/*****************************************************************************
 * rawvideo.c: Pseudo video decoder/packetizer for raw video data
 *****************************************************************************
 * Copyright (C) 2001, 2002 VLC authors and VideoLAN
 * $Id$
 *
 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This program 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <vlc_common.h>
#include <vlc_plugin.h>
#include <vlc_codec.h>

/*****************************************************************************
 * decoder_sys_t : raw video decoder descriptor
 *****************************************************************************/
struct decoder_sys_t
{
    /*
     * Input properties
     */
    size_t size;
    unsigned pitches[PICTURE_PLANE_MAX];
    unsigned lines[PICTURE_PLANE_MAX];

    /*
     * Common properties
     */
    date_t pts;
};

/****************************************************************************
 * Local prototypes
 ****************************************************************************/
static int  OpenDecoder   ( vlc_object_t * );
static int  OpenPacketizer( vlc_object_t * );
static void CloseCommon   ( vlc_object_t * );

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
vlc_module_begin ()
    set_description( N_("Pseudo raw video decoder") )
    set_capability( "decoder", 50 )
    set_category( CAT_INPUT )
    set_subcategory( SUBCAT_INPUT_VCODEC )
    set_callbacks( OpenDecoder, CloseCommon )

    add_submodule ()
    set_description( N_("Pseudo raw video packetizer") )
    set_capability( "packetizer", 100 )
    set_callbacks( OpenPacketizer, CloseCommon )
vlc_module_end ()

/**
 * Common initialization for decoder and packetizer
 */
static int OpenCommon( decoder_t *p_dec )
{
    const vlc_chroma_description_t *dsc =
        vlc_fourcc_GetChromaDescription( p_dec->fmt_in.i_codec );
    if( dsc == NULL || dsc->plane_count == 0 )
        return VLC_EGENERIC;

    if( p_dec->fmt_in.video.i_width <= 0 || p_dec->fmt_in.video.i_height == 0 )
    {
        msg_Err( p_dec, "invalid display size %dx%d",
                 p_dec->fmt_in.video.i_width, p_dec->fmt_in.video.i_height );
        return VLC_EGENERIC;
    }

    /* Allocate the memory needed to store the decoder's structure */
    decoder_sys_t *p_sys = calloc(1, sizeof(*p_sys));
    if( unlikely(p_sys == NULL) )
        return VLC_ENOMEM;

    if( !p_dec->fmt_in.video.i_visible_width )
        p_dec->fmt_in.video.i_visible_width = p_dec->fmt_in.video.i_width;
    if( !p_dec->fmt_in.video.i_visible_height )
        p_dec->fmt_in.video.i_visible_height = p_dec->fmt_in.video.i_height;

    es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );

    date_Init( &p_sys->pts, p_dec->fmt_out.video.i_frame_rate,
               p_dec->fmt_out.video.i_frame_rate_base );
    if( p_dec->fmt_out.video.i_frame_rate == 0 ||
        p_dec->fmt_out.video.i_frame_rate_base == 0)
    {
        msg_Warn( p_dec, "invalid frame rate %d/%d, using 25 fps instead",
                  p_dec->fmt_out.video.i_frame_rate,
                  p_dec->fmt_out.video.i_frame_rate_base);
        date_Init( &p_sys->pts, 25, 1 );
    }

    for( unsigned i = 0; i < dsc->plane_count; i++ )
    {
        unsigned pitch = p_dec->fmt_in.video.i_width * dsc->pixel_size
                         * dsc->p[i].w.num / dsc->p[i].w.den;
        unsigned lines = p_dec->fmt_in.video.i_height
                         * dsc->p[i].h.num / dsc->p[i].h.den;

        p_sys->pitches[i] = pitch;
        p_sys->lines[i] = lines;
        p_sys->size += pitch * lines;
    }

    p_dec->p_sys           = p_sys;
    return VLC_SUCCESS;
}

/*****************************************************************************
 * Flush:
 *****************************************************************************/
static void Flush( decoder_t *p_dec )
{
    decoder_sys_t *p_sys = p_dec->p_sys;

    date_Set( &p_sys->pts, VLC_TS_INVALID );
}

/****************************************************************************
 * DecodeBlock: the whole thing
 ****************************************************************************
 * This function must be fed with complete frames.
 ****************************************************************************/
static void *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;

    if( pp_block == NULL || *pp_block == NULL )
        return NULL;

    block_t *p_block = *pp_block;

    if( p_block->i_flags & BLOCK_FLAG_DISCONTINUITY )
        date_Set( &p_sys->pts, p_block->i_dts );

    if( p_block->i_pts <= VLC_TS_INVALID && p_block->i_dts <= VLC_TS_INVALID &&
        !date_Get( &p_sys->pts ) )
    {
        /* We've just started the stream, wait for the first PTS. */
        block_Release( p_block );
        return NULL;
    }

    /* Date management: If there is a pts avaliable, use that. */
    if( p_block->i_pts > VLC_TS_INVALID )
    {
        date_Set( &p_sys->pts, p_block->i_pts );
    }
    else if( p_block->i_dts > VLC_TS_INVALID )
    {
        /* NB, davidf doesn't quite agree with this in general, it is ok
         * for rawvideo since it is in order (ie pts=dts), however, it
         * may not be ok for an out-of-order codec, so don't copy this
         * without thinking */
        date_Set( &p_sys->pts, p_block->i_dts );
    }

    if( p_block->i_buffer < p_sys->size )
    {
        msg_Warn( p_dec, "invalid frame size (%zu < %zu)",
                  p_block->i_buffer, p_sys->size );

        block_Release( p_block );
        return NULL;
    }

    *pp_block = NULL;
    return p_block;
}

/*****************************************************************************
 * FillPicture:
 *****************************************************************************/
static void FillPicture( decoder_t *p_dec, block_t *p_block, picture_t *p_pic )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    const uint8_t *p_src = p_block->p_buffer;

    for( int i = 0; i < p_pic->i_planes; i++ )
    {
        uint8_t *p_dst = p_pic->p[i].p_pixels;

        for( int x = 0; x < p_pic->p[i].i_visible_lines; x++ )
        {
            memcpy( p_dst, p_src, p_pic->p[i].i_visible_pitch );
            p_src += p_sys->pitches[i];
            p_dst += p_pic->p[i].i_pitch;
        }

        p_src += p_sys->pitches[i]
               * (p_sys->lines[i] - p_pic->p[i].i_visible_lines);
    }
}

/*****************************************************************************
 * DecodeFrame: decodes a video frame.
 *****************************************************************************/
static picture_t *DecodeFrame( decoder_t *p_dec, block_t **pp_block )
{
    block_t *p_block = DecodeBlock( p_dec, pp_block );
    if( p_block == NULL )
        return NULL;

    decoder_sys_t *p_sys = p_dec->p_sys;

    /* Get a new picture */
    picture_t *p_pic = decoder_NewPicture( p_dec );
    if( p_pic == NULL )
    {
        block_Release( p_block );
        return NULL;
    }

    FillPicture( p_dec, p_block, p_pic );

    /* Date management: 1 frame per packet */
    p_pic->date = date_Get( &p_dec->p_sys->pts );
    date_Increment( &p_sys->pts, 1 );

    if( p_block->i_flags & BLOCK_FLAG_INTERLACED_MASK )
    {
        p_pic->b_progressive = false;
        p_pic->i_nb_fields = 2;
        if( p_block->i_flags & BLOCK_FLAG_TOP_FIELD_FIRST )
            p_pic->b_top_field_first = true;
        else
            p_pic->b_top_field_first = false;
    }
    else
        p_pic->b_progressive = true;

    block_Release( p_block );
    return p_pic;
}

static int OpenDecoder( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t *)p_this;

    int ret = OpenCommon( p_dec );
    if( ret == VLC_SUCCESS )
    {
        p_dec->pf_decode_video = DecodeFrame;
        p_dec->pf_flush        = Flush;
    }
    return ret;
}

/*****************************************************************************
 * SendFrame: send a video frame to the stream output.
 *****************************************************************************/
static block_t *SendFrame( decoder_t *p_dec, block_t **pp_block )
{
    block_t *p_block = DecodeBlock( p_dec, pp_block );
    if( p_block == NULL )
        return NULL;

    decoder_sys_t *p_sys = p_dec->p_sys;

    /* Date management: 1 frame per packet */
    p_block->i_dts = p_block->i_pts = date_Get( &p_sys->pts );
    date_Increment( &p_sys->pts, 1 );
    return p_block;
}

static int OpenPacketizer( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t *)p_this;

    int ret = OpenCommon( p_dec );
    if( ret == VLC_SUCCESS )
        p_dec->pf_packetize = SendFrame;
    return ret;
}

/**
 * Common deinitialization
 */
static void CloseCommon( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t*)p_this;
    free( p_dec->p_sys );
}