/* -*- c-basic-offset: 8; -*- */

/* theora.c: Ogg Theora data handlers for libshout

 * $Id: theora.c 11416 2006-05-22 00:32:49Z brendan $

 *

 *  Copyright (C) 2004 the Icecast team <team@icecast.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

 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

#ifdef HAVE_CONFIG_H

# include <config.h>

#endif

#ifdef HAVE_INTTYPES_H

# include <inttypes.h>

#endif

#include <theora/theora.h>

#include "shout_private.h"

#include "shout_ogg.h"

/* -- local data structures -- */

typedef struct {

	theora_info ti;

	theora_comment tc;

	uint32_t granule_shift;

	double per_frame;

    uint64_t start_frame;

    int initial_frames;

    int get_start_frame;

} theora_data_t;

/* -- local prototypes -- */

static int read_theora_page(ogg_codec_t *codec, ogg_page *page);

static void free_theora_data(void *codec_data);

static int theora_ilog(unsigned int v);

/* -- theora functions -- */

int _shout_open_theora(ogg_codec_t *codec, ogg_page *page)

{

	ogg_packet packet;

	theora_data_t *theora_data = calloc(1, sizeof(theora_data_t));

	if (! theora_data)

		return SHOUTERR_MALLOC;

	theora_info_init(&theora_data->ti);

	theora_comment_init(&theora_data->tc);

	ogg_stream_packetout(&codec->os, &packet);

	if (theora_decode_header(&theora_data->ti, &theora_data->tc, &packet) < 0) {

		free_theora_data(theora_data);

		return SHOUTERR_UNSUPPORTED;

	}

	codec->codec_data = theora_data;

	codec->read_page = read_theora_page;

	codec->free_data = free_theora_data;

	codec->headers = 1;

    theora_data->initial_frames = 0;

	return SHOUTERR_SUCCESS;

}

static int read_theora_page(ogg_codec_t *codec, ogg_page *page)

{

	theora_data_t *theora_data = codec->codec_data;

	ogg_packet packet;

	ogg_int64_t granulepos, iframe, pframe;

	granulepos = ogg_page_granulepos(page);

	if (granulepos == 0)

	{

		while (ogg_stream_packetout(&codec->os, &packet) > 0) {

			if (theora_decode_header(&theora_data->ti, &theora_data->tc, &packet) < 0)

				return SHOUTERR_INSANE;

			codec->headers++;

		}

		if (codec->headers == 3)

        {

			theora_data->granule_shift = theora_ilog(theora_data->ti.keyframe_frequency_force - 1);

            theora_data->per_frame = (double)theora_data->ti.fps_denominator / theora_data->ti.fps_numerator * 1000000;

            theora_data->get_start_frame = 1;

		}

		return SHOUTERR_SUCCESS;

	}

    while (ogg_stream_packetout(&codec->os, &packet) > 0)

    {

        if (theora_data->get_start_frame)

            theora_data->initial_frames++;

    }

	if (granulepos > 0 && codec->headers >= 3)

    {

        iframe = granulepos >> theora_data->granule_shift;

        pframe = granulepos - (iframe << theora_data->granule_shift);

        if (theora_data->get_start_frame)

        {

            /* work out the real start frame, which may not be 0 */

            theora_data->start_frame = iframe + pframe - theora_data->initial_frames;

            codec->senttime = 0;

            theora_data->get_start_frame = 0;

        }

        else

        {

            uint64_t frames = ((iframe + pframe) - theora_data->start_frame);

            codec->senttime = (uint64_t)(frames * theora_data->per_frame);

        }

	}

	return SHOUTERR_SUCCESS;

}

static void free_theora_data(void *codec_data)

{

	theora_data_t *theora_data = (theora_data_t *)codec_data;

	theora_info_clear(&theora_data->ti);

	theora_comment_clear(&theora_data->tc);

	free(theora_data);

}

static int theora_ilog(unsigned int v)

{

	int ret = 0;

	while (v) {

		ret++;

		v >>= 1;

	}

	return ret;

}