third_party/speex/libspeex/speex_header.c

   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 */
  48 static 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 /*
  67 typedef 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
  86 EXPORT 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
 121 EXPORT 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
 145 EXPORT 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
 197 EXPORT void speex_header_free(void *ptr)
 198 {
 199    speex_free(ptr);
 200 }