gstreamer/ext/flac/gstflacdec.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <string.h>
#include <sys/soundcard.h>

/*#define DEBUG_ENABLED */
#include "gstflacdec.h"

#include "flac_compat.h"

extern GstPadTemplate *gst_flacdec_src_template, *gst_flacdec_sink_template;

/* elementfactory information */
GstElementDetails flacdec_details = {
  "FLAC decoder",
  "Codec/Audio/Decoder",
  "LGPL",
  "Decodes FLAC lossless audio streams",
  VERSION,
  "Wim Taymans <wim.taymans@chello.be>",
  "(C) 2001",
};

/* FlacDec signals and args */
enum {
  /* FILL ME */
  LAST_SIGNAL
};

enum {
  ARG_0,
	ARG_METADATA
};

static void 		gst_flacdec_class_init		(FlacDecClass *klass);
static void 		gst_flacdec_init		(FlacDec *flacdec);

static void 		gst_flacdec_loop		(GstElement *element);
static GstElementStateReturn
			gst_flacdec_change_state 	(GstElement *element);
static const GstFormat* gst_flacdec_get_src_formats 	(GstPad *pad);
static gboolean 	gst_flacdec_convert_src	 	(GstPad *pad, GstFormat src_format, gint64 src_value,
		        				 GstFormat *dest_format, gint64 *dest_value);
static const GstQueryType* 
			gst_flacdec_get_src_query_types (GstPad *pad);
static gboolean		gst_flacdec_src_query 		(GstPad *pad, GstQueryType type,
	               					 GstFormat *format, gint64 *value);
static const GstEventMask* 
			gst_flacdec_get_src_event_masks (GstPad *pad);
static gboolean 	gst_flacdec_src_event 		(GstPad *pad, GstEvent *event);
static void 	gst_flacdec_get_property 	(GObject *object, 
		            			 guint prop_id, 
						 GValue *value, 
						 GParamSpec *pspec);
static void 	gst_flacdec_set_property 	(GObject *object, 
		            			 guint prop_id, 
						 const GValue *value, 
						 GParamSpec *pspec);

static FLAC__SeekableStreamDecoderReadStatus 	
			gst_flacdec_read 		(const FLAC__SeekableStreamDecoder *decoder, 
							 FLAC__byte buffer[], unsigned *bytes, 
							 void *client_data);
static FLAC__SeekableStreamDecoderSeekStatus 	
			gst_flacdec_seek 		(const FLAC__SeekableStreamDecoder *decoder, 
							 FLAC__uint64 position, void *client_data);
static FLAC__SeekableStreamDecoderTellStatus 	
			gst_flacdec_tell 		(const FLAC__SeekableStreamDecoder *decoder, 
							 FLAC__uint64 *position, void *client_data);
static FLAC__SeekableStreamDecoderLengthStatus 	
			gst_flacdec_length 		(const FLAC__SeekableStreamDecoder *decoder, 
							 FLAC__uint64 *length, void *client_data);
static FLAC__bool 	gst_flacdec_eof 		(const FLAC__SeekableStreamDecoder *decoder, 
							 void *client_data);
static FLAC__StreamDecoderWriteStatus 	
			gst_flacdec_write 		(const FLAC__SeekableStreamDecoder *decoder, 
							 const FLAC__Frame *frame, 
							 const FLAC__int32 * const buffer[], 
							 void *client_data);
static void 		gst_flacdec_metadata_callback 	(const FLAC__SeekableStreamDecoder *decoder, 
							 const FLAC__StreamMetadata *metadata, 
							 void *client_data);
static void 		gst_flacdec_error_callback 	(const FLAC__SeekableStreamDecoder *decoder, 
							 FLAC__StreamDecoderErrorStatus status, 
							 void *client_data);

static GstElementClass *parent_class = NULL;
/*static guint gst_flacdec_signals[LAST_SIGNAL] = { 0 }; */

GType
flacdec_get_type(void) {
  static GType flacdec_type = 0;

  if (!flacdec_type) {
    static const GTypeInfo flacdec_info = {
      sizeof(FlacDecClass),
      NULL,
      NULL,
      (GClassInitFunc)gst_flacdec_class_init,
      NULL,
      NULL,
      sizeof(FlacDec),
      0,
      (GInstanceInitFunc)gst_flacdec_init,
    };
    flacdec_type = g_type_register_static (GST_TYPE_ELEMENT, "FlacDec", &flacdec_info, 0);
  }
  return flacdec_type;
}

static void
gst_flacdec_class_init (FlacDecClass *klass) 
{
  GstElementClass *gstelement_class;
	GObjectClass *gobject_class;

  gstelement_class = (GstElementClass*)klass;
	gobject_class = (GObjectClass*) klass;

  parent_class = g_type_class_ref(GST_TYPE_ELEMENT);
	
	g_object_class_install_property (gobject_class, ARG_METADATA,
    g_param_spec_boxed ("metadata", "Metadata", "(logical) Stream metadata",
                         GST_TYPE_CAPS, G_PARAM_READABLE));

	gobject_class->get_property = gst_flacdec_get_property;
  gobject_class->set_property = gst_flacdec_set_property;
	
  gstelement_class->change_state = gst_flacdec_change_state;
}

static void 
gst_flacdec_init (FlacDec *flacdec) 
{
  flacdec->sinkpad = gst_pad_new_from_template (gst_flacdec_sink_template, "sink");
  gst_element_add_pad (GST_ELEMENT (flacdec), flacdec->sinkpad);
  gst_pad_set_convert_function (flacdec->sinkpad, NULL);

  gst_element_set_loop_function (GST_ELEMENT (flacdec), gst_flacdec_loop);
  flacdec->srcpad = gst_pad_new_from_template (gst_flacdec_src_template, "src");
  gst_element_add_pad (GST_ELEMENT (flacdec), flacdec->srcpad);
  gst_pad_set_formats_function (flacdec->srcpad, gst_flacdec_get_src_formats);
  gst_pad_set_convert_function (flacdec->srcpad, gst_flacdec_convert_src);
  gst_pad_set_query_type_function (flacdec->srcpad, gst_flacdec_get_src_query_types);
  gst_pad_set_query_function (flacdec->srcpad, gst_flacdec_src_query);
  gst_pad_set_event_mask_function (flacdec->srcpad, gst_flacdec_get_src_event_masks);
  gst_pad_set_event_function (flacdec->srcpad, gst_flacdec_src_event);

  flacdec->decoder = FLAC__seekable_stream_decoder_new ();
  flacdec->total_samples = 0;
  flacdec->init = TRUE;
  flacdec->eos = FALSE;
  flacdec->seek_pending = FALSE;
	flacdec->metadata = NULL;

  FLAC__seekable_stream_decoder_set_read_callback (flacdec->decoder, gst_flacdec_read);
  FLAC__seekable_stream_decoder_set_seek_callback (flacdec->decoder, gst_flacdec_seek);
  FLAC__seekable_stream_decoder_set_tell_callback (flacdec->decoder, gst_flacdec_tell);
  FLAC__seekable_stream_decoder_set_length_callback (flacdec->decoder, gst_flacdec_length);
  FLAC__seekable_stream_decoder_set_eof_callback (flacdec->decoder, gst_flacdec_eof);
#if FLAC_VERSION >= 0x010003
  FLAC__seekable_stream_decoder_set_write_callback (flacdec->decoder, gst_flacdec_write);
#else
  FLAC__seekable_stream_decoder_set_write_callback (flacdec->decoder,
	(FLAC__StreamDecoderWriteStatus (*)
		(const FLAC__SeekableStreamDecoder *decoder, 
		 const FLAC__Frame *frame,
		 const FLAC__int32 *buffer[], 
		 void *client_data))
		(gst_flacdec_write));
#endif
  FLAC__seekable_stream_decoder_set_metadata_respond (flacdec->decoder, FLAC__METADATA_TYPE_VORBIS_COMMENT);
  FLAC__seekable_stream_decoder_set_metadata_callback (flacdec->decoder, gst_flacdec_metadata_callback);
  FLAC__seekable_stream_decoder_set_error_callback (flacdec->decoder, gst_flacdec_error_callback);
  FLAC__seekable_stream_decoder_set_client_data (flacdec->decoder, flacdec);
}

static gboolean
gst_flacdec_update_metadata (FlacDec *flacdec, const FLAC__StreamMetadata *metadata)
{
  guint32 number_of_comments, cursor, str_len;
  gchar *p_value, *value, *name, *str_ptr;
  GstProps *props = NULL;
  GstPropsEntry *entry;
	
  /* clear old one */
  if (flacdec->metadata) {
    gst_caps_unref (flacdec->metadata);
    flacdec->metadata = NULL;
  }

  /* create props to hold the key/value pairs */
  props = gst_props_empty_new ();
  
  number_of_comments = metadata->data.vorbis_comment.num_comments;
  value = NULL;
  GST_DEBUG (GST_CAT_CAPS, "%d tag(s) found",  number_of_comments);
  for (cursor = 0; cursor < number_of_comments; cursor++)
  {			
    str_ptr = metadata->data.vorbis_comment.comments[cursor].entry;
    str_len = GUINT32_FROM_LE (metadata->data.vorbis_comment.comments[cursor].length);
    p_value = g_strstr_len ( str_ptr, str_len , "=" );
    if (p_value)
    {			
      name = g_strndup (str_ptr, p_value - str_ptr);
      value = g_strndup (p_value + 1, str_ptr + str_len - p_value);
			
      entry = gst_props_entry_new (name, GST_PROPS_STRING_TYPE, value);
      gst_props_add_entry (props, (GstPropsEntry *) entry);

      GST_DEBUG (GST_CAT_CAPS, "%s : %s", name, value);

      g_free (name);
      g_free (value);
    }
  }
	
  flacdec->metadata = gst_caps_new ("vorbisfile_metadata",
                                    "application/x-gst-metadata",
                                    props);
  g_object_notify (G_OBJECT (flacdec), "metadata");
	
  return TRUE;
}


static void 
gst_flacdec_metadata_callback (const FLAC__SeekableStreamDecoder *decoder,
			       const FLAC__StreamMetadata *metadata, void *client_data)
{
  FlacDec *flacdec;
	
  flacdec = GST_FLACDEC (client_data);

  switch (metadata->type)
  {
    case FLAC__METADATA_TYPE_STREAMINFO:
         flacdec->stream_samples = metadata->data.stream_info.total_samples;
 	 break;
    case FLAC__METADATA_TYPE_VORBIS_COMMENT:
         gst_flacdec_update_metadata (flacdec, metadata);		  
	 break;
    default:
         break;
  }
}

static void 
gst_flacdec_error_callback (const FLAC__SeekableStreamDecoder *decoder, 
			    FLAC__StreamDecoderErrorStatus status, void *client_data)
{
  FlacDec *flacdec;
  gchar *error;

  flacdec = GST_FLACDEC (client_data);

  switch (status) {
    case FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC:
      error = "lost sync";
      break;
    case FLAC__STREAM_DECODER_ERROR_STATUS_BAD_HEADER:
      error = "bad header";
      break;
    case FLAC__STREAM_DECODER_ERROR_STATUS_FRAME_CRC_MISMATCH:
      error = "CRC mismatch";
      break;
    default:
      error = "unkown error";
      break;
  }

  GST_DEBUG (0, error);
				  
  gst_element_error (GST_ELEMENT (flacdec), error);
}

static FLAC__SeekableStreamDecoderSeekStatus 	
gst_flacdec_seek (const FLAC__SeekableStreamDecoder *decoder, 
		  FLAC__uint64 position, void *client_data)
{
  FlacDec *flacdec;

  flacdec = GST_FLACDEC (client_data);

  GST_DEBUG (0, "seek %" G_GINT64_FORMAT, position);
  if (!gst_bytestream_seek (flacdec->bs, position, GST_SEEK_METHOD_SET)) {
    return FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_ERROR;
  }
  return FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_OK;
}

static FLAC__SeekableStreamDecoderTellStatus 	
gst_flacdec_tell (const FLAC__SeekableStreamDecoder *decoder, 
		  FLAC__uint64 *position, void *client_data)
{
  FlacDec *flacdec;

  flacdec = GST_FLACDEC (client_data);

  *position = gst_bytestream_tell (flacdec->bs);
  if (*position == -1)
    return FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_ERROR;

  GST_DEBUG (0, "tell %" G_GINT64_FORMAT, *position);

  return FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_OK;
}

static FLAC__SeekableStreamDecoderLengthStatus 	
gst_flacdec_length (const FLAC__SeekableStreamDecoder *decoder, 
		    FLAC__uint64 *length, void *client_data)
{
  FlacDec *flacdec;

  flacdec = GST_FLACDEC (client_data);

  *length = gst_bytestream_length (flacdec->bs);
  if (*length == -1)
    return FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_ERROR;

  GST_DEBUG (0, "length %" G_GINT64_FORMAT, *length);

  return FLAC__SEEKABLE_STREAM_DECODER_LENGTH_STATUS_OK;
}

static FLAC__bool
gst_flacdec_eof (const FLAC__SeekableStreamDecoder *decoder, 
		 void *client_data)
{
  FlacDec *flacdec;

  flacdec = GST_FLACDEC (client_data);
  GST_DEBUG (0, "eof %d", flacdec->eos);

  return flacdec->eos;
}

static FLAC__SeekableStreamDecoderReadStatus
gst_flacdec_read (const FLAC__SeekableStreamDecoder *decoder, 
		  FLAC__byte buffer[], unsigned *bytes, 
		  void *client_data)
{
  FlacDec *flacdec;
  gint insize = 0;
  guint8 *indata;

  flacdec = GST_FLACDEC (client_data);

  //g_print ("read %u\n", *bytes);
  
  while (insize == 0) {
    insize = gst_bytestream_peek_bytes (flacdec->bs, &indata, *bytes);
    if (insize < *bytes) {
      GstEvent *event;
      guint32 avail;
			    
      gst_bytestream_get_status (flacdec->bs, &avail, &event);

      switch (GST_EVENT_TYPE (event)) {
        case GST_EVENT_EOS:
          GST_DEBUG (0, "eos");
          flacdec->eos = TRUE; 
	  gst_event_unref (event);
          if (avail == 0) {
            return 0;
          }
          break;
        case GST_EVENT_DISCONTINUOUS:
          GST_DEBUG (0, "discont");

	  /* we are not yet sending the discont, we'll do that in the next write operation */
	  flacdec->need_discont = TRUE;
	  gst_event_unref (event);
	  break;
        default:
	  gst_pad_event_default (flacdec->sinkpad, event);
          break;
      }
      if (avail > 0)
        insize = gst_bytestream_peek_bytes (flacdec->bs, &indata, avail);
      else
        insize = 0;
    }
  }

  memcpy (buffer, indata, insize);
  *bytes = insize;
  gst_bytestream_flush_fast (flacdec->bs, insize);

  return FLAC__SEEKABLE_STREAM_DECODER_READ_STATUS_OK;
}

static FLAC__StreamDecoderWriteStatus
gst_flacdec_write (const FLAC__SeekableStreamDecoder *decoder, 
		   const FLAC__Frame *frame, 
		   const FLAC__int32 * const buffer[], 
		   void *client_data)
{
  FlacDec *flacdec;
  GstBuffer *outbuf;
  guint depth = frame->header.bits_per_sample;
  guint channels = frame->header.channels;
  guint samples = frame->header.blocksize;
  guint j, i;

  flacdec = GST_FLACDEC (client_data);

  if (flacdec->need_discont) {
    gint64 time = 0, bytes = 0;
    GstFormat format;
    GstEvent *discont;

    flacdec->need_discont = FALSE;

    if (flacdec->seek_pending) {
      flacdec->total_samples = flacdec->seek_value;
    }

    GST_DEBUG (0, "send discont");

    format = GST_FORMAT_TIME;
    gst_pad_convert (flacdec->srcpad, GST_FORMAT_DEFAULT, flacdec->total_samples,
		  &format, &time);
    format = GST_FORMAT_BYTES;
    gst_pad_convert (flacdec->srcpad, GST_FORMAT_DEFAULT, flacdec->total_samples,
		  &format, &bytes);
    discont = gst_event_new_discontinuous (FALSE, GST_FORMAT_TIME, time,
		                         GST_FORMAT_BYTES, bytes,
		                         GST_FORMAT_DEFAULT, flacdec->total_samples, 
					 NULL);
	  
    gst_pad_push (flacdec->srcpad, GST_BUFFER (discont));
  }
  
  if (!GST_PAD_CAPS (flacdec->srcpad)) {
    gst_pad_try_set_caps (flacdec->srcpad,
		    GST_CAPS_NEW (
		      "flac_caps",
		      "audio/raw",
		        "format", 	GST_PROPS_STRING ("int"),
                         "law",         GST_PROPS_INT (0),
                         "endianness",  GST_PROPS_INT (G_BYTE_ORDER),
                         "signed",      GST_PROPS_BOOLEAN (TRUE),
                         "width",       GST_PROPS_INT (depth),
                         "depth",       GST_PROPS_INT (depth),
                         "rate",     	GST_PROPS_INT (frame->header.sample_rate),
                         "channels", 	GST_PROPS_INT (channels)
		    ));

    flacdec->depth = depth;
    flacdec->channels = channels;
    flacdec->frequency = frame->header.sample_rate;
  }

  outbuf = gst_buffer_new ();
  GST_BUFFER_SIZE (outbuf) = samples * channels * ((depth+7)>>3);
  GST_BUFFER_DATA (outbuf) = g_malloc (GST_BUFFER_SIZE (outbuf));
  GST_BUFFER_TIMESTAMP (outbuf) = flacdec->total_samples * GST_SECOND / frame->header.sample_rate;

  if (depth == 8) {
    guint8 *outbuffer = (guint8 *)GST_BUFFER_DATA (outbuf);

    for (i=0; i<samples; i++) {
      for (j=0; j < channels; j++) {
        *outbuffer++ = (guint8) buffer[j][i];
      }
    }
  }
  else if (depth == 16) {
    guint16 *outbuffer = (guint16 *)GST_BUFFER_DATA (outbuf);

    for (i=0; i<samples; i++) {
      for (j=0; j < channels; j++) {
        *outbuffer++ = (guint16) buffer[j][i];
      }
    }
  }
  else {
    g_warning ("flacdec: invalid depth %d found\n", depth);
    return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
  }

  flacdec->total_samples += samples;

  gst_pad_push (flacdec->srcpad, outbuf);

  return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
}

static void 
gst_flacdec_loop (GstElement *element) 
{
  FlacDec *flacdec;
  gboolean res;

  flacdec = GST_FLACDEC (element);

  GST_DEBUG (GST_CAT_PLUGIN_INFO, "flacdec: entering loop");
  if (flacdec->init) {
    GST_DEBUG (GST_CAT_PLUGIN_INFO, "flacdec: initializing decoder");
    FLAC__seekable_stream_decoder_init (flacdec->decoder);
    /* FLAC__seekable_stream_decoder_process_metadata (flacdec->decoder); */
    flacdec->init = FALSE;
  }

  if (flacdec->seek_pending) {
    GST_DEBUG (GST_CAT_EVENT, "perform seek to sample %" G_GINT64_FORMAT, 
		              flacdec->seek_value);

    if (FLAC__seekable_stream_decoder_seek_absolute (flacdec->decoder, 
			                             flacdec->seek_value)) 
    {
      flacdec->total_samples = flacdec->seek_value;
      GST_DEBUG (GST_CAT_EVENT, "seek done");
    }
    else {
      GST_DEBUG (GST_CAT_EVENT, "seek failed");
    }
    flacdec->seek_pending = FALSE;
  }

  GST_DEBUG (GST_CAT_PLUGIN_INFO, "flacdec: processing single");
  res = FLAC__seekable_stream_decoder_process_single (flacdec->decoder);
  GST_DEBUG (GST_CAT_PLUGIN_INFO, "flacdec: checking for EOS");
  if (FLAC__seekable_stream_decoder_get_state (flacdec->decoder) == 
		  FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM) 
  {
    GstEvent *event;

    GST_DEBUG (GST_CAT_PLUGIN_INFO, "flacdec: sending EOS event");
    FLAC__seekable_stream_decoder_finish(flacdec->decoder);
    flacdec->init = TRUE;

    event = gst_event_new (GST_EVENT_EOS);
    gst_pad_push (flacdec->srcpad, GST_BUFFER (event));
    gst_element_set_eos (element);
  }
  GST_DEBUG (GST_CAT_PLUGIN_INFO, "flacdec: _loop end");
}

GST_PAD_FORMATS_FUNCTION (gst_flacdec_get_src_formats,
  GST_FORMAT_DEFAULT,
  GST_FORMAT_BYTES,
  GST_FORMAT_TIME
)

static gboolean
gst_flacdec_convert_src (GstPad *pad, GstFormat src_format, gint64 src_value,
		         GstFormat *dest_format, gint64 *dest_value)
{
  gboolean res = TRUE;
  FlacDec *flacdec = GST_FLACDEC (gst_pad_get_parent (pad));
  guint scale = 1;
  gint bytes_per_sample;

  bytes_per_sample = flacdec->channels * ((flacdec->depth+7)>>3);

  switch (src_format) {
    case GST_FORMAT_BYTES:
      switch (*dest_format) {
        case GST_FORMAT_DEFAULT:
          if (bytes_per_sample == 0)
            return FALSE;
          *dest_value = src_value / bytes_per_sample;
          break;
        case GST_FORMAT_TIME:
	{
          gint byterate = bytes_per_sample * flacdec->frequency;

          if (byterate == 0)
            return FALSE;
          *dest_value = src_value * GST_SECOND / byterate;
          break;
	}
        default:
          res = FALSE;
      }
      break;
    case GST_FORMAT_DEFAULT:
      switch (*dest_format) {
        case GST_FORMAT_BYTES:
	  *dest_value = src_value * bytes_per_sample;
          break;
        case GST_FORMAT_TIME:
	  if (flacdec->frequency == 0)
	    return FALSE;
          *dest_value = src_value * GST_SECOND / flacdec->frequency;
          break;
        default:
          res = FALSE;
      }
      break;
    case GST_FORMAT_TIME:
      switch (*dest_format) {
        case GST_FORMAT_BYTES:
          scale = bytes_per_sample;
        case GST_FORMAT_DEFAULT:
	  *dest_value = src_value * scale * flacdec->frequency / GST_SECOND;
          break;
        default:
          res = FALSE;
      }
      break;
    default:
      res = FALSE;
  }
  return res;
}

GST_PAD_QUERY_TYPE_FUNCTION (gst_flacdec_get_src_query_types,
  GST_QUERY_TOTAL,
  GST_QUERY_POSITION
)

static gboolean
gst_flacdec_src_query (GstPad *pad, GstQueryType type,
	               GstFormat *format, gint64 *value)
{
  gboolean res = TRUE;
  FlacDec *flacdec = GST_FLACDEC (gst_pad_get_parent (pad));

  switch (type) {
    case GST_QUERY_TOTAL:
    {
      guint64 samples;

      if (flacdec->stream_samples == 0)
        samples = flacdec->total_samples;
      else
        samples = flacdec->stream_samples;

      gst_pad_convert (flacdec->srcpad, 
		       GST_FORMAT_DEFAULT, 
		       samples, 
		       format, value);
      break;
    }
    case GST_QUERY_POSITION:
      gst_pad_convert (flacdec->srcpad, 
		       GST_FORMAT_DEFAULT, 
		       flacdec->total_samples, 
		       format, value);
      break;
    default:
      res = FALSE;
      break;
  }

  return res;
}
	  
GST_PAD_EVENT_MASK_FUNCTION (gst_flacdec_get_src_event_masks,
    { GST_EVENT_SEEK, GST_SEEK_FLAG_ACCURATE }
);

static gboolean
gst_flacdec_src_event (GstPad *pad, GstEvent *event)
{ 
  gboolean res = TRUE;
  FlacDec *flacdec = GST_FLACDEC (gst_pad_get_parent (pad));
  GstFormat format;

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_SEEK:
      format = GST_FORMAT_DEFAULT;

      if (gst_pad_convert (flacdec->srcpad, 
			   GST_EVENT_SEEK_FORMAT (event), 
			   GST_EVENT_SEEK_OFFSET (event), 
			   &format, &flacdec->seek_value))
        flacdec->seek_pending = TRUE;
      else
	res = FALSE;
      break;
    default:
      res = FALSE;
      break;
  }
  gst_event_unref (event);
  return res;
}

static GstElementStateReturn
gst_flacdec_change_state (GstElement *element)
{
  FlacDec *flacdec = GST_FLACDEC (element);

  switch (GST_STATE_TRANSITION (element)) {
    case GST_STATE_NULL_TO_READY:
    case GST_STATE_READY_TO_PAUSED:
      flacdec->bs = gst_bytestream_new (flacdec->sinkpad);
      flacdec->seek_pending = FALSE;
      flacdec->total_samples = 0;
      flacdec->init = TRUE;
      flacdec->eos = FALSE;
      FLAC__seekable_stream_decoder_reset (flacdec->decoder);
      break;
    case GST_STATE_PAUSED_TO_PLAYING:
      flacdec->eos = FALSE;
    case GST_STATE_PLAYING_TO_PAUSED:
      break;
    case GST_STATE_PAUSED_TO_READY:
      gst_bytestream_destroy (flacdec->bs);
      break;
    case GST_STATE_READY_TO_NULL:
    default:
      break;
  }

  if (GST_ELEMENT_CLASS (parent_class)->change_state)
    return GST_ELEMENT_CLASS (parent_class)->change_state (element);

  return GST_STATE_SUCCESS;
}

static void
gst_flacdec_set_property (GObject *object, guint prop_id, 
		             const GValue *value, GParamSpec *pspec)
{
  FlacDec *flacdec;
	      
  g_return_if_fail (GST_IS_FLACDEC (object));

  flacdec = GST_FLACDEC (object);

  switch (prop_id) {
    default:
      g_warning ("Unknown property id\n");
  }
}

static void 
gst_flacdec_get_property (GObject *object, guint prop_id, 
		             GValue *value, GParamSpec *pspec)
{
  FlacDec *flacdec;
	      
  g_return_if_fail (GST_IS_FLACDEC(object));

  flacdec = GST_FLACDEC (object);

  switch (prop_id) {
    case ARG_METADATA:
      g_value_set_boxed (value, flacdec->metadata);
      break;
    default:
      g_warning ("Unknown property id\n");
  }
}