ref: e09adf59442cd36888eaea1d76e66ff3259d16b8
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 }