/*****************************************************************************
 * rawdv.c : raw DV input module for vlc
 *****************************************************************************
 * Copyright (C) 2001-2007 VLC authors and VideoLAN
 * $Id: 77dc254586388865b7849e462ddbdc20421950ad $
 *
 * Authors: Gildas Bazin <gbazin@netcourrier.com>
 *          Paul Corke <paul dot corke at datatote dot co dot uk>
 *
 * 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_demux.h>

#include "rawdv.h"

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
#define HURRYUP_TEXT N_( "Hurry up" )
#define HURRYUP_LONGTEXT N_( "The demuxer will advance timestamps if the " \
                "input can't keep up with the rate." )

static int  Open ( vlc_object_t * );
static void Close( vlc_object_t * );

vlc_module_begin ()
    set_shortname( "DV" )
    set_description( N_("DV (Digital Video) demuxer") )
    set_capability( "demux", 3 )
    set_category( CAT_INPUT )
    set_subcategory( SUBCAT_INPUT_DEMUX )
    add_bool( "rawdv-hurry-up", false, HURRYUP_TEXT, HURRYUP_LONGTEXT, false )
    set_callbacks( Open, Close )
    add_shortcut( "rawdv" )
vlc_module_end ()


/*****************************************************************************
 A little bit of background information (copied over from libdv glossary).

 - DIF block: A block of 80 bytes. This is the basic data framing unit of the
       DVC tape format, analogous to sectors of hard disc.

 - Video Section: Each DIF sequence contains a video section, consisting of
       135 DIF blocks, which are further subdivided into Video Segments.

 - Video Segment: A video segment consists of 5 DIF blocks, each corresponding
       to a single compressed macroblock.

*****************************************************************************/

/*****************************************************************************
 * Definitions of structures used by this plugin
 *****************************************************************************/
typedef struct {
    int8_t sct;      /* Section type (header,subcode,aux,audio,video) */
    int8_t dsn;      /* DIF sequence number (0-12) */
    int    fsc;      /* First (0)/Second channel (1) */
    int8_t dbn;      /* DIF block number (0-134) */
} dv_id_t;

typedef struct {
    int    dsf;      /* DIF sequence flag: 525/60 (0) or 625,50 (1) */
    int8_t apt;
    int    tf1;
    int8_t ap1;
    int    tf2;
    int8_t ap2;
    int    tf3;
    int8_t ap3;
} dv_header_t;

struct demux_sys_t
{
    int    frame_size;

    es_out_id_t *p_es_video;
    es_format_t  fmt_video;

    es_out_id_t *p_es_audio;
    es_format_t  fmt_audio;

    int    i_dsf;
    double f_rate;
    int    i_bitrate;

    /* program clock reference (in units of 90kHz) */
    mtime_t i_pcr;
    bool b_hurry_up;
};

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int Demux( demux_t * );
static int Control( demux_t *, int i_query, va_list args );

/*****************************************************************************
 * Open: initializes raw DV demux structures
 *****************************************************************************/
static int Open( vlc_object_t * p_this )
{
    demux_t     *p_demux = (demux_t*)p_this;
    demux_sys_t *p_sys;

    const uint8_t *p_peek, *p_peek_backup;

    uint32_t    i_dword;
    dv_header_t dv_header;
    dv_id_t     dv_id;

    /* It isn't easy to recognize a raw DV stream. The chances that we'll
     * mistake a stream from another type for a raw DV stream are too high, so
     * we'll rely on the file extension to trigger this demux. Alternatively,
     * it is possible to force this demux. */

    /* Check for DV file extension */
    if( !demux_IsPathExtension( p_demux, ".dv" ) && !p_demux->b_force )
        return VLC_EGENERIC;

    if( stream_Peek( p_demux->s, &p_peek, DV_PAL_FRAME_SIZE ) <
        DV_NTSC_FRAME_SIZE )
    {
        /* Stream too short ... */
        msg_Err( p_demux, "cannot peek()" );
        return VLC_EGENERIC;
    }
    p_peek_backup = p_peek;

    /* fill in the dv_id_t structure */
    i_dword = GetDWBE( p_peek ); p_peek += 4;
    dv_id.sct = i_dword >> (32 - 3);
    i_dword <<= 8;
    dv_id.dsn = i_dword >> (32 - 4);
    i_dword <<= 4;
    dv_id.fsc = i_dword >> (32 - 1);
    i_dword <<= 4;
    dv_id.dbn = i_dword >> (32 - 8);
    i_dword <<= 8;

    if( dv_id.sct != 0 )
    {
        msg_Warn( p_demux, "not a raw DV stream header" );
        return VLC_EGENERIC;
    }

    /* fill in the dv_header_t structure */
    dv_header.dsf = i_dword >> (32 - 1);
    i_dword <<= 1;
    if( i_dword >> (32 - 1) ) /* incorrect bit */
    {
        msg_Warn( p_demux, "incorrect bit" );
        return VLC_EGENERIC;
    }

    i_dword = GetDWBE( p_peek ); p_peek += 4;
    i_dword <<= 5;
    dv_header.apt = i_dword >> (32 - 3);
    i_dword <<= 3;
    dv_header.tf1 = i_dword >> (32 - 1);
    i_dword <<= 5;
    dv_header.ap1 = i_dword >> (32 - 3);
    i_dword <<= 3;
    dv_header.tf2 = i_dword >> (32 - 1);
    i_dword <<= 5;
    dv_header.ap2 = i_dword >> (32 - 3);
    i_dword <<= 3;
    dv_header.tf3 = i_dword >> (32 - 1);
    i_dword <<= 5;
    dv_header.ap3 = i_dword >> (32 - 3);

    p_peek += 72;                                  /* skip rest of DIF block */

    p_demux->p_sys      = p_sys = malloc( sizeof( demux_sys_t ) );
    if( !p_sys )
        return VLC_ENOMEM;

    p_sys->b_hurry_up = var_CreateGetBool( p_demux, "rawdv-hurry-up" );
    msg_Dbg( p_demux, "Realtime DV Source: %s", (p_sys->b_hurry_up)?"Yes":"No" );

    p_sys->i_dsf = dv_header.dsf;
    p_sys->frame_size = dv_header.dsf ? DV_PAL_FRAME_SIZE
                                      : DV_NTSC_FRAME_SIZE;
    p_sys->f_rate = dv_header.dsf ? 25 : 29.97;

    p_sys->i_pcr = 0;
    p_sys->p_es_video = NULL;
    p_sys->p_es_audio = NULL;

    p_sys->i_bitrate = 0;

    es_format_Init( &p_sys->fmt_video, VIDEO_ES, VLC_CODEC_DV );
    p_sys->fmt_video.video.i_width = 720;
    p_sys->fmt_video.video.i_height= dv_header.dsf ? 576 : 480;;

    p_sys->p_es_video = es_out_Add( p_demux->out, &p_sys->fmt_video );

    /* Audio stuff */
    p_peek = p_peek_backup + 80*6+80*16*3 + 3; /* beginning of AAUX pack */
    if( *p_peek == 0x50 )
    {
        dv_get_audio_format( &p_sys->fmt_audio, &p_peek[1] );
        p_sys->p_es_audio = es_out_Add( p_demux->out, &p_sys->fmt_audio );
    }

    p_demux->pf_demux   = Demux;
    p_demux->pf_control = Control;
    return VLC_SUCCESS;
}

/*****************************************************************************
 * Close: frees unused data
 *****************************************************************************/
static void Close( vlc_object_t *p_this )
{
    demux_t     *p_demux = (demux_t*)p_this;
    demux_sys_t *p_sys  = p_demux->p_sys;

    var_Destroy( p_demux, "rawdv-hurry-up");
    free( p_sys );
}

/*****************************************************************************
 * Demux: reads and demuxes data packets
 *****************************************************************************
 * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 *****************************************************************************/
static int Demux( demux_t *p_demux )
{
    demux_sys_t *p_sys  = p_demux->p_sys;
    block_t     *p_block;
    bool  b_audio = false;

    if( p_sys->b_hurry_up )
    {
         /* 3 frames */
        p_sys->i_pcr = mdate() + (p_sys->i_dsf ? 120000 : 90000);
    }

    /* Call the pace control */
    es_out_Control( p_demux->out, ES_OUT_SET_PCR, VLC_TS_0 + p_sys->i_pcr );
    p_block = stream_Block( p_demux->s, p_sys->frame_size );
    if( p_block == NULL )
    {
        /* EOF */
        return 0;
    }

    if( p_sys->p_es_audio )
    {
        es_out_Control( p_demux->out, ES_OUT_GET_ES_STATE,
                        p_sys->p_es_audio, &b_audio );
    }

    p_block->i_dts =
    p_block->i_pts = VLC_TS_0 + p_sys->i_pcr;

    if( b_audio )
    {
        block_t *p_audio_block = dv_extract_audio( p_block );
        if( p_audio_block )
            es_out_Send( p_demux->out, p_sys->p_es_audio, p_audio_block );
    }

    es_out_Send( p_demux->out, p_sys->p_es_video, p_block );

    if( !p_sys->b_hurry_up )
    {
        p_sys->i_pcr += ( INT64_C(1000000) / p_sys->f_rate );
    }

    return 1;
}

/*****************************************************************************
 * Control:
 *****************************************************************************/
static int Control( demux_t *p_demux, int i_query, va_list args )
{
    demux_sys_t *p_sys  = p_demux->p_sys;

    /* XXX: DEMUX_SET_TIME is precise here */
    return demux_vaControlHelper( p_demux->s,
                                   0, -1,
                                   p_sys->frame_size * p_sys->f_rate * 8,
                                   p_sys->frame_size, i_query, args );
}