asterisk/formats/format_pcm.c
Gaurav Khurana 0827d5cc53 Add the ability to read the media file type from HTTP header for playback
How it works today:
media_cache tries to parse out the extension of the media file to be played
from the URI provided to Asterisk while caching the file.

What's expected:
Better will be to have Asterisk get extension from other ways too. One of the
common ways is to get the type of content from the CONTENT-TYPE header in the
HTTP response for fetching the media file using the URI provided.

Steps to Reproduce:
Provide a URL of the form: http://host/media/1234 to Asterisk for media
playback. It fails to play and logs show the following error line:

[Sep 15 15:48:05] WARNING [29148] [C-00000092] file.c:
File http://host/media/1234 does not exist in any format

Scenario this issue is blocking:
In the case where the media files are stored in some cloud object store,
following can block the media being played via Asterisk:

Cloud storage generally needs authenticated access to the storage. The way
to do that is by using signed URIs. With the signed URIs there's no way to
preserve the name of the file.
In most cases Cloud storage returns a key to access the object and preserving
file name is also not a thing there

ASTERISK-27286

 Reporter: Gaurav Khurana

Change-Id: I1b14692a49b2c1ac67688f58757184122e92ba89
2018-04-30 16:30:44 -04:00

582 lines
15 KiB
C

/*
* 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
);