mpgv.c
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上传日期:2009-03-27
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- /*****************************************************************************
- * mpgv.c : MPEG-I/II Video demuxer
- *****************************************************************************
- * Copyright (C) 2001-2004 VideoLAN
- * $Id: mpgv.c 7239 2004-04-02 03:24:53Z fenrir $
- *
- * 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 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 <stdlib.h> /* malloc(), free() */
- #include <vlc/vlc.h>
- #include <vlc/input.h>
- #include "vlc_codec.h"
- /*****************************************************************************
- * Module descriptor
- *****************************************************************************/
- static int Open ( vlc_object_t * );
- static void Close( vlc_object_t * );
- vlc_module_begin();
- set_description( _("MPEG-I/II video demuxer" ) );
- set_capability( "demux2", 100 );
- set_callbacks( Open, Close );
- add_shortcut( "mpgv" );
- vlc_module_end();
- /*****************************************************************************
- * Local prototypes
- *****************************************************************************/
- struct demux_sys_t
- {
- vlc_bool_t b_start;
- es_out_id_t *p_es;
- decoder_t *p_packetizer;
- };
- static int Demux( demux_t * );
- static int Control( demux_t *, int, va_list );
- #define MPGV_PACKET_SIZE 4096
- /*****************************************************************************
- * Open: initializes demux structures
- *****************************************************************************/
- static int Open( vlc_object_t * p_this )
- {
- demux_t *p_demux = (demux_t*)p_this;
- demux_sys_t *p_sys;
- vlc_bool_t b_forced = VLC_FALSE;
- uint8_t *p_peek;
- es_format_t fmt;
- if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
- {
- msg_Err( p_demux, "cannot peek" );
- return VLC_EGENERIC;
- }
- if( !strncmp( p_demux->psz_demux, "mpgv", 4 ) )
- {
- b_forced = VLC_TRUE;
- }
- if( p_peek[0] != 0x00 || p_peek[1] != 0x00 || p_peek[2] != 0x01 )
- {
- if( !b_forced )
- {
- msg_Warn( p_demux, "ES module discarded (no startcode)" );
- return VLC_EGENERIC;
- }
- msg_Err( p_demux, "this doesn't look like an MPEG ES stream, continuing" );
- }
- if( p_peek[3] > 0xb9 )
- {
- if( !b_forced )
- {
- msg_Warn( p_demux, "ES module discarded (system startcode)" );
- return VLC_EGENERIC;
- }
- msg_Err( p_demux, "this seems to be a system stream (PS plug-in ?), but continuing" );
- }
- p_demux->pf_demux = Demux;
- p_demux->pf_control= Control;
- p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
- p_sys->b_start = VLC_TRUE;
- p_sys->p_es = NULL;
- /*
- * Load the mpegvideo packetizer
- */
- p_sys->p_packetizer = vlc_object_create( p_demux, VLC_OBJECT_PACKETIZER );
- p_sys->p_packetizer->pf_decode_audio = NULL;
- p_sys->p_packetizer->pf_decode_video = NULL;
- p_sys->p_packetizer->pf_decode_sub = NULL;
- p_sys->p_packetizer->pf_packetize = NULL;
- es_format_Init( &p_sys->p_packetizer->fmt_in, VIDEO_ES,
- VLC_FOURCC( 'm', 'p', 'g', 'v' ) );
- es_format_Init( &p_sys->p_packetizer->fmt_out, UNKNOWN_ES, 0 );
- p_sys->p_packetizer->p_module =
- module_Need( p_sys->p_packetizer, "packetizer", NULL, 0 );
- if( p_sys->p_packetizer->p_module == NULL)
- {
- vlc_object_destroy( p_sys->p_packetizer );
- msg_Err( p_demux, "cannot find mpgv packetizer" );
- free( p_sys );
- return VLC_EGENERIC;
- }
- /*
- * create the output
- */
- es_format_Init( &fmt, VIDEO_ES, VLC_FOURCC( 'm', 'p', 'g', 'v' ) );
- p_sys->p_es = es_out_Add( p_demux->out, &fmt );
- 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;
- module_Unneed( p_sys->p_packetizer, p_sys->p_packetizer->p_module );
- vlc_object_destroy( p_sys->p_packetizer );
- 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_in, *p_block_out;
- if( ( p_block_in = stream_Block( p_demux->s, MPGV_PACKET_SIZE ) ) == NULL )
- {
- return 0;
- }
- if( p_sys->b_start )
- {
- p_block_in->i_pts =
- p_block_in->i_dts = 1;
- }
- else
- {
- p_block_in->i_pts =
- p_block_in->i_dts = 0;
- }
- while( (p_block_out = p_sys->p_packetizer->pf_packetize( p_sys->p_packetizer, &p_block_in )) )
- {
- p_sys->b_start = VLC_FALSE;
- while( p_block_out )
- {
- block_t *p_next = p_block_out->p_next;
- es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_block_out->i_dts );
- p_block_out->p_next = NULL;
- es_out_Send( p_demux->out, p_sys->p_es, p_block_out );
- p_block_out = p_next;
- }
- }
- 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; */
- /* FIXME calculate the bitrate */
- if( i_query == DEMUX_SET_TIME )
- return VLC_EGENERIC;
- else
- return demux2_vaControlHelper( p_demux->s,
- 0, -1,
- 0, 1, i_query, args );
- }