cvd.c

来自「VLC媒体播放程序」· C语言 代码 · 共 277 行

/*****************************************************************************
 * cvd.c : CVD Subtitle decoder thread
 *****************************************************************************
 * Copyright (C) 2003, 2004 VideoLAN
 * $Id: cvd.c,v 1.15 2004/01/25 19:27:09 rocky Exp $
 *
 * Authors: Rocky Bernstein
 *   based on code from:
 *       Julio Sanchez Fernandez (http://subhandler.sourceforge.net)
 *       Samuel Hocevar <[e-mail]>
 *       Laurent Aimar <[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., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#include <vlc/vlc.h>
#include <vlc/vout.h>
#include <vlc/decoder.h>

#include "subtitle.h"
#include "cvd.h"
#include "common.h"

/*****************************************************************************
 * Module descriptor.
 *****************************************************************************/
static int  DecoderOpen   ( vlc_object_t * );
static int  PacketizerOpen( vlc_object_t * );

vlc_module_begin();
    set_description( _("CVD subtitle decoder") );
    set_capability( "decoder", 50 );
    set_callbacks( DecoderOpen, VCDSubClose );

    add_integer ( MODULE_STRING "-debug", 0, NULL,
		  DEBUG_TEXT, DEBUG_LONGTEXT, VLC_TRUE );

    add_integer ( MODULE_STRING "-horizontal-correct", 0, NULL,
                  HORIZONTAL_CORRECT, HORIZONTAL_CORRECT_LONGTEXT, VLC_FALSE );

    add_integer ( MODULE_STRING "-vertical-correct", 0, NULL,
                  VERTICAL_CORRECT, VERTICAL_CORRECT_LONGTEXT, VLC_FALSE );

    add_string( MODULE_STRING "-aspect-ratio", "", NULL,
                SUB_ASPECT_RATIO_TEXT, SUB_ASPECT_RATIO_LONGTEXT, 
		VLC_TRUE );

    add_integer( MODULE_STRING "-duration-scaling", 3, NULL,
		 DURATION_SCALE_TEXT, DURATION_SCALE_LONGTEXT,
		 VLC_TRUE );

    add_submodule();
    set_description( _("Chaoji VCD subtitle packetizer") );
    set_capability( "packetizer", 50 );
    set_callbacks( PacketizerOpen, VCDSubClose );
vlc_module_end();

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/

static block_t *Reassemble( decoder_t *, block_t ** );
static void     Decode   ( decoder_t *, block_t ** );
static block_t *Packetize( decoder_t *, block_t ** );


/*****************************************************************************
 * DecoderOpen
 *****************************************************************************
 * Tries to launch a decoder and return score so that the interface is able
 * to chose.
 *****************************************************************************/
static int
DecoderOpen( 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( 'c','v','d',' ' ) )
    {
        return VLC_EGENERIC;
    }


    p_dec->p_sys = p_sys = malloc( sizeof( decoder_sys_t ) );

    p_sys->i_debug       = config_GetInt( p_this, MODULE_STRING "-debug" );
    p_sys->b_packetizer  = VLC_FALSE;
    p_sys->p_vout        = NULL;
    p_sys->i_image       = -1;
    p_sys->subtitle_data = NULL;

    VCDSubInitSubtitleBlock( p_sys );

    es_format_Init( &p_dec->fmt_out, SPU_ES, VLC_FOURCC( 'c','v','d',' ' ) );


    p_dec->pf_decode_sub = Decode;
    p_dec->pf_packetize  = Packetize;

    dbg_print( (DECODE_DBG_CALL|DECODE_DBG_EXT) , "");

    return VLC_SUCCESS;
}

/*****************************************************************************
 * PacketizerOpen
 *****************************************************************************
 * Tries to launch a decoder and return score so that the interface is able
 * to chose.
 *****************************************************************************/
static int PacketizerOpen( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t*)p_this;

    if( DecoderOpen( p_this ) )
    {
        return VLC_EGENERIC;
    }
    p_dec->p_sys->b_packetizer = VLC_TRUE;

    return VLC_SUCCESS;
}

/*****************************************************************************
 * Decode:
 *****************************************************************************/
static void
Decode ( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    block_t       *p_spu = Reassemble( p_dec, pp_block );

    dbg_print( (DECODE_DBG_CALL) , "");

    if( p_spu )
    {
        p_sys->i_spu = block_ChainExtract( p_spu, p_sys->buffer, 65536 );
        p_sys->i_pts = p_spu->i_pts;
        block_ChainRelease( p_spu );

        if( ( p_sys->p_vout = VCDSubFindVout( p_dec ) ) )
        {
            /* Parse and decode */
            E_(ParsePacket)( p_dec );

            vlc_object_release( p_sys->p_vout );
        }

        VCDSubInitSubtitleBlock ( p_sys );
    }

}

/*****************************************************************************
 * Packetize:
 *****************************************************************************/
static block_t *
Packetize( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    block_t       *p_spu = Reassemble( p_dec, pp_block );

    if( p_spu )
    {
        p_spu->i_dts = p_spu->i_pts;
        p_spu->i_length = 0;

        VCDSubInitSubtitleBlock( p_sys );

        return block_ChainGather( p_spu );
    }
    return NULL;
}

/* following functions are local */

#define SPU_HEADER_LEN 1

/*****************************************************************************
 Reassemble:

 Data for single screen subtitle may come in several non-contiguous
 packets of a stream. This routine is called when the next packet in
 the stream comes in. The job of this routine is to parse the header,
 if this is the beginning, and combine the packets into one complete
 subtitle unit.

 If everything is complete, we will return a block. Otherwise return
 NULL.

 *****************************************************************************/
static block_t *
Reassemble( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    block_t *p_block;
    uint8_t *p_buffer;

    if( pp_block == NULL || *pp_block == NULL )
    {
        return NULL;
    }
    p_block = *pp_block;
    *pp_block = NULL;

    if( p_block->i_buffer < SPU_HEADER_LEN )
    {
      msg_Dbg( p_dec, "invalid packet header (size %d < %d)" ,
               p_block->i_buffer, SPU_HEADER_LEN );
      block_Release( p_block );
      return NULL;
    }

    p_buffer = p_block->p_buffer;

    dbg_print( (DECODE_DBG_CALL|DECODE_DBG_PACKET), 
	       "header: 0x%02x 0x%02x 0x%02x 0x%02x, 0x%02x, 0x%02x, size: %i",
	       p_buffer[1], p_buffer[2], p_buffer[3], p_buffer[4],
	       p_buffer[5], p_buffer[6],
	       p_block->i_buffer);

    if( config_GetInt( p_dec, "spu-channel" ) != p_buffer[0] )
      return NULL;

    /* From the scant data on the format, there is only only way known
       to detect the first packet in a subtitle.  The first packet
       seems to have a valid PTS while later packets for the same
       image don't. */

    if ( p_sys->state == SUBTITLE_BLOCK_EMPTY && p_block->i_pts == 0 ) {
      msg_Warn( p_dec, 
		"first packet expected but no PTS present -- skipped\n");
      return NULL;
    }

    if ( p_sys->subtitle_data_pos == 0 ) {
      /* First packet in the subtitle block */
      E_(ParseHeader)( p_dec, p_buffer, p_block );
      VCDSubInitSubtitleData(p_sys);
    }

    /* FIXME - remove append_data and use chainappend */
    VCDSubAppendData( p_dec, p_buffer + SPU_HEADER_LEN, 
		      p_block->i_buffer - SPU_HEADER_LEN );

    block_ChainAppend( &p_sys->p_block, p_block );

    p_sys->i_spu += p_block->i_buffer - SPU_HEADER_LEN;

    if ( p_sys->subtitle_data_pos == p_sys->i_spu_size ) {
      E_(ParseMetaInfo)( p_dec );
      return p_sys->p_block;
    } else {
      /* Not last block in subtitle, so wait for another. */
      p_sys->state = SUBTITLE_BLOCK_PARTIAL;
    }

    
    return NULL;
}