format_vox.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2005, Digium, Inc.
00005  *
00006  * Mark Spencer <markster@digium.com>
00007  *
00008  * See http://www.asterisk.org for more information about
00009  * the Asterisk project. Please do not directly contact
00010  * any of the maintainers of this project for assistance;
00011  * the project provides a web site, mailing lists and IRC
00012  * channels for your use.
00013  *
00014  * This program is free software, distributed under the terms of
00015  * the GNU General Public License Version 2. See the LICENSE file
00016  * at the top of the source tree.
00017  */
00018 
00019 /*! \file
00020  *
00021  * \brief Flat, binary, ADPCM vox file format.
00022  * \arg File name extensions: vox
00023  * 
00024  * \ingroup formats
00025  */
00026 
00027 /*** MODULEINFO
00028    <support_level>extended</support_level>
00029  ***/
00030  
00031 #include "asterisk.h"
00032 
00033 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 419592 $")
00034 
00035 #include "asterisk/mod_format.h"
00036 #include "asterisk/module.h"
00037 #include "asterisk/endian.h"
00038 #include "asterisk/format_cache.h"
00039 
00040 #define BUF_SIZE  80    /* 80 bytes, 160 samples */
00041 #define VOX_SAMPLES  160
00042 
00043 static struct ast_frame *vox_read(struct ast_filestream *s, int *whennext)
00044 {
00045    int res;
00046 
00047    /* Send a frame from the file to the appropriate channel */
00048    AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
00049    if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) < 1) {
00050       if (res)
00051          ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
00052       return NULL;
00053    }
00054    *whennext = s->fr.samples = res * 2;
00055    s->fr.datalen = res;
00056    return &s->fr;
00057 }
00058 
00059 static int vox_write(struct ast_filestream *s, struct ast_frame *f)
00060 {
00061    int res;
00062    if ((res = fwrite(f->data.ptr, 1, f->datalen, s->f)) != f->datalen) {
00063          ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
00064          return -1;
00065    }
00066    return 0;
00067 }
00068 
00069 static int vox_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
00070 {
00071    off_t offset = 0, min = 0, cur, max, distance;
00072 
00073    if ((cur = ftello(fs->f)) < 0) {
00074       ast_log(AST_LOG_WARNING, "Unable to determine current position in g719 filestream %p: %s\n", fs, strerror(errno));
00075       return -1;
00076    }
00077 
00078    if (fseeko(fs->f, 0, SEEK_END) < 0) {
00079       ast_log(AST_LOG_WARNING, "Unable to seek to end of g719 filestream %p: %s\n", fs, strerror(errno));
00080       return -1;
00081    }
00082 
00083    if ((max = ftello(fs->f)) < 0) {
00084       ast_log(AST_LOG_WARNING, "Unable to determine max position in g719 filestream %p: %s\n", fs, strerror(errno));
00085       return -1;
00086    }
00087 
00088    /* have to fudge to frame here, so not fully to sample */
00089    distance = sample_offset/2;
00090    if (whence == SEEK_SET) {
00091       offset = distance;
00092    } else if (whence == SEEK_CUR || whence == SEEK_FORCECUR) {
00093       offset = distance + cur;
00094    } else if (whence == SEEK_END) {
00095       offset = max - distance;
00096    }
00097    if (whence != SEEK_FORCECUR) {
00098       offset = (offset > max)?max:offset;
00099       offset = (offset < min)?min:offset;
00100    }
00101    return fseeko(fs->f, offset, SEEK_SET);
00102 }
00103 
00104 static int vox_trunc(struct ast_filestream *fs)
00105 {
00106    int fd;
00107    off_t cur;
00108 
00109    if ((fd = fileno(fs->f)) < 0) {
00110       ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for vox filestream %p: %s\n", fs, strerror(errno));
00111       return -1;
00112    }
00113    if ((cur = ftello(fs->f)) < 0) {
00114       ast_log(AST_LOG_WARNING, "Unable to determine current position in vox filestream %p: %s\n", fs, strerror(errno));
00115       return -1;
00116    }
00117    /* Truncate file to current length */
00118    return ftruncate(fd, cur);}
00119 
00120 static off_t vox_tell(struct ast_filestream *fs)
00121 {
00122      off_t offset;
00123      offset = ftello(fs->f) << 1;
00124      return offset; 
00125 }
00126 
00127 static struct ast_format_def vox_f = {
00128    .name = "vox",
00129    .exts = "vox",
00130    .write = vox_write,
00131    .seek = vox_seek,
00132    .trunc = vox_trunc,
00133    .tell = vox_tell,
00134    .read = vox_read,
00135    .buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
00136 };
00137 
00138 static int load_module(void)
00139 {
00140    vox_f.format = ast_format_adpcm;
00141    if (ast_format_def_register(&vox_f))
00142       return AST_MODULE_LOAD_FAILURE;
00143    return AST_MODULE_LOAD_SUCCESS;
00144 }
00145 
00146 static int unload_module(void)
00147 {
00148    return ast_format_def_unregister(vox_f.name);
00149 }
00150 
00151 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Dialogic VOX (ADPCM) File Format",
00152    .support_level = AST_MODULE_SUPPORT_EXTENDED,
00153    .load = load_module,
00154    .unload = unload_module,
00155    .load_pri = AST_MODPRI_APP_DEPEND
00156 );

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