Wed Aug 7 17:16:05 2019

Asterisk developer's documentation


format_ogg_vorbis.c File Reference

OGG/Vorbis streams. More...

#include "asterisk.h"
#include <vorbis/codec.h>
#include <vorbis/vorbisenc.h>
#include <vorbis/vorbisfile.h>
#include "asterisk/mod_format.h"
#include "asterisk/module.h"

Go to the source code of this file.

Data Structures

struct  ogg_vorbis_desc

Defines

#define BLOCK_SIZE   4096
#define BUF_SIZE   (2*SAMPLES_MAX)
#define SAMPLES_MAX   512

Functions

static int _ov_header_fseek_wrap (FILE *f, ogg_int64_t off, int whence)
 AST_MODULE_INFO (ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER,"OGG/Vorbis audio",.load=load_module,.unload=unload_module,.load_pri=AST_MODPRI_APP_DEPEND)
static int load_module (void)
static void ogg_vorbis_close (struct ast_filestream *fs)
 Close a OGG/Vorbis filestream.
static int ogg_vorbis_open (struct ast_filestream *s)
 Create a new OGG/Vorbis filestream and set it up for reading.
static struct ast_frameogg_vorbis_read (struct ast_filestream *fs, int *whennext)
 Read a frame full of audio data from the filestream.
static int ogg_vorbis_rewrite (struct ast_filestream *s, const char *comment)
 Create a new OGG/Vorbis filestream and set it up for writing.
static int ogg_vorbis_seek (struct ast_filestream *fs, off_t sample_offset, int whence)
 Seek to a specific position in an OGG/Vorbis filestream.
static off_t ogg_vorbis_tell (struct ast_filestream *fs)
 Tell the current position in OGG/Vorbis filestream measured in pcms.
static int ogg_vorbis_trunc (struct ast_filestream *fs)
 Trucate an OGG/Vorbis filestream.
static int ogg_vorbis_write (struct ast_filestream *fs, struct ast_frame *f)
 Write audio data from a frame to an OGG/Vorbis filestream.
static int unload_module (void)
static void write_stream (struct ogg_vorbis_desc *s, FILE *f)
 Write out any pending encoded data.

Variables

static ov_callbacks OV_CALLBACKS_NOCLOSE
static struct ast_format vorbis_f

Detailed Description

OGG/Vorbis streams.

Definition in file format_ogg_vorbis.c.


Define Documentation

#define BLOCK_SIZE   4096

Definition at line 56 of file format_ogg_vorbis.c.

#define BUF_SIZE   (2*SAMPLES_MAX)

Definition at line 54 of file format_ogg_vorbis.c.

#define SAMPLES_MAX   512

Definition at line 53 of file format_ogg_vorbis.c.


Function Documentation

static int _ov_header_fseek_wrap ( FILE *  f,
ogg_int64_t  off,
int  whence 
) [static]

Definition at line 88 of file format_ogg_vorbis.c.

00089 {
00090    if (f == NULL) {
00091       return -1;
00092    }
00093    return fseek(f, off, whence);
00094 }

AST_MODULE_INFO ( ASTERISK_GPL_KEY  ,
AST_MODFLAG_LOAD_ORDER  ,
"OGG/Vorbis audio"  ,
load = load_module,
unload = unload_module,
load_pri = AST_MODPRI_APP_DEPEND 
)
static int load_module ( void   )  [static]

Definition at line 437 of file format_ogg_vorbis.c.

References ast_format_register, AST_MODULE_LOAD_FAILURE, and AST_MODULE_LOAD_SUCCESS.

00438 {
00439    if (ast_format_register(&vorbis_f))
00440       return AST_MODULE_LOAD_FAILURE;
00441    return AST_MODULE_LOAD_SUCCESS;
00442 }

static void ogg_vorbis_close ( struct ast_filestream fs  )  [static]

Close a OGG/Vorbis filestream.

Parameters:
fs A OGG/Vorbis filestream.

Definition at line 278 of file format_ogg_vorbis.c.

References ast_filestream::_private, ast_filestream::f, ogg_vorbis_desc::ov_f, ogg_vorbis_desc::vd, write_stream(), and ogg_vorbis_desc::writing.

00279 {
00280    struct ogg_vorbis_desc *s = (struct ogg_vorbis_desc *) fs->_private;
00281 
00282    if (s->writing) {
00283       /* Tell the Vorbis encoder that the stream is finished
00284        * and write out the rest of the data */
00285       vorbis_analysis_wrote(&s->vd, 0);
00286       write_stream(s, fs->f);
00287    } else {
00288       /* clear OggVorbis_File handle */
00289       ov_clear(&s->ov_f);
00290    }
00291 }

static int ogg_vorbis_open ( struct ast_filestream s  )  [static]

Create a new OGG/Vorbis filestream and set it up for reading.

Parameters:
s File that points to on disk storage of the OGG/Vorbis data.
Returns:
The new filestream.

Definition at line 109 of file format_ogg_vorbis.c.

References ast_filestream::_private, ast_log(), DEFAULT_SAMPLE_RATE, desc, ast_filestream::f, LOG_ERROR, ogg_vorbis_desc::ov_f, and ogg_vorbis_desc::writing.

00110 {
00111    int result;
00112    struct ogg_vorbis_desc *desc = (struct ogg_vorbis_desc *) s->_private;
00113 
00114    /* initialize private description block */
00115    memset(desc, 0, sizeof(struct ogg_vorbis_desc));
00116    desc->writing = 0;
00117 
00118    /* actually open file */
00119    result = ov_open_callbacks(s->f, &desc->ov_f, NULL, 0, OV_CALLBACKS_NOCLOSE);
00120    if (result != 0) {
00121       ast_log(LOG_ERROR, "Error opening Ogg/Vorbis file stream.\n");
00122       return -1;
00123    }
00124 
00125    /* check stream(s) type */
00126    if (desc->ov_f.vi->channels != 1) {
00127       ast_log(LOG_ERROR, "Only monophonic OGG/Vorbis files are currently supported!\n");
00128       ov_clear(&desc->ov_f);
00129       return -1;
00130    }
00131 
00132    if (desc->ov_f.vi->rate != DEFAULT_SAMPLE_RATE) {
00133       ast_log(LOG_ERROR, "Only 8000Hz OGG/Vorbis files are currently supported!\n");
00134       ov_clear(&desc->ov_f);
00135       return -1;
00136    }
00137 
00138    return 0;
00139 }

static struct ast_frame* ogg_vorbis_read ( struct ast_filestream fs,
int *  whennext 
) [static, read]

Read a frame full of audio data from the filestream.

Parameters:
fs The filestream.
whennext Number of sample times to schedule the next call.
Returns:
A pointer to a frame containing audio data or NULL ifthere is no more audio data.

Definition at line 299 of file format_ogg_vorbis.c.

References __BIG_ENDIAN, ast_filestream::_private, AST_FORMAT_SLINEAR, AST_FRAME_SET_BUFFER, AST_FRAME_VOICE, AST_FRIENDLY_OFFSET, ast_log(), ast_filestream::buf, BUF_SIZE, ast_frame_subclass::codec, ast_frame::data, ast_frame::datalen, desc, ast_filestream::fr, ast_frame::frametype, LOG_WARNING, ast_frame::mallocd, ogg_vorbis_desc::ov_f, ast_frame::ptr, ast_frame::samples, ast_frame::subclass, and ogg_vorbis_desc::writing.

00301 {
00302    struct ogg_vorbis_desc *desc = (struct ogg_vorbis_desc *) fs->_private;
00303    int current_bitstream = -10;
00304    char *out_buf;
00305    long bytes_read;
00306 
00307    if (desc->writing) {
00308       ast_log(LOG_WARNING, "Reading is not suport on OGG/Vorbis on write files.\n");
00309       return NULL;
00310    }
00311 
00312    /* initialize frame */
00313    fs->fr.frametype = AST_FRAME_VOICE;
00314    fs->fr.subclass.codec = AST_FORMAT_SLINEAR;
00315    fs->fr.mallocd = 0;
00316    AST_FRAME_SET_BUFFER(&fs->fr, fs->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
00317    out_buf = (char *) (fs->fr.data.ptr);  /* SLIN data buffer */
00318 
00319    /* read samples from OV interface */
00320    bytes_read = ov_read(
00321       &desc->ov_f,
00322       out_buf,                /* Buffer to write data */
00323       BUF_SIZE,                  /* Size of buffer */
00324       (__BYTE_ORDER == __BIG_ENDIAN),  /* Endianes (0 for little) */
00325       2,                      /* 1 = 8bit, 2 = 16bit */
00326       1,                      /* 0 = unsigned, 1 = signed */
00327       &current_bitstream            /* Returns the current bitstream section */
00328    );
00329 
00330    /* check returned data */
00331    if (bytes_read <= 0) {
00332       /* End of stream */
00333       return NULL;
00334    }
00335 
00336    /* Return decoded bytes */
00337    fs->fr.datalen = bytes_read;
00338    fs->fr.samples = bytes_read / 2;
00339    *whennext = fs->fr.samples;
00340    return &fs->fr;
00341 }

static int ogg_vorbis_rewrite ( struct ast_filestream s,
const char *  comment 
) [static]

Create a new OGG/Vorbis filestream and set it up for writing.

Parameters:
s File pointer that points to on-disk storage.
comment Comment that should be embedded in the OGG/Vorbis file.
Returns:
A new filestream.

Definition at line 147 of file format_ogg_vorbis.c.

References ast_filestream::_private, ast_log(), ast_random(), DEFAULT_SAMPLE_RATE, ogg_vorbis_desc::eos, errno, ast_filestream::f, LOG_ERROR, LOG_WARNING, ogg_vorbis_desc::og, ogg_vorbis_desc::os, ogg_vorbis_desc::vb, ogg_vorbis_desc::vc, ogg_vorbis_desc::vd, ogg_vorbis_desc::vi, ogg_vorbis_desc::writing, and ogg_vorbis_desc::writing_pcm_pos.

00149 {
00150    ogg_packet header;
00151    ogg_packet header_comm;
00152    ogg_packet header_code;
00153    struct ogg_vorbis_desc *tmp = (struct ogg_vorbis_desc *) s->_private;
00154 
00155    tmp->writing = 1;
00156    tmp->writing_pcm_pos = 0;
00157 
00158    vorbis_info_init(&tmp->vi);
00159 
00160    if (vorbis_encode_init_vbr(&tmp->vi, 1, DEFAULT_SAMPLE_RATE, 0.4)) {
00161       ast_log(LOG_ERROR, "Unable to initialize Vorbis encoder!\n");
00162       return -1;
00163    }
00164 
00165    vorbis_comment_init(&tmp->vc);
00166    vorbis_comment_add_tag(&tmp->vc, "ENCODER", "Asterisk PBX");
00167    if (comment)
00168       vorbis_comment_add_tag(&tmp->vc, "COMMENT", (char *) comment);
00169 
00170    vorbis_analysis_init(&tmp->vd, &tmp->vi);
00171    vorbis_block_init(&tmp->vd, &tmp->vb);
00172 
00173    ogg_stream_init(&tmp->os, ast_random());
00174 
00175    vorbis_analysis_headerout(&tmp->vd, &tmp->vc, &header, &header_comm,
00176               &header_code);
00177    ogg_stream_packetin(&tmp->os, &header);
00178    ogg_stream_packetin(&tmp->os, &header_comm);
00179    ogg_stream_packetin(&tmp->os, &header_code);
00180 
00181    while (!tmp->eos) {
00182       if (ogg_stream_flush(&tmp->os, &tmp->og) == 0)
00183          break;
00184       if (!fwrite(tmp->og.header, 1, tmp->og.header_len, s->f)) {
00185          ast_log(LOG_WARNING, "fwrite() failed: %s\n", strerror(errno));
00186       }
00187       if (!fwrite(tmp->og.body, 1, tmp->og.body_len, s->f)) {
00188          ast_log(LOG_WARNING, "fwrite() failed: %s\n", strerror(errno));
00189       }
00190       if (ogg_page_eos(&tmp->og))
00191          tmp->eos = 1;
00192    }
00193 
00194    return 0;
00195 }

static int ogg_vorbis_seek ( struct ast_filestream fs,
off_t  sample_offset,
int  whence 
) [static]

Seek to a specific position in an OGG/Vorbis filestream.

Parameters:
s The filestream to take action on.
sample_offset New position for the filestream, measured in 8KHz samples.
whence Location to measure
Returns:
0 on success, -1 on failure.

Definition at line 382 of file format_ogg_vorbis.c.

References ast_filestream::_private, ast_log(), desc, LOG_WARNING, ogg_vorbis_tell(), ogg_vorbis_desc::ov_f, and ogg_vorbis_desc::writing.

00383 {
00384    int seek_result = -1;
00385    off_t relative_pcm_pos;
00386    struct ogg_vorbis_desc *desc = (struct ogg_vorbis_desc *) fs->_private;
00387 
00388    if (desc->writing) {
00389       ast_log(LOG_WARNING, "Seeking is not supported on OGG/Vorbis streams in writing mode!\n");
00390       return -1;
00391    }
00392 
00393    /* ov_pcm_seek support seeking only from begining (SEEK_SET), the rest must be emulated */
00394    switch (whence) {
00395    case SEEK_SET:
00396       seek_result = ov_pcm_seek(&desc->ov_f, sample_offset);
00397       break;
00398    case SEEK_CUR:
00399       if ((relative_pcm_pos = ogg_vorbis_tell(fs)) < 0) {
00400          seek_result = -1;
00401          break;
00402       }
00403       seek_result = ov_pcm_seek(&desc->ov_f, relative_pcm_pos + sample_offset);
00404       break;
00405    case SEEK_END:
00406       if ((relative_pcm_pos = ov_pcm_total(&desc->ov_f, -1)) < 0) {
00407          seek_result = -1;
00408          break;
00409       }
00410       seek_result = ov_pcm_seek(&desc->ov_f, relative_pcm_pos - sample_offset);
00411       break;
00412    default:
00413       ast_log(LOG_WARNING, "Unknown *whence* to seek on OGG/Vorbis streams!\n");
00414       break;
00415    }
00416 
00417    /* normalize error value to -1,0 */
00418    return (seek_result == 0) ? 0 : -1;
00419 }

static off_t ogg_vorbis_tell ( struct ast_filestream fs  )  [static]

Tell the current position in OGG/Vorbis filestream measured in pcms.

Parameters:
s The filestream to take action on.
Returns:
0 or greater with the position measured in samples, or -1 for false.

Definition at line 360 of file format_ogg_vorbis.c.

References ast_filestream::_private, desc, ogg_vorbis_desc::ov_f, ogg_vorbis_desc::writing, and ogg_vorbis_desc::writing_pcm_pos.

Referenced by ogg_vorbis_seek().

00361 {
00362    off_t pos;
00363    struct ogg_vorbis_desc *desc = (struct ogg_vorbis_desc *) fs->_private;
00364 
00365    if (desc->writing) {
00366       return desc->writing_pcm_pos;
00367    }
00368 
00369    if ((pos = ov_pcm_tell(&desc->ov_f)) < 0) {
00370       return -1;
00371    }
00372    return pos;
00373 }

static int ogg_vorbis_trunc ( struct ast_filestream fs  )  [static]

Trucate an OGG/Vorbis filestream.

Parameters:
s The filestream to truncate.
Returns:
0 on success, -1 on failure.

Definition at line 349 of file format_ogg_vorbis.c.

References ast_log(), and LOG_WARNING.

00350 {
00351    ast_log(LOG_WARNING, "Truncation is not supported on OGG/Vorbis streams!\n");
00352    return -1;
00353 }

static int ogg_vorbis_write ( struct ast_filestream fs,
struct ast_frame f 
) [static]

Write audio data from a frame to an OGG/Vorbis filestream.

Parameters:
fs An OGG/Vorbis filestream.
f A frame containing audio to be written to the filestream.
Returns:
-1 if there was an error, 0 on success.

Definition at line 234 of file format_ogg_vorbis.c.

References ast_filestream::_private, AST_FORMAT_SLINEAR, AST_FRAME_VOICE, ast_getformatname(), ast_log(), ast_frame_subclass::codec, ast_frame::data, ast_frame::datalen, ast_filestream::f, ast_frame::frametype, LOG_ERROR, LOG_WARNING, ast_frame::ptr, ast_frame::samples, ast_frame::subclass, ogg_vorbis_desc::vd, write_stream(), ogg_vorbis_desc::writing, and ogg_vorbis_desc::writing_pcm_pos.

00235 {
00236    int i;
00237    float **buffer;
00238    short *data;
00239    struct ogg_vorbis_desc *s = (struct ogg_vorbis_desc *) fs->_private;
00240 
00241    if (!s->writing) {
00242       ast_log(LOG_ERROR, "This stream is not set up for writing!\n");
00243       return -1;
00244    }
00245 
00246    if (f->frametype != AST_FRAME_VOICE) {
00247       ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
00248       return -1;
00249    }
00250    if (f->subclass.codec != AST_FORMAT_SLINEAR) {
00251       ast_log(LOG_WARNING, "Asked to write non-SLINEAR frame (%s)!\n",
00252          ast_getformatname(f->subclass.codec));
00253       return -1;
00254    }
00255    if (!f->datalen)
00256       return -1;
00257 
00258    data = (short *) f->data.ptr;
00259 
00260    buffer = vorbis_analysis_buffer(&s->vd, f->samples);
00261 
00262    for (i = 0; i < f->samples; i++)
00263       buffer[0][i] = (double)data[i] / 32768.0;
00264 
00265    vorbis_analysis_wrote(&s->vd, f->samples);
00266 
00267    write_stream(s, fs->f);
00268 
00269    s->writing_pcm_pos +=  f->samples;
00270 
00271    return 0;
00272 }

static int unload_module ( void   )  [static]

Definition at line 444 of file format_ogg_vorbis.c.

References ast_format_unregister(), and ast_format::name.

00445 {
00446    return ast_format_unregister(vorbis_f.name);
00447 }

static void write_stream ( struct ogg_vorbis_desc s,
FILE *  f 
) [static]

Write out any pending encoded data.

Parameters:
s An OGG/Vorbis filestream.
f The file to write to.

Definition at line 202 of file format_ogg_vorbis.c.

References ast_log(), ogg_vorbis_desc::eos, errno, LOG_WARNING, ogg_vorbis_desc::og, ogg_vorbis_desc::op, ogg_vorbis_desc::os, ogg_vorbis_desc::vb, and ogg_vorbis_desc::vd.

Referenced by ogg_vorbis_close(), and ogg_vorbis_write().

00203 {
00204    while (vorbis_analysis_blockout(&s->vd, &s->vb) == 1) {
00205       vorbis_analysis(&s->vb, NULL);
00206       vorbis_bitrate_addblock(&s->vb);
00207 
00208       while (vorbis_bitrate_flushpacket(&s->vd, &s->op)) {
00209          ogg_stream_packetin(&s->os, &s->op);
00210          while (!s->eos) {
00211             if (ogg_stream_pageout(&s->os, &s->og) == 0) {
00212                break;
00213             }
00214             if (!fwrite(s->og.header, 1, s->og.header_len, f)) {
00215             ast_log(LOG_WARNING, "fwrite() failed: %s\n", strerror(errno));
00216             }
00217             if (!fwrite(s->og.body, 1, s->og.body_len, f)) {
00218                ast_log(LOG_WARNING, "fwrite() failed: %s\n", strerror(errno));
00219             }
00220             if (ogg_page_eos(&s->og)) {
00221                s->eos = 1;
00222             }
00223          }
00224       }
00225    }
00226 }


Variable Documentation

ov_callbacks OV_CALLBACKS_NOCLOSE [static]

Definition at line 96 of file format_ogg_vorbis.c.

struct ast_format vorbis_f [static]

Definition at line 421 of file format_ogg_vorbis.c.


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