libfreerdp-codec/rfx_quantization.c

   1 /**
   2  * FreeRDP: A Remote Desktop Protocol client.
   3  * RemoteFX Codec Library - Quantization
   4  *
   5  * Copyright 2011 Vic Lee
   6  *
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *     http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  */
  19
  20 #include "rfx_quantization.h"
  21
  22 static void rfx_quantization_decode_block(sint16* buffer, int buffer_size, uint32 factor)
  23 {
  24         sint16* dst;
  25
  26         if (factor == 0)
  27                 return;
  28
  29         for (dst = buffer; buffer_size > 0; dst++, buffer_size--)
  30         {
  31                 *dst <<= factor;
  32         }
  33 }
  34
  35 void rfx_quantization_decode(sint16* buffer, const uint32* quantization_values)
  36 {
  37         /* Scale the values so that they are represented as 11.5 fixed-point number */
  38         rfx_quantization_decode_block(buffer, 4096, 5);
  39
  40         rfx_quantization_decode_block(buffer, 1024, quantization_values[8] - 6); /* HL1 */
  41         rfx_quantization_decode_block(buffer + 1024, 1024, quantization_values[7] - 6); /* LH1 */
  42         rfx_quantization_decode_block(buffer + 2048, 1024, quantization_values[9] - 6); /* HH1 */
  43         rfx_quantization_decode_block(buffer + 3072, 256, quantization_values[5] - 6); /* HL2 */
  44         rfx_quantization_decode_block(buffer + 3328, 256, quantization_values[4] - 6); /* LH2 */
  45         rfx_quantization_decode_block(buffer + 3584, 256, quantization_values[6] - 6); /* HH2 */
  46         rfx_quantization_decode_block(buffer + 3840, 64, quantization_values[2] - 6); /* HL3 */
  47         rfx_quantization_decode_block(buffer + 3904, 64, quantization_values[1] - 6); /* LH3 */
  48         rfx_quantization_decode_block(buffer + 3968, 64, quantization_values[3] - 6); /* HH3 */
  49         rfx_quantization_decode_block(buffer + 4032, 64, quantization_values[0] - 6); /* LL3 */
  50 }
  51
  52 static void rfx_quantization_encode_block(sint16* buffer, int buffer_size, uint32 factor)
  53 {
  54         sint16* dst;
  55         sint16 half;
  56
  57         if (factor == 0)
  58                 return;
  59
  60         half = (1 << (factor - 1));
  61         for (dst = buffer; buffer_size > 0; dst++, buffer_size--)
  62         {
  63                 *dst = (*dst + half) >> factor;
  64         }
  65 }
  66
  67 void rfx_quantization_encode(sint16* buffer, const uint32* quantization_values)
  68 {
  69         rfx_quantization_encode_block(buffer, 1024, quantization_values[8] - 6); /* HL1 */
  70         rfx_quantization_encode_block(buffer + 1024, 1024, quantization_values[7] - 6); /* LH1 */
  71         rfx_quantization_encode_block(buffer + 2048, 1024, quantization_values[9] - 6); /* HH1 */
  72         rfx_quantization_encode_block(buffer + 3072, 256, quantization_values[5] - 6); /* HL2 */
  73         rfx_quantization_encode_block(buffer + 3328, 256, quantization_values[4] - 6); /* LH2 */
  74         rfx_quantization_encode_block(buffer + 3584, 256, quantization_values[6] - 6); /* HH2 */
  75         rfx_quantization_encode_block(buffer + 3840, 64, quantization_values[2] - 6); /* HL3 */
  76         rfx_quantization_encode_block(buffer + 3904, 64, quantization_values[1] - 6); /* LH3 */
  77         rfx_quantization_encode_block(buffer + 3968, 64, quantization_values[3] - 6); /* HH3 */
  78         rfx_quantization_encode_block(buffer + 4032, 64, quantization_values[0] - 6); /* LL3 */
  79
  80         /* The coefficients are scaled by << 5 at RGB->YCbCr phase, so we round it back here */
  81         rfx_quantization_encode_block(buffer, 4096, 5);
  82 }