asterisk/formats/format_pcm.c

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2023-05-25 18:45:57 +00:00
/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 1999 - 2006, Digium, Inc.
*
* Mark Spencer <markster@digium.com>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
/*! \file
*
* \brief Flat, binary, ulaw PCM file format.
* \arg File name extension: alaw, al, alw, pcm, ulaw, ul, mu, ulw, g722, au
*
* \ingroup formats
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/mod_format.h"
#include "asterisk/module.h"
#include "asterisk/endian.h"
#include "asterisk/ulaw.h"
#include "asterisk/alaw.h"
#include "asterisk/format_cache.h"
#define BUF_SIZE 160 /* 160 bytes, and same number of samples */
static char ulaw_silence[BUF_SIZE];
static char alaw_silence[BUF_SIZE];
/* #define REALTIME_WRITE */ /* XXX does it work at all ? */
#ifdef REALTIME_WRITE
struct pcm_desc {
unsigned long start_time;
};
/* Returns time in msec since system boot. */
static unsigned long get_time(void)
{
struct tms buf;
clock_t cur;
cur = times( &buf );
if( cur < 0 ) {
ast_log( LOG_WARNING, "Cannot get current time\n" );
return 0;
}
return cur * 1000 / sysconf( _SC_CLK_TCK );
}
static int pcma_open(struct ast_filestream *s)
{
if (ast_format_cmp(s->fmt->format, ast_format_alaw) == AST_FORMAT_CMP_EQUAL)
pd->starttime = get_time();
return 0;
}
static int pcma_rewrite(struct ast_filestream *s, const char *comment)
{
return pcma_open(s);
}
#endif
static struct ast_frame *pcm_read(struct ast_filestream *s, int *whennext)
{
size_t res;
/* Send a frame from the file to the appropriate channel */
AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) < 1) {
if (res) {
ast_log(LOG_WARNING, "Short read of %s data (expected %d bytes, read %zu): %s\n",
ast_format_get_name(s->fr.subclass.format), s->fr.datalen, res,
strerror(errno));
}
return NULL;
}
s->fr.datalen = res;
*whennext = s->fr.samples = res;
return &s->fr;
}
static int pcm_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
{
off_t cur, max, offset = 0;
int ret = -1; /* assume error */
if ((cur = ftello(fs->f)) < 0) {
ast_log(AST_LOG_WARNING, "Unable to determine current position in pcm filestream %p: %s\n", fs, strerror(errno));
return -1;
}
if (fseeko(fs->f, 0, SEEK_END) < 0) {
ast_log(AST_LOG_WARNING, "Unable to seek to end of pcm filestream %p: %s\n", fs, strerror(errno));
return -1;
}
if ((max = ftello(fs->f)) < 0) {
ast_log(AST_LOG_WARNING, "Unable to determine max position in pcm filestream %p: %s\n", fs, strerror(errno));
return -1;
}
switch (whence) {
case SEEK_SET:
offset = sample_offset;
break;
case SEEK_END:
offset = max - sample_offset;
break;
case SEEK_CUR:
case SEEK_FORCECUR:
offset = cur + sample_offset;
break;
default:
ast_log(LOG_WARNING, "invalid whence %d, assuming SEEK_SET\n", whence);
offset = sample_offset;
}
if (offset < 0) {
ast_log(LOG_WARNING, "negative offset %ld, resetting to 0\n", (long) offset);
offset = 0;
}
if (whence == SEEK_FORCECUR && offset > max) { /* extend the file */
size_t left = offset - max;
const char *src = (ast_format_cmp(fs->fmt->format, ast_format_alaw) == AST_FORMAT_CMP_EQUAL) ? alaw_silence : ulaw_silence;
while (left) {
size_t written = fwrite(src, 1, MIN(left, BUF_SIZE), fs->f);
if (written < MIN(left, BUF_SIZE)) {
break; /* error */
}
left -= written;
}
ret = 0; /* successful */
} else {
if (offset > max) {
ast_log(LOG_WARNING, "offset too large %ld, truncating to %ld\n", (long) offset, (long) max);
offset = max;
}
ret = fseeko(fs->f, offset, SEEK_SET);
}
return ret;
}
static int pcm_trunc(struct ast_filestream *fs)
{
int cur, fd;
if ((fd = fileno(fs->f)) < 0) {
ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for pcm filestream %p: %s\n", fs, strerror(errno));
return -1;
}
if ((cur = ftello(fs->f)) < 0) {
ast_log(AST_LOG_WARNING, "Unable to determine current position in pcm filestream %p: %s\n", fs, strerror(errno));
return -1;
}
/* Truncate file to current length */
return ftruncate(fd, cur);
}
static off_t pcm_tell(struct ast_filestream *fs)
{
return ftello(fs->f);
}
static int pcm_write(struct ast_filestream *fs, struct ast_frame *f)
{
int res;
#ifdef REALTIME_WRITE
if (ast_format_cmp(s->fmt->format, ast_format_alaw) == AST_FORMAT_CMP_EQUAL) {
struct pcm_desc *pd = (struct pcm_desc *)fs->_private;
struct stat stat_buf;
unsigned long cur_time = get_time();
unsigned long fpos = ( cur_time - pd->start_time ) * 8; /* 8 bytes per msec */
/* Check if we have written to this position yet. If we have, then increment pos by one frame
* for some degree of protection against receiving packets in the same clock tick.
*/
fstat(fileno(fs->f), &stat_buf );
if (stat_buf.st_size > fpos )
fpos += f->datalen; /* Incrementing with the size of this current frame */
if (stat_buf.st_size < fpos) {
/* fill the gap with 0x55 rather than 0. */
char buf[1024];
unsigned long cur, to_write;
cur = stat_buf.st_size;
if (fseek(fs->f, cur, SEEK_SET) < 0) {
ast_log( LOG_WARNING, "Cannot seek in file: %s\n", strerror(errno) );
return -1;
}
memset(buf, 0x55, 512);
while (cur < fpos) {
to_write = fpos - cur;
if (to_write > sizeof(buf))
to_write = sizeof(buf);
if (fwrite(buf, 1, to_write, fs->f) != to_write) {
ast_log(LOG_ERROR, "Failed to write to file: %s\n", strerror(errno));
return -1;
}
cur += to_write;
}
}
if (fseek(s->f, fpos, SEEK_SET) < 0) {
ast_log( LOG_WARNING, "Cannot seek in file: %s\n", strerror(errno) );
return -1;
}
}
#endif /* REALTIME_WRITE */
if ((res = fwrite(f->data.ptr, 1, f->datalen, fs->f)) != f->datalen) {
ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
return -1;
}
return 0;
}
/* SUN .au support routines */
#define MIN_AU_HEADER_SIZE 24
#define AU_HEADER(var) uint32_t var[6]
#define AU_HDR_MAGIC_OFF 0
#define AU_HDR_HDR_SIZE_OFF 1
#define AU_HDR_DATA_SIZE_OFF 2
#define AU_HDR_ENCODING_OFF 3
#define AU_HDR_SAMPLE_RATE_OFF 4
#define AU_HDR_CHANNELS_OFF 5
#define AU_ENC_8BIT_ULAW 1
#define AU_MAGIC 0x2e736e64
#if __BYTE_ORDER == __BIG_ENDIAN
#define htoll(b) (b)
#define htols(b) (b)
#define ltohl(b) (b)
#define ltohs(b) (b)
#else
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define htoll(b) \
(((((b) ) & 0xFF) << 24) | \
((((b) >> 8) & 0xFF) << 16) | \
((((b) >> 16) & 0xFF) << 8) | \
((((b) >> 24) & 0xFF) ))
#define htols(b) \
(((((b) ) & 0xFF) << 8) | \
((((b) >> 8) & 0xFF) ))
#define ltohl(b) htoll(b)
#define ltohs(b) htols(b)
#else
#error "Endianess not defined"
#endif
#endif
struct au_desc {
uint32_t hdr_size;
};
static int check_header(struct ast_filestream *fs)
{
AU_HEADER(header);
uint32_t magic;
uint32_t hdr_size;
uint32_t data_size;
uint32_t encoding;
uint32_t sample_rate;
uint32_t channels;
struct au_desc *desc = fs->_private;
FILE *f = fs->f;
if (fread(header, 1, MIN_AU_HEADER_SIZE, f) != MIN_AU_HEADER_SIZE) {
ast_log(LOG_WARNING, "Read failed (header)\n");
return -1;
}
magic = ltohl(header[AU_HDR_MAGIC_OFF]);
if (magic != (uint32_t) AU_MAGIC) {
ast_log(LOG_WARNING, "Bad magic: 0x%x\n", magic);
}
hdr_size = ltohl(header[AU_HDR_HDR_SIZE_OFF]);
if (hdr_size < MIN_AU_HEADER_SIZE) {
hdr_size = MIN_AU_HEADER_SIZE;
}
/* data_size = ltohl(header[AU_HDR_DATA_SIZE_OFF]); */
encoding = ltohl(header[AU_HDR_ENCODING_OFF]);
if (encoding != AU_ENC_8BIT_ULAW) {
ast_log(LOG_WARNING, "Unexpected format: %u. Only 8bit ULAW allowed (%d)\n", encoding, AU_ENC_8BIT_ULAW);
return -1;
}
sample_rate = ltohl(header[AU_HDR_SAMPLE_RATE_OFF]);
if (sample_rate != DEFAULT_SAMPLE_RATE) {
ast_log(LOG_WARNING, "Sample rate can only be 8000 not %u\n", sample_rate);
return -1;
}
channels = ltohl(header[AU_HDR_CHANNELS_OFF]);
if (channels != 1) {
ast_log(LOG_WARNING, "Not in mono: channels=%u\n", channels);
return -1;
}
/* Skip to data */
fseek(f, 0, SEEK_END);
data_size = ftell(f) - hdr_size;
if (fseek(f, hdr_size, SEEK_SET) == -1 ) {
ast_log(LOG_WARNING, "Failed to skip to data: %u\n", hdr_size);
return -1;
}
/* We'll need this later */
desc->hdr_size = hdr_size;
return data_size;
}
static int update_header(struct ast_filestream *fs)
{
off_t cur, end;
uint32_t datalen;
int bytes;
struct au_desc *desc = fs->_private;
FILE *f = fs->f;
cur = ftell(f);
fseek(f, 0, SEEK_END);
end = ftell(f);
/* data starts 24 bytes in */
bytes = end - desc->hdr_size;
datalen = htoll(bytes);
if (cur < 0) {
ast_log(LOG_WARNING, "Unable to find our position\n");
return -1;
}
if (fseek(f, AU_HDR_DATA_SIZE_OFF * sizeof(uint32_t), SEEK_SET)) {
ast_log(LOG_WARNING, "Unable to set our position\n");
return -1;
}
if (fwrite(&datalen, 1, sizeof(datalen), f) != sizeof(datalen)) {
ast_log(LOG_WARNING, "Unable to set write file size\n");
return -1;
}
if (fseek(f, cur, SEEK_SET)) {
ast_log(LOG_WARNING, "Unable to return to position\n");
return -1;
}
return 0;
}
static int write_header(struct ast_filestream *fs)
{
struct au_desc *desc = fs->_private;
FILE *f = fs->f;
AU_HEADER(header);
header[AU_HDR_MAGIC_OFF] = htoll((uint32_t) AU_MAGIC);
header[AU_HDR_HDR_SIZE_OFF] = htoll(desc->hdr_size);
header[AU_HDR_DATA_SIZE_OFF] = 0;
header[AU_HDR_ENCODING_OFF] = htoll(AU_ENC_8BIT_ULAW);
header[AU_HDR_SAMPLE_RATE_OFF] = htoll(DEFAULT_SAMPLE_RATE);
header[AU_HDR_CHANNELS_OFF] = htoll(1);
/* Write an au header, ignoring sizes which will be filled in later */
fseek(f, 0, SEEK_SET);
if (fwrite(header, 1, MIN_AU_HEADER_SIZE, f) != MIN_AU_HEADER_SIZE) {
ast_log(LOG_WARNING, "Unable to write header\n");
return -1;
}
return 0;
}
static int au_open(struct ast_filestream *s)
{
if (check_header(s) < 0)
return -1;
return 0;
}
static int au_rewrite(struct ast_filestream *s, const char *comment)
{
struct au_desc *desc = s->_private;
desc->hdr_size = MIN_AU_HEADER_SIZE;
if (write_header(s))
return -1;
return 0;
}
/* XXX check this, probably incorrect */
static int au_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
{
off_t min, max, cur;
long offset = 0;
struct au_desc *desc = fs->_private;
min = desc->hdr_size;
if ((cur = ftello(fs->f)) < 0) {
ast_log(AST_LOG_WARNING, "Unable to determine current position in au filestream %p: %s\n", fs, strerror(errno));
return -1;
}
if (fseeko(fs->f, 0, SEEK_END) < 0) {
ast_log(AST_LOG_WARNING, "Unable to seek to end of au filestream %p: %s\n", fs, strerror(errno));
return -1;
}
if ((max = ftello(fs->f)) < 0) {
ast_log(AST_LOG_WARNING, "Unable to determine max position in au filestream %p: %s\n", fs, strerror(errno));
return -1;
}
if (whence == SEEK_SET)
offset = sample_offset + min;
else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
offset = sample_offset + cur;
else if (whence == SEEK_END)
offset = max - sample_offset;
if (whence != SEEK_FORCECUR) {
offset = (offset > max) ? max : offset;
}
/* always protect the header space. */
offset = (offset < min) ? min : offset;
return fseeko(fs->f, offset, SEEK_SET);
}
static int au_trunc(struct ast_filestream *fs)
{
int fd;
off_t cur;
if ((fd = fileno(fs->f)) < 0) {
ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for au filestream %p: %s\n", fs, strerror(errno));
return -1;
}
if ((cur = ftello(fs->f)) < 0) {
ast_log(AST_LOG_WARNING, "Unable to determine current position in au filestream %p: %s\n", fs, strerror(errno));
return -1;
}
/* Truncate file to current length */
if (ftruncate(fd, cur)) {
return -1;
}
return update_header(fs);
}
static off_t au_tell(struct ast_filestream *fs)
{
struct au_desc *desc = fs->_private;
off_t offset = ftello(fs->f);
return offset - desc->hdr_size;
}
static struct ast_frame *g722_read(struct ast_filestream *s, int *whennext)
{
struct ast_frame *f = pcm_read(s, whennext);
*whennext = s->fr.samples = (*whennext * 2);
return f;
}
static int g722_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
{
return pcm_seek(fs, sample_offset / 2, whence);
}
static off_t g722_tell(struct ast_filestream *fs)
{
return pcm_tell(fs) * 2;
}
static struct ast_format_def alaw_f = {
.name = "alaw",
.exts = "alaw|al|alw",
.write = pcm_write,
.seek = pcm_seek,
.trunc = pcm_trunc,
.tell = pcm_tell,
.read = pcm_read,
.buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
#ifdef REALTIME_WRITE
.open = pcma_open,
.rewrite = pcma_rewrite,
.desc_size = sizeof(struct pcm_desc),
#endif
};
static struct ast_format_def pcm_f = {
.name = "pcm",
.exts = "pcm|ulaw|ul|mu|ulw",
.mime_types = "audio/basic",
.write = pcm_write,
.seek = pcm_seek,
.trunc = pcm_trunc,
.tell = pcm_tell,
.read = pcm_read,
.buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
};
static struct ast_format_def g722_f = {
.name = "g722",
.exts = "g722",
.write = pcm_write,
.seek = g722_seek,
.trunc = pcm_trunc,
.tell = g722_tell,
.read = g722_read,
.buf_size = (BUF_SIZE * 2) + AST_FRIENDLY_OFFSET,
};
static struct ast_format_def au_f = {
.name = "au",
.exts = "au",
.open = au_open,
.rewrite = au_rewrite,
.write = pcm_write,
.seek = au_seek,
.trunc = au_trunc,
.tell = au_tell,
.read = pcm_read,
.buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET, /* this many shorts */
.desc_size = sizeof(struct au_desc),
};
static int unload_module(void)
{
return ast_format_def_unregister(pcm_f.name)
|| ast_format_def_unregister(alaw_f.name)
|| ast_format_def_unregister(au_f.name)
|| ast_format_def_unregister(g722_f.name);
}
static int load_module(void)
{
int i;
/* XXX better init ? */
for (i = 0; i < ARRAY_LEN(ulaw_silence); i++)
ulaw_silence[i] = AST_LIN2MU(0);
for (i = 0; i < ARRAY_LEN(alaw_silence); i++)
alaw_silence[i] = AST_LIN2A(0);
pcm_f.format = ast_format_ulaw;
alaw_f.format = ast_format_alaw;
au_f.format = ast_format_ulaw;
g722_f.format = ast_format_g722;
if ( ast_format_def_register(&pcm_f)
|| ast_format_def_register(&alaw_f)
|| ast_format_def_register(&au_f)
|| ast_format_def_register(&g722_f) ) {
unload_module();
return AST_MODULE_LOAD_DECLINE;
}
return AST_MODULE_LOAD_SUCCESS;
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Raw/Sun uLaw/ALaw 8KHz (PCM,PCMA,AU), G.722 16Khz",
.support_level = AST_MODULE_SUPPORT_CORE,
.load = load_module,
.unload = unload_module,
.load_pri = AST_MODPRI_APP_DEPEND
);