if2_to_ets.cpp revision 4f1efc098cb5791c3e9f483f2af84aef70d2d0a0 
1/* ------------------------------------------------------------------
2 * Copyright (C) 1998-2009 PacketVideo
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
13 * express or implied.
14 * See the License for the specific language governing permissions
15 * and limitations under the License.
16 * -------------------------------------------------------------------
17 */
18/****************************************************************************************
19Portions of this file are derived from the following 3GPP standard:
20
21    3GPP TS 26.073
22    ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec
23    Available from http://www.3gpp.org
24
25(C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC)
26Permission to distribute, modify and use this file under the standard license
27terms listed above has been obtained from the copyright holder.
28****************************************************************************************/
29/*
30------------------------------------------------------------------------------
31
32 Pathname: ./audio/gsm-amr/c/src/if2_to_ets.c
33 Funtions: if2_to_ets
34
35*/
36
37/*----------------------------------------------------------------------------
38; INCLUDES
39----------------------------------------------------------------------------*/
40#include "frame_type_3gpp.h"
41#include "if2_to_ets.h"
42#include "typedef.h"
43#include "bitreorder_tab.h"
44/*----------------------------------------------------------------------------
45; MACROS
46; Define module specific macros here
47----------------------------------------------------------------------------*/
48
49/*----------------------------------------------------------------------------
50; DEFINES
51; Include all pre-processor statements here. Include conditional
52; compile variables also.
53----------------------------------------------------------------------------*/
54
55
56/*----------------------------------------------------------------------------
57; LOCAL FUNCTION DEFINITIONS
58; Function Prototype declaration
59----------------------------------------------------------------------------*/
60
61/*----------------------------------------------------------------------------
62; LOCAL VARIABLE DEFINITIONS
63; Variable declaration - defined here and used outside this module
64----------------------------------------------------------------------------*/
65
66
67
68/*
69------------------------------------------------------------------------------
70 FUNCTION NAME: if2_to_ets
71------------------------------------------------------------------------------
72 INPUT AND OUTPUT DEFINITIONS
73
74 Inputs:
75    frame_type_3gpp = decoder speech bit rate (enum Frame_Type_3GPP)
76    if2_input_ptr   = pointer to input encoded speech bits in IF2 format (Word8)
77    ets_output_ptr  = pointer to output encoded speech bits in ETS format (Word16)
78
79 Outputs:
80    ets_output_ptr  = pointer to encoded speech bits in the ETS format (Word16)
81
82 Returns:
83    None
84
85 Global Variables Used:
86    None
87
88 Local Variables Needed:
89    None
90
91------------------------------------------------------------------------------
92 FUNCTION DESCRIPTION
93
94 This function performs a transformation on the data buffers. It converts the
95 data format from IF2 to ETS. IF2 is the storage format where the frame type
96 is in the first four bits of the first byte. The upper four bits of that byte
97 contain the first four encoded speech bits for the frame. The following bytes
98 contain the rest of the encoded speech bits. The final byte has padded zeros
99 to make the frame byte aligned. ETS format has the encoded speech
100 bits each separate with only one bit stored in each word.
101
102------------------------------------------------------------------------------
103 REQUIREMENTS
104
105 None
106
107------------------------------------------------------------------------------
108 REFERENCES
109
110AMR Speech Codec Frame Structure", 3GPP TS 26.101 version 4.1.0 Release 4, June 2001
111
112------------------------------------------------------------------------------
113 PSEUDO-CODE
114
115
116
117------------------------------------------------------------------------------
118 RESOURCES USED [optional]
119
120 When the code is written for a specific target processor the
121 the resources used should be documented below.
122
123 HEAP MEMORY USED: x bytes
124
125 STACK MEMORY USED: x bytes
126
127 CLOCK CYCLES: (cycle count equation for this function) + (variable
128                used to represent cycle count for each subroutine
129                called)
130     where: (cycle count variable) = cycle count for [subroutine
131                                     name]
132
133------------------------------------------------------------------------------
134 CAUTION [optional]
135 [State any special notes, constraints or cautions for users of this function]
136
137------------------------------------------------------------------------------
138*/
139
140void if2_to_ets(
141    enum Frame_Type_3GPP frame_type_3gpp,
142    UWord8   *if2_input_ptr,
143    Word16   *ets_output_ptr)
144{
145
146    Word16 i;
147    Word16 j;
148    Word16 x = 0;
149
150    /*
151     * The following section of code accesses bits in the IF2 method of
152     * bit ordering. Each bit is given its own location in the buffer pointed
153     * to by ets_output_ptr. The bits (for modes less than AMR_SID) are
154     * reordered using the tables in bitreorder.c before the data is stored
155     * into the buffer pointed to by ets_output_ptr.
156     */
157
158    if (frame_type_3gpp < AMR_SID)
159    {
160        for (j = 4; j < 8; j++)
161        {
162            ets_output_ptr[reorderBits[frame_type_3gpp][x++]] =
163                (if2_input_ptr[0] >> j) & 0x01;
164        }
165        for (i = 1; i < numCompressedBytes[frame_type_3gpp]; i++)
166        {
167            for (j = 0; j < 8; j++)
168            {
169                if (x >= numOfBits[frame_type_3gpp])
170                {
171                    break;
172                }
173                ets_output_ptr[reorderBits[frame_type_3gpp][x++]] =
174                    (if2_input_ptr[i] >> j) & 0x01;
175            }
176        }
177    }
178    else
179    {
180        for (j = 4; j < 8; j++)
181        {
182            ets_output_ptr[x++] =
183                (if2_input_ptr[0] >> j) & 0x01;
184        }
185        for (i = 1; i < numCompressedBytes[frame_type_3gpp]; i++)
186        {
187            for (j = 0; j < 8; j++)
188            {
189                ets_output_ptr[x++] =
190                    (if2_input_ptr[i] >> j) & 0x01;
191            }
192        }
193    }
194
195    return;
196}
197