ref: 37b86df09ff381bcc4f60802d43e57bd9bfcac73
dir: /sys/src/cmd/audio/mp3dec/decoder.c/
/*
* libmad - MPEG audio decoder library
* Copyright (C) 2000-2004 Underbit Technologies, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id: decoder.c,v 1.22 2004/01/23 09:41:32 rob Exp $
*/
# ifdef HAVE_CONFIG_H
# include "config.h"
# endif
# include "global.h"
# ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
# endif
# ifdef HAVE_SYS_WAIT_H
# include <sys/wait.h>
# endif
# ifdef HAVE_UNISTD_H
# include <unistd.h>
# endif
# ifdef HAVE_FCNTL_H
# include <fcntl.h>
# endif
# ifdef HAVE_ERRNO_H
# include <errno.h>
# endif
# include "stream.h"
# include "frame.h"
# include "synth.h"
# include "decoder.h"
/*
* NAME: decoder->init()
* DESCRIPTION: initialize a decoder object with callback routines
*/
void mad_decoder_init(struct mad_decoder *decoder, void *data,
enum mad_flow (*input_func)(void *,
struct mad_stream *),
enum mad_flow (*header_func)(void *,
struct mad_header const *),
enum mad_flow (*filter_func)(void *,
struct mad_stream const *,
struct mad_frame *),
enum mad_flow (*output_func)(void *,
struct mad_header const *,
struct mad_pcm *),
enum mad_flow (*error_func)(void *,
struct mad_stream *,
struct mad_frame *),
enum mad_flow (*message_func)(void *,
void *, unsigned int *))
{
decoder->mode = -1;
decoder->options = 0;
decoder->async.pid = 0;
decoder->async.in = -1;
decoder->async.out = -1;
decoder->sync = 0;
decoder->cb_data = data;
decoder->input_func = input_func;
decoder->header_func = header_func;
decoder->filter_func = filter_func;
decoder->output_func = output_func;
decoder->error_func = error_func;
decoder->message_func = message_func;
}
int mad_decoder_finish(struct mad_decoder *decoder)
{
# if defined(USE_ASYNC)
if (decoder->mode == MAD_DECODER_MODE_ASYNC && decoder->async.pid) {
pid_t pid;
int status;
close(decoder->async.in);
do
pid = waitpid(decoder->async.pid, &status, 0);
while (pid == -1 && errno == EINTR);
decoder->mode = -1;
close(decoder->async.out);
decoder->async.pid = 0;
decoder->async.in = -1;
decoder->async.out = -1;
if (pid == -1)
return -1;
return (!WIFEXITED(status) || WEXITSTATUS(status)) ? -1 : 0;
}
# endif
return 0;
}
# if defined(USE_ASYNC)
static
enum mad_flow send_io(int fd, void const *data, size_t len)
{
char const *ptr = data;
ssize_t count;
while (len) {
do
count = write(fd, ptr, len);
while (count == -1 && errno == EINTR);
if (count == -1)
return MAD_FLOW_BREAK;
len -= count;
ptr += count;
}
return MAD_FLOW_CONTINUE;
}
static
enum mad_flow receive_io(int fd, void *buffer, size_t len)
{
char *ptr = buffer;
ssize_t count;
while (len) {
do
count = read(fd, ptr, len);
while (count == -1 && errno == EINTR);
if (count == -1)
return (errno == EAGAIN) ? MAD_FLOW_IGNORE : MAD_FLOW_BREAK;
else if (count == 0)
return MAD_FLOW_STOP;
len -= count;
ptr += count;
}
return MAD_FLOW_CONTINUE;
}
static
enum mad_flow receive_io_blocking(int fd, void *buffer, size_t len)
{
int flags, blocking;
enum mad_flow result;
flags = fcntl(fd, F_GETFL);
if (flags == -1)
return MAD_FLOW_BREAK;
blocking = flags & ~O_NONBLOCK;
if (blocking != flags &&
fcntl(fd, F_SETFL, blocking) == -1)
return MAD_FLOW_BREAK;
result = receive_io(fd, buffer, len);
if (flags != blocking &&
fcntl(fd, F_SETFL, flags) == -1)
return MAD_FLOW_BREAK;
return result;
}
static
enum mad_flow send(int fd, void const *message, unsigned int size)
{
enum mad_flow result;
/* send size */
result = send_io(fd, &size, sizeof(size));
/* send message */
if (result == MAD_FLOW_CONTINUE)
result = send_io(fd, message, size);
return result;
}
static
enum mad_flow receive(int fd, void **message, unsigned int *size)
{
enum mad_flow result;
unsigned int actual;
if (*message == 0)
*size = 0;
/* receive size */
result = receive_io(fd, &actual, sizeof(actual));
/* receive message */
if (result == MAD_FLOW_CONTINUE) {
if (actual > *size)
actual -= *size;
else {
*size = actual;
actual = 0;
}
if (*size > 0) {
if (*message == 0) {
*message = malloc(*size);
if (*message == 0)
return MAD_FLOW_BREAK;
}
result = receive_io_blocking(fd, *message, *size);
}
/* throw away remainder of message */
while (actual && result == MAD_FLOW_CONTINUE) {
char sink[256];
unsigned int len;
len = actual > sizeof(sink) ? sizeof(sink) : actual;
result = receive_io_blocking(fd, sink, len);
actual -= len;
}
}
return result;
}
static
enum mad_flow check_message(struct mad_decoder *decoder)
{
enum mad_flow result;
void *message = 0;
unsigned int size;
result = receive(decoder->async.in, &message, &size);
if (result == MAD_FLOW_CONTINUE) {
if (decoder->message_func == 0)
size = 0;
else {
result = decoder->message_func(decoder->cb_data, message, &size);
if (result == MAD_FLOW_IGNORE ||
result == MAD_FLOW_BREAK)
size = 0;
}
if (send(decoder->async.out, message, size) != MAD_FLOW_CONTINUE)
result = MAD_FLOW_BREAK;
}
if (message)
free(message);
return result;
}
# endif
static
enum mad_flow error_default(void *data, struct mad_stream *stream,
struct mad_frame *frame)
{
int *bad_last_frame = data;
switch (stream->error) {
case MAD_ERROR_BADCRC:
if (*bad_last_frame)
mad_frame_mute(frame);
else
*bad_last_frame = 1;
return MAD_FLOW_IGNORE;
default:
return MAD_FLOW_CONTINUE;
}
}
static
int run_sync(struct mad_decoder *decoder)
{
enum mad_flow (*error_func)(void *, struct mad_stream *, struct mad_frame *);
void *error_data;
int bad_last_frame = 0;
struct mad_stream *stream;
struct mad_frame *frame;
struct mad_synth *synth;
int result = 0;
if (decoder->input_func == 0)
return 0;
if (decoder->error_func) {
error_func = decoder->error_func;
error_data = decoder->cb_data;
}
else {
error_func = error_default;
error_data = &bad_last_frame;
}
stream = &decoder->sync->stream;
frame = &decoder->sync->frame;
synth = &decoder->sync->synth;
mad_stream_init(stream);
mad_frame_init(frame);
mad_synth_init(synth);
mad_stream_options(stream, decoder->options);
do {
switch (decoder->input_func(decoder->cb_data, stream)) {
case MAD_FLOW_STOP:
goto done;
case MAD_FLOW_BREAK:
goto fail;
case MAD_FLOW_IGNORE:
continue;
case MAD_FLOW_CONTINUE:
break;
}
while (1) {
# if defined(USE_ASYNC)
if (decoder->mode == MAD_DECODER_MODE_ASYNC) {
switch (check_message(decoder)) {
case MAD_FLOW_IGNORE:
case MAD_FLOW_CONTINUE:
break;
case MAD_FLOW_BREAK:
goto fail;
case MAD_FLOW_STOP:
goto done;
}
}
# endif
if (decoder->header_func) {
if (mad_header_decode(&frame->header, stream) == -1) {
if (!MAD_RECOVERABLE(stream->error))
break;
switch (error_func(error_data, stream, frame)) {
case MAD_FLOW_STOP:
goto done;
case MAD_FLOW_BREAK:
goto fail;
case MAD_FLOW_IGNORE:
case MAD_FLOW_CONTINUE:
default:
continue;
}
}
switch (decoder->header_func(decoder->cb_data, &frame->header)) {
case MAD_FLOW_STOP:
goto done;
case MAD_FLOW_BREAK:
goto fail;
case MAD_FLOW_IGNORE:
continue;
case MAD_FLOW_CONTINUE:
break;
}
}
if (mad_frame_decode(frame, stream) == -1) {
if (!MAD_RECOVERABLE(stream->error))
break;
switch (error_func(error_data, stream, frame)) {
case MAD_FLOW_STOP:
goto done;
case MAD_FLOW_BREAK:
goto fail;
case MAD_FLOW_IGNORE:
break;
case MAD_FLOW_CONTINUE:
default:
continue;
}
}
else
bad_last_frame = 0;
if (decoder->filter_func) {
switch (decoder->filter_func(decoder->cb_data, stream, frame)) {
case MAD_FLOW_STOP:
goto done;
case MAD_FLOW_BREAK:
goto fail;
case MAD_FLOW_IGNORE:
continue;
case MAD_FLOW_CONTINUE:
break;
}
}
mad_synth_frame(synth, frame);
if (decoder->output_func) {
switch (decoder->output_func(decoder->cb_data,
&frame->header, &synth->pcm)) {
case MAD_FLOW_STOP:
goto done;
case MAD_FLOW_BREAK:
goto fail;
case MAD_FLOW_IGNORE:
case MAD_FLOW_CONTINUE:
break;
}
}
}
}
while (stream->error == MAD_ERROR_BUFLEN);
fail:
result = -1;
done:
mad_synth_finish(synth);
mad_frame_finish(frame);
mad_stream_finish(stream);
return result;
}
# if defined(USE_ASYNC)
static
int run_async(struct mad_decoder *decoder)
{
pid_t pid;
int ptoc[2], ctop[2], flags;
if (pipe(ptoc) == -1)
return -1;
if (pipe(ctop) == -1) {
close(ptoc[0]);
close(ptoc[1]);
return -1;
}
flags = fcntl(ptoc[0], F_GETFL);
if (flags == -1 ||
fcntl(ptoc[0], F_SETFL, flags | O_NONBLOCK) == -1) {
close(ctop[0]);
close(ctop[1]);
close(ptoc[0]);
close(ptoc[1]);
return -1;
}
pid = fork();
if (pid == -1) {
close(ctop[0]);
close(ctop[1]);
close(ptoc[0]);
close(ptoc[1]);
return -1;
}
decoder->async.pid = pid;
if (pid) {
/* parent */
close(ptoc[0]);
close(ctop[1]);
decoder->async.in = ctop[0];
decoder->async.out = ptoc[1];
return 0;
}
/* child */
close(ptoc[1]);
close(ctop[0]);
decoder->async.in = ptoc[0];
decoder->async.out = ctop[1];
_exit(run_sync(decoder));
/* not reached */
return -1;
}
# endif
/*
* NAME: decoder->run()
* DESCRIPTION: run the decoder thread either synchronously or asynchronously
*/
int mad_decoder_run(struct mad_decoder *decoder, enum mad_decoder_mode mode)
{
int result;
int (*run)(struct mad_decoder *) = 0;
switch (decoder->mode = mode) {
case MAD_DECODER_MODE_SYNC:
run = run_sync;
break;
case MAD_DECODER_MODE_ASYNC:
# if defined(USE_ASYNC)
run = run_async;
# endif
break;
}
if (run == 0)
return -1;
decoder->sync = malloc(sizeof(*decoder->sync));
if (decoder->sync == 0)
return -1;
result = run(decoder);
free(decoder->sync);
decoder->sync = 0;
return result;
}
/*
* NAME: decoder->message()
* DESCRIPTION: send a message to and receive a reply from the decoder process
*/
int mad_decoder_message(struct mad_decoder *decoder,
void *message, unsigned int *len)
{
# if defined(USE_ASYNC)
if (decoder->mode != MAD_DECODER_MODE_ASYNC ||
send(decoder->async.out, message, *len) != MAD_FLOW_CONTINUE ||
receive(decoder->async.in, &message, len) != MAD_FLOW_CONTINUE)
return -1;
return 0;
# else
return -1;
# endif
}