Diff: decoder.cpp

Revision:

0:7627c79db971

Child:

2:f28cf0afd021

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/decoder.cpp	Fri Nov 26 12:18:30 2010 +0000
@@ -0,0 +1,582 @@
+/*
+ * 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 1.1 2010/11/23 20:12:57 andy Exp $
+ */
+
+#  include "config.h"
+
+# 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
+
+# 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         = (enum mad_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 = (int *)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 = (struct mad_sync_s *)malloc(sizeof(*decoder->sync));
+  decoder->sync->synth = (struct mad_synth *)AHBMEM;   // 12kb in upper memory
+  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
+}