formats/format_h263.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2006, Digium, Inc.
   5  *
   6  * Mark Spencer <markster@digium.com>
   7  *
   8  * See http://www.asterisk.org for more information about
   9  * the Asterisk project. Please do not directly contact
  10  * any of the maintainers of this project for assistance;
  11  * the project provides a web site, mailing lists and IRC
  12  * channels for your use.
  13  *
  14  * This program is free software, distributed under the terms of
  15  * the GNU General Public License Version 2. See the LICENSE file
  16  * at the top of the source tree.
  17  */
  18
  19 /*! \file
  20  *
  21  * \brief Save to raw, headerless h263 data.
  22  * \arg File name extension: h263
  23  * \ingroup formats
  24  * \arg See \ref AstVideo
  25  */
  26
  27 #include "asterisk.h"
  28
  29 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  30
  31 #include <unistd.h>
  32 #include <netinet/in.h>
  33 #include <arpa/inet.h>
  34 #include <stdlib.h>
  35 #include <sys/time.h>
  36 #include <stdio.h>
  37 #include <errno.h>
  38 #include <string.h>
  39
  40 #include "asterisk/lock.h"
  41 #include "asterisk/channel.h"
  42 #include "asterisk/file.h"
  43 #include "asterisk/logger.h"
  44 #include "asterisk/sched.h"
  45 #include "asterisk/module.h"
  46 #include "asterisk/endian.h"
  47
  48 /* Some Ideas for this code came from makeh263e.c by Jeffrey Chilton */
  49
  50 /* Portions of the conversion code are by guido@sienanet.it */
  51
  52 /* According to:
  53  * http://lists.mpegif.org/pipermail/mp4-tech/2005-July/005741.html
  54  * the maximum actual frame size is not 2048, but 8192.  Since the maximum
  55  * theoretical limit is not much larger (32k = 15bits), we'll go for that
  56  * size to ensure we don't corrupt frames sent to us (unless they're
  57  * ridiculously large). */
  58 #define BUF_SIZE        32768   /* Four real h.263 Frames */
  59
  60 struct h263_desc {
  61         unsigned int lastts;
  62 };
  63
  64
  65 static int h263_open(struct ast_filestream *s)
  66 {
  67         unsigned int ts;
  68         int res;
  69
  70         if ((res = fread(&ts, 1, sizeof(ts), s->f)) < sizeof(ts)) {
  71                 ast_log(LOG_WARNING, "Empty file!\n");
  72                 return -1;
  73         }
  74         return 0;
  75 }
  76
  77 static struct ast_frame *h263_read(struct ast_filestream *s, int *whennext)
  78 {
  79         int res;
  80         int mark;
  81         unsigned short len;
  82         unsigned int ts;
  83         struct h263_desc *fs = (struct h263_desc *)s->_private;
  84
  85         /* Send a frame from the file to the appropriate channel */
  86         if ((res = fread(&len, 1, sizeof(len), s->f)) < 1)
  87                 return NULL;
  88         len = ntohs(len);
  89         mark = (len & 0x8000) ? 1 : 0;
  90         len &= 0x7fff;
  91         if (len > BUF_SIZE) {
  92                 ast_log(LOG_WARNING, "Length %d is too long\n", len);
  93                 return NULL;
  94         }
  95         s->fr.frametype = AST_FRAME_VIDEO;
  96         s->fr.subclass = AST_FORMAT_H263;
  97         s->fr.mallocd = 0;
  98         AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, len);
  99         if ((res = fread(s->fr.data, 1, s->fr.datalen, s->f)) != s->fr.datalen) {
 100                 if (res)
 101                         ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
 102                 return NULL;
 103         }
 104         s->fr.samples = fs->lastts;     /* XXX what ? */
 105         s->fr.datalen = len;
 106         s->fr.subclass |= mark;
 107         s->fr.delivery.tv_sec = 0;
 108         s->fr.delivery.tv_usec = 0;
 109         if ((res = fread(&ts, 1, sizeof(ts), s->f)) == sizeof(ts)) {
 110                 fs->lastts = ntohl(ts);
 111                 *whennext = fs->lastts * 4/45;
 112         } else
 113                 *whennext = 0;
 114         return &s->fr;
 115 }
 116
 117 static int h263_write(struct ast_filestream *fs, struct ast_frame *f)
 118 {
 119         int res;
 120         unsigned int ts;
 121         unsigned short len;
 122         int subclass;
 123         int mark=0;
 124         if (f->frametype != AST_FRAME_VIDEO) {
 125                 ast_log(LOG_WARNING, "Asked to write non-video frame!\n");
 126                 return -1;
 127         }
 128         subclass = f->subclass;
 129         if (subclass & 0x1)
 130                 mark=0x8000;
 131         subclass &= ~0x1;
 132         if (subclass != AST_FORMAT_H263) {
 133                 ast_log(LOG_WARNING, "Asked to write non-h263 frame (%d)!\n", f->subclass);
 134                 return -1;
 135         }
 136         ts = htonl(f->samples);
 137         if ((res = fwrite(&ts, 1, sizeof(ts), fs->f)) != sizeof(ts)) {
 138                         ast_log(LOG_WARNING, "Bad write (%d/4): %s\n", res, strerror(errno));
 139                         return -1;
 140         }
 141         len = htons(f->datalen | mark);
 142         if ((res = fwrite(&len, 1, sizeof(len), fs->f)) != sizeof(len)) {
 143                         ast_log(LOG_WARNING, "Bad write (%d/2): %s\n", res, strerror(errno));
 144                         return -1;
 145         }
 146         if ((res = fwrite(f->data, 1, f->datalen, fs->f)) != f->datalen) {
 147                         ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
 148                         return -1;
 149         }
 150         return 0;
 151 }
 152
 153 static int h263_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 154 {
 155         /* No way Jose */
 156         return -1;
 157 }
 158
 159 static int h263_trunc(struct ast_filestream *fs)
 160 {
 161         /* Truncate file to current length */
 162         if (ftruncate(fileno(fs->f), ftello(fs->f)) < 0)
 163                 return -1;
 164         return 0;
 165 }
 166
 167 static off_t h263_tell(struct ast_filestream *fs)
 168 {
 169         off_t offset = ftello(fs->f);
 170         return offset;  /* XXX totally bogus, needs fixing */
 171 }
 172
 173 static const struct ast_format h263_f = {
 174         .name = "h263",
 175         .exts = "h263",
 176         .format = AST_FORMAT_H263,
 177         .open = h263_open,
 178         .write = h263_write,
 179         .seek = h263_seek,
 180         .trunc = h263_trunc,
 181         .tell = h263_tell,
 182         .read = h263_read,
 183         .buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
 184         .desc_size = sizeof(struct h263_desc),
 185 };
 186
 187 static int load_module(void)
 188 {
 189         return ast_format_register(&h263_f);
 190 }
 191
 192 static int unload_module(void)
 193 {
 194         return ast_format_unregister(h263_f.name);
 195 }
 196
 197 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Raw H.263 data");