/* GStreamer

 * Copyright (C) 2005 Michael Smith <msmith@fluendo.com>

 *

 * gstoggparse.c: ogg stream parser

 *

 * 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.

 */

/* This ogg parser is essentially a subset of the ogg demuxer - rather than

 * fully demuxing into packets, we only parse out the pages, create one

 * GstBuffer per page, set all the appropriate flags on those pages, set caps

 * appropriately (particularly the 'streamheader' which gives all the header

 * pages required for initialing decode).

 *

 * It's dramatically simpler than the full demuxer as it does not  support 

 * seeking.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <gst/gst.h>

#include <ogg/ogg.h>

#include <string.h>

static const GstElementDetails gst_ogg_parse_details =

GST_ELEMENT_DETAILS ("Ogg parser",

    "Codec/Parser",

    "parse ogg streams into pages (info about ogg: http://xiph.org)",

    "Michael Smith <msmith@fluendo.com>");

GST_DEBUG_CATEGORY_STATIC (gst_ogg_parse_debug);

#define GST_CAT_DEFAULT gst_ogg_parse_debug

#define GST_TYPE_OGG_PARSE (gst_ogg_parse_get_type())

#define GST_OGG_PARSE(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_OGG_PARSE, GstOggParse))

#define GST_OGG_PARSE_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_OGG_PARSE, GstOggParse))

#define GST_IS_OGG_PARSE(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_OGG_PARSE))

#define GST_IS_OGG_PARSE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_OGG_PARSE))

static GType gst_ogg_parse_get_type (void);

typedef struct _GstOggParse GstOggParse;

typedef struct _GstOggParseClass GstOggParseClass;

/* Each ogg logical stream has a GstOggStream associated with it */

typedef struct

{

  /*ogg_stream_state stream; *//* We need this to get the packets out in order

     to do codec identification, for various

     codec-specific tasks */

  gboolean in_headers;          /* Initially true, false once we've read all the

                                   headers for this logical stream */

  guint32 serialno;             /* Unique serial number of this stream */

  GSList *headers;              /* List of ogg pages that we'll set on caps */

  GSList *unknown_pages;        /* List of pages we haven't yet classified */

} GstOggStream;

struct _GstOggParse

{

  GstElement element;

  GstPad *sinkpad;              /* Sink pad we're reading data from */

  GstPad *srcpad;               /* Source pad we're writing to */

  GSList *oggstreams;           /* list of GstOggStreams for known streams */

  gint64 offset;                /* Current stream offset */

  gboolean in_headers;          /* Set if we're reading headers for streams */

  gboolean last_page_not_bos;   /* Set if we've seen a non-BOS page */

  ogg_sync_state sync;          /* Ogg page synchronisation */

  GstCaps *caps;                /* Our src caps */

};

struct _GstOggParseClass

{

  GstElementClass parent_class;

};

static void gst_ogg_parse_base_init (gpointer g_class);

static void gst_ogg_parse_class_init (GstOggParseClass * klass);

static void gst_ogg_parse_init (GstOggParse * ogg);

static GstElementClass *parent_class = NULL;

static GType

gst_ogg_parse_get_type (void)

{

  static GType ogg_parse_type = 0;

  if (!ogg_parse_type) {

    static const GTypeInfo ogg_parse_info = {

      sizeof (GstOggParseClass),

      gst_ogg_parse_base_init,

      NULL,

      (GClassInitFunc) gst_ogg_parse_class_init,

      NULL,

      NULL,

      sizeof (GstOggParse),

      0,

      (GInstanceInitFunc) gst_ogg_parse_init,

    };

    ogg_parse_type = g_type_register_static (GST_TYPE_ELEMENT, "GstOggParse",

        &ogg_parse_info, 0);

  }

  return ogg_parse_type;

}

static void

free_stream (GstOggStream * stream)

{

  g_slist_foreach (stream->headers, (GFunc) gst_mini_object_unref, NULL);

  g_slist_foreach (stream->unknown_pages, (GFunc) gst_mini_object_unref, NULL);

  g_free (stream);

}

static void

gst_ogg_parse_delete_all_streams (GstOggParse * ogg)

{

  g_slist_foreach (ogg->oggstreams, (GFunc) free_stream, NULL);

  g_slist_free (ogg->oggstreams);

  ogg->oggstreams = NULL;

}

static GstOggStream *

gst_ogg_parse_new_stream (GstOggParse * parser, guint32 serialno)

{

  GstOggStream *ret;

  GST_DEBUG_OBJECT (parser, "creating new stream %08x", serialno);

  ret = g_new0 (GstOggStream, 1);

  ret->serialno = serialno;

  ret->in_headers = 1;

  /*

     if (ogg_stream_init (&ret->stream, serialno) != 0) {

     GST_ERROR ("Could not initialize ogg_stream struct for serial %08lx.",

     serialno);

     return NULL;

     }

   */

  parser->oggstreams = g_slist_append (parser->oggstreams, ret);

  return ret;

}

static GstOggStream *

gst_ogg_parse_find_stream (GstOggParse * parser, guint32 serialno)

{

  GSList *l;

  for (l = parser->oggstreams; l != NULL; l = l->next) {

    GstOggStream *stream = (GstOggStream *) l->data;

    if (stream->serialno == serialno)

      return stream;

  }

  return NULL;

}

/* signals and args */

enum

{

  /* FILL ME */

  LAST_SIGNAL

};

enum

{

  ARG_0

      /* FILL ME */

};

static GstStaticPadTemplate ogg_parse_src_template_factory =

GST_STATIC_PAD_TEMPLATE ("src",

    GST_PAD_SRC,

    GST_PAD_ALWAYS,

    GST_STATIC_CAPS ("application/ogg")

    );

static GstStaticPadTemplate ogg_parse_sink_template_factory =

GST_STATIC_PAD_TEMPLATE ("sink",

    GST_PAD_SINK,

    GST_PAD_ALWAYS,

    GST_STATIC_CAPS ("application/ogg")

    );

static void gst_ogg_parse_dispose (GObject * object);

static GstStateChangeReturn gst_ogg_parse_change_state (GstElement * element,

    GstStateChange transition);

static GstFlowReturn gst_ogg_parse_chain (GstPad * pad, GstBuffer * buffer);

static void

gst_ogg_parse_base_init (gpointer g_class)

{

  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);

  gst_element_class_set_details (element_class, &gst_ogg_parse_details);

  gst_element_class_add_pad_template (element_class,

      gst_static_pad_template_get (&ogg_parse_sink_template_factory));

  gst_element_class_add_pad_template (element_class,

      gst_static_pad_template_get (&ogg_parse_src_template_factory));

}

static void

gst_ogg_parse_class_init (GstOggParseClass * klass)

{

  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);

  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

  parent_class = g_type_class_peek_parent (klass);

  gstelement_class->change_state = gst_ogg_parse_change_state;

  gobject_class->dispose = gst_ogg_parse_dispose;

}

static void

gst_ogg_parse_init (GstOggParse * ogg)

{

  /* create the sink and source pads */

  ogg->sinkpad =

      gst_pad_new_from_static_template (&ogg_parse_sink_template_factory,

      "sink");

  ogg->srcpad =

      gst_pad_new_from_static_template (&ogg_parse_src_template_factory, "src");

  /* TODO: Are there any events we must handle? */

  /* gst_pad_set_event_function (ogg->sinkpad, gst_ogg_parse_handle_event); */

  gst_pad_set_chain_function (ogg->sinkpad, gst_ogg_parse_chain);

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

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

  ogg->oggstreams = NULL;

}

static void

gst_ogg_parse_dispose (GObject * object)

{

  GstOggParse *ogg = GST_OGG_PARSE (object);

  GST_LOG_OBJECT (ogg, "Disposing of object %p", ogg);

  ogg_sync_clear (&ogg->sync);

  gst_ogg_parse_delete_all_streams (ogg);

  if (ogg->caps) {

    gst_caps_unref (ogg->caps);

    ogg->caps = NULL;

  }

  if (G_OBJECT_CLASS (parent_class)->dispose)

    G_OBJECT_CLASS (parent_class)->dispose (object);

}

/* submit the given buffer to the ogg sync.

 *

 * Returns the number of bytes submited.

 */

static gint

gst_ogg_parse_submit_buffer (GstOggParse * ogg, GstBuffer * buffer)

{

  guint size;

  guint8 *data;

  gchar *oggbuffer;

  size = GST_BUFFER_SIZE (buffer);

  data = GST_BUFFER_DATA (buffer);

  /* We now have a buffer, submit it to the ogg sync layer */

  oggbuffer = ogg_sync_buffer (&ogg->sync, size);

  memcpy (oggbuffer, data, size);

  ogg_sync_wrote (&ogg->sync, size);

  /* We've copied all the neccesary data, so we're done with the buffer */

  gst_buffer_unref (buffer);

  return size;

}

static void

gst_ogg_parse_append_header (GValue * array, GstBuffer * buf)

{

  GValue value = { 0 };

  /* We require a copy to avoid circular refcounts */

  GstBuffer *buffer = gst_buffer_copy (buf);

  GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_IN_CAPS);

  g_value_init (&value, GST_TYPE_BUFFER);

  gst_value_set_buffer (&value, buffer);

  gst_value_array_append_value (array, &value);

  g_value_unset (&value);

}

typedef enum

{

  PAGE_HEADER,                  /* Header page */

  PAGE_DATA,                    /* Data page */

  PAGE_PENDING,                 /* We don't know yet, we'll have to see some future pages */

} page_type;

static page_type

gst_ogg_parse_is_header (GstOggParse * ogg, GstOggStream * stream,

    ogg_page * page)

{

  ogg_int64_t gpos = ogg_page_granulepos (page);

  if (gpos < 0)

    return PAGE_PENDING;

  /* This is good enough for now, but technically requires codec-specific

   * behaviour to be perfect. This is where we need the mooted library for 

   * this stuff, which nobody has written.

   */

  if (gpos > 0)

    return PAGE_DATA;

  else

    return PAGE_HEADER;

}

static GstBuffer *

gst_ogg_parse_buffer_from_page (ogg_page * page,

    guint64 offset, gboolean delta, GstClockTime timestamp)

{

  int size = page->header_len + page->body_len;

  GstBuffer *buf = gst_buffer_new_and_alloc (size);

  memcpy (GST_BUFFER_DATA (buf), page->header, page->header_len);

  memcpy (GST_BUFFER_DATA (buf) + page->header_len, page->body, page->body_len);

  GST_BUFFER_TIMESTAMP (buf) = timestamp;

  GST_BUFFER_OFFSET (buf) = offset;

  GST_BUFFER_OFFSET_END (buf) = offset + size;

  return buf;

}

/* Reads in buffers, parses them, reframes into one-buffer-per-ogg-page, submits

 * pages to output pad.

 */

static GstFlowReturn

gst_ogg_parse_chain (GstPad * pad, GstBuffer * buffer)

{

  GstOggParse *ogg;

  GstFlowReturn result = GST_FLOW_OK;

  gint ret = -1;

  guint32 serialno;

  GstBuffer *pagebuffer;

  GstClockTime buffertimestamp = GST_BUFFER_TIMESTAMP (buffer);

  ogg = GST_OGG_PARSE (GST_OBJECT_PARENT (pad));

  GST_LOG_OBJECT (ogg, "Chain function received buffer of size %d",

      GST_BUFFER_SIZE (buffer));

  gst_ogg_parse_submit_buffer (ogg, buffer);

  while (ret != 0 && result == GST_FLOW_OK) {

    ogg_page page;

    /* We use ogg_sync_pageseek() rather than ogg_sync_pageout() so that we can

     * track how many bytes the ogg layer discarded (in the case of sync errors,

     * etc.); this allows us to accurately track the current stream offset

     */

    ret = ogg_sync_pageseek (&ogg->sync, &page);

    if (ret == 0) {

      /* need more data, that's fine... */

      break;

    } else if (ret < 0) {

      /* discontinuity; track how many bytes we skipped (-ret) */

      ogg->offset -= ret;

    } else {

#ifndef GST_DISABLE_GST_DEBUG

      gint64 granule = ogg_page_granulepos (&page);

      int bos = ogg_page_bos (&page);

#endif

      guint64 startoffset = ogg->offset;

      GST_LOG_OBJECT (ogg, "Timestamping outgoing buffer as %" GST_TIME_FORMAT,

          GST_TIME_ARGS (buffertimestamp));

      /* Turn our page into a GstBuffer TODO: better timestamps? Requires format

       * parsing. */

      pagebuffer = gst_ogg_parse_buffer_from_page (&page, startoffset, FALSE,

          buffertimestamp);

      /* We read out 'ret' bytes, so we set the next offset appropriately */

      ogg->offset += ret;

      serialno = ogg_page_serialno (&page);

      GST_LOG_OBJECT (ogg,

          "processing ogg page (serial %08x, pageno %ld, "

          "granule pos %" G_GUINT64_FORMAT ", bos %d, offset %"

          G_GUINT64_FORMAT "-%" G_GUINT64_FORMAT ")",

          serialno, ogg_page_pageno (&page),

          granule, bos, startoffset, ogg->offset);

      if (ogg_page_bos (&page)) {

        /* If we've seen this serialno before, this is technically an error,

         * we log this case but accept it - this one replaces the previous

         * stream with this serialno. We can do this since we're streaming, and

         * not supporting seeking...

         */

        GstOggStream *stream = gst_ogg_parse_find_stream (ogg, serialno);

        if (stream != NULL) {

          GST_LOG_OBJECT (ogg, "Incorrect stream; repeats serial number %u "

              "at offset %lld", serialno, ogg->offset);

        }

        if (ogg->last_page_not_bos) {

          GST_LOG_OBJECT (ogg, "Deleting all referenced streams, found a new "

              "chain starting with serial %u", serialno);

          gst_ogg_parse_delete_all_streams (ogg);

        }

        stream = gst_ogg_parse_new_stream (ogg, serialno);

        ogg->last_page_not_bos = FALSE;

        gst_buffer_ref (pagebuffer);

        stream->headers = g_slist_append (stream->headers, pagebuffer);

        if (!ogg->in_headers) {

          GST_LOG_OBJECT (ogg, "Found start of new chain at offset %llu",

              startoffset);

          ogg->in_headers = 1;

        }

        /* For now, we just keep the header buffer in the stream->headers list;

         * it actually gets output once we've collected the entire set

         */

      } else {

        /* Non-BOS page. Either: we're outside headers, and this isn't a 

         * header (normal data), outside headers and this is (error!), inside

         * headers, this is (append header), or inside headers and this isn't 

         * (we've found the end of headers; flush the lot!)

         *

         * Before that, we flag that the last page seen (this one) was not a 

         * BOS page; that way we know that when we next see a BOS page it's a

         * new chain, and we can flush all existing streams.

         */

        page_type type;

        GstOggStream *stream = gst_ogg_parse_find_stream (ogg, serialno);

        if (!stream) {

          GST_LOG_OBJECT (ogg, "Non-BOS page unexpectedly found at %lld",

              ogg->offset);

          goto failure;

        }

        ogg->last_page_not_bos = TRUE;

        type = gst_ogg_parse_is_header (ogg, stream, &page);

        if (type == PAGE_PENDING && ogg->in_headers) {

          gst_buffer_ref (pagebuffer);

          stream->unknown_pages = g_slist_append (stream->unknown_pages,

              pagebuffer);

        } else if (type == PAGE_HEADER) {

          if (!ogg->in_headers) {

            GST_LOG_OBJECT (ogg, "Header page unexpectedly found outside "

                "headers at offset %lld", ogg->offset);

            goto failure;

          } else {

            /* Append the header to the buffer list, after any unknown previous

             * pages

             */

            stream->headers = g_slist_concat (stream->headers,

                stream->unknown_pages);

            g_slist_free (stream->unknown_pages);

            gst_buffer_ref (pagebuffer);

            stream->headers = g_slist_append (stream->headers, pagebuffer);

          }

        } else {                /* PAGE_DATA, or PAGE_PENDING but outside headers */

          if (ogg->in_headers) {

            /* First non-header page... set caps, flush headers.

             *

             * First up, we build a single GValue list of all the pagebuffers

             * we're using for the headers, in order.

             * Then we set this on the caps structure. Then we can start pushing

             * buffers for the headers, and finally we send this non-header

             * page.

             */

            GstCaps *caps;

            GstStructure *structure;

            GValue array = { 0 };

            gint count = 0;

            gboolean found_pending_headers = FALSE;

            GSList *l;

            g_value_init (&array, GST_TYPE_ARRAY);

            for (l = ogg->oggstreams; l != NULL; l = l->next) {

              GstOggStream *stream = (GstOggStream *) l->data;

              if (g_slist_length (stream->headers) == 0) {