1/* Copyright (C) 2002 Jean-Marc Valin
2   File: speex_header.c
3   Describes the Speex header
4
5   Redistribution and use in source and binary forms, with or without
6   modification, are permitted provided that the following conditions
7   are met:
8
9   - Redistributions of source code must retain the above copyright
10   notice, this list of conditions and the following disclaimer.
11
12   - Redistributions in binary form must reproduce the above copyright
13   notice, this list of conditions and the following disclaimer in the
14   documentation and/or other materials provided with the distribution.
15
16   - Neither the name of the Xiph.org Foundation nor the names of its
17   contributors may be used to endorse or promote products derived from
18   this software without specific prior written permission.
19
20   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23   A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
24   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
27   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31
32*/
33
34#ifdef HAVE_CONFIG_H
35#include "config.h"
36#endif
37
38#include "arch.h"
39#include <speex/speex_header.h>
40#include <speex/speex.h>
41#include "os_support.h"
42
43#ifndef NULL
44#define NULL 0
45#endif
46
47/** Convert little endian */
48static inline spx_int32_t le_int(spx_int32_t i)
49{
50#if !defined(__LITTLE_ENDIAN__) && ( defined(WORDS_BIGENDIAN) || defined(__BIG_ENDIAN__) )
51   spx_uint32_t ui, ret;
52   ui = i;
53   ret =  ui>>24;
54   ret |= (ui>>8)&0x0000ff00;
55   ret |= (ui<<8)&0x00ff0000;
56   ret |= (ui<<24);
57   return ret;
58#else
59   return i;
60#endif
61}
62
63#define ENDIAN_SWITCH(x) {x=le_int(x);}
64
65
66/*
67typedef struct SpeexHeader {
68   char speex_string[8];
69   char speex_version[SPEEX_HEADER_VERSION_LENGTH];
70   int speex_version_id;
71   int header_size;
72   int rate;
73   int mode;
74   int mode_bitstream_version;
75   int nb_channels;
76   int bitrate;
77   int frame_size;
78   int vbr;
79   int frames_per_packet;
80   int extra_headers;
81   int reserved1;
82   int reserved2;
83} SpeexHeader;
84*/
85
86EXPORT void speex_init_header(SpeexHeader *header, int rate, int nb_channels, const SpeexMode *m)
87{
88   int i;
89   const char *h="Speex   ";
90   /*
91   strncpy(header->speex_string, "Speex   ", 8);
92   strncpy(header->speex_version, SPEEX_VERSION, SPEEX_HEADER_VERSION_LENGTH-1);
93   header->speex_version[SPEEX_HEADER_VERSION_LENGTH-1]=0;
94   */
95   for (i=0;i<8;i++)
96      header->speex_string[i]=h[i];
97   for (i=0;i<SPEEX_HEADER_VERSION_LENGTH-1 && SPEEX_VERSION[i];i++)
98      header->speex_version[i]=SPEEX_VERSION[i];
99   for (;i<SPEEX_HEADER_VERSION_LENGTH;i++)
100      header->speex_version[i]=0;
101
102   header->speex_version_id = 1;
103   header->header_size = sizeof(SpeexHeader);
104
105   header->rate = rate;
106   header->mode = m->modeID;
107   header->mode_bitstream_version = m->bitstream_version;
108   if (m->modeID<0)
109      speex_warning("This mode is meant to be used alone");
110   header->nb_channels = nb_channels;
111   header->bitrate = -1;
112   speex_mode_query(m, SPEEX_MODE_FRAME_SIZE, &header->frame_size);
113   header->vbr = 0;
114
115   header->frames_per_packet = 0;
116   header->extra_headers = 0;
117   header->reserved1 = 0;
118   header->reserved2 = 0;
119}
120
121EXPORT char *speex_header_to_packet(SpeexHeader *header, int *size)
122{
123   SpeexHeader *le_header;
124   le_header = (SpeexHeader*)speex_alloc(sizeof(SpeexHeader));
125
126   SPEEX_COPY(le_header, header, 1);
127
128   /*Make sure everything is now little-endian*/
129   ENDIAN_SWITCH(le_header->speex_version_id);
130   ENDIAN_SWITCH(le_header->header_size);
131   ENDIAN_SWITCH(le_header->rate);
132   ENDIAN_SWITCH(le_header->mode);
133   ENDIAN_SWITCH(le_header->mode_bitstream_version);
134   ENDIAN_SWITCH(le_header->nb_channels);
135   ENDIAN_SWITCH(le_header->bitrate);
136   ENDIAN_SWITCH(le_header->frame_size);
137   ENDIAN_SWITCH(le_header->vbr);
138   ENDIAN_SWITCH(le_header->frames_per_packet);
139   ENDIAN_SWITCH(le_header->extra_headers);
140
141   *size = sizeof(SpeexHeader);
142   return (char *)le_header;
143}
144
145EXPORT SpeexHeader *speex_packet_to_header(char *packet, int size)
146{
147   int i;
148   SpeexHeader *le_header;
149   const char *h = "Speex   ";
150   for (i=0;i<8;i++)
151      if (packet[i]!=h[i])
152      {
153         speex_notify("This doesn't look like a Speex file");
154         return NULL;
155      }
156
157   /*FIXME: Do we allow larger headers?*/
158   if (size < (int)sizeof(SpeexHeader))
159   {
160      speex_notify("Speex header too small");
161      return NULL;
162   }
163
164   le_header = (SpeexHeader*)speex_alloc(sizeof(SpeexHeader));
165
166   SPEEX_COPY(le_header, (SpeexHeader*)packet, 1);
167
168   /*Make sure everything is converted correctly from little-endian*/
169   ENDIAN_SWITCH(le_header->speex_version_id);
170   ENDIAN_SWITCH(le_header->header_size);
171   ENDIAN_SWITCH(le_header->rate);
172   ENDIAN_SWITCH(le_header->mode);
173   ENDIAN_SWITCH(le_header->mode_bitstream_version);
174   ENDIAN_SWITCH(le_header->nb_channels);
175   ENDIAN_SWITCH(le_header->bitrate);
176   ENDIAN_SWITCH(le_header->frame_size);
177   ENDIAN_SWITCH(le_header->vbr);
178   ENDIAN_SWITCH(le_header->frames_per_packet);
179   ENDIAN_SWITCH(le_header->extra_headers);
180
181   if (le_header->mode >= SPEEX_NB_MODES || le_header->mode < 0)
182   {
183      speex_notify("Invalid mode specified in Speex header");
184      speex_free (le_header);
185      return NULL;
186   }
187
188   if (le_header->nb_channels>2)
189      le_header->nb_channels = 2;
190   if (le_header->nb_channels<1)
191      le_header->nb_channels = 1;
192
193   return le_header;
194
195}
196
197EXPORT void speex_header_free(void *ptr)
198{
199   speex_free(ptr);
200}
201