gstreamer/ext/vorbis/vorbisparse.c

/* GStreamer
 * Copyright (C) <2004> Thomas Vander Stichele <thomas at apestaart dot org>
 *
 * 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.
 */

/**
 * SECTION:element-vorbisparse
 * @short_description: parses vorbis streams 
 * @see_also: vorbisdec, oggdemux
 *
 * <refsect2>
 * <para>
 * The vorbisparse element will parse the header packets of the Vorbis
 * stream and put them as the streamheader in the caps. This is used in the
 * multifdsink case where you want to stream live vorbis streams to multiple
 * clients, each client has to receive the streamheaders first before they can
 * consume the vorbis packets.
 * </para>
 * <title>Example pipelines</title>
 * <para>
 * <programlisting>
 * gst-launch -v filesrc location=sine.ogg ! oggdemux ! vorbisparse ! fakesink
 * </programlisting>
 * This pipeline shows that the streamheader is set in the caps.
 * </para>
 * </refsect2>
 *
 * Last reviewed on 2006-03-01 (0.10.4)
 */

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

#include "vorbisparse.h"

GST_DEBUG_CATEGORY_EXTERN (vorbisparse_debug);
#define GST_CAT_DEFAULT vorbisparse_debug

static GstElementDetails vorbis_parse_details = {
  "VorbisParse",
  "Codec/Parser/Audio",
  "parse raw vorbis streams",
  "Thomas Vander Stichele <thomas at apestaart dot org>"
};

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

enum
{
  ARG_0
};

static GstStaticPadTemplate vorbis_parse_sink_factory =
GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("audio/x-vorbis")
    );

static GstStaticPadTemplate vorbis_parse_src_factory =
GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("audio/x-vorbis")
    );

GST_BOILERPLATE (GstVorbisParse, gst_vorbis_parse, GstElement,
    GST_TYPE_ELEMENT);

static GstFlowReturn vorbis_parse_chain (GstPad * pad, GstBuffer * buffer);
static GstStateChangeReturn vorbis_parse_change_state (GstElement * element,
    GstStateChange transition);
static gboolean vorbis_parse_sink_event (GstPad * pad, GstEvent * event);

static void
gst_vorbis_parse_base_init (gpointer g_class)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);

  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&vorbis_parse_src_factory));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&vorbis_parse_sink_factory));
  gst_element_class_set_details (element_class, &vorbis_parse_details);
}

static void
gst_vorbis_parse_class_init (GstVorbisParseClass * klass)
{
  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);

  gstelement_class->change_state = vorbis_parse_change_state;
}

static void
gst_vorbis_parse_init (GstVorbisParse * parse, GstVorbisParseClass * g_class)
{
  parse->sinkpad =
      gst_pad_new_from_static_template (&vorbis_parse_sink_factory, "sink");
  gst_pad_set_chain_function (parse->sinkpad, vorbis_parse_chain);
  gst_pad_set_event_function (parse->sinkpad, vorbis_parse_sink_event);
  gst_element_add_pad (GST_ELEMENT (parse), parse->sinkpad);

  parse->srcpad =
      gst_pad_new_from_static_template (&vorbis_parse_src_factory, "src");
  gst_element_add_pad (GST_ELEMENT (parse), parse->srcpad);
}

static void
vorbis_parse_set_header_on_caps (GstVorbisParse * parse, GstCaps * caps)
{
  GstBuffer *buf1, *buf2, *buf3;
  GstStructure *structure;
  GValue array = { 0 };
  GValue value = { 0 };

  g_assert (parse);
  g_assert (parse->streamheader);
  g_assert (parse->streamheader->next);
  g_assert (parse->streamheader->next->next);
  buf1 = parse->streamheader->data;
  g_assert (buf1);
  buf2 = parse->streamheader->next->data;
  g_assert (buf2);
  buf3 = parse->streamheader->next->next->data;
  g_assert (buf3);

  structure = gst_caps_get_structure (caps, 0);

  /* mark buffers */
  GST_BUFFER_FLAG_SET (buf1, GST_BUFFER_FLAG_IN_CAPS);
  GST_BUFFER_FLAG_SET (buf2, GST_BUFFER_FLAG_IN_CAPS);
  GST_BUFFER_FLAG_SET (buf3, GST_BUFFER_FLAG_IN_CAPS);

  /* put buffers in a fixed list */
  g_value_init (&array, GST_TYPE_ARRAY);
  g_value_init (&value, GST_TYPE_BUFFER);
  gst_value_set_buffer (&value, buf1);
  gst_value_array_append_value (&array, &value);
  g_value_unset (&value);
  g_value_init (&value, GST_TYPE_BUFFER);
  gst_value_set_buffer (&value, buf2);
  gst_value_array_append_value (&array, &value);
  g_value_unset (&value);
  g_value_init (&value, GST_TYPE_BUFFER);
  gst_value_set_buffer (&value, buf3);
  gst_value_array_append_value (&array, &value);
  gst_structure_set_value (structure, "streamheader", &array);
  g_value_unset (&value);
  g_value_unset (&array);
}

static void
vorbis_parse_push_headers (GstVorbisParse * parse)
{
  /* mark and put on caps */
  GstCaps *caps;
  GstBuffer *outbuf;
  ogg_packet packet;

  /* get the headers into the caps, passing them to vorbis as we go */
  caps = gst_caps_make_writable (gst_pad_get_caps (parse->srcpad));
  vorbis_parse_set_header_on_caps (parse, caps);
  GST_DEBUG_OBJECT (parse, "here are the caps: %" GST_PTR_FORMAT, caps);
  gst_pad_set_caps (parse->srcpad, caps);
  gst_caps_unref (caps);

  /* push out buffers, ignoring return value... */
  outbuf = GST_BUFFER_CAST (parse->streamheader->data);
  packet.packet = GST_BUFFER_DATA (outbuf);
  packet.bytes = GST_BUFFER_SIZE (outbuf);
  packet.granulepos = GST_BUFFER_OFFSET_END (outbuf);
  packet.packetno = 1;
  packet.e_o_s = 0;
  vorbis_synthesis_headerin (&parse->vi, &parse->vc, &packet);
  parse->sample_rate = parse->vi.rate;

  gst_buffer_set_caps (outbuf, GST_PAD_CAPS (parse->srcpad));
  gst_pad_push (parse->srcpad, outbuf);

  outbuf = GST_BUFFER_CAST (parse->streamheader->next->data);
  packet.packet = GST_BUFFER_DATA (outbuf);
  packet.bytes = GST_BUFFER_SIZE (outbuf);
  packet.granulepos = GST_BUFFER_OFFSET_END (outbuf);
  packet.packetno = 2;
  packet.e_o_s = 0;
  vorbis_synthesis_headerin (&parse->vi, &parse->vc, &packet);

  gst_buffer_set_caps (outbuf, GST_PAD_CAPS (parse->srcpad));
  gst_pad_push (parse->srcpad, outbuf);

  outbuf = GST_BUFFER_CAST (parse->streamheader->next->next->data);
  packet.packet = GST_BUFFER_DATA (outbuf);
  packet.bytes = GST_BUFFER_SIZE (outbuf);
  packet.granulepos = GST_BUFFER_OFFSET_END (outbuf);
  packet.packetno = 3;
  packet.e_o_s = 0;
  vorbis_synthesis_headerin (&parse->vi, &parse->vc, &packet);

  gst_buffer_set_caps (outbuf, GST_PAD_CAPS (parse->srcpad));
  gst_pad_push (parse->srcpad, outbuf);

  g_list_free (parse->streamheader);
  parse->streamheader = NULL;

  parse->streamheader_sent = TRUE;
}

static void
vorbis_parse_clear_queue (GstVorbisParse * parse)
{
  while (parse->buffer_queue->length) {
    GstBuffer *buf;

    buf = GST_BUFFER_CAST (g_queue_pop_head (parse->buffer_queue));
    gst_buffer_unref (buf);
  }
}

static GstFlowReturn
vorbis_parse_push_buffer (GstVorbisParse * parse, GstBuffer * buf,
    gint64 granulepos)
{
  guint64 samples;

  /* our hack as noted below */
  samples = GST_BUFFER_OFFSET (buf);

  GST_BUFFER_OFFSET_END (buf) = granulepos;
  GST_BUFFER_DURATION (buf) = samples * GST_SECOND / parse->sample_rate;
  GST_BUFFER_OFFSET (buf) = granulepos * GST_SECOND / parse->sample_rate;
  GST_BUFFER_TIMESTAMP (buf) =
      GST_BUFFER_OFFSET (buf) - GST_BUFFER_DURATION (buf);

  gst_buffer_set_caps (buf, GST_PAD_CAPS (parse->srcpad));

  return gst_pad_push (parse->srcpad, buf);
}

static GstFlowReturn
vorbis_parse_drain_queue_prematurely (GstVorbisParse * parse)
{
  GstFlowReturn ret = GST_FLOW_OK;
  gint64 granulepos = MAX (parse->prev_granulepos, 0);

  /* got an EOS event, make sure to push out any buffers that were in the queue
   * -- won't normally be the case, but this catches the
   * didn't-get-a-granulepos-on-the-last-packet case. Assuming a continuous
   * stream. */

  while (!g_queue_is_empty (parse->buffer_queue)) {
    GstBuffer *buf;

    buf = GST_BUFFER_CAST (g_queue_pop_head (parse->buffer_queue));

    granulepos += GST_BUFFER_OFFSET (buf);
    ret = vorbis_parse_push_buffer (parse, buf, granulepos);

    if (ret != GST_FLOW_OK)
      goto done;
  }

  parse->prev_granulepos = granulepos;

done:
  return ret;
}

static GstFlowReturn
vorbis_parse_drain_queue (GstVorbisParse * parse, gint64 granulepos)
{
  GstFlowReturn ret = GST_FLOW_OK;
  GList *walk;
  gint64 cur = granulepos;
  gint64 gp;

  for (walk = parse->buffer_queue->head; walk; walk = walk->next)
    cur -= GST_BUFFER_OFFSET (walk->data);

  if (parse->prev_granulepos != -1)
    cur = MAX (cur, parse->prev_granulepos);

  while (!g_queue_is_empty (parse->buffer_queue)) {
    GstBuffer *buf;

    buf = GST_BUFFER_CAST (g_queue_pop_head (parse->buffer_queue));

    cur += GST_BUFFER_OFFSET (buf);
    gp = CLAMP (cur, 0, granulepos);

    ret = vorbis_parse_push_buffer (parse, buf, gp);

    if (ret != GST_FLOW_OK)
      goto done;
  }

  parse->prev_granulepos = granulepos;

done:
  return ret;
}

static GstFlowReturn
vorbis_parse_queue_buffer (GstVorbisParse * parse, GstBuffer * buf)
{
  GstFlowReturn ret = GST_FLOW_OK;
  long blocksize;
  ogg_packet packet;

  buf = gst_buffer_make_metadata_writable (buf);

  packet.packet = GST_BUFFER_DATA (buf);
  packet.bytes = GST_BUFFER_SIZE (buf);
  packet.granulepos = GST_BUFFER_OFFSET_END (buf);
  packet.packetno = parse->packetno + parse->buffer_queue->length;
  packet.e_o_s = 0;

  blocksize = vorbis_packet_blocksize (&parse->vi, &packet);

  /* temporarily store the sample count in OFFSET -- we overwrite this later */

  if (parse->prev_blocksize < 0)
    GST_BUFFER_OFFSET (buf) = 0;
  else
    GST_BUFFER_OFFSET (buf) = (blocksize + parse->prev_blocksize) / 4;

  parse->prev_blocksize = blocksize;

  g_queue_push_tail (parse->buffer_queue, buf);

  if (GST_BUFFER_OFFSET_END_IS_VALID (buf))
    ret = vorbis_parse_drain_queue (parse, GST_BUFFER_OFFSET_END (buf));

  return ret;
}

static GstFlowReturn
vorbis_parse_chain (GstPad * pad, GstBuffer * buffer)
{
  GstFlowReturn ret;
  GstBuffer *buf;
  GstVorbisParse *parse;

  parse = GST_VORBIS_PARSE (gst_pad_get_parent (pad));

  buf = GST_BUFFER (buffer);
  parse->packetno++;

  if (parse->packetno <= 3) {
    /* if 1 <= packetno <= 3, it's streamheader,
     * so put it on the streamheader list and return */
    parse->streamheader = g_list_append (parse->streamheader, buf);
    ret = GST_FLOW_OK;
  } else {
    if (!parse->streamheader_sent)
      vorbis_parse_push_headers (parse);

    ret = vorbis_parse_queue_buffer (parse, buf);
  }

  gst_object_unref (parse);

  return ret;
}

static gboolean
vorbis_parse_sink_event (GstPad * pad, GstEvent * event)
{
  gboolean ret;
  GstVorbisParse *parse;

  parse = GST_VORBIS_PARSE (gst_pad_get_parent (pad));

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_FLUSH_START:
      vorbis_parse_clear_queue (parse);
      parse->prev_granulepos = -1;
      parse->prev_blocksize = -1;
      ret = gst_pad_event_default (pad, event);
      break;
    case GST_EVENT_EOS:
      vorbis_parse_drain_queue_prematurely (parse);
      ret = gst_pad_event_default (pad, event);
      break;
    default:
      ret = gst_pad_event_default (pad, event);
      break;
  }

  gst_object_unref (parse);

  return ret;
}

static GstStateChangeReturn
vorbis_parse_change_state (GstElement * element, GstStateChange transition)
{
  GstVorbisParse *parse = GST_VORBIS_PARSE (element);
  GstStateChangeReturn ret;

  switch (transition) {
    case GST_STATE_CHANGE_READY_TO_PAUSED:
      vorbis_info_init (&parse->vi);
      vorbis_comment_init (&parse->vc);
      parse->prev_granulepos = -1;
      parse->prev_blocksize = -1;
      parse->packetno = 0;
      parse->streamheader_sent = FALSE;
      parse->buffer_queue = g_queue_new ();
      break;
    default:
      break;
  }

  ret = parent_class->change_state (element, transition);

  switch (transition) {
    case GST_STATE_CHANGE_PAUSED_TO_READY:
      vorbis_info_clear (&parse->vi);
      vorbis_comment_clear (&parse->vc);
      vorbis_parse_clear_queue (parse);
      g_queue_free (parse->buffer_queue);
      parse->buffer_queue = NULL;
      break;
    default:
      break;
  }

  return ret;
}