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- /*
- * 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 $
- */
- # include "libmad_config.h"
- # include "libmad_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
- # include <stdlib.h>
- # 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
- }
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