vc1.c

VLC Player Source Code

/*****************************************************************************
 * vc1.c
 *****************************************************************************
 * Copyright (C) 2001, 2002, 2006 the VideoLAN team
 * $Id$
 *
 * Authors: Laurent Aimar <[e-mail]>
 *          Gildas Bazin <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 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 General Public License for more details.
 *
 * You should have received a copy of the GNU 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>
#include <vlc_block.h>

#include "vlc_bits.h"
#include "vlc_block_helper.h"

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
static int  Open ( vlc_object_t * );
static void Close( vlc_object_t * );

vlc_module_begin();
    set_category( CAT_SOUT );
    set_subcategory( SUBCAT_SOUT_PACKETIZER );
    set_description( N_("VC-1 packetizer") );
    set_capability( "packetizer", 50 );
    set_callbacks( Open, Close );
vlc_module_end();

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
struct decoder_sys_t
{
    /*
     * Input properties
     */
    block_bytestream_t bytestream;
    int i_state;
    size_t i_offset;
    uint8_t p_startcode[3];

    /* Current sequence header */
    bool b_sequence_header;
    struct
    {
        block_t *p_sh;
        bool b_advanced_profile;
        bool b_interlaced;
        bool b_frame_interpolation;
        bool b_range_reduction;
        bool b_has_bframe;
    } sh;
    bool b_entry_point;
    struct
    {
        block_t *p_ep;
    } ep;

    /* */
    bool  b_frame;

    /* Current frame being built */
    block_t    *p_frame;
    block_t    **pp_last;


    mtime_t i_interpolated_dts;
};

enum
{
    STATE_NOSYNC,
    STATE_NEXT_SYNC
};

typedef enum
{
    IDU_TYPE_SEQUENCE_HEADER = 0x0f,
    IDU_TYPE_ENTRY_POINT = 0x0e,
    IDU_TYPE_FRAME = 0x0D,
    IDU_TYPE_FIELD = 0x0C,
    IDU_TYPE_SLICE = 0x0B,
    IDU_TYPE_END_OF_SEQUENCE = 0x0B,

    IDU_TYPE_SEQUENCE_LEVEL_USER_DATA = 0x1F,
    IDU_TYPE_ENTRY_POINT_USER_DATA = 0x1E,
    IDU_TYPE_FRAME_USER_DATA = 0x1D,
    IDU_TYPE_FIELD_USER_DATA = 0x1C,
    IDU_TYPE_SLICE_USER_DATA = 0x1B,
} idu_type_t;

static block_t *Packetize( decoder_t *p_dec, block_t **pp_block );

/*****************************************************************************
 * Open: probe the packetizer and return score
 *****************************************************************************
 * Tries to launch a decoder and return score so that the interface is able
 * to choose.
 *****************************************************************************/
static int Open( vlc_object_t *p_this )
{
    decoder_t     *p_dec = (decoder_t*)p_this;
    decoder_sys_t *p_sys;

    if( p_dec->fmt_in.i_codec !=  VLC_FOURCC( 'W', 'V', 'C', '1' ) )
        return VLC_EGENERIC;

    p_dec->pf_packetize = Packetize;

    /* Create the output format */
    es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
    p_dec->p_sys = p_sys = malloc( sizeof( decoder_sys_t ) );

    p_sys->i_state = STATE_NOSYNC;
    p_sys->bytestream = block_BytestreamInit();
    p_sys->p_startcode[0] = 0x00;
    p_sys->p_startcode[1] = 0x00;
    p_sys->p_startcode[2] = 0x01;
    p_sys->i_offset = 0;

    p_sys->b_sequence_header = false;
    p_sys->sh.p_sh = NULL;
    p_sys->b_entry_point = false;
    p_sys->ep.p_ep = NULL;

    p_sys->b_frame = false;
    p_sys->p_frame = NULL;
    p_sys->pp_last = &p_sys->p_frame;

    p_sys->i_interpolated_dts = -1;


    if( p_dec->fmt_in.i_extra > 0 )
    {
        block_t *p_init = block_New( p_dec, p_dec->fmt_in.i_extra );
        block_t *p_pic;

        memcpy( p_init->p_buffer, p_dec->fmt_in.p_extra,
                p_dec->fmt_in.i_extra );

        while( ( p_pic = Packetize( p_dec, &p_init ) ) )
            block_Release( p_pic ); /* Should not happen (only sequence header) */
    }

    return VLC_SUCCESS;
}

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

    block_BytestreamRelease( &p_sys->bytestream );
    if( p_sys->p_frame )
        block_Release( p_sys->p_frame );
    free( p_sys );
}

/*****************************************************************************
 * Packetize: packetize an access unit
 *****************************************************************************/
static block_t *ParseIDU( decoder_t *p_dec, block_t *p_frag );

static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    block_t       *p_pic;

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

    if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
    {
        if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
        {
            p_sys->i_state = STATE_NOSYNC;
            block_BytestreamFlush( &p_sys->bytestream );

            if( p_sys->p_frame )
                block_ChainRelease( p_sys->p_frame );
            p_sys->p_frame = NULL;
            p_sys->pp_last = &p_sys->p_frame;
            p_sys->b_frame = false;
        }
//        p_sys->i_interpolated_dts = 0;
        block_Release( *pp_block );
        return NULL;
    }

    block_BytestreamPush( &p_sys->bytestream, *pp_block );

    for( ;; )
    {
        switch( p_sys->i_state )
        {

        case STATE_NOSYNC:
            if( block_FindStartcodeFromOffset( &p_sys->bytestream, &p_sys->i_offset, p_sys->p_startcode, 3 ) == VLC_SUCCESS )
                p_sys->i_state = STATE_NEXT_SYNC;

            if( p_sys->i_offset )
            {
                block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
                p_sys->i_offset = 0;
                block_BytestreamFlush( &p_sys->bytestream );
            }

            if( p_sys->i_state != STATE_NEXT_SYNC )
                return NULL; /* Need more data */

            p_sys->i_offset = 4; /* To find next startcode */

        case STATE_NEXT_SYNC:
            /* TODO: If p_block == NULL, flush the buffer without checking the
             * next sync word */

            /* Find the next startcode */
            if( block_FindStartcodeFromOffset( &p_sys->bytestream, &p_sys->i_offset, p_sys->p_startcode, 3 ) != VLC_SUCCESS )
                return NULL; /* Need more data */

            /* Get the new fragment and set the pts/dts */
            p_pic = block_New( p_dec, p_sys->i_offset );
            block_BytestreamFlush( &p_sys->bytestream );
            p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
            p_pic->i_dts = p_sys->bytestream.p_block->i_dts;
            p_pic->i_rate = p_sys->bytestream.p_block->i_rate;

            block_GetBytes( &p_sys->bytestream, p_pic->p_buffer, p_pic->i_buffer );

            p_sys->i_offset = 0;

            /* Parse and return complete frame */
            p_pic = ParseIDU( p_dec, p_pic );

            /* Don't reuse the same timestamps several times */
            if( p_sys->p_frame &&
                p_sys->p_frame->i_dts == p_sys->bytestream.p_block->i_dts &&
                p_sys->p_frame->i_pts == p_sys->bytestream.p_block->i_pts )
            {
                p_sys->bytestream.p_block->i_pts = -1;
                p_sys->bytestream.p_block->i_dts = -1;
            }

            /* */
            if( !p_pic )
            {
                p_sys->i_state = STATE_NOSYNC;
                break;
            }
            /* */
            if( p_sys->i_interpolated_dts < 0 )
            {
                msg_Dbg( p_dec, "need a starting pts/dts" );
                p_sys->i_state = STATE_NOSYNC;
                block_Release( p_pic );
                break;
            }

            /* So p_block doesn't get re-added several times */
            *pp_block = block_BytestreamPop( &p_sys->bytestream );

            p_sys->i_state = STATE_NOSYNC;

            return p_pic;
        }
    }
}

/* DecodeRIDU: decode the startcode emulation prevention (same than h264) */
static void DecodeRIDU( uint8_t *p_ret, int *pi_ret, uint8_t *src, int i_src )
{
    uint8_t *end = &src[i_src];
    uint8_t *dst_end = &p_ret[*pi_ret];
    uint8_t *dst = p_ret;

    while( src < end && dst < dst_end )
    {
        if( src < end - 3 && src[0] == 0x00 && src[1] == 0x00 &&
            src[2] == 0x03 )
        {
            *dst++ = 0x00;
            *dst++ = 0x00;

            src += 3;
            continue;
        }
        *dst++ = *src++;
    }

    *pi_ret = dst - p_ret;
}
/* BuildExtraData: gather sequence header and entry point */
static void BuildExtraData( decoder_t *p_dec )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    es_format_t *p_es = &p_dec->fmt_out;
    int i_extra;
    if( !p_sys->b_sequence_header || !p_sys->b_entry_point )
        return;

    i_extra = p_sys->sh.p_sh->i_buffer + p_sys->ep.p_ep->i_buffer;
    if( p_es->i_extra != i_extra )
    {
        p_es->i_extra = i_extra;
        p_es->p_extra = realloc( p_dec->fmt_out.p_extra, p_es->i_extra );
    }