FreeRDP/libfreerdp-codec/rfx_differential.c

48 lines
1.2 KiB
C

/**
* FreeRDP: A Remote Desktop Protocol client.
* RemoteFX Codec Library - Differential Encoding
*
* Copyright 2011 Vic Lee
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "rfx_differential.h"
void rfx_differential_decode(sint16* buffer, int buffer_size)
{
sint16* src;
sint16* dst;
for (src = buffer, dst = buffer + 1; buffer_size > 1; src++, dst++, buffer_size--)
{
*dst += *src;
}
}
void rfx_differential_encode(sint16* buffer, int buffer_size)
{
sint16 n1, n2;
sint16* dst;
for (n1 = *buffer, dst = buffer + 1; buffer_size > 1; dst++, buffer_size--)
{
n2 = *dst;
*dst -= n1;
n1 = n2;
}
}