asterisk/codecs/codec_mp3_d.c

321 lines
7.2 KiB
C
Executable File

/*
* Asterisk -- A telephony toolkit for Linux.
*
* MP3 Decoder
*
* The MP3 code is from freeamp, which in turn is from xingmp3's release
* which I can't seem to find anywhere
*
* Copyright (C) 1999, Mark Spencer
*
* Mark Spencer <markster@linux-support.net>
*
* This program is free software, distributed under the terms of
* the GNU General Public License
*/
#include <asterisk/lock.h>
#include <asterisk/translate.h>
#include <asterisk/module.h>
#include <asterisk/logger.h>
#include <asterisk/channel.h>
#include <pthread.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <netinet/in.h>
#include <string.h>
#include <stdio.h>
#include "mp3/include/L3.h"
#include "mp3/include/mhead.h"
#include "mp3anal.h"
/* Sample frame data */
#include "mp3_slin_ex.h"
#define MAX_OUT_FRAME 320
#define MAX_FRAME_SIZE 1441
#define MAX_OUTPUT_LEN 2304
static pthread_mutex_t localuser_lock = AST_MUTEX_INITIALIZER;
static int localusecnt=0;
static char *tdesc = "MP3/PCM16 (signed linear) Translator (Decoder only)";
struct ast_translator_pvt {
MPEG m;
MPEG_HEAD head;
DEC_INFO info;
struct ast_frame f;
/* Space to build offset */
char offset[AST_FRIENDLY_OFFSET];
/* Mini buffer */
char outbuf[MAX_OUT_FRAME];
/* Enough to store a full second */
short buf[32000];
/* Tail of signed linear stuff */
int tail;
/* Current bitrate */
int bitrate;
/* XXX What's forward? XXX */
int forward;
/* Have we called head info yet? */
int init;
int copy;
};
#define mp3_coder_pvt ast_translator_pvt
static struct ast_translator_pvt *mp3_new(void)
{
struct mp3_coder_pvt *tmp;
tmp = malloc(sizeof(struct mp3_coder_pvt));
if (tmp) {
tmp->init = 0;
tmp->tail = 0;
tmp->copy = -1;
mpeg_init(&tmp->m);
}
return tmp;
}
static struct ast_frame *mp3tolin_sample(void)
{
static struct ast_frame f;
int size;
if (mp3_badheader(mp3_slin_ex)) {
ast_log(LOG_WARNING, "Bad MP3 sample??\n");
return NULL;
}
size = mp3_framelen(mp3_slin_ex);
if (size < 1) {
ast_log(LOG_WARNING, "Failed to size??\n");
return NULL;
}
f.frametype = AST_FRAME_VOICE;
f.subclass = AST_FORMAT_MP3;
f.data = mp3_slin_ex;
f.datalen = sizeof(mp3_slin_ex);
/* Dunno how long an mp3 frame is -- kinda irrelevant anyway */
f.samples = 240;
f.mallocd = 0;
f.offset = 0;
f.src = __PRETTY_FUNCTION__;
return &f;
}
static struct ast_frame *mp3tolin_frameout(struct ast_translator_pvt *tmp)
{
if (!tmp->tail)
return NULL;
/* Signed linear is no particular frame size, so just send whatever
we have in the buffer in one lump sum */
tmp->f.frametype = AST_FRAME_VOICE;
tmp->f.subclass = AST_FORMAT_SLINEAR;
tmp->f.datalen = tmp->tail * 2;
/* Assume 8000 Hz */
tmp->f.samples = tmp->tail;
tmp->f.mallocd = 0;
tmp->f.offset = AST_FRIENDLY_OFFSET;
tmp->f.src = __PRETTY_FUNCTION__;
tmp->f.data = tmp->buf;
/* Reset tail pointer */
tmp->tail = 0;
#if 0
/* Save a sample frame */
{
static int fd = -1;
if (fd < 0)
fd = open("mp3out.raw", O_WRONLY | O_CREAT | O_TRUNC, 0644);
write(fd, tmp->f.data, tmp->f.datalen);
}
#endif
return &tmp->f;
}
static int mp3_init(struct ast_translator_pvt *tmp, int len)
{
if (!audio_decode_init(&tmp->m, &tmp->head, len,0,0,1 /* Convert to mono */,24000)) {
ast_log(LOG_WARNING, "audio_decode_init() failed\n");
return -1;
}
audio_decode_info(&tmp->m, &tmp->info);
#if 0
ast_verbose(
"Channels: %d\nOutValues: %d\nSample Rate: %d\nBits: %d\nFramebytes: %d\nType: %d\n",
tmp->info.channels, tmp->info.outvalues, tmp->info.samprate, tmp->info.bits,tmp->info.framebytes,tmp->info.type);
#endif
return 0;
}
#ifndef MIN
#define MIN(a,b) (((a) < (b)) ? (a) : (b))
#endif
#if 1
static int add_to_buf(short *dst, int maxdst, short *src, int srclen, int samprate)
{
float inc, cur, sum=0;
int cnt=0, pos, ptr, lastpos = -1;
/* Resample source to destination converting from its sampling rate to 8000 Hz */
if (samprate == 8000) {
/* Quickly, all we have to do is copy */
memcpy(dst, src, 2 * MIN(maxdst, srclen));
return MIN(maxdst, srclen);
}
if (samprate < 8000) {
ast_log(LOG_WARNING, "Don't know how to resample a source less than 8000 Hz!\n");
/* XXX Wrong thing to do XXX */
memcpy(dst, src, 2 * MIN(maxdst, srclen));
return MIN(maxdst, srclen);
}
/* Ugh, we actually *have* to resample */
inc = 8000.0 / (float)samprate;
cur = 0;
ptr = 0;
pos = 0;
#if 0
ast_verbose("Incrementing by %f, in = %d bytes, out = %d bytes\n", inc, srclen, maxdst);
#endif
while((pos < maxdst) && (ptr < srclen)) {
if (pos != lastpos) {
if (lastpos > -1) {
sum = sum / (float)cnt;
dst[pos - 1] = (int) sum;
#if 0
ast_verbose("dst[%d] = %d\n", pos - 1, dst[pos - 1]);
#endif
}
/* Each time we have a first pass */
sum = 0;
cnt = 0;
} else {
sum += src[ptr];
}
ptr++;
cur += inc;
cnt++;
lastpos = pos;
pos = (int)cur;
}
return pos;
}
#endif
static int mp3tolin_framein(struct ast_translator_pvt *tmp, struct ast_frame *f)
{
/* Assuming there's space left, decode into the current buffer at
the tail location */
int framelen;
short tmpbuf[8000];
IN_OUT x;
#if 0
if (tmp->copy < 0) {
tmp->copy = open("sample.out", O_WRONLY | O_CREAT | O_TRUNC, 0700);
}
if (tmp->copy > -1)
write(tmp->copy, f->data, f->datalen);
#endif
/* Check if it's a valid frame */
if (mp3_badheader((unsigned char *)f->data)) {
ast_log(LOG_WARNING, "Invalid MP3 header\n");
return -1;
}
if ((framelen = mp3_framelen((unsigned char *)f->data) != f->datalen)) {
ast_log(LOG_WARNING, "Calculated length %d does not match real length %d\n", framelen, f->datalen);
return -1;
}
/* Start by putting this in the mp3 buffer */
if((framelen = head_info3(f->data,
f->datalen, &tmp->head, &tmp->bitrate, &tmp->forward)) > 0) {
if (!tmp->init) {
if (mp3_init(tmp, framelen))
return -1;
else
tmp->init++;
}
if (tmp->tail + MAX_OUTPUT_LEN/2 < sizeof(tmp->buf)/2) {
x = audio_decode(&tmp->m, f->data, tmpbuf);
audio_decode_info(&tmp->m, &tmp->info);
if (!x.in_bytes) {
ast_log(LOG_WARNING, "Invalid MP3 data\n");
} else {
#if 1
/* Resample to 8000 Hz */
tmp->tail += add_to_buf(tmp->buf + tmp->tail,
sizeof(tmp->buf) / 2 - tmp->tail,
tmpbuf,
x.out_bytes/2,
tmp->info.samprate);
#else
memcpy(tmp->buf + tmp->tail, tmpbuf, x.out_bytes);
/* Signed linear output */
tmp->tail+=x.out_bytes/2;
#endif
}
} else {
ast_log(LOG_WARNING, "Out of buffer space\n");
return -1;
}
} else {
ast_log(LOG_WARNING, "Not a valid MP3 frame\n");
}
return 0;
}
static void mp3_destroy_stuff(struct ast_translator_pvt *pvt)
{
close(pvt->copy);
free(pvt);
}
static struct ast_translator mp3tolin =
{ "mp3tolin",
AST_FORMAT_MP3, AST_FORMAT_SLINEAR,
mp3_new,
mp3tolin_framein,
mp3tolin_frameout,
mp3_destroy_stuff,
mp3tolin_sample
};
int unload_module(void)
{
int res;
ast_pthread_mutex_lock(&localuser_lock);
res = ast_unregister_translator(&mp3tolin);
if (localusecnt)
res = -1;
ast_pthread_mutex_unlock(&localuser_lock);
return res;
}
int load_module(void)
{
int res;
res=ast_register_translator(&mp3tolin);
return res;
}
char *description(void)
{
return tdesc;
}
int usecount(void)
{
int res;
STANDARD_USECOUNT(res);
return res;
}
char *key()
{
return ASTERISK_GPL_KEY;
}