apps/codecs/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-speex.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 #ifdef ROCKBOX
  51    return letoh32(i);
  52 #elif !defined(__LITTLE_ENDIAN__) && ( defined(WORDS_BIGENDIAN) || defined(__BIG_ENDIAN__) )
  53    spx_uint32_t ui, ret;
  54    ui = i;
  55    ret =  ui>>24;
  56    ret |= (ui>>8)&0x0000ff00;
  57    ret |= (ui<<8)&0x00ff0000;
  58    ret |= (ui<<24);
  59    return ret;
  60 #else
  61    return i;
  62 #endif
  63 }
  64
  65 #define ENDIAN_SWITCH(x) {x=le_int(x);}
  66
  67
  68 /*
  69 typedef struct SpeexHeader {
  70    char speex_string[8];
  71    char speex_version[SPEEX_HEADER_VERSION_LENGTH];
  72    int speex_version_id;
  73    int header_size;
  74    int rate;
  75    int mode;
  76    int mode_bitstream_version;
  77    int nb_channels;
  78    int bitrate;
  79    int frame_size;
  80    int vbr;
  81    int frames_per_packet;
  82    int extra_headers;
  83    int reserved1;
  84    int reserved2;
  85 } SpeexHeader;
  86 */
  87
  88 #ifndef SPEEX_DISABLE_ENCODER
  89 void speex_init_header(SpeexHeader *header, int rate, int nb_channels, const SpeexMode *m)
  90 {
  91    int i;
  92    const char *h="Speex   ";
  93    /*
  94    strncpy(header->speex_string, "Speex   ", 8);
  95    strncpy(header->speex_version, SPEEX_VERSION, SPEEX_HEADER_VERSION_LENGTH-1);
  96    header->speex_version[SPEEX_HEADER_VERSION_LENGTH-1]=0;
  97    */
  98    for (i=0;i<8;i++)
  99       header->speex_string[i]=h[i];
 100    for (i=0;i<SPEEX_HEADER_VERSION_LENGTH-1 && SPEEX_VERSION[i];i++)
 101       header->speex_version[i]=SPEEX_VERSION[i];
 102    for (;i<SPEEX_HEADER_VERSION_LENGTH;i++)
 103       header->speex_version[i]=0;
 104
 105    header->speex_version_id = 1;
 106    header->header_size = sizeof(SpeexHeader);
 107
 108    header->rate = rate;
 109    header->mode = m->modeID;
 110    header->mode_bitstream_version = m->bitstream_version;
 111    if (m->modeID<0)
 112       speex_warning("This mode is meant to be used alone");
 113    header->nb_channels = nb_channels;
 114    header->bitrate = -1;
 115    speex_mode_query(m, SPEEX_MODE_FRAME_SIZE, &header->frame_size);
 116    header->vbr = 0;
 117
 118    header->frames_per_packet = 0;
 119    header->extra_headers = 0;
 120    header->reserved1 = 0;
 121    header->reserved2 = 0;
 122 }
 123
 124 char *speex_header_to_packet(SpeexHeader *header, int *size)
 125 {
 126    SpeexHeader *le_header;
 127    le_header = (SpeexHeader*)speex_alloc(sizeof(SpeexHeader));
 128
 129    SPEEX_COPY(le_header, header, 1);
 130
 131    /*Make sure everything is now little-endian*/
 132    ENDIAN_SWITCH(le_header->speex_version_id);
 133    ENDIAN_SWITCH(le_header->header_size);
 134    ENDIAN_SWITCH(le_header->rate);
 135    ENDIAN_SWITCH(le_header->mode);
 136    ENDIAN_SWITCH(le_header->mode_bitstream_version);
 137    ENDIAN_SWITCH(le_header->nb_channels);
 138    ENDIAN_SWITCH(le_header->bitrate);
 139    ENDIAN_SWITCH(le_header->frame_size);
 140    ENDIAN_SWITCH(le_header->vbr);
 141    ENDIAN_SWITCH(le_header->frames_per_packet);
 142    ENDIAN_SWITCH(le_header->extra_headers);
 143
 144    *size = sizeof(SpeexHeader);
 145    return (char *)le_header;
 146 }
 147 #endif /* SPEEX_DISABLE_ENCODER */
 148
 149 static SpeexHeader global_le_header; /* Avoid malloc */
 150 SpeexHeader *speex_packet_to_header(char *packet, int size)
 151 {
 152    int i;
 153    SpeexHeader *le_header = &global_le_header;
 154    const char *h = "Speex   ";
 155    for (i=0;i<8;i++)
 156       if (packet[i]!=h[i])
 157       {
 158          speex_notify("This doesn't look like a Speex file");
 159          return NULL;
 160       }
 161
 162    /*FIXME: Do we allow larger headers?*/
 163    if (size < (int)sizeof(SpeexHeader))
 164    {
 165       speex_notify("Speex header too small");
 166       return NULL;
 167    }
 168
 169    /* le_header = (SpeexHeader*)speex_alloc(sizeof(SpeexHeader)); */
 170
 171    SPEEX_COPY(le_header, (SpeexHeader*)packet, 1);
 172
 173    /*Make sure everything is converted correctly from little-endian*/
 174    ENDIAN_SWITCH(le_header->speex_version_id);
 175    ENDIAN_SWITCH(le_header->header_size);
 176    ENDIAN_SWITCH(le_header->rate);
 177    ENDIAN_SWITCH(le_header->mode);
 178    ENDIAN_SWITCH(le_header->mode_bitstream_version);
 179    ENDIAN_SWITCH(le_header->nb_channels);
 180    ENDIAN_SWITCH(le_header->bitrate);
 181    ENDIAN_SWITCH(le_header->frame_size);
 182    ENDIAN_SWITCH(le_header->vbr);
 183    ENDIAN_SWITCH(le_header->frames_per_packet);
 184    ENDIAN_SWITCH(le_header->extra_headers);
 185
 186    return le_header;
 187
 188 }