentInfo.V_samp_factor, componentInfo.V_samp_factor);
}
/* Loop to process one whole iMCU row */
int last_MCU_col = m_cinfo.m_MCUs_per_row - 1;
int last_iMCU_row = m_cinfo.m_total_iMCU_rows - 1;
JBLOCK[][] MCU_buffer = new JBLOCK[JpegConstants.C_MAX_BLOCKS_IN_MCU][];
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.Component_info[m_cinfo.m_cur_comp_info[ci]];
int start_col = MCU_col_num * componentInfo.MCU_width;
int blockcnt = (MCU_col_num < last_MCU_col) ? componentInfo.MCU_width : componentInfo.last_col_width;
for (int yindex = 0; yindex < componentInfo.MCU_height; yindex++)
{
int xindex = 0;
if (m_iMCU_row_num < last_iMCU_row || yindex + yoffset < componentInfo.last_row_height)
{
/* Fill in pointers to real blocks in this row */
for (xindex = 0; xindex < blockcnt; xindex++)
{
int bufLength = buffer[ci][yindex + yoffset].Length;
int start = start_col + xindex;
MCU_buffer[blkn] = new JBLOCK[bufLength - start];
for (int j = start; j < bufLength; j++)
MCU_buffer[blkn][j - start] = buffer[ci][yindex + yoffset][j];
blkn++;
}
}
else
{
/* At bottom of image, need a whole row of dummy blocks */
xindex = 0;
}
/* Fill in any dummy blocks needed in this row.
* Dummy blocks are filled in the same way as in jccoefct.c:
* all zeroes in the AC entries, DC entries equal to previous
* block's DC value. The init routine has already zeroed the
* AC entries, so we need only set the DC entries correctly.
*/
for (; xindex < componentInfo.MCU_width; xindex++)
{
MCU_buffer[blkn] = m_dummy_buffer[blkn];
MCU_buffer[blkn][0][0] = MCU_buffer[blkn - 1][0][0];
blkn++;
}
}
}
/* Try to write the MCU. */
if (!m_cinfo.m_entropy.encode_mcu(MCU_buffer))
{
/* Suspension forced; update state counters and exit */
m_MCU_vert_offset = yoffset;
m_mcu_ctr = MCU_col_num;
return false;
}
}
/* Completed an MCU row, but perhaps not an iMCU row */
m_mcu_ctr = 0;
}
/* Completed the iMCU row, advance counters for next one */
m_iMCU_row_num++;
start_iMCU_row();
return true;
}
// There is always only one block per MCU
private bool decode_mcu_AC_refine(JBLOCK[] MCU_data)
{
int p1 = 1 << m_cinfo.m_Al; /* 1 in the bit position being coded */
int m1 = -1 << m_cinfo.m_Al; /* -1 in the bit position being coded */
/* Process restart marker if needed; may have to suspend */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
{
if (!process_restart())
return false;
}
}
/* If we've run out of data, don't modify the MCU.
*/
if (!m_insufficient_data)
{
/* Load up working state */
int get_buffer;
int bits_left;
bitread_working_state br_state = new bitread_working_state();
BITREAD_LOAD_STATE(m_bitstate, out get_buffer, out bits_left, ref br_state);
int EOBRUN = m_saved.EOBRUN; /* only part of saved state we need */
/* If we are forced to suspend, we must undo the assignments to any newly
* nonzero coefficients in the block, because otherwise we'd get confused
* next time about which coefficients were already nonzero.
* But we need not undo addition of bits to already-nonzero coefficients;
* instead, we can test the current bit to see if we already did it.
*/
int num_newnz = 0;
int[] newnz_pos = new int[JpegConstants.DCTSIZE2];
/* initialize coefficient loop counter to start of band */
int k = m_cinfo.m_Ss;
if (EOBRUN == 0)
{
for (; k <= m_cinfo.m_Se; k++)
{
int s;
if (!HUFF_DECODE(out s, ref br_state, m_ac_derived_tbl, ref get_buffer, ref bits_left))
{
undo_decode_mcu_AC_refine(MCU_data, newnz_pos, num_newnz);
return false;
}
int r = s >> 4;
s &= 15;
if (s != 0)
{
if (s != 1)
{
/* size of new coef should always be 1 */
m_cinfo.WARNMS(J_MESSAGE_CODE.JWRN_HUFF_BAD_CODE);
}
if (!CHECK_BIT_BUFFER(ref br_state, 1, ref get_buffer, ref bits_left))
{
undo_decode_mcu_AC_refine(MCU_data, newnz_pos, num_newnz);
return false;
}
if (GET_BITS(1, get_buffer, ref bits_left) != 0)
{
/* newly nonzero coef is positive */
s = p1;
}
else
{
/* newly nonzero coef is negative */
s = m1;
}
}
else
{
if (r != 15)
{
EOBRUN = 1 << r; /* EOBr, run length is 2^r + appended bits */
if (r != 0)
{
if (!CHECK_BIT_BUFFER(ref br_state, r, ref get_buffer, ref bits_left))
{
undo_decode_mcu_AC_refine(MCU_data, newnz_pos, num_newnz);
return false;
}
r = GET_BITS(r, get_buffer, ref bits_left);
EOBRUN += r;
}
break; /* rest of block is handled by EOB logic */
}
/* note s = 0 for processing ZRL */
}
/* Advance over already-nonzero coefs and r still-zero coefs,
* appending correction bits to the nonzeroes. A correction bit is 1
* if the absolute value of the coefficient must be increased.
*/
do
{
int blockIndex = JpegUtils.jpeg_natural_order[k];
short thiscoef = MCU_data[0][blockIndex];
if (thiscoef != 0)
{
if (!CHECK_BIT_BUFFER(ref br_state, 1, ref get_buffer, ref bits_left))
{
undo_decode_mcu_AC_refine(MCU_data, newnz_pos, num_newnz);
return false;
}
if (GET_BITS(1, get_buffer, ref bits_left) != 0)
{
if ((thiscoef & p1) == 0)
{
/* do nothing if already set it */
if (thiscoef >= 0)
MCU_data[0][blockIndex] += (short)p1;
else
MCU_data[0][blockIndex] += (short)m1;
}
}
}
else
{
if (--r < 0)
break; /* reached target zero coefficient */
}
k++;
}
while (k <= m_cinfo.m_Se);
if (s != 0)
{
int pos = JpegUtils.jpeg_natural_order[k];
/* Output newly nonzero coefficient */
MCU_data[0][pos] = (short)s;
/* Remember its position in case we have to suspend */
newnz_pos[num_newnz++] = pos;
}
}
}
if (EOBRUN > 0)
{
/* Scan any remaining coefficient positions after the end-of-band
* (the last newly nonzero coefficient, if any). Append a correction
* bit to each already-nonzero coefficient. A correction bit is 1
* if the absolute value of the coefficient must be increased.
*/
for (; k <= m_cinfo.m_Se; k++)
{
int blockIndex = JpegUtils.jpeg_natural_order[k];
short thiscoef = MCU_data[0][blockIndex];
if (thiscoef != 0)
{
if (!CHECK_BIT_BUFFER(ref br_state, 1, ref get_buffer, ref bits_left))
{
//undo_decode_mcu_AC_refine(MCU_data[0], newnz_pos, num_newnz);
undo_decode_mcu_AC_refine(MCU_data, newnz_pos, num_newnz);
return false;
}
if (GET_BITS(1, get_buffer, ref bits_left) != 0)
{
if ((thiscoef & p1) == 0)
{
/* do nothing if already changed it */
if (thiscoef >= 0)
MCU_data[0][blockIndex] += (short)p1;
else
MCU_data[0][blockIndex] += (short)m1;
}
}
}
}
/* Count one block completed in EOB run */
EOBRUN--;
}
/* Completed MCU, so update state */
BITREAD_SAVE_STATE(ref m_bitstate, get_buffer, bits_left);
m_saved.EOBRUN = EOBRUN; /* only part of saved state we need */
}
/* Account for restart interval (no-op if not using restarts) */
m_restarts_to_go--;
return true;
}
/// <summary>
/// MCU decoding for AC initial scan (either spectral selection,
/// or first pass of successive approximation).
/// </summary>
private bool decode_mcu_AC_first(JBLOCK[] MCU_data)
{
/* Process restart marker if needed; may have to suspend */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
{
if (!process_restart())
return false;
}
}
/* If we've run out of data, just leave the MCU set to zeroes.
* This way, we return uniform gray for the remainder of the segment.
*/
if (!m_insufficient_data)
{
/* Load up working state.
* We can avoid loading/saving bitread state if in an EOB run.
*/
int EOBRUN = m_saved.EOBRUN; /* only part of saved state we need */
/* There is always only one block per MCU */
if (EOBRUN > 0)
{
/* if it's a band of zeroes... */
/* ...process it now (we do nothing) */
EOBRUN--;
}
else
{
int get_buffer;
int bits_left;
bitread_working_state br_state = new bitread_working_state();
BITREAD_LOAD_STATE(m_bitstate, out get_buffer, out bits_left, ref br_state);
for (int k = m_cinfo.m_Ss; k <= m_cinfo.m_Se; k++)
{
int s;
if (!HUFF_DECODE(out s, ref br_state, m_ac_derived_tbl, ref get_buffer, ref bits_left))
return false;
int r = s >> 4;
s &= 15;
if (s != 0)
{
k += r;
if (!CHECK_BIT_BUFFER(ref br_state, s, ref get_buffer, ref bits_left))
return false;
r = GET_BITS(s, get_buffer, ref bits_left);
s = HUFF_EXTEND(r, s);
/* Scale and output coefficient in natural (dezigzagged) order */
MCU_data[0][JpegUtils.jpeg_natural_order[k]] = (short)(s << m_cinfo.m_Al);
}
else
{
if (r == 15)
{
/* ZRL */
k += 15; /* skip 15 zeroes in band */
}
else
{
/* EOBr, run length is 2^r + appended bits */
EOBRUN = 1 << r;
if (r != 0)
{
/* EOBr, r > 0 */
if (!CHECK_BIT_BUFFER(ref br_state, r, ref get_buffer, ref bits_left))
return false;
r = GET_BITS(r, get_buffer, ref bits_left);
EOBRUN += r;
}
EOBRUN--; /* this band is processed at this moment */
break; /* force end-of-band */
}
}
}
BITREAD_SAVE_STATE(ref m_bitstate, get_buffer, bits_left);
}
/* Completed MCU, so update state */
m_saved.EOBRUN = EOBRUN; /* only part of saved state we need */
}
/* Account for restart interval (no-op if not using restarts) */
m_restarts_to_go--;
return true;
}
/// <summary>
/// MCU encoding for DC successive approximation refinement scan.
/// Note: we assume such scans can be multi-component, although the spec
/// is not very clear on the point.
/// </summary>
private bool encode_mcu_DC_refine(JBLOCK[][] MCU_data)
{
/* Emit restart marker if needed */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
emit_restart(m_next_restart_num);
}
/* Encode the MCU data blocks */
for (int blkn = 0; blkn < m_cinfo.m_blocks_in_MCU; blkn++)
{
/* We simply emit the Al'th bit of the DC coefficient value. */
int temp = MCU_data[blkn][0][0];
emit_bits(temp >> m_cinfo.m_Al, 1);
}
/* Update restart-interval state too */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
{
m_restarts_to_go = m_cinfo.m_restart_interval;
m_next_restart_num++;
m_next_restart_num &= 7;
}
m_restarts_to_go--;
}
return true;
}
/*
* Huffman MCU decoding.
* Each of these routines decodes and returns one MCU's worth of
* Huffman-compressed coefficients.
* The coefficients are reordered from zigzag order into natural array order,
* but are not dequantized.
*
* The i'th block of the MCU is stored into the block pointed to by
* MCU_data[i]. WE ASSUME THIS AREA IS INITIALLY ZEROED BY THE CALLER.
*
* We return false if data source requested suspension. In that case no
* changes have been made to permanent state. (Exception: some output
* coefficients may already have been assigned. This is harmless for
* spectral selection, since we'll just re-assign them on the next call.
* Successive approximation AC refinement has to be more careful, however.)
*/
/// <summary>
/// MCU decoding for DC initial scan (either spectral selection,
/// or first pass of successive approximation).
/// </summary>
private bool decode_mcu_DC_first(JBLOCK[] MCU_data)
{
/* Process restart marker if needed; may have to suspend */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
{
if (!process_restart())
return false;
}
}
/* If we've run out of data, just leave the MCU set to zeroes.
* This way, we return uniform gray for the remainder of the segment.
*/
if (!m_insufficient_data)
{
/* Load up working state */
int get_buffer;
int bits_left;
bitread_working_state br_state = new bitread_working_state();
BITREAD_LOAD_STATE(m_bitstate, out get_buffer, out bits_left, ref br_state);
savable_state state = new savable_state();
state.Assign(m_saved);
/* Outer loop handles each block in the MCU */
for (int blkn = 0; blkn < m_cinfo.m_blocks_in_MCU; blkn++)
{
int ci = m_cinfo.m_MCU_membership[blkn];
/* Decode a single block's worth of coefficients */
/* Section F.2.2.1: decode the DC coefficient difference */
int s;
if (!HUFF_DECODE(out s, ref br_state, m_derived_tbls[m_cinfo.Comp_info[m_cinfo.m_cur_comp_info[ci]].Dc_tbl_no], ref get_buffer, ref bits_left))
return false;
if (s != 0)
{
if (!CHECK_BIT_BUFFER(ref br_state, s, ref get_buffer, ref bits_left))
return false;
int r = GET_BITS(s, get_buffer, ref bits_left);
s = HUFF_EXTEND(r, s);
}
/* Convert DC difference to actual value, update last_dc_val */
s += state.last_dc_val[ci];
state.last_dc_val[ci] = s;
/* Scale and output the coefficient (assumes jpeg_natural_order[0]=0) */
MCU_data[blkn][0] = (short)(s << m_cinfo.m_Al);
}
/* Completed MCU, so update state */
BITREAD_SAVE_STATE(ref m_bitstate, get_buffer, bits_left);
m_saved.Assign(state);
}
/* Account for restart interval (no-op if not using restarts) */
m_restarts_to_go--;
return true;
}
/// <summary>
/// MCU encoding for AC initial scan (either spectral selection,
/// or first pass of successive approximation).
/// </summary>
private bool encode_mcu_AC_first(JBLOCK[][] MCU_data)
{
/* Emit restart marker if needed */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
emit_restart(m_next_restart_num);
}
/* Encode the AC coefficients per section G.1.2.2, fig. G.3 */
/* r = run length of zeros */
int r = 0;
for (int k = m_cinfo.m_Ss; k <= m_cinfo.m_Se; k++)
{
int temp = MCU_data[0][0][JpegUtils.jpeg_natural_order[k]];
if (temp == 0)
{
r++;
continue;
}
/* We must apply the point transform by Al. For AC coefficients this
* is an integer division with rounding towards 0. To do this portably
* in C, we shift after obtaining the absolute value; so the code is
* interwoven with finding the abs value (temp) and output bits (temp2).
*/
int temp2;
if (temp < 0)
{
temp = -temp; /* temp is abs value of input */
temp >>= m_cinfo.m_Al; /* apply the point transform */
/* For a negative coef, want temp2 = bitwise complement of abs(coef) */
temp2 = ~temp;
}
else
{
temp >>= m_cinfo.m_Al; /* apply the point transform */
temp2 = temp;
}
/* Watch out for case that nonzero coef is zero after point transform */
if (temp == 0)
{
r++;
continue;
}
/* Emit any pending EOBRUN */
if (m_EOBRUN > 0)
emit_eobrun();
/* if run length > 15, must emit special run-length-16 codes (0xF0) */
while (r > 15)
{
emit_symbol(m_ac_tbl_no, 0xF0);
r -= 16;
}
/* Find the number of bits needed for the magnitude of the coefficient */
int nbits = 1; /* there must be at least one 1 bit */
while ((temp >>= 1) != 0)
nbits++;
/* Check for out-of-range coefficient values */
if (nbits > MAX_HUFFMAN_COEF_BITS)
m_cinfo.ERREXIT(J_MESSAGE_CODE.JERR_BAD_DCT_COEF);
/* Count/emit Huffman symbol for run length / number of bits */
emit_symbol(m_ac_tbl_no, (r << 4) + nbits);
/* Emit that number of bits of the value, if positive, */
/* or the complement of its magnitude, if negative. */
emit_bits(temp2, nbits);
r = 0; /* reset zero run length */
}
if (r > 0)
{
/* If there are trailing zeroes, */
m_EOBRUN++; /* count an EOB */
if (m_EOBRUN == 0x7FFF)
emit_eobrun(); /* force it out to avoid overflow */
}
/* Update restart-interval state too */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
{
m_restarts_to_go = m_cinfo.m_restart_interval;
m_next_restart_num++;
m_next_restart_num &= 7;
}
m_restarts_to_go--;
}
return true;
}
/// <summary>
/// Process some data in subsequent passes of a multi-pass case.
/// We process the equivalent of one fully interleaved MCU row ("iMCU" row)
/// per call, ie, v_samp_factor block rows for each component in the scan.
/// The data is obtained from the virtual arrays and fed to the entropy coder.
/// Returns true if the iMCU row is completed, false if suspended.
/// </summary>
private bool compressOutput()
{
/* Align the virtual buffers for the components used in this scan.
*/
JBLOCK[][][] buffer = new JBLOCK[JpegConstants.MAX_COMPS_IN_SCAN][][];
for (int ci = 0; ci < m_cinfo.m_comps_in_scan; ci++)
{
jpeg_component_info componentInfo = m_cinfo.Component_info[m_cinfo.m_cur_comp_info[ci]];
buffer[ci] = m_whole_image[componentInfo.Component_index].Access(
m_iMCU_row_num * componentInfo.V_samp_factor, componentInfo.V_samp_factor);
}
/* 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.Component_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++)
{
int bufLength = buffer[ci][yindex + yoffset].Length;
int start = start_col + xindex;
m_MCU_buffer[blkn] = new JBLOCK[bufLength - start];
for (int j = start; j < bufLength; j++)
m_MCU_buffer[blkn][j - start] = buffer[ci][yindex + yoffset][j];
blkn++;
}
}
}
/* Try to write the MCU. */
if (!m_cinfo.m_entropy.encode_mcu(m_MCU_buffer))
{
/* Suspension forced; update state counters and exit */
m_MCU_vert_offset = yoffset;
m_mcu_ctr = MCU_col_num;
return false;
}
}
/* Completed an MCU row, but perhaps not an iMCU row */
m_mcu_ctr = 0;
}
/* Completed the iMCU row, advance counters for next one */
m_iMCU_row_num++;
start_iMCU_row();
return true;
}
/// <summary>
/// MCU encoding for DC initial scan (either spectral selection,
/// or first pass of successive approximation).
/// </summary>
private bool encode_mcu_DC_first(JBLOCK[][] MCU_data)
{
/* Emit restart marker if needed */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
emit_restart(m_next_restart_num);
}
/* Encode the MCU data blocks */
for (int blkn = 0; blkn < m_cinfo.m_blocks_in_MCU; blkn++)
{
/* Compute the DC value after the required point transform by Al.
* This is simply an arithmetic right shift.
*/
int temp2 = IRIGHT_SHIFT(MCU_data[blkn][0][0], m_cinfo.m_Al);
/* DC differences are figured on the point-transformed values. */
int ci = m_cinfo.m_MCU_membership[blkn];
int temp = temp2 - m_last_dc_val[ci];
m_last_dc_val[ci] = temp2;
/* Encode the DC coefficient difference per section G.1.2.1 */
temp2 = temp;
if (temp < 0)
{
/* temp is abs value of input */
temp = -temp;
/* For a negative input, want temp2 = bitwise complement of abs(input) */
/* This code assumes we are on a two's complement machine */
temp2--;
}
/* Find the number of bits needed for the magnitude of the coefficient */
int nbits = 0;
while (temp != 0)
{
nbits++;
temp >>= 1;
}
/* Check for out-of-range coefficient values.
* Since we're encoding a difference, the range limit is twice as much.
*/
if (nbits > MAX_HUFFMAN_COEF_BITS + 1)
m_cinfo.ERREXIT(J_MESSAGE_CODE.JERR_BAD_DCT_COEF);
/* Count/emit the Huffman-coded symbol for the number of bits */
emit_symbol(m_cinfo.Component_info[m_cinfo.m_cur_comp_info[ci]].Dc_tbl_no, nbits);
/* Emit that number of bits of the value, if positive, */
/* or the complement of its magnitude, if negative. */
if (nbits != 0)
{
/* emit_bits rejects calls with size 0 */
emit_bits(temp2, nbits);
}
}
/* Update restart-interval state too */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
{
m_restarts_to_go = m_cinfo.m_restart_interval;
m_next_restart_num++;
m_next_restart_num &= 7;
}
m_restarts_to_go--;
}
return true;
}
private byte[] DecodeGroup(JBLOCK block, int[] @group)
{
return(Hash(block, @group));
}
public abstract bool decode_mcu(JBLOCK[] MCU_data);
/// <summary>
/// Consume input data and store it in the full-image coefficient buffer.
/// We read as much as one fully interleaved MCU row ("iMCU" row) per call,
/// ie, v_samp_factor block rows for each component in the scan.
/// </summary>
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);
}
// This version is used for floating-point DCT implementations.
private void forwardDCTFloatImpl(int quant_tbl_no, byte[][] sample_data, JBLOCK[] coef_blocks, int start_row, int start_col, int num_blocks)
{
/* This routine is heavily used, so it's worth coding it tightly. */
float[] workspace = new float [JpegConstants.DCTSIZE2]; /* work area for FDCT subroutine */
for (int bi = 0; bi < num_blocks; bi++, start_col += JpegConstants.DCTSIZE)
{
/* Load data into workspace, applying unsigned->signed conversion */
int workspaceIndex = 0;
for (int elemr = 0; elemr < JpegConstants.DCTSIZE; elemr++)
{
for (int column = 0; column < JpegConstants.DCTSIZE; column++)
{
workspace[workspaceIndex] = (float)((int)sample_data[start_row + elemr][start_col + column] - JpegConstants.CENTERJSAMPLE);
workspaceIndex++;
}
}
/* Perform the DCT */
jpeg_fdct_float(workspace);
/* Quantize/descale the coefficients, and store into coef_blocks[] */
for (int i = 0; i < JpegConstants.DCTSIZE2; i++)
{
/* Apply the quantization and scaling factor */
float temp = workspace[i] * m_float_divisors[quant_tbl_no][i];
/* Round to nearest integer.
* Since C does not specify the direction of rounding for negative
* quotients, we have to force the dividend positive for portability.
* The maximum coefficient size is +-16K (for 12-bit data), so this
* code should work for either 16-bit or 32-bit ints.
*/
coef_blocks[bi][i] = (short)((int)(temp + (float)16384.5) - 16384);
}
}
}
/// <summary>
/// Variant of decompress_data for use when doing block smoothing.
/// </summary>
private ReadResult decompress_smooth_data(ComponentBuffer[] output_buf)
{
/* Force some input to be done if we are getting ahead of the input. */
while (m_cinfo.m_input_scan_number <= m_cinfo.m_output_scan_number && !m_cinfo.m_inputctl.EOIReached())
{
if (m_cinfo.m_input_scan_number == m_cinfo.m_output_scan_number)
{
/* If input is working on current scan, we ordinarily want it to
* have completed the current row. But if input scan is DC,
* we want it to keep one row ahead so that next block row's DC
* values are up to date.
*/
int delta = (m_cinfo.m_Ss == 0) ? 1 : 0;
if (m_cinfo.m_input_iMCU_row > m_cinfo.m_output_iMCU_row + delta)
{
break;
}
}
if (m_cinfo.m_inputctl.consume_input() == ReadResult.JPEG_SUSPENDED)
{
return(ReadResult.JPEG_SUSPENDED);
}
}
int last_iMCU_row = m_cinfo.m_total_iMCU_rows - 1;
/* OK, output from the virtual arrays. */
for (int ci = 0; ci < m_cinfo.m_num_components; ci++)
{
jpeg_component_info componentInfo = m_cinfo.Comp_info[ci];
/* Don't bother to IDCT an uninteresting component. */
if (!componentInfo.component_needed)
{
continue;
}
int block_rows;
int access_rows;
bool last_row;
/* Count non-dummy DCT block rows in this iMCU row. */
if (m_cinfo.m_output_iMCU_row < last_iMCU_row)
{
block_rows = componentInfo.V_samp_factor;
access_rows = block_rows * 2; /* this and next iMCU row */
last_row = false;
}
else
{
/* NB: can't use last_row_height here; it is input-side-dependent! */
block_rows = componentInfo.height_in_blocks % componentInfo.V_samp_factor;
if (block_rows == 0)
{
block_rows = componentInfo.V_samp_factor;
}
access_rows = block_rows; /* this iMCU row only */
last_row = true;
}
/* Align the virtual buffer for this component. */
JBLOCK[][] buffer = null;
bool first_row;
int bufferRowOffset = 0;
if (m_cinfo.m_output_iMCU_row > 0)
{
access_rows += componentInfo.V_samp_factor; /* prior iMCU row too */
buffer = m_whole_image[ci].Access((m_cinfo.m_output_iMCU_row - 1) * componentInfo.V_samp_factor, access_rows);
bufferRowOffset = componentInfo.V_samp_factor; /* point to current iMCU row */
first_row = false;
}
else
{
buffer = m_whole_image[ci].Access(0, access_rows);
first_row = true;
}
/* Fetch component-dependent info */
int coefBitsOffset = ci * SAVED_COEFS;
int Q00 = componentInfo.quant_table.quantval[0];
int Q01 = componentInfo.quant_table.quantval[Q01_POS];
int Q10 = componentInfo.quant_table.quantval[Q10_POS];
int Q20 = componentInfo.quant_table.quantval[Q20_POS];
int Q11 = componentInfo.quant_table.quantval[Q11_POS];
int Q02 = componentInfo.quant_table.quantval[Q02_POS];
int outputIndex = ci;
/* Loop over all DCT blocks to be processed. */
for (int block_row = 0; block_row < block_rows; block_row++)
{
int bufferIndex = bufferRowOffset + block_row;
int prev_block_row = 0;
if (first_row && block_row == 0)
{
prev_block_row = bufferIndex;
}
else
{
prev_block_row = bufferIndex - 1;
}
int next_block_row = 0;
if (last_row && block_row == block_rows - 1)
{
next_block_row = bufferIndex;
}
else
{
next_block_row = bufferIndex + 1;
}
/* We fetch the surrounding DC values using a sliding-register approach.
* Initialize all nine here so as to do the right thing on narrow pics.
*/
int DC1 = buffer[prev_block_row][0][0];
int DC2 = DC1;
int DC3 = DC1;
int DC4 = buffer[bufferIndex][0][0];
int DC5 = DC4;
int DC6 = DC4;
int DC7 = buffer[next_block_row][0][0];
int DC8 = DC7;
int DC9 = DC7;
int output_col = 0;
int last_block_column = componentInfo.Width_in_blocks - 1;
for (int block_num = 0; block_num <= last_block_column; block_num++)
{
/* Fetch current DCT block into workspace so we can modify it. */
JBLOCK workspace = new JBLOCK();
Buffer.BlockCopy(buffer[bufferIndex][0].data, 0, workspace.data, 0, workspace.data.Length * sizeof(short));
/* Update DC values */
if (block_num < last_block_column)
{
DC3 = buffer[prev_block_row][1][0];
DC6 = buffer[bufferIndex][1][0];
DC9 = buffer[next_block_row][1][0];
}
/* Compute coefficient estimates per K.8.
* An estimate is applied only if coefficient is still zero,
* and is not known to be fully accurate.
*/
/* AC01 */
int Al = m_coef_bits_latch[m_coef_bits_savedOffset + coefBitsOffset + 1];
if (Al != 0 && workspace[1] == 0)
{
int pred;
int num = 36 * Q00 * (DC4 - DC6);
if (num >= 0)
{
pred = ((Q01 << 7) + num) / (Q01 << 8);
if (Al > 0 && pred >= (1 << Al))
{
pred = (1 << Al) - 1;
}
}
else
{
pred = ((Q01 << 7) - num) / (Q01 << 8);
if (Al > 0 && pred >= (1 << Al))
{
pred = (1 << Al) - 1;
}
pred = -pred;
}
workspace[1] = (short)pred;
}
/* AC10 */
Al = m_coef_bits_latch[m_coef_bits_savedOffset + coefBitsOffset + 2];
if (Al != 0 && workspace[8] == 0)
{
int pred;
int num = 36 * Q00 * (DC2 - DC8);
if (num >= 0)
{
pred = ((Q10 << 7) + num) / (Q10 << 8);
if (Al > 0 && pred >= (1 << Al))
{
pred = (1 << Al) - 1;
}
}
else
{
pred = ((Q10 << 7) - num) / (Q10 << 8);
if (Al > 0 && pred >= (1 << Al))
{
pred = (1 << Al) - 1;
}
pred = -pred;
}
workspace[8] = (short)pred;
}
/* AC20 */
Al = m_coef_bits_latch[m_coef_bits_savedOffset + coefBitsOffset + 3];
if (Al != 0 && workspace[16] == 0)
{
int pred;
int num = 9 * Q00 * (DC2 + DC8 - 2 * DC5);
if (num >= 0)
{
pred = ((Q20 << 7) + num) / (Q20 << 8);
if (Al > 0 && pred >= (1 << Al))
{
pred = (1 << Al) - 1;
}
}
else
{
pred = ((Q20 << 7) - num) / (Q20 << 8);
if (Al > 0 && pred >= (1 << Al))
{
pred = (1 << Al) - 1;
}
pred = -pred;
}
workspace[16] = (short)pred;
}
/* AC11 */
Al = m_coef_bits_latch[m_coef_bits_savedOffset + coefBitsOffset + 4];
if (Al != 0 && workspace[9] == 0)
{
int pred;
int num = 5 * Q00 * (DC1 - DC3 - DC7 + DC9);
if (num >= 0)
{
pred = ((Q11 << 7) + num) / (Q11 << 8);
if (Al > 0 && pred >= (1 << Al))
{
pred = (1 << Al) - 1;
}
}
else
{
pred = ((Q11 << 7) - num) / (Q11 << 8);
if (Al > 0 && pred >= (1 << Al))
{
pred = (1 << Al) - 1;
}
pred = -pred;
}
workspace[9] = (short)pred;
}
/* AC02 */
Al = m_coef_bits_latch[m_coef_bits_savedOffset + coefBitsOffset + 5];
if (Al != 0 && workspace[2] == 0)
{
int pred;
int num = 9 * Q00 * (DC4 + DC6 - 2 * DC5);
if (num >= 0)
{
pred = ((Q02 << 7) + num) / (Q02 << 8);
if (Al > 0 && pred >= (1 << Al))
{
pred = (1 << Al) - 1;
}
}
else
{
pred = ((Q02 << 7) - num) / (Q02 << 8);
if (Al > 0 && pred >= (1 << Al))
{
pred = (1 << Al) - 1;
}
pred = -pred;
}
workspace[2] = (short)pred;
}
/* OK, do the IDCT */
m_cinfo.m_idct.inverse(componentInfo.Component_index, workspace.data, output_buf[outputIndex], 0, output_col);
/* Advance for next column */
DC1 = DC2;
DC2 = DC3;
DC4 = DC5;
DC5 = DC6;
DC7 = DC8;
DC8 = DC9;
bufferIndex++;
prev_block_row++;
next_block_row++;
output_col += componentInfo.DCT_scaled_size;
}
outputIndex += componentInfo.DCT_scaled_size;
}
}
m_cinfo.m_output_iMCU_row++;
if (m_cinfo.m_output_iMCU_row < m_cinfo.m_total_iMCU_rows)
{
return(ReadResult.JPEG_ROW_COMPLETED);
}
return(ReadResult.JPEG_SCAN_COMPLETED);
}
/// <summary>
/// Consume input data and store it in the full-image coefficient buffer.
/// We read as much as one fully interleaved MCU row ("iMCU" row) per call,
/// ie, v_samp_factor block rows for each component in the scan.
/// </summary>
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;
}
/// <summary>
/// Encode and output one MCU's worth of Huffman-compressed coefficients.
/// </summary>
private bool encode_mcu_huff(JBLOCK[][] MCU_data)
{
/* Load up working state */
savable_state state;
state = m_saved;
/* Emit restart marker if needed */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
{
if (!emit_restart(state, m_next_restart_num))
return false;
}
}
/* Encode the MCU data blocks */
for (int blkn = 0; blkn < m_cinfo.m_blocks_in_MCU; blkn++)
{
int ci = m_cinfo.m_MCU_membership[blkn];
if (!encode_one_block(state, MCU_data[blkn][0].data, state.last_dc_val[ci],
m_dc_derived_tbls[m_cinfo.Component_info[m_cinfo.m_cur_comp_info[ci]].Dc_tbl_no],
m_ac_derived_tbls[m_cinfo.Component_info[m_cinfo.m_cur_comp_info[ci]].Ac_tbl_no]))
{
return false;
}
/* Update last_dc_val */
state.last_dc_val[ci] = MCU_data[blkn][0][0];
}
/* Completed MCU, so update state */
m_saved = state;
/* Update restart-interval state too */
if (m_cinfo.m_restart_interval != 0)
{
if (m_restarts_to_go == 0)
{
m_restarts_to_go = m_cinfo.m_restart_interval;
m_next_restart_num++;
m_next_restart_num &= 7;
}
m_restarts_to_go--;
}
return true;
}
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. */
JBLOCK[] buffer = new JBLOCK[JpegConstants.D_MAX_BLOCKS_IN_MCU];
for (int i = 0; i < JpegConstants.D_MAX_BLOCKS_IN_MCU; i++)
{
buffer[i] = new JBLOCK();
for (int ii = 0; ii < buffer[i].data.Length; ii++)
buffer[i].data[ii] = -12851;
m_MCU_buffer[i] = buffer[i];
}
m_useDummyConsumeData = true;
m_decompressor = DecompressorType.OnePass;
m_coef_arrays = null; /* flag for no virtual arrays */
}
}
/// <summary>
/// Process some data.
/// We process the equivalent of one fully interleaved MCU row ("iMCU" row)
/// per call, ie, v_samp_factor block rows for each component in the scan.
/// The data is obtained from the virtual arrays and fed to the entropy coder.
/// Returns true if the iMCU row is completed, false if suspended.
///
/// NB: input_buf is ignored; it is likely to be a null pointer.
/// </summary>
public virtual bool compress_data(byte[][][] input_buf)
{
/* Align the virtual buffers for the components used in this scan. */
JBLOCK[][][] buffer = new JBLOCK[JpegConstants.MAX_COMPS_IN_SCAN][][];
for (int ci = 0; ci < m_cinfo.m_comps_in_scan; ci++)
{
jpeg_component_info componentInfo = m_cinfo.Component_info[m_cinfo.m_cur_comp_info[ci]];
buffer[ci] = m_whole_image[componentInfo.Component_index].Access(
m_iMCU_row_num * componentInfo.V_samp_factor, componentInfo.V_samp_factor);
}
/* Loop to process one whole iMCU row */
int last_MCU_col = m_cinfo.m_MCUs_per_row - 1;
int last_iMCU_row = m_cinfo.m_total_iMCU_rows - 1;
JBLOCK[][] MCU_buffer = new JBLOCK[JpegConstants.C_MAX_BLOCKS_IN_MCU][];
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.Component_info[m_cinfo.m_cur_comp_info[ci]];
int start_col = MCU_col_num * componentInfo.MCU_width;
int blockcnt = (MCU_col_num < last_MCU_col) ? componentInfo.MCU_width : componentInfo.last_col_width;
for (int yindex = 0; yindex < componentInfo.MCU_height; yindex++)
{
int xindex = 0;
if (m_iMCU_row_num < last_iMCU_row || yindex + yoffset < componentInfo.last_row_height)
{
/* Fill in pointers to real blocks in this row */
for (xindex = 0; xindex < blockcnt; xindex++)
{
int bufLength = buffer[ci][yindex + yoffset].Length;
int start = start_col + xindex;
MCU_buffer[blkn] = new JBLOCK[bufLength - start];
for (int j = start; j < bufLength; j++)
{
MCU_buffer[blkn][j - start] = buffer[ci][yindex + yoffset][j];
}
blkn++;
}
}
else
{
/* At bottom of image, need a whole row of dummy blocks */
xindex = 0;
}
/* Fill in any dummy blocks needed in this row.
* Dummy blocks are filled in the same way as in jccoefct.c:
* all zeroes in the AC entries, DC entries equal to previous
* block's DC value. The init routine has already zeroed the
* AC entries, so we need only set the DC entries correctly.
*/
for (; xindex < componentInfo.MCU_width; xindex++)
{
MCU_buffer[blkn] = m_dummy_buffer[blkn];
MCU_buffer[blkn][0][0] = MCU_buffer[blkn - 1][0][0];
blkn++;
}
}
}
/* Try to write the MCU. */
if (!m_cinfo.m_entropy.encode_mcu(MCU_buffer))
{
/* Suspension forced; update state counters and exit */
m_MCU_vert_offset = yoffset;
m_mcu_ctr = MCU_col_num;
return(false);
}
}
/* Completed an MCU row, but perhaps not an iMCU row */
m_mcu_ctr = 0;
}
/* Completed the iMCU row, advance counters for next one */
m_iMCU_row_num++;
start_iMCU_row();
return(true);
}
