/* GStreamer OGM parsing

 * Copyright (C) 2004 Ronald Bultje <rbultje@ronald.bitfreak.net>

 * Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>

 *

 * 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., 51 Franklin St, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <stdio.h>

#include <string.h>

#include <gst/gst.h>

#include <gst/tag/tag.h>

#include <gst/riff/riff-media.h>

#include <gst/riff/riff-read.h>

#include "gstogg.h"

GST_DEBUG_CATEGORY_STATIC (gst_ogm_parse_debug);

#define GST_CAT_DEFAULT gst_ogm_parse_debug

#define GST_TYPE_OGM_VIDEO_PARSE (gst_ogm_video_parse_get_type())

#define GST_IS_OGM_VIDEO_PARSE(obj) \

  (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_OGM_VIDEO_PARSE))

#define GST_TYPE_OGM_AUDIO_PARSE (gst_ogm_audio_parse_get_type())

#define GST_IS_OGM_AUDIO_PARSE(obj) \

  (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_OGM_AUDIO_PARSE))

#define GST_TYPE_OGM_TEXT_PARSE (gst_ogm_text_parse_get_type())

#define GST_IS_OGM_TEXT_PARSE(obj) \

  (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_OGM_TEXT_PARSE))

#define GST_TYPE_OGM_PARSE (gst_ogm_parse_get_type())

#define GST_OGM_PARSE(obj) \

  (G_TYPE_CHECK_INSTANCE_CAST((obj), GST_TYPE_OGM_PARSE, GstOgmParse))

#define GST_OGM_PARSE_CLASS(klass) \

  (G_TYPE_CHECK_CLASS_CAST((klass), GST_TYPE_OGM_PARSE, GstOgmParse))

#define GST_IS_OGM_PARSE(obj) \

  (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_OGM_PARSE))

#define GST_IS_OGM_PARSE_CLASS(klass) \

  (G_TYPE_CHECK_CLASS_TYPE((klass), GST_TYPE_OGM_PARSE))

#define GST_OGM_PARSE_GET_CLASS(obj) \

  (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_OGM_PARSE, GstOgmParseClass))

typedef struct _stream_header_video

{

  gint32 width;

  gint32 height;

} stream_header_video;

typedef struct _stream_header_audio

{

  gint16 channels;

  gint16 blockalign;

  gint32 avgbytespersec;

} stream_header_audio;

/* sizeof(stream_header) might differ due to structure packing and

 * alignment differences on some architectures, so not using that */

#define OGM_STREAM_HEADER_SIZE (8+4+4+8+8+4+4+4+8)

typedef struct _stream_header

{

  gchar streamtype[8];

  gchar subtype[4 + 1];

  /* size of the structure */

  gint32 size;

  /* in reference time */

  gint64 time_unit;

  gint64 samples_per_unit;

  /* in media time */

  gint32 default_len;

  gint32 buffersize;

  gint32 bits_per_sample;

  union

  {

    stream_header_video video;

    stream_header_audio audio;

    /* text has no additional data */

  } s;

} stream_header;

typedef struct _GstOgmParse

{

  GstElement element;

  /* pads */

  GstPad *srcpad, *sinkpad;

  GstPadTemplate *srcpadtempl;

  /* we need to cache events that we receive before creating the source pad */

  GList *cached_events;

  /* audio or video */

  stream_header hdr;

  /* expected next granulepos (used for timestamp guessing) */

  guint64 next_granulepos;

} GstOgmParse;

typedef struct _GstOgmParseClass

{

  GstElementClass parent_class;

} GstOgmParseClass;

static GstStaticPadTemplate sink_factory_video =

GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,

    GST_STATIC_CAPS ("application/x-ogm-video"));

static GstStaticPadTemplate sink_factory_audio =

GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,

    GST_STATIC_CAPS ("application/x-ogm-audio"));

static GstStaticPadTemplate sink_factory_text =

GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,

    GST_STATIC_CAPS ("application/x-ogm-text"));

static GstPadTemplate *video_src_templ, *audio_src_templ, *text_src_templ;

static GType gst_ogm_audio_parse_get_type (void);

static GType gst_ogm_video_parse_get_type (void);

static GType gst_ogm_text_parse_get_type (void);

static GType gst_ogm_parse_get_type (void);

static void gst_ogm_audio_parse_base_init (GstOgmParseClass * klass);

static void gst_ogm_video_parse_base_init (GstOgmParseClass * klass);

static void gst_ogm_text_parse_base_init (GstOgmParseClass * klass);

static void gst_ogm_parse_class_init (GstOgmParseClass * klass);

static void gst_ogm_parse_init (GstOgmParse * ogm);

static void gst_ogm_video_parse_init (GstOgmParse * ogm);

static void gst_ogm_audio_parse_init (GstOgmParse * ogm);

static void gst_ogm_text_parse_init (GstOgmParse * ogm);

static gboolean gst_ogm_parse_sink_event (GstPad * pad, GstObject * parent,

    GstEvent * event);

static gboolean gst_ogm_parse_sink_query (GstPad * pad, GstObject * parent,

    GstQuery * query);

static gboolean gst_ogm_parse_sink_convert (GstPad * pad, GstFormat src_format,

    gint64 src_value, GstFormat * dest_format, gint64 * dest_value);

static GstFlowReturn gst_ogm_parse_chain (GstPad * pad, GstObject * parent,

    GstBuffer * buffer);

static GstStateChangeReturn gst_ogm_parse_change_state (GstElement * element,

    GstStateChange transition);

static GstElementClass *parent_class = NULL;

static GType

gst_ogm_parse_get_type (void)

{

  static GType ogm_parse_type = 0;

  if (!ogm_parse_type) {

    static const GTypeInfo ogm_parse_info = {

      sizeof (GstOgmParseClass),

      NULL,

      NULL,

      (GClassInitFunc) gst_ogm_parse_class_init,

      NULL,

      NULL,

      sizeof (GstOgmParse),

      0,

      (GInstanceInitFunc) gst_ogm_parse_init,

    };

    ogm_parse_type =

        g_type_register_static (GST_TYPE_ELEMENT,

        "GstOgmParse", &ogm_parse_info, 0);

  }

  return ogm_parse_type;

}

static GType

gst_ogm_audio_parse_get_type (void)

{

  static GType ogm_audio_parse_type = 0;

  if (!ogm_audio_parse_type) {

    static const GTypeInfo ogm_audio_parse_info = {

      sizeof (GstOgmParseClass),

      (GBaseInitFunc) gst_ogm_audio_parse_base_init,

      NULL,

      NULL,

      NULL,

      NULL,

      sizeof (GstOgmParse),

      0,

      (GInstanceInitFunc) gst_ogm_audio_parse_init,

    };

    ogm_audio_parse_type =

        g_type_register_static (GST_TYPE_OGM_PARSE,

        "GstOgmAudioParse", &ogm_audio_parse_info, 0);

  }

  return ogm_audio_parse_type;

}

static GType

gst_ogm_video_parse_get_type (void)

{

  static GType ogm_video_parse_type = 0;

  if (!ogm_video_parse_type) {

    static const GTypeInfo ogm_video_parse_info = {

      sizeof (GstOgmParseClass),

      (GBaseInitFunc) gst_ogm_video_parse_base_init,

      NULL,

      NULL,

      NULL,

      NULL,

      sizeof (GstOgmParse),

      0,

      (GInstanceInitFunc) gst_ogm_video_parse_init,

    };

    ogm_video_parse_type =

        g_type_register_static (GST_TYPE_OGM_PARSE,

        "GstOgmVideoParse", &ogm_video_parse_info, 0);

  }

  return ogm_video_parse_type;

}

static GType

gst_ogm_text_parse_get_type (void)

{

  static GType ogm_text_parse_type = 0;

  if (!ogm_text_parse_type) {

    static const GTypeInfo ogm_text_parse_info = {

      sizeof (GstOgmParseClass),

      (GBaseInitFunc) gst_ogm_text_parse_base_init,

      NULL,

      NULL,

      NULL,

      NULL,

      sizeof (GstOgmParse),

      0,

      (GInstanceInitFunc) gst_ogm_text_parse_init,

    };

    ogm_text_parse_type =

        g_type_register_static (GST_TYPE_OGM_PARSE,

        "GstOgmTextParse", &ogm_text_parse_info, 0);

  }

  return ogm_text_parse_type;

}

static void

gst_ogm_audio_parse_base_init (GstOgmParseClass * klass)

{

  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

  GstCaps *caps = gst_riff_create_audio_template_caps ();

  gst_element_class_set_static_metadata (element_class,

      "OGM audio stream parser", "Codec/Parser/Audio",

      "parse an OGM audio header and stream",

      "GStreamer maintainers <gstreamer-devel@lists.freedesktop.org>");

  gst_element_class_add_static_pad_template (element_class,

      &sink_factory_audio);

  audio_src_templ =

      gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_SOMETIMES, caps);

  gst_element_class_add_pad_template (element_class, audio_src_templ);

  gst_caps_unref (caps);

}

static void

gst_ogm_video_parse_base_init (GstOgmParseClass * klass)

{

  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

  GstCaps *caps = gst_riff_create_video_template_caps ();

  gst_element_class_set_static_metadata (element_class,

      "OGM video stream parser", "Codec/Parser/Video",

      "parse an OGM video header and stream",

      "GStreamer maintainers <gstreamer-devel@lists.freedesktop.org>");

  gst_element_class_add_static_pad_template (element_class,

      &sink_factory_video);

  video_src_templ =

      gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_SOMETIMES, caps);

  gst_element_class_add_pad_template (element_class, video_src_templ);

  gst_caps_unref (caps);

}

static void

gst_ogm_text_parse_base_init (GstOgmParseClass * klass)

{

  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

  GstCaps *caps = gst_caps_new_simple ("text/x-raw", "format", G_TYPE_STRING,

      "utf8", NULL);

  gst_element_class_set_static_metadata (element_class,

      "OGM text stream parser", "Codec/Decoder/Subtitle",

      "parse an OGM text header and stream",

      "GStreamer maintainers <gstreamer-devel@lists.freedesktop.org>");

  gst_element_class_add_static_pad_template (element_class, &sink_factory_text);

  text_src_templ = gst_pad_template_new ("src",

      GST_PAD_SRC, GST_PAD_SOMETIMES, caps);

  gst_element_class_add_pad_template (element_class, text_src_templ);

  gst_caps_unref (caps);

}

static void

gst_ogm_parse_class_init (GstOgmParseClass * klass)

{

  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);

  parent_class = g_type_class_peek_parent (klass);

  gstelement_class->change_state =

      GST_DEBUG_FUNCPTR (gst_ogm_parse_change_state);

}

static void

gst_ogm_parse_init (GstOgmParse * ogm)

{

  memset (&ogm->hdr, 0, sizeof (ogm->hdr));

  ogm->next_granulepos = 0;

  ogm->srcpad = NULL;

  ogm->cached_events = NULL;

}

static void

gst_ogm_audio_parse_init (GstOgmParse * ogm)

{

  ogm->sinkpad = gst_pad_new_from_static_template (&sink_factory_audio, "sink");

  gst_pad_set_query_function (ogm->sinkpad,

      GST_DEBUG_FUNCPTR (gst_ogm_parse_sink_query));

  gst_pad_set_chain_function (ogm->sinkpad,

      GST_DEBUG_FUNCPTR (gst_ogm_parse_chain));

  gst_pad_set_event_function (ogm->sinkpad,

      GST_DEBUG_FUNCPTR (gst_ogm_parse_sink_event));

  gst_element_add_pad (GST_ELEMENT (ogm), ogm->sinkpad);

  ogm->srcpad = NULL;

  ogm->srcpadtempl = audio_src_templ;

}

static void

gst_ogm_video_parse_init (GstOgmParse * ogm)

{

  ogm->sinkpad = gst_pad_new_from_static_template (&sink_factory_video, "sink");

  gst_pad_set_query_function (ogm->sinkpad,

      GST_DEBUG_FUNCPTR (gst_ogm_parse_sink_query));

  gst_pad_set_chain_function (ogm->sinkpad,

      GST_DEBUG_FUNCPTR (gst_ogm_parse_chain));

  gst_pad_set_event_function (ogm->sinkpad,

      GST_DEBUG_FUNCPTR (gst_ogm_parse_sink_event));

  gst_element_add_pad (GST_ELEMENT (ogm), ogm->sinkpad);

  ogm->srcpad = NULL;

  ogm->srcpadtempl = video_src_templ;

}

static void

gst_ogm_text_parse_init (GstOgmParse * ogm)

{

  ogm->sinkpad = gst_pad_new_from_static_template (&sink_factory_text, "sink");

  gst_pad_set_query_function (ogm->sinkpad,

      GST_DEBUG_FUNCPTR (gst_ogm_parse_sink_query));

  gst_pad_set_chain_function (ogm->sinkpad,

      GST_DEBUG_FUNCPTR (gst_ogm_parse_chain));

  gst_pad_set_event_function (ogm->sinkpad,

      GST_DEBUG_FUNCPTR (gst_ogm_parse_sink_event));

  gst_element_add_pad (GST_ELEMENT (ogm), ogm->sinkpad);

  ogm->srcpad = NULL;

  ogm->srcpadtempl = text_src_templ;

}

static gboolean

gst_ogm_parse_sink_convert (GstPad * pad,

    GstFormat src_format, gint64 src_value,

    GstFormat * dest_format, gint64 * dest_value)

{

  gboolean res = FALSE;

  GstOgmParse *ogm = GST_OGM_PARSE (gst_pad_get_parent (pad));

  switch (src_format) {

    case GST_FORMAT_DEFAULT:

      switch (*dest_format) {

        case GST_FORMAT_TIME:

          switch (ogm->hdr.streamtype[0]) {

            case 'a':

              *dest_value = GST_SECOND * src_value / ogm->hdr.samples_per_unit;

              res = TRUE;

              break;

            case 'v':

            case 't':

              *dest_value = (GST_SECOND / 10000000) *

                  ogm->hdr.time_unit * src_value;

              res = TRUE;

              break;

            default:

              break;

          }

          break;

        default:

          break;

      }

      break;

    case GST_FORMAT_TIME:

      switch (*dest_format) {

        case GST_FORMAT_DEFAULT:

          switch (ogm->hdr.streamtype[0]) {

            case 'a':

              *dest_value = ogm->hdr.samples_per_unit * src_value / GST_SECOND;

              res = TRUE;

              break;

            case 'v':

            case 't':

              *dest_value = src_value /

                  ((GST_SECOND / 10000000) * ogm->hdr.time_unit);

              res = TRUE;

              break;

            default:

              break;

          }

          break;

        default:

          break;

      }

      break;

    default:

      break;

  }

  gst_object_unref (ogm);

  return res;

}

static gboolean

gst_ogm_parse_sink_query (GstPad * pad, GstObject * parent, GstQuery * query)

{

  GstOgmParse *ogm = GST_OGM_PARSE (parent);

  GstFormat format;

  gboolean res = FALSE;

  switch (GST_QUERY_TYPE (query)) {

    case GST_QUERY_POSITION:

    {

      gint64 val;

      gst_query_parse_position (query, &format, NULL);

      if (format != GST_FORMAT_DEFAULT && format != GST_FORMAT_TIME)

        break;

      if ((res = gst_ogm_parse_sink_convert (pad,

                  GST_FORMAT_DEFAULT, ogm->next_granulepos, &format, &val))) {

        /* don't know the total length here.. */

        gst_query_set_position (query, format, val);

      }

      break;

    }

    case GST_QUERY_CONVERT:

    {

      GstFormat src_fmt, dest_fmt;

      gint64 src_val, dest_val;

      /* peel off input */

      gst_query_parse_convert (query, &src_fmt, &src_val, &dest_fmt, &dest_val);

      if ((res = gst_ogm_parse_sink_convert (pad, src_fmt, src_val,

                  &dest_fmt, &dest_val))) {

        gst_query_set_convert (query, src_fmt, src_val, dest_fmt, dest_val);

      }

      break;

    }

    default:

      res = gst_pad_query_default (pad, parent, query);

      break;

  }

  return res;

}

static GstFlowReturn

gst_ogm_parse_stream_header (GstOgmParse * ogm, const guint8 * data, guint size)

{

  GstCaps *caps = NULL;

  /* stream header */

  if (size < OGM_STREAM_HEADER_SIZE)

    goto buffer_too_small;

  if (!memcmp (data, "video\000\000\000", 8)) {

    ogm->hdr.s.video.width = GST_READ_UINT32_LE (&data[44]);

    ogm->hdr.s.video.height = GST_READ_UINT32_LE (&data[48]);

  } else if (!memcmp (data, "audio\000\000\000", 8)) {

    ogm->hdr.s.audio.channels = GST_READ_UINT32_LE (&data[44]);

    ogm->hdr.s.audio.blockalign = GST_READ_UINT32_LE (&data[46]);

    ogm->hdr.s.audio.avgbytespersec = GST_READ_UINT32_LE (&data[48]);

  } else if (!memcmp (data, "text\000\000\000\000", 8)) {

    /* nothing here */

  } else {

    goto cannot_decode;

  }

  memcpy (ogm->hdr.streamtype, &data[0], 8);

  memcpy (ogm->hdr.subtype, &data[8], 4);

  ogm->hdr.subtype[4] = '\0';

  ogm->hdr.size = GST_READ_UINT32_LE (&data[12]);

  ogm->hdr.time_unit = GST_READ_UINT64_LE (&data[16]);

  ogm->hdr.samples_per_unit = GST_READ_UINT64_LE (&data[24]);

  ogm->hdr.default_len = GST_READ_UINT32_LE (&data[32]);

  ogm->hdr.buffersize = GST_READ_UINT32_LE (&data[36]);

  ogm->hdr.bits_per_sample = GST_READ_UINT32_LE (&data[40]);

  switch (ogm->hdr.streamtype[0]) {

    case 'a':{

      guint codec_id = 0;

      if (sscanf (ogm->hdr.subtype, "%04x", &codec_id) != 1) {

        GST_WARNING_OBJECT (ogm, "cannot parse subtype %s", ogm->hdr.subtype);

      }

      /* FIXME: Need to do something with the reorder map */

      caps =

          gst_riff_create_audio_caps (codec_id, NULL, NULL, NULL, NULL, NULL,

          NULL);

      if (caps == NULL) {

        GST_WARNING_OBJECT (ogm, "no audio caps for codec %u found", codec_id);

        caps = gst_caps_new_simple ("audio/x-ogm-unknown", "codec_id",

            G_TYPE_INT, (gint) codec_id, NULL);

      }

      gst_caps_set_simple (caps,

          "channels", G_TYPE_INT, ogm->hdr.s.audio.channels,

          "rate", G_TYPE_INT, ogm->hdr.samples_per_unit, NULL);

      GST_LOG_OBJECT (ogm, "Type: %s, subtype: 0x%04x, channels: %d, "

          "samplerate: %d, blockalign: %d, bps: %d, caps = %" GST_PTR_FORMAT,

          ogm->hdr.streamtype, codec_id, ogm->hdr.s.audio.channels,

          (gint) ogm->hdr.samples_per_unit, ogm->hdr.s.audio.blockalign,

          ogm->hdr.s.audio.avgbytespersec, caps);

      break;

    }

    case 'v':{

      guint32 fourcc;

      gint time_unit;

      fourcc = GST_MAKE_FOURCC (ogm->hdr.subtype[0],

          ogm->hdr.subtype[1], ogm->hdr.subtype[2], ogm->hdr.subtype[3]);

      caps = gst_riff_create_video_caps (fourcc, NULL, NULL, NULL, NULL, NULL);

      if (caps == NULL) {

        gchar *fstr =

            g_strdup_printf ("%" GST_FOURCC_FORMAT, GST_FOURCC_ARGS (fourcc));

        GST_WARNING_OBJECT (ogm, "could not find video caps for fourcc '%s'",

            fstr);

        caps =

            gst_caps_new_simple ("video/x-ogm-unknown", "fourcc", G_TYPE_STRING,

            fstr, NULL);

        g_free (fstr);

        break;

      }

      GST_LOG_OBJECT (ogm, "Type: %s, subtype: %" GST_FOURCC_FORMAT

          ", size: %dx%d, timeunit: %" G_GINT64_FORMAT

          " (fps: %lf), s/u: %" G_GINT64_FORMAT ", "

          "def.len: %d, bufsize: %d, bps: %d, caps = %" GST_PTR_FORMAT,

          ogm->hdr.streamtype, GST_FOURCC_ARGS (fourcc),

          ogm->hdr.s.video.width, ogm->hdr.s.video.height,

          ogm->hdr.time_unit, 10000000. / ogm->hdr.time_unit,

          ogm->hdr.samples_per_unit, ogm->hdr.default_len,

          ogm->hdr.buffersize, ogm->hdr.bits_per_sample, caps);

      /* GST_TYPE_FRACTION contains gint */

      if (ogm->hdr.time_unit > G_MAXINT || ogm->hdr.time_unit < 1)

        GST_WARNING_OBJECT (ogm, "timeunit is out of range");

      time_unit = (gint) CLAMP (ogm->hdr.time_unit, 1, G_MAXINT);

      gst_caps_set_simple (caps,

          "width", G_TYPE_INT, ogm->hdr.s.video.width,

          "height", G_TYPE_INT, ogm->hdr.s.video.height,

          "framerate", GST_TYPE_FRACTION, 10000000, time_unit, NULL);

      break;

    }

    case 't':{

      GST_LOG_OBJECT (ogm, "Type: %s, s/u: %" G_GINT64_FORMAT

          ", timeunit=%" G_GINT64_FORMAT,

          ogm->hdr.streamtype, ogm->hdr.samples_per_unit, ogm->hdr.time_unit);

      caps = gst_caps_new_simple ("text/x-raw", "format", G_TYPE_STRING,

          "utf8", NULL);

      break;

    }

    default:

      g_assert_not_reached ();

  }

  if (caps == NULL)

    goto cannot_decode;

  if (!gst_caps_is_fixed (caps))

    goto non_fixed_caps;

  if (ogm->srcpad) {

    GstCaps *current_caps = gst_pad_get_current_caps (ogm->srcpad);

    if (current_caps) {

      if (caps && !gst_caps_is_equal (current_caps, caps)) {

        GST_WARNING_OBJECT (ogm, "Already an existing pad %s:%s",

            GST_DEBUG_PAD_NAME (ogm->srcpad));

        gst_pad_set_active (ogm->srcpad, FALSE);

        gst_element_remove_pad (GST_ELEMENT (ogm), ogm->srcpad);

        ogm->srcpad = NULL;

      } else {

        GST_DEBUG_OBJECT (ogm, "Existing pad has the same caps, do nothing");

      }

      gst_caps_unref (current_caps);

    }

  }

  if (ogm->srcpad == NULL) {

    GList *l, *cached_events;

    ogm->srcpad = gst_pad_new_from_template (ogm->srcpadtempl, "src");

    gst_pad_use_fixed_caps (ogm->srcpad);

    gst_pad_set_active (ogm->srcpad, TRUE);

    gst_element_add_pad (GST_ELEMENT (ogm), ogm->srcpad);

    GST_INFO_OBJECT (ogm, "Added pad %s:%s with caps %" GST_PTR_FORMAT,

        GST_DEBUG_PAD_NAME (ogm->srcpad), caps);

    GST_OBJECT_LOCK (ogm);

    cached_events = ogm->cached_events;

    ogm->cached_events = NULL;

    GST_OBJECT_UNLOCK (ogm);

    for (l = cached_events; l; l = l->next) {

      GstEvent *event = GST_EVENT_CAST (l->data);

      GST_DEBUG_OBJECT (ogm, "Pushing cached event %" GST_PTR_FORMAT, event);

      gst_pad_push_event (ogm->srcpad, event);

    }

    g_list_free (cached_events);

    gst_pad_set_caps (ogm->srcpad, caps);

    {

      GstTagList *tags;

      tags = gst_tag_list_new (GST_TAG_SUBTITLE_CODEC, "Ogm", NULL);

      gst_pad_push_event (ogm->srcpad, gst_event_new_tag (tags));

    }

  }

  gst_caps_unref (caps);

  return GST_FLOW_OK;

/* ERRORS */

buffer_too_small:

  {

    GST_ELEMENT_ERROR (ogm, STREAM, WRONG_TYPE, ("Buffer too small"), (NULL));

    return GST_FLOW_ERROR;

  }

cannot_decode:

  {

    GST_ELEMENT_ERROR (ogm, STREAM, DECODE, (NULL), ("unknown ogm format"));

    return GST_FLOW_ERROR;

  }

non_fixed_caps:

  {

    gst_caps_unref (caps);

    GST_ELEMENT_ERROR (ogm, STREAM, DECODE, (NULL), ("broken ogm format"));

    return GST_FLOW_ERROR;

  }

}

static GstFlowReturn

gst_ogm_parse_comment_packet (GstOgmParse * ogm, GstBuffer * buf)

{

  GstFlowReturn ret;

  if (ogm->srcpad == NULL) {

    GST_DEBUG ("no source pad");

    return GST_FLOW_FLUSHING;

  }

  /* if this is not a subtitle stream, push the vorbiscomment packet

   * on downstream, the respective decoder will handle it; if it is

   * a subtitle stream, we will have to handle the comment ourself */

  if (ogm->hdr.streamtype[0] == 't') {

    GstTagList *tags;

    tags = gst_tag_list_from_vorbiscomment_buffer (buf,

        (guint8 *) "\003vorbis", 7, NULL);

    if (tags) {

      GST_DEBUG_OBJECT (ogm, "tags = %" GST_PTR_FORMAT, tags);

      gst_pad_push_event (ogm->srcpad, gst_event_new_tag (tags));

    } else {

      GST_DEBUG_OBJECT (ogm, "failed to extract tags from vorbis comment");

    }

    /* do not push packet downstream, just let parent unref it */

    ret = GST_FLOW_OK;

  } else {

    ret = gst_pad_push (ogm->srcpad, buf);

  }

  return ret;

}

static void

gst_ogm_text_parse_strip_trailing_zeroes (GstOgmParse * ogm, GstBuffer * buf)

{

  GstMapInfo map;

  gsize size;

  g_assert (gst_buffer_is_writable (buf));

  /* zeroes are not valid UTF-8 characters, so strip them from output */

  gst_buffer_map (buf, &map, GST_MAP_WRITE);

  size = map.size;

  while (size > 0 && map.data[size - 1] == '\0') {

    --size;

  }

  gst_buffer_unmap (buf, &map);

}

static GstFlowReturn

gst_ogm_parse_data_packet (GstOgmParse * ogm, GstBuffer * buf,

    const guint8 * data, gsize size)

{

  GstFlowReturn ret;

  GstBuffer *sbuf;

  gboolean keyframe;

  guint len, n, xsize = 0;

  if ((data[0] & 0x01) != 0)

    goto invalid_startcode;

  /* data - push on */

  len = ((data[0] & 0xc0) >> 6) | ((data[0] & 0x02) << 1);

  keyframe = (((data[0] & 0x08) >> 3) != 0);

  if ((1 + len) > size)

    goto buffer_too_small;

  for (n = len; n > 0; n--) {

    xsize = (xsize << 8) | data[n];

  }

  GST_LOG_OBJECT (ogm, "[0x%02x] samples: %d, hdrbytes: %d, datasize: %"

      G_GSIZE_FORMAT, data[0], xsize, len, size - len - 1);

  sbuf =

      gst_buffer_copy_region (buf, GST_BUFFER_COPY_ALL, len + 1,

      size - len - 1);

  if (GST_BUFFER_OFFSET_END_IS_VALID (buf))

    ogm->next_granulepos = GST_BUFFER_OFFSET_END (buf);

  switch (ogm->hdr.streamtype[0]) {

    case 't':

    case 'v':{

      GstClockTime ts, next_ts;

      guint samples;

      samples = (ogm->hdr.streamtype[0] == 'v') ? 1 : xsize;

      if (!keyframe) {

        GST_BUFFER_FLAG_SET (sbuf, GST_BUFFER_FLAG_DELTA_UNIT);

      }

      /* shouldn't this be granulepos - samples? (tpm) */

      ts = gst_util_uint64_scale (ogm->next_granulepos,

          ogm->hdr.time_unit * GST_SECOND, 10000000);

      next_ts = gst_util_uint64_scale (ogm->next_granulepos + samples,

          ogm->hdr.time_unit * GST_SECOND, 10000000);

      GST_BUFFER_TIMESTAMP (sbuf) = ts;

      GST_BUFFER_DURATION (sbuf) = next_ts - ts;

      ogm->next_granulepos += samples;

      if (ogm->hdr.streamtype[0] == 't') {

        gst_ogm_text_parse_strip_trailing_zeroes (ogm, sbuf);

      }

      break;

    }

    case 'a':{

      GstClockTime ts, next_ts;

      /* shouldn't this be granulepos - samples? (tpm) */

      ts = gst_util_uint64_scale_int (ogm->next_granulepos,

          GST_SECOND, ogm->hdr.samples_per_unit);

      next_ts = gst_util_uint64_scale_int (ogm->next_granulepos + xsize,

          GST_SECOND, ogm->hdr.samples_per_unit);

      GST_BUFFER_TIMESTAMP (sbuf) = ts;

      GST_BUFFER_DURATION (sbuf) = next_ts - ts;

      ogm->next_granulepos += xsize;

      break;

    }

    default:

      g_assert_not_reached ();

      break;

  }

  if (ogm->srcpad) {

    GST_LOG_OBJECT (ogm, "Pushing buffer with ts=%" GST_TIME_FORMAT,

        GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (sbuf)));

    ret = gst_pad_push (ogm->srcpad, sbuf);

    if (ret != GST_FLOW_OK) {

      GST_DEBUG_OBJECT (ogm, "Flow on %s:%s = %s",

          GST_DEBUG_PAD_NAME (ogm->srcpad), gst_flow_get_name (ret));

    }

  } else {

    ret = GST_FLOW_FLUSHING;

  }

  return ret;

/* ERRORS */

invalid_startcode:

  {

    GST_ELEMENT_ERROR (ogm, STREAM, DECODE, (NULL),

        ("unexpected packet startcode 0x%02x", data[0]));

    return GST_FLOW_ERROR;

  }

buffer_too_small:

  {

    GST_ELEMENT_ERROR (ogm, STREAM, DECODE, (NULL),

        ("buffer too small, len+1=%u, size=%" G_GSIZE_FORMAT, len + 1, size));

    return GST_FLOW_ERROR;

  }

}

static GstFlowReturn

gst_ogm_parse_chain (GstPad * pad, GstObject * parent, GstBuffer * buf)

{

  GstFlowReturn ret = GST_FLOW_OK;

  GstOgmParse *ogm = GST_OGM_PARSE (parent);

  GstMapInfo map;

  gst_buffer_map (buf, &map, GST_MAP_READ);

  if (map.size < 1)

    goto buffer_too_small;

  GST_LOG_OBJECT (ogm, "Packet with start code 0x%02x", map.data[0]);

  switch (map.data[0]) {

    case 0x01:{

      ret = gst_ogm_parse_stream_header (ogm, map.data + 1, map.size - 1);

      break;

    }

    case 0x03:{

      ret = gst_ogm_parse_comment_packet (ogm, buf);

      break;

    }

    default:{