gstreamer/gst/avi/gstavidemux.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@temple-baptist.com>
 *
 * 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.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <string.h>

#include "gst/riff/riff-media.h"
#include "gstavidemux.h"
#include "avi-ids.h"

GST_DEBUG_CATEGORY_STATIC (avidemux_debug);
#define GST_CAT_DEFAULT avidemux_debug

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

enum {
  ARG_0,
  ARG_STREAMINFO,
  /* FILL ME */
};

static GstStaticPadTemplate sink_templ =
GST_STATIC_PAD_TEMPLATE (
  "sink",
  GST_PAD_SINK,
  GST_PAD_ALWAYS,
  GST_STATIC_CAPS ("video/x-msvideo")
);

static void 	gst_avi_demux_base_init	        (GstAviDemuxClass *klass);
static void 	gst_avi_demux_class_init	(GstAviDemuxClass *klass);
static void 	gst_avi_demux_init		(GstAviDemux *avi);

static void	gst_avi_demux_reset		(GstAviDemux *avi);
static void 	gst_avi_demux_loop 		(GstElement  *element);

static gboolean gst_avi_demux_send_event 	(GstElement  *element,
						 GstEvent    *event);

static const GstEventMask *
		gst_avi_demux_get_event_mask 	(GstPad      *pad);
static gboolean gst_avi_demux_handle_src_event 	(GstPad      *pad,
						 GstEvent    *event);
static const GstFormat *
		gst_avi_demux_get_src_formats 	(GstPad      *pad); 
static const GstQueryType *
		gst_avi_demux_get_src_query_types (GstPad    *pad);
static gboolean gst_avi_demux_handle_src_query 	(GstPad      *pad,
						 GstQueryType type, 
						 GstFormat   *format,
						 gint64      *value);
static gboolean gst_avi_demux_src_convert 	(GstPad      *pad,
						 GstFormat    src_format,
						 gint64       src_value,
	        	          		 GstFormat   *dest_format,
						 gint64      *dest_value);

static GstElementStateReturn
		gst_avi_demux_change_state 	(GstElement  *element);

static void     gst_avi_demux_get_property      (GObject     *object,
						 guint        prop_id, 	
						 GValue      *value,
						 GParamSpec  *pspec);

static GstRiffReadClass *parent_class = NULL;
/*static guint gst_avi_demux_signals[LAST_SIGNAL] = { 0 }; */

GType
gst_avi_demux_get_type(void) 
{
  static GType avi_demux_type = 0;

  if (!avi_demux_type) {
    static const GTypeInfo avi_demux_info = {
      sizeof (GstAviDemuxClass),      
      (GBaseInitFunc) gst_avi_demux_base_init,
      NULL,
      (GClassInitFunc) gst_avi_demux_class_init,
      NULL,
      NULL,
      sizeof (GstAviDemux),
      0,
      (GInstanceInitFunc) gst_avi_demux_init,
    };

    avi_demux_type =
	g_type_register_static (GST_TYPE_RIFF_READ,
				"GstAviDemux",
				&avi_demux_info, 0);
  }

  return avi_demux_type;
}

static void
gst_avi_demux_base_init (GstAviDemuxClass *klass)
{
  static GstElementDetails gst_avi_demux_details = GST_ELEMENT_DETAILS (
    "Avi demuxer",
    "Codec/Demuxer",
    "Demultiplex an avi file into audio and video",
    "Erik Walthinsen <omega@cse.ogi.edu>\n"
    "Wim Taymans <wim.taymans@chello.be>\n"
    "Ronald Bultje <rbultje@ronald.bitfreak.net>"
  );
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
  GstPadTemplate *videosrctempl, *audiosrctempl;
  GstCaps *audcaps, *vidcaps;

  audcaps = gst_riff_create_audio_template_caps ();
  audiosrctempl = gst_pad_template_new ("audio_%02d",
					GST_PAD_SRC,
					GST_PAD_SOMETIMES,
					audcaps);

  vidcaps = gst_riff_create_video_template_caps ();
  gst_caps_append (vidcaps, gst_riff_create_iavs_template_caps ());
  videosrctempl = gst_pad_template_new ("video_%02d",
					GST_PAD_SRC,
					GST_PAD_SOMETIMES,
					vidcaps);

  gst_element_class_add_pad_template (element_class, audiosrctempl);
  gst_element_class_add_pad_template (element_class, videosrctempl);
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&sink_templ));
  gst_element_class_set_details (element_class, &gst_avi_demux_details);
}

static void
gst_avi_demux_class_init (GstAviDemuxClass *klass) 
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

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

  g_object_class_install_property (gobject_class, ARG_STREAMINFO,
    g_param_spec_boxed ("streaminfo", "Streaminfo", "Streaminfo",
                        GST_TYPE_CAPS, G_PARAM_READABLE));

  GST_DEBUG_CATEGORY_INIT (avidemux_debug, "avidemux",
			   0, "Demuxer for AVI streams");

  parent_class = g_type_class_ref (GST_TYPE_RIFF_READ);
  
  gobject_class->get_property = gst_avi_demux_get_property;
  
  gstelement_class->change_state = gst_avi_demux_change_state;
  gstelement_class->send_event = gst_avi_demux_send_event;
}

static void 
gst_avi_demux_init (GstAviDemux *avi) 
{
  GST_FLAG_SET (avi, GST_ELEMENT_EVENT_AWARE);

  avi->sinkpad = gst_pad_new_from_template (
	gst_static_pad_template_get (&sink_templ), "sink");
  gst_element_add_pad (GST_ELEMENT (avi), avi->sinkpad);
  GST_RIFF_READ (avi)->sinkpad = avi->sinkpad;

  gst_element_set_loop_function (GST_ELEMENT (avi), gst_avi_demux_loop);
  gst_avi_demux_reset (avi);

  avi->streaminfo = NULL;
  avi->index_entries = NULL;
  memset (&avi->stream, 0, sizeof (avi->stream));
}

static void
gst_avi_demux_reset (GstAviDemux *avi)
{
  gint i;

  for (i = 0; i < avi->num_streams; i++) {
    g_free (avi->stream[i].strh);
    gst_element_remove_pad (GST_ELEMENT (avi), avi->stream[i].pad);
  }
  memset (&avi->stream, 0, sizeof (avi->stream));

  avi->num_streams = 0;
  avi->num_v_streams = 0;
  avi->num_a_streams = 0;

  avi->state = GST_AVI_DEMUX_START;
  avi->level_up = 0;

  if (avi->index_entries) {
    g_free (avi->index_entries);
    avi->index_entries = NULL;
  }
  avi->index_size = 0;

  avi->num_frames = 0;
  avi->us_per_frame = 0;

  avi->seek_offset = (guint64) -1;

  gst_caps_replace (&avi->streaminfo, NULL);
}

static void
gst_avi_demux_streaminfo (GstAviDemux *avi)
{
  /* compression formats are added later - a bit hacky */

  gst_caps_replace (&avi->streaminfo,
      gst_caps_new_simple ("application/x-gst-streaminfo", NULL));

  /*g_object_notify(G_OBJECT(avi), "streaminfo");*/
}

static gst_avi_index_entry *
gst_avi_demux_index_next (GstAviDemux *avi,
			  gint         stream_nr,
			  gint         start,
			  guint32      flags)
{
  gint i;
  gst_avi_index_entry *entry = NULL;

  for (i = start; i < avi->index_size; i++) {
    entry = &avi->index_entries[i];

    if (entry->stream_nr == stream_nr && (entry->flags & flags) == flags) {
      break;
    }
  }

  return entry;
}

static gst_avi_index_entry *
gst_avi_demux_index_entry_for_time (GstAviDemux *avi,
				    gint         stream_nr,
				    guint64      time,
				    guint32      flags)
{
  gst_avi_index_entry *entry = NULL, *last_entry = NULL;
  gint i;

  i = -1;
  do {
    entry = gst_avi_demux_index_next (avi, stream_nr, i + 1, flags);
    if (!entry)
      return NULL;

    i = entry->index_nr;

    if (entry->ts <= time) {
      last_entry = entry;
    }
  } while (entry->ts <= time);

  return last_entry;
}

static gst_avi_index_entry *
gst_avi_demux_index_entry_for_byte (GstAviDemux *avi,
				    gint         stream_nr,
				    guint64      byte,
				    guint32      flags)
{
  gst_avi_index_entry *entry = NULL, *last_entry = NULL;
  gint i;

  i = -1;
  do {
    entry = gst_avi_demux_index_next (avi, stream_nr, i + 1, flags);
    if (!entry)
      return NULL;

    i = entry->index_nr;

    if (entry->bytes_before <= byte) {
      last_entry = entry;
    }
  } while (entry->bytes_before <= byte);

  return last_entry;
}

static gst_avi_index_entry *
gst_avi_demux_index_entry_for_frame (GstAviDemux *avi,
				     gint         stream_nr,
				     guint32      frame,
				     guint32      flags)
{
  gst_avi_index_entry *entry = NULL, *last_entry = NULL;
  gint i;

  i = -1;
  do {
    entry = gst_avi_demux_index_next (avi, stream_nr, i + 1, flags);
    if (!entry)
      return NULL;

    i = entry->index_nr;

    if (entry->frames_before <= frame) {
      last_entry = entry;
    }
  } while (entry->frames_before <= frame);

  return last_entry;
}

static const GstFormat *
gst_avi_demux_get_src_formats (GstPad *pad) 
{
  avi_stream_context *stream = gst_pad_get_element_private (pad);

  static const GstFormat src_a_formats[] = {
    GST_FORMAT_TIME,
    GST_FORMAT_BYTES,
    GST_FORMAT_DEFAULT,
    0
  };
  static const GstFormat src_v_formats[] = {
    GST_FORMAT_TIME,
    GST_FORMAT_DEFAULT,
    0
  };

  return (stream->strh->type == GST_RIFF_FCC_auds ?
	  src_a_formats : src_v_formats);
}

static gboolean
gst_avi_demux_src_convert (GstPad    *pad,
			   GstFormat  src_format,
			   gint64     src_value,
	                   GstFormat *dest_format,
			   gint64    *dest_value)
{
  gboolean res = TRUE;
  /*GstAviDemux *avi = GST_AVI_DEMUX (gst_pad_get_parent (pad));*/
  avi_stream_context *stream = gst_pad_get_element_private (pad);

  if (stream->strh->type != GST_RIFF_FCC_auds && 
      (src_format == GST_FORMAT_BYTES ||
       *dest_format == GST_FORMAT_BYTES))
    return FALSE;

  switch (src_format) {
    case GST_FORMAT_TIME:
      switch (*dest_format) {
	case GST_FORMAT_BYTES:
          *dest_value = src_value * stream->strh->rate /
			(stream->strh->scale * GST_SECOND);
          break;
        case GST_FORMAT_DEFAULT:
          *dest_value = src_value * stream->strh->rate /
			(stream->strh->scale * GST_SECOND);
          break;
	default:
	  res = FALSE;
	  break;
      }
      break;
    case GST_FORMAT_BYTES:
      switch (*dest_format) {
	case GST_FORMAT_TIME:
          *dest_value = ((gfloat) src_value) * GST_SECOND / stream->strh->rate;
	  break;
	default:
	  res = FALSE;
	  break;
      }
      break;
    case GST_FORMAT_DEFAULT:
      switch (*dest_format) {
	case GST_FORMAT_TIME:
          *dest_value = ((((gfloat) src_value) * stream->strh->scale)  /
			stream->strh->rate) * GST_SECOND;
	  break;
	default:
	  res = FALSE;
	  break;
      }
      break;
    default:
      res = FALSE;
  }

  return res;
}

static const GstQueryType *
gst_avi_demux_get_src_query_types (GstPad *pad) 
{
  static const GstQueryType src_types[] = {
    GST_QUERY_TOTAL,
    GST_QUERY_POSITION,
    0
  };

  return src_types;
}

static gboolean
gst_avi_demux_handle_src_query (GstPad      *pad,
				GstQueryType type, 
				GstFormat   *format,
				gint64      *value)
{
  gboolean res = TRUE;
  /*GstAviDemux *avi = GST_AVI_DEMUX (gst_pad_get_parent (pad));*/
  avi_stream_context *stream = gst_pad_get_element_private (pad);

  switch (type) {
    case GST_QUERY_TOTAL:
      switch (*format) {
        case GST_FORMAT_TIME:
          *value = (((gfloat) stream->strh->scale) * stream->strh->length /
			stream->strh->rate) * GST_SECOND;
	  break;
        case GST_FORMAT_BYTES:
          if (stream->strh->type == GST_RIFF_FCC_auds) {
            *value = stream->total_bytes;
	  }
	  else
	    res = FALSE;
	  break;
        case GST_FORMAT_DEFAULT:
          if (stream->strh->type == GST_RIFF_FCC_auds)
            *value = stream->strh->length * stream->strh->samplesize;
	  else if (stream->strh->type == GST_RIFF_FCC_vids)
            *value = stream->strh->length;
	  else
	    res = FALSE;
	  break;
	default:
          res = FALSE;
	  break;
      }
      break;
    case GST_QUERY_POSITION:
      switch (*format) {
        case GST_FORMAT_TIME:
          if (stream->strh->samplesize &&
	      stream->strh->type == GST_RIFF_FCC_auds) {
            *value = ((gfloat) stream->current_byte) * GST_SECOND /
			stream->strh->rate;
	  }
	  else {
            *value = (((gfloat) stream->current_frame) * stream->strh->scale /
			stream->strh->rate) * GST_SECOND;
	  }
	  break;
        case GST_FORMAT_BYTES:
          *value = stream->current_byte;
	  break;
        case GST_FORMAT_DEFAULT:
          if (stream->strh->samplesize &&
	      stream->strh->type == GST_RIFF_FCC_auds) 
            *value = stream->current_byte * stream->strh->samplesize;
	  else 
            *value = stream->current_frame;
	  break;
	default:
          res = FALSE;
	  break;
      }
      break;
    default:
      res = FALSE;
      break;
  }

  return res;
}

static GstCaps *
gst_avi_demux_src_getcaps (GstPad *pad)
{
  avi_stream_context *stream = gst_pad_get_element_private (pad);

  return gst_caps_copy (stream->caps);
}

static gint32
gst_avi_demux_sync_streams (GstAviDemux *avi,
			    guint64      time)
{
  gint i;
  guint32 min_index = G_MAXUINT;
  avi_stream_context *stream;
  gst_avi_index_entry *entry;

  for (i = 0; i < avi->num_streams; i++) {
    stream = &avi->stream[i];

    GST_DEBUG ("finding %d for time %" G_GINT64_FORMAT, i, time);

    entry = gst_avi_demux_index_entry_for_time (avi, stream->num, time,
						GST_RIFF_IF_KEYFRAME);
    if (entry) {
      min_index = MIN (entry->index_nr, min_index);
    }
  }
  GST_DEBUG ("first index at %d", min_index);
  
  /* now we know the entry we need to sync on. calculate number of frames to
   * skip fro there on and the stream stats */
  for (i = 0; i < avi->num_streams; i++) {
    gst_avi_index_entry *next_entry;
    stream = &avi->stream[i];

    /* next entry */
    next_entry = gst_avi_demux_index_next (avi, stream->num,
					   min_index, 0);
    /* next entry with keyframe */
    entry = gst_avi_demux_index_next (avi, stream->num, min_index,
				      GST_RIFF_IF_KEYFRAME);

    stream->current_byte = next_entry->bytes_before;
    stream->current_frame = next_entry->frames_before;
    stream->skip = entry->frames_before - next_entry->frames_before;

    GST_DEBUG ("%d skip %d", stream->num, stream->skip);
  }

  GST_DEBUG ("final index at %d", min_index);

  return min_index;
}

static gboolean
gst_avi_demux_send_event (GstElement *element,
			  GstEvent   *event)
{
  const GList *pads;

  pads = gst_element_get_pad_list (element);

  while (pads) { 
    GstPad *pad = GST_PAD (pads->data);

    if (GST_PAD_DIRECTION (pad) == GST_PAD_SRC) {
      /* we ref the event here as we might have to try again if the event
       * failed on this pad */
      gst_event_ref (event);
      if (gst_avi_demux_handle_src_event (pad, event)) {
	gst_event_unref (event);

	return TRUE;
      }
    }
    
    pads = g_list_next (pads);
  }
  
  gst_event_unref (event);

  return FALSE;
}

static const GstEventMask *
gst_avi_demux_get_event_mask (GstPad *pad)
{
  static const GstEventMask masks[] = {
    { GST_EVENT_SEEK, GST_SEEK_METHOD_SET | GST_SEEK_FLAG_KEY_UNIT },
    { 0, }
  };

  return masks;
}
	
static gboolean
gst_avi_demux_handle_src_event (GstPad   *pad,
				GstEvent *event)
{
  gboolean res = TRUE;
  GstAviDemux *avi = GST_AVI_DEMUX (gst_pad_get_parent (pad));
  avi_stream_context *stream;
  
  stream = gst_pad_get_element_private (pad);

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_SEEK:
      GST_DEBUG ("seek format %d, %08x", GST_EVENT_SEEK_FORMAT (event),
		 stream->strh->type);

      switch (GST_EVENT_SEEK_FORMAT (event)) {
	case GST_FORMAT_BYTES:
	case GST_FORMAT_DEFAULT:
	case GST_FORMAT_TIME: {
	  gst_avi_index_entry *seek_entry, *entry = NULL;
	  gint64 desired_offset = GST_EVENT_SEEK_OFFSET (event);
	  guint32 flags;
          guint64 min_index;

	  /* no seek on audio yet */
	  if (stream->strh->type == GST_RIFF_FCC_auds) {
	    res = FALSE;
	    goto done;
	  }
          GST_DEBUG ("seeking to %" G_GINT64_FORMAT, desired_offset);

          flags = GST_RIFF_IF_KEYFRAME;
          switch (GST_EVENT_SEEK_FORMAT (event)) {
	    case GST_FORMAT_BYTES:
              entry = gst_avi_demux_index_entry_for_byte (avi, stream->num,
							  desired_offset,
							  flags);
              break;
	    case GST_FORMAT_DEFAULT:
              entry = gst_avi_demux_index_entry_for_frame (avi, stream->num,
							   desired_offset,
							   flags);
              break;
	    case GST_FORMAT_TIME:
              entry = gst_avi_demux_index_entry_for_time (avi, stream->num,
							  desired_offset,
							  flags);
              break;
          }

	  if (entry) {
	    min_index = gst_avi_demux_sync_streams (avi, entry->ts);
            seek_entry = &avi->index_entries[min_index];

	    avi->seek_offset = seek_entry->offset + avi->index_offset;
            avi->last_seek = entry->ts;
	  } else {
            GST_DEBUG ("no index entry found for format=%d value=%"
		       G_GINT64_FORMAT, GST_EVENT_SEEK_FORMAT (event),
		       desired_offset);
	    res = FALSE;
	  }
	  break;
	}
	default:
	  res = FALSE;
          break;
      }
      break;
    default:
      res = FALSE;
      break;
  }

done:
  gst_event_unref (event);

  return res;
}

/*
 * "Open" a RIFF file.
 */

gboolean
gst_avi_demux_stream_init (GstAviDemux *avi)
{
  GstRiffRead *riff = GST_RIFF_READ (avi);
  guint32 doctype;

  if (!gst_riff_read_header (riff, &doctype))
    return FALSE;
  if (doctype != GST_RIFF_RIFF_AVI) {
    gst_element_error (avi, STREAM, WRONG_TYPE, NULL, NULL);
    return FALSE;
  }

  return TRUE;
}

/*
 * Read 'avih' header.
 */

gboolean
gst_avi_demux_stream_avih (GstAviDemux *avi,
			   guint32     *flags,
			   guint32     *streams)
{
  GstRiffRead *riff = GST_RIFF_READ (avi);
  guint32 tag;
  GstBuffer *buf;
  gst_riff_avih avih, *_avih;

  if (!gst_riff_read_data (riff, &tag, &buf))
    return FALSE;

  if (tag != GST_RIFF_TAG_avih) {
    g_warning ("Not a avih chunk");
    gst_buffer_unref (buf);
    return FALSE;
  }
  if (GST_BUFFER_SIZE (buf) < sizeof (gst_riff_avih)) {
    g_warning ("Too small avih (%d available, %d needed)",
	       GST_BUFFER_SIZE (buf), sizeof (gst_riff_avih));
    gst_buffer_unref (buf);
    return FALSE;
  }

  _avih = (gst_riff_avih *) GST_BUFFER_DATA (buf);
  avih.us_frame    = GUINT32_FROM_LE (_avih->us_frame);
  avih.max_bps     = GUINT32_FROM_LE (_avih->max_bps);
  avih.pad_gran    = GUINT32_FROM_LE (_avih->pad_gran);
  avih.flags       = GUINT32_FROM_LE (_avih->flags);
  avih.tot_frames  = GUINT32_FROM_LE (_avih->tot_frames);
  avih.init_frames = GUINT32_FROM_LE (_avih->init_frames);
  avih.streams     = GUINT32_FROM_LE (_avih->streams);
  avih.bufsize     = GUINT32_FROM_LE (_avih->bufsize);
  avih.width       = GUINT32_FROM_LE (_avih->width);
  avih.height      = GUINT32_FROM_LE (_avih->height);
  avih.scale       = GUINT32_FROM_LE (_avih->scale);
  avih.rate        = GUINT32_FROM_LE (_avih->rate);
  avih.start       = GUINT32_FROM_LE (_avih->start);
  avih.length      = GUINT32_FROM_LE (_avih->length);

  /* debug stuff */
  GST_INFO ("avih tag found:");
  GST_INFO (" us_frame    %u",     avih.us_frame);
  GST_INFO (" max_bps     %u",     avih.max_bps);
  GST_INFO (" pad_gran    %u",     avih.pad_gran);
  GST_INFO (" flags       0x%08x", avih.flags);
  GST_INFO (" tot_frames  %u",     avih.tot_frames);
  GST_INFO (" init_frames %u",     avih.init_frames);
  GST_INFO (" streams     %u",     avih.streams);
  GST_INFO (" bufsize     %u",     avih.bufsize);
  GST_INFO (" width       %u",     avih.width);
  GST_INFO (" height      %u",     avih.height);
  GST_INFO (" scale       %u",     avih.scale);
  GST_INFO (" rate        %u",     avih.rate);
  GST_INFO (" start       %u",     avih.start);
  GST_INFO (" length      %u",     avih.length);

  avi->num_frames = avih.tot_frames;
  avi->us_per_frame = avih.us_frame;
  *streams = avih.streams;
  *flags = avih.flags;

  gst_buffer_unref (buf);

  return TRUE;
}

/*
 * Add a stream.
 */

static gboolean
gst_avi_demux_add_stream (GstAviDemux *avi)
{
  GstElementClass *klass = GST_ELEMENT_GET_CLASS (avi);
  GstRiffRead *riff = GST_RIFF_READ (avi);
  guint32 tag;
  gst_riff_strh *strh;
  gchar *name = NULL, *padname = NULL;
  GstCaps *caps = NULL;
  GstPadTemplate *templ = NULL;
  GstPad *pad;
  avi_stream_context *stream;
  union {
    gst_riff_strf_vids *vids;
    gst_riff_strf_auds *auds;
    gst_riff_strf_iavs *iavs;
  } strf;

  /* the stream starts with a 'strh' header */
  if (!(tag = gst_riff_peek_tag (riff, NULL)))
    return FALSE;
  if (tag != GST_RIFF_TAG_strh) {
    g_warning ("Invalid stream header (no strh at begin)");
    goto skip_stream;
  }
  if (!gst_riff_read_strh (riff, &strh))
    return FALSE;

  /* then comes a 'strf' of that specific type */
  if (!(tag = gst_riff_peek_tag (riff, NULL)))
    return FALSE;
  if (tag != GST_RIFF_TAG_strf) {
    gst_element_error (avi, STREAM, DEMUX, NULL,
		       ("Invalid AVI header (no strf as second tag)"));
    goto skip_stream;
  }
  switch (strh->type) {
    case GST_RIFF_FCC_vids:
      if (!gst_riff_read_strf_vids (riff, &strf.vids))
        return FALSE;
      break;
    case GST_RIFF_FCC_auds:
      if (!gst_riff_read_strf_auds (riff, &strf.auds))
        return FALSE;
      break;
    case GST_RIFF_FCC_iavs:
      if (!gst_riff_read_strf_iavs (riff, &strf.iavs))
        return FALSE;
      break;
    default:
      g_warning ("Unknown stream type " GST_FOURCC_FORMAT,
		 GST_FOURCC_ARGS (strh->type));
      goto skip_stream;
  }

  /* read other things */
  while (TRUE) {
    if (!(tag = gst_riff_peek_tag (riff, &avi->level_up)))
      return FALSE;
    else if (avi->level_up) {
      avi->level_up--;
      break;
    }

    switch (tag) {
      case GST_RIFF_TAG_strn:
        if (name)
          g_free (name);
        if (!gst_riff_read_ascii (riff, &tag, &name))
          return FALSE;
        break;

      default:
        GST_WARNING ("Unknown tag " GST_FOURCC_FORMAT " in AVI header",
		     GST_FOURCC_ARGS (tag));
        /* fall-through */

      case GST_RIFF_TAG_strd: /* what is this? */
      case GST_RIFF_TAG_JUNK:
        if (!gst_riff_read_skip (riff))
          return FALSE;
        break;
    }

    if (avi->level_up) {
      avi->level_up--;
      break;
    }
  }

  /* create stream name + pad */
  switch (strh->type) {
    case GST_RIFF_FCC_vids:
      padname = g_strdup_printf ("video_%02d", avi->num_v_streams);
      templ = gst_element_class_get_pad_template (klass, "video_%02d");
      caps = gst_riff_create_video_caps (strf.vids->compression, strh, strf.vids);
      g_free (strf.vids);
      avi->num_v_streams++;
      break;
    case GST_RIFF_FCC_auds:
      padname = g_strdup_printf ("audio_%02d", avi->num_a_streams);
      templ = gst_element_class_get_pad_template (klass, "audio_%02d");
      caps = gst_riff_create_audio_caps (strf.auds->format, strh, strf.auds);
      g_free (strf.auds);
      avi->num_a_streams++;
      break;
    case GST_RIFF_FCC_iavs:
      padname = g_strdup_printf ("video_%02d", avi->num_v_streams);
      templ = gst_element_class_get_pad_template (klass, "video_%02d");
      caps = gst_riff_create_iavs_caps (strh->fcc_handler, strh, strf.iavs);
      g_free (strf.iavs);
      avi->num_v_streams++;
      break;
    default:
      g_assert (0);
  }

  /* set proper settings and add it */
  pad =  gst_pad_new_from_template (templ, padname);
  g_free (padname);

  gst_pad_set_formats_function (pad, gst_avi_demux_get_src_formats);
  gst_pad_set_event_mask_function (pad, gst_avi_demux_get_event_mask);
  gst_pad_set_event_function (pad, gst_avi_demux_handle_src_event);
  gst_pad_set_query_type_function (pad, gst_avi_demux_get_src_query_types);
  gst_pad_set_query_function (pad, gst_avi_demux_handle_src_query);
  gst_pad_set_convert_function (pad, gst_avi_demux_src_convert);
  gst_pad_set_getcaps_function (pad, gst_avi_demux_src_getcaps);

  stream = &avi->stream[avi->num_streams];
  stream->caps = caps ? caps : gst_caps_new_empty ();
  stream->pad = pad;
  stream->strh = strh;
  stream->num = avi->num_streams;
  stream->delay = 0LL;
  stream->total_bytes = 0LL;
  stream->total_frames = 0;
  stream->current_frame = 0;
  stream->current_byte = 0;
  stream->current_entry = -1;
  stream->skip = 0;
  gst_pad_set_element_private (pad, stream);
  avi->num_streams++;

  /* auto-negotiates */
  gst_element_add_pad (GST_ELEMENT (avi), pad);

  return TRUE;

skip_stream:
  while (TRUE) {
    if (!(tag = gst_riff_peek_tag (riff, &avi->level_up)))
      return FALSE;
    if (avi->level_up) {
      avi->level_up--;
      break;
    }
    if (!gst_riff_read_skip (riff))
      return FALSE;
  }

  /* add a "NULL" stream */
  avi->num_streams++;

  return TRUE; /* recoverable */
}

/*
 * Read an openDML-2.0 extension header.
 */

static gboolean
gst_avi_demux_stream_odml (GstAviDemux *avi)
{
  GstRiffRead *riff = GST_RIFF_READ (avi);
  guint32 tag;

  /* read contents */
  while (TRUE) {
    if (!(tag = gst_riff_peek_tag (riff, &avi->level_up)))
      return FALSE;
    else if (avi->level_up) {
      avi->level_up--;
      break;
    }

    switch (tag) {
      case GST_RIFF_TAG_dmlh: {
        gst_riff_dmlh dmlh, *_dmlh;
        GstBuffer *buf;

        if (!gst_riff_read_data (riff, &tag, &buf))
          return FALSE;
        if (GST_BUFFER_SIZE (buf) < sizeof (gst_riff_dmlh)) {
          g_warning ("DMLH entry is too small (%d bytes, %d needed)",
		     GST_BUFFER_SIZE (buf), sizeof (gst_riff_dmlh));
          gst_buffer_unref (buf);
          break;
        }
        _dmlh = (gst_riff_dmlh *) GST_BUFFER_DATA (buf);
        dmlh.totalframes = GUINT32_FROM_LE (_dmlh->totalframes);

        GST_INFO ("dmlh tag found:");
        GST_INFO (" totalframes: %u", dmlh.totalframes);

        avi->num_frames = dmlh.totalframes;
        gst_buffer_unref (buf);
        break;
      }

      default:
        GST_WARNING ("Unknown tag " GST_FOURCC_FORMAT " in AVI header",
		     GST_FOURCC_ARGS (tag));
        /* fall-through */

      case GST_RIFF_TAG_JUNK:
        if (!gst_riff_read_skip (riff))
          return FALSE;
        break;
    }

    if (avi->level_up) {
      avi->level_up--;
      break;
    }
  }

  return TRUE;
}

/*
 * Seek to index, read it, seek back.
 */

gboolean
gst_avi_demux_stream_index (GstAviDemux *avi)
{
  GstBuffer *buf = NULL;
  guint i;
  GstEvent *event;
  GstRiffRead *riff = GST_RIFF_READ (avi);
  guint64 pos_before, pos_after, length;
  guint32 tag;

  /* first, we need to know the current position (to seek back
   * when we're done) and the total length of the file. */
  length = gst_bytestream_length (riff->bs);
  pos_before = gst_bytestream_tell (riff->bs);

  /* skip movi */
  if (!gst_riff_read_skip (riff))
    return FALSE;

  /* assure that we've got data left */
  pos_after = gst_bytestream_tell (riff->bs);
  if (pos_after + 8 > length) {
    g_warning ("File said that it has an index, but there is no index data!");
    goto end;
  }

  /* assure that it's an index */
  if (!(tag = gst_riff_peek_tag (riff, NULL)))
    return FALSE;
  if (tag != GST_RIFF_TAG_idx1) {
    g_warning ("No index after data, but " GST_FOURCC_FORMAT,
	       GST_FOURCC_ARGS (tag));
    goto end;
  }

  /* read index */
  if (!gst_riff_read_data (riff, &tag, &buf))
    return FALSE;

  /* parse all entries */
  avi->index_size = GST_BUFFER_SIZE (buf) / sizeof (gst_riff_index_entry);
  avi->index_entries = g_malloc (avi->index_size * sizeof (gst_avi_index_entry));
  GST_INFO ("%u index entries", avi->index_size);

  for (i = 0; i < avi->index_size; i++) {
    gst_riff_index_entry entry, *_entry;
    avi_stream_context *stream;
    gint stream_nr;
    gst_avi_index_entry *target;
    GstFormat format;

    _entry = &((gst_riff_index_entry *) GST_BUFFER_DATA (buf))[i];
    entry.id     = GUINT32_FROM_LE (_entry->id);
    entry.offset = GUINT32_FROM_LE (_entry->offset);
    entry.flags  = GUINT32_FROM_LE (_entry->flags);
    entry.size   = GUINT32_FROM_LE (_entry->size);
    target = &avi->index_entries[i];

    stream_nr = CHUNKID_TO_STREAMNR (entry.id);
    if (stream_nr >= avi->num_streams || stream_nr < 0) {
      g_warning ("Index entry %d has invalid stream nr %d",
		 i, stream_nr);
      target->stream_nr = -1;
      continue;
    }
    target->stream_nr = stream_nr;
    stream = &avi->stream[stream_nr];

    target->index_nr = i;
    target->flags    = entry.flags;
    target->size     = entry.size;
    target->offset   = entry.offset;

    /* figure out if the index is 0 based or relative to the MOVI start */
    if (i == 0) {
      if (target->offset < pos_before)
	avi->index_offset = pos_before + 8;
      else
	avi->index_offset = 0;
    }

    target->bytes_before = stream->total_bytes;
    target->frames_before = stream->total_frames;

    format = GST_FORMAT_TIME;
    if (stream->strh->type == GST_RIFF_FCC_auds) {
      /* all audio frames are keyframes */
      target->flags |= GST_RIFF_IF_KEYFRAME;
    }
      
    if (stream->strh->samplesize && stream->strh->type == GST_RIFF_FCC_auds) {
      /* constant rate stream */
      gst_pad_convert (stream->pad, GST_FORMAT_BYTES,
		       stream->total_bytes, &format, &target->ts);
    } else {
      /* VBR stream */
      gst_pad_convert (stream->pad, GST_FORMAT_DEFAULT,
		       stream->total_frames, &format, &target->ts);
    }

    stream->total_bytes += target->size;
    stream->total_frames++;
  }

  /* debug our indexes */
  for (i = 0; i < avi->num_streams; i++) {
    avi_stream_context *stream;

    stream = &avi->stream[i];
    GST_DEBUG ("stream %u: %u frames, %" G_GINT64_FORMAT " bytes", 
	       i, stream->total_frames, stream->total_bytes);
  }

end:
  if (buf)
    gst_buffer_unref (buf);

  /* seek back to the data */
  if (!(event = gst_riff_read_seek (riff, pos_before)))
    return FALSE;
  gst_event_unref (event);

  return TRUE;
}

/*
 * Scan the file for all chunks to "create" a new index.
 */

gboolean
gst_avi_demux_stream_scan (GstAviDemux *avi)
{
  //GstRiffRead *riff = GST_RIFF_READ (avi);

  /* FIXME */

  return TRUE;
}

/*
 * Read full AVI headers.
 */

gboolean
gst_avi_demux_stream_header (GstAviDemux *avi)
{
  GstRiffRead *riff = GST_RIFF_READ (avi);
  guint32 tag, flags, streams;

  /* the header consists of a 'hdrl' LIST tag */
  if (!(tag = gst_riff_peek_tag (riff, NULL)))
    return FALSE;
  if (tag != GST_RIFF_TAG_LIST) {
    gst_element_error (avi, STREAM, DEMUX, NULL,
		       ("Invalid AVI header (no LIST at start): "
		       GST_FOURCC_FORMAT, GST_FOURCC_ARGS (tag)));
    return FALSE;
  }
  if (!gst_riff_read_list (riff, &tag))
    return FALSE;
  if (tag != GST_RIFF_LIST_hdrl) {
    gst_element_error (avi, STREAM, DEMUX, NULL,
		       ("Invalid AVI header (no hdrl at start): "
		       GST_FOURCC_FORMAT, GST_FOURCC_ARGS (tag)));
    return FALSE;
  }

  /* the hdrl starts with a 'avih' header */
  if (!(tag = gst_riff_peek_tag (riff, NULL)))
    return FALSE;
  if (tag != GST_RIFF_TAG_avih) {
    gst_element_error (avi, STREAM, DEMUX, NULL,
		       ("Invalid AVI header (no avih at start): "
		       GST_FOURCC_FORMAT, GST_FOURCC_ARGS (tag)));
    return FALSE;
  }
  if (!gst_avi_demux_stream_avih (avi, &flags, &streams))
    return FALSE;

  /* now, read the elements from the header until the end */
  while (TRUE) {
    if (!(tag = gst_riff_peek_tag (riff, &avi->level_up)))
      return FALSE;
    else if (avi->level_up) {
      avi->level_up--;
      break;
    }

    switch (tag) {
      case GST_RIFF_TAG_LIST:
        if (!(tag = gst_riff_peek_list (riff)))
          return FALSE;

        switch (tag) {
          case GST_RIFF_LIST_strl:
            if (!gst_riff_read_list (riff, &tag) ||
                !gst_avi_demux_add_stream (avi))
              return FALSE;
            break;

          case GST_RIFF_LIST_odml:
            if (!gst_riff_read_list (riff, &tag) ||
                !gst_avi_demux_stream_odml (avi))
              return FALSE;
            break;

          default:
            GST_WARNING ("Unknown list " GST_FOURCC_FORMAT " in AVI header",
			 GST_FOURCC_ARGS (tag));
            /* fall-through */

          case GST_RIFF_TAG_JUNK:
            if (!gst_riff_read_skip (riff))
              return FALSE;
            break;
        }

        break;

      default:
        GST_WARNING ("Unknown tag " GST_FOURCC_FORMAT " in AVI header",
		     GST_FOURCC_ARGS (tag));
        /* fall-through */

      case GST_RIFF_TAG_JUNK:
        if (!gst_riff_read_skip (riff))
          return FALSE;
        break;
    }

    if (avi->level_up) {
      avi->level_up--;
      break;
    }
  }

  if (avi->num_streams != streams) {
    g_warning ("Stream header mentioned %d streams, but %d available",
	       streams, avi->num_streams);
  }

  /* we've got streaminfo now */
  g_object_notify (G_OBJECT(avi), "streaminfo");

  /* Now, find the data (i.e. skip all junk between header and data) */
  while (1) {
    if (!(tag = gst_riff_peek_tag (riff, NULL)))
      return FALSE;
    if (tag != GST_RIFF_TAG_LIST) {
      if (!gst_riff_read_skip (riff))
        return FALSE;
      continue;
    }
    if (!(tag = gst_riff_peek_list (riff)))
      return FALSE;
    if (tag != GST_RIFF_LIST_movi) {
      if (tag == GST_RIFF_LIST_INFO) {
        if (!gst_riff_read_list (riff, &tag) ||
            !gst_riff_read_info (riff))
         return FALSE;
      } else  if (!gst_riff_read_skip (riff)) {
        return FALSE;
      }
      continue;
    }
    break;
  }

  /* create or read stream index (for seeking) */
  if (flags & GST_RIFF_AVIH_HASINDEX) {
    if (!gst_avi_demux_stream_index (avi))
      return FALSE;
  } else {
    if (!gst_avi_demux_stream_scan (avi))
      return FALSE;
  }

  return TRUE;
}

/*
 * Handle seek.
 */

static gboolean
gst_avi_demux_handle_seek (GstAviDemux *avi)
{
  GstRiffRead *riff = GST_RIFF_READ (avi);
  guint i;
  GstEvent *event;

  /* FIXME: if we seek in an openDML file, we will have multiple
   * primary levels. Seeking in between those will cause havoc. */

  if (!(event = gst_riff_read_seek (riff, avi->seek_offset)))
    return FALSE;
  gst_event_unref (event);

  for (i = 0; i < avi->num_streams; i++) {
    avi_stream_context *stream = &avi->stream[i];

    if (GST_PAD_IS_USABLE (stream->pad)) {
      event = gst_event_new_discontinuous (FALSE, GST_FORMAT_TIME, 
				avi->last_seek + stream->delay , NULL);
      gst_pad_push (stream->pad, GST_DATA (event));
    }
  }

  return TRUE;
}

/*
 * Read data.
 */

gboolean
gst_avi_demux_stream_data (GstAviDemux *avi)
{
  GstRiffRead *riff = GST_RIFF_READ (avi);
  guint32 tag;
  guint stream_nr;
  gst_avi_index_entry *entry;

  if (avi->seek_offset != (guint64) -1) {
    if (!gst_avi_demux_handle_seek (avi))
      return FALSE;
    avi->seek_offset = (guint64) -1;
  }

  /* peek first (for the end of this 'list/movi' section) */
  if (!(tag = gst_riff_peek_tag (riff, &avi->level_up)))
    return FALSE;

  /* if we're at top-level, we didn't read the 'movi'
   * list tag yet. This can also be 'AVIX' in case of
   * openDML-2.0 AVI files. Lastly, it might be idx1,
   * in which case we skip it so we come at EOS. */
  while (g_list_length (riff->level) < 2) {
    if (!(tag = gst_riff_peek_tag (riff, NULL)))
      return FALSE;

    switch (tag) {
      case GST_RIFF_TAG_LIST:
        if (!(tag = gst_riff_peek_list (riff)))
          return FALSE;

        switch (tag) {
          case GST_RIFF_LIST_AVIX:
          case GST_RIFF_LIST_movi:
            if (!gst_riff_read_list (riff, &tag))
              return FALSE;
            /* we're now going to read buffers! */
            break;

          default:
            GST_WARNING ("Unknown list " GST_FOURCC_FORMAT " before AVI data",
			 GST_FOURCC_ARGS (tag));
            /* fall-through */

          case GST_RIFF_TAG_JUNK:
            if (!gst_riff_read_skip (riff))
              return FALSE;
            break;
        }

        break;

      default:
        GST_WARNING ("Unknown tag " GST_FOURCC_FORMAT " before AVI data",
		     GST_FOURCC_ARGS (tag));
        /* fall-through */

      case GST_RIFF_TAG_idx1:
      case GST_RIFF_TAG_JUNK:
        if (!gst_riff_read_skip (riff))
          return FALSE;
        break;
    }
  }

  /* And then, we get the data */
  if (!(tag = gst_riff_peek_tag (riff, NULL)))
    return FALSE;
  stream_nr = CHUNKID_TO_STREAMNR (tag);
  if (stream_nr < 0 || stream_nr >= avi->num_streams) {
    /* recoverable */
    g_warning ("Invalid stream ID %d (" GST_FOURCC_FORMAT ")",
	       stream_nr, GST_FOURCC_ARGS (tag));
    if (!gst_riff_read_skip (riff))
      return FALSE;
  } else {
    avi_stream_context *stream;
    GstClockTime next_ts;
    GstFormat format;
    GstBuffer *buf;

    /* get buffer */
    if (!gst_riff_read_data (riff, &tag, &buf))
      return FALSE;

    /* get time of this buffer */
    stream = &avi->stream[stream_nr];
    entry = gst_avi_demux_index_next (avi, stream_nr,
				      stream->current_entry + 1, 0);
    if (entry) {
      stream->current_entry = entry->index_nr;
      if (entry->flags & GST_RIFF_IF_KEYFRAME) {
        GST_BUFFER_FLAG_SET (buf, GST_BUFFER_KEY_UNIT);
      }
    }
    format = GST_FORMAT_TIME;
    gst_pad_query (stream->pad, GST_QUERY_POSITION,
		   &format, &next_ts);

    /* set delay (if any) */
    if (stream->strh->init_frames == stream->current_frame &&
        stream->delay == 0)
      stream->delay = next_ts;

    stream->current_frame++;
    stream->current_byte += GST_BUFFER_SIZE (buf);

    /* should we skip this data? */
    if (stream->skip) {
      stream->skip--;
      gst_buffer_unref (buf);
    } else {
      if (!stream->pad || !GST_PAD_IS_USABLE (stream->pad)) {
        gst_buffer_unref (buf);
      } else {
        GstClockTime dur_ts;

        GST_BUFFER_TIMESTAMP (buf) = next_ts;
        gst_pad_query (stream->pad, GST_QUERY_POSITION,
		       &format, &dur_ts);
        GST_BUFFER_DURATION (buf) = dur_ts - next_ts;

        gst_pad_push (stream->pad, GST_DATA (buf));
      }
    }
  }

  return TRUE;
}

static void
gst_avi_demux_loop (GstElement *element)
{
  GstAviDemux *avi = GST_AVI_DEMUX (element);

  switch (avi->state) {
    case GST_AVI_DEMUX_START:
      if (!gst_avi_demux_stream_init (avi))
        return;
      avi->state = GST_AVI_DEMUX_HEADER;
      /* fall-through */

    case GST_AVI_DEMUX_HEADER:
      if (!gst_avi_demux_stream_header (avi))
        return;
      avi->state = GST_AVI_DEMUX_MOVI;
      /* fall-through */

    case GST_AVI_DEMUX_MOVI:
      if (!gst_avi_demux_stream_data (avi))
        return;
      break;

    default:
      g_assert (0);
  }
}

static GstElementStateReturn
gst_avi_demux_change_state (GstElement *element)
{
  GstAviDemux *avi = GST_AVI_DEMUX (element);

  switch (GST_STATE_TRANSITION (element)) {
    case GST_STATE_READY_TO_PAUSED:
      gst_avi_demux_streaminfo (avi);
      break;
    case GST_STATE_PAUSED_TO_READY:
      gst_avi_demux_reset (avi);
      break;
    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_avi_demux_get_property (GObject    *object,
			    guint       prop_id,
			    GValue     *value,
			    GParamSpec *pspec)
{
  GstAviDemux *avi = GST_AVI_DEMUX (object);

  switch (prop_id) {
    case ARG_STREAMINFO:
      g_value_set_boxed (value, avi->streaminfo);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}