mpeg4video.c

video linux conference

/*****************************************************************************
 * mpeg4video.c: mpeg 4 video packetizer
 *****************************************************************************
 * Copyright (C) 2001, 2002 VideoLAN
 * $Id: mpeg4video.c 11349 2005-06-08 07:34:58Z gbazin $
 *
 * Authors: Laurent Aimar <[e-mail]>
 *          Eric Petit <[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., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#include <stdlib.h>                                      /* malloc(), free() */

#include <vlc/vlc.h>
#include <vlc/decoder.h>
#include <vlc/sout.h>
#include <vlc/input.h>                  /* hmmm, just for INPUT_RATE_DEFAULT */

#include "vlc_bits.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( _("MPEG4 video packetizer") );
    set_capability( "packetizer", 50 );
    set_callbacks( Open, Close );
vlc_module_end();


/****************************************************************************
 * Local prototypes
 ****************************************************************************/
static block_t *Packetize( decoder_t *, block_t ** );

struct decoder_sys_t
{
    /*
     * Common properties
     */
    mtime_t i_interpolated_pts;
    mtime_t i_interpolated_dts;
    mtime_t i_last_ref_pts;
    mtime_t i_last_time_ref;
    mtime_t i_time_ref;
    mtime_t i_last_time;
    mtime_t i_last_timeincr;

    vlc_bool_t  b_vop;
    int         i_buffer;
    int         i_buffer_size;
    uint8_t     *p_buffer;
    unsigned int i_flags;

    int         i_fps_num;
    int         i_fps_den;
    int         i_last_incr;
    int         i_last_incr_diff;

    vlc_bool_t  b_frame;
};

static int m4v_FindStartCode( uint8_t **, uint8_t * );
static int m4v_VOLParse( decoder_t *, es_format_t *, uint8_t *, int );
static int vlc_log2( unsigned int );

#define VIDEO_OBJECT_MASK                       0x01f
#define VIDEO_OBJECT_LAYER_MASK                 0x00f

#define VIDEO_OBJECT_START_CODE                 0x100
#define VIDEO_OBJECT_LAYER_START_CODE           0x120
#define VISUAL_OBJECT_SEQUENCE_START_CODE       0x1b0
#define VISUAL_OBJECT_SEQUENCE_END_CODE         0x1b1
#define USER_DATA_START_CODE                    0x1b2
#define GROUP_OF_VOP_START_CODE                 0x1b3
#define VIDEO_SESSION_ERROR_CODE                0x1b4
#define VISUAL_OBJECT_START_CODE                0x1b5
#define VOP_START_CODE                          0x1b6
#define FACE_OBJECT_START_CODE                  0x1ba
#define FACE_OBJECT_PLANE_START_CODE            0x1bb
#define MESH_OBJECT_START_CODE                  0x1bc
#define MESH_OBJECT_PLANE_START_CODE            0x1bd
#define STILL_TEXTURE_OBJECT_START_CODE         0x1be
#define TEXTURE_SPATIAL_LAYER_START_CODE        0x1bf
#define TEXTURE_SNR_LAYER_START_CODE            0x1c0

/*****************************************************************************
 * Open: probe the packetizer and return score
 *****************************************************************************/
static int Open( vlc_object_t *p_this )
{
    decoder_t     *p_dec = (decoder_t*)p_this;
    decoder_sys_t *p_sys;

    switch( p_dec->fmt_in.i_codec )
    {
        case VLC_FOURCC( 'm', '4', 's', '2'):
        case VLC_FOURCC( 'M', '4', 'S', '2'):
        case VLC_FOURCC( 'm', 'p', '4', 's'):
        case VLC_FOURCC( 'M', 'P', '4', 'S'):
        case VLC_FOURCC( 'm', 'p', '4', 'v'):
        case VLC_FOURCC( 'M', 'P', '4', 'V'):
        case VLC_FOURCC( 'D', 'I', 'V', 'X'):
        case VLC_FOURCC( 'd', 'i', 'v', 'x'):
        case VLC_FOURCC( 'X', 'V', 'I', 'D'):
        case VLC_FOURCC( 'X', 'v', 'i', 'D'):
        case VLC_FOURCC( 'x', 'v', 'i', 'd'):
        case VLC_FOURCC( 'D', 'X', '5', '0'):
        case VLC_FOURCC( 'd', 'x', '5', '0'):
        case VLC_FOURCC( 0x04, 0,   0,   0):
        case VLC_FOURCC( '3', 'I', 'V', '2'):
        case VLC_FOURCC( 'm', '4', 'c', 'c'):
        case VLC_FOURCC( 'M', '4', 'C', 'C'):
            break;

        default:
            return VLC_EGENERIC;
    }

    /* Allocate the memory needed to store the decoder's structure */
    if( ( p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) ) ) == NULL )
    {
        msg_Err( p_dec, "out of memory" );
        return VLC_EGENERIC;
    }
    memset( p_sys, 0, sizeof(decoder_sys_t) );

    /* Setup properties */
    es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
    p_dec->fmt_out.i_codec = VLC_FOURCC( 'm', 'p', '4', 'v' );

    if( p_dec->fmt_in.i_extra )
    {
        /* We have a vol */
        p_dec->fmt_out.i_extra = p_dec->fmt_in.i_extra;
        p_dec->fmt_out.p_extra = malloc( p_dec->fmt_in.i_extra );
        memcpy( p_dec->fmt_out.p_extra, p_dec->fmt_in.p_extra,
                p_dec->fmt_in.i_extra );

        msg_Dbg( p_dec, "opening with vol size:%d", p_dec->fmt_in.i_extra );
        m4v_VOLParse( p_dec, &p_dec->fmt_out,
                      p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
    }
    else
    {
        /* No vol, we'll have to look for one later on */
        p_dec->fmt_out.i_extra = 0;
        p_dec->fmt_out.p_extra = 0;
    }

    /* Set callback */
    p_dec->pf_packetize = Packetize;

    return VLC_SUCCESS;
}

/*****************************************************************************
 * Close: clean up the packetizer
 *****************************************************************************/
static void Close( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t*)p_this;

    if( p_dec->p_sys->p_buffer ) free( p_dec->p_sys->p_buffer );
    free( p_dec->p_sys );
}

/****************************************************************************
 * Packetize: the whole thing
 ****************************************************************************/
static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;

    block_t *p_chain_out = NULL;
    block_t *p_block;
    uint8_t *p_vol = NULL;
    uint8_t *p_start;

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

    p_block = *pp_block;

    /* Append data */
    if( p_sys->i_buffer + p_block->i_buffer > p_sys->i_buffer_size )
    {
        p_sys->i_buffer_size += p_block->i_buffer + 1024;
        p_sys->p_buffer = realloc( p_sys->p_buffer, p_sys->i_buffer_size );
    }
    memcpy( &p_sys->p_buffer[p_sys->i_buffer], p_block->p_buffer,
            p_block->i_buffer );
    p_sys->i_buffer += p_block->i_buffer;

    if( p_sys->i_buffer > 10*1000000 )
    {
        msg_Warn( p_dec, "reseting context" );
        p_sys->i_buffer = 0;
    }

    /* Search vop */
    p_start = &p_sys->p_buffer[p_sys->i_buffer - p_block->i_buffer - 4];
    if( p_start < p_sys->p_buffer )
    {
        p_start = p_sys->p_buffer;
    }
    for( ;; )
    {
        if( m4v_FindStartCode( &p_start, &p_sys->p_buffer[p_sys->i_buffer] ) )
        {
            block_Release( p_block );
            *pp_block = NULL;
            return p_chain_out;
        }
        /* fprintf( stderr, "start code=0x1%2.2x\n", p_start[3] ); */

        if( p_vol )
        {
            /* Copy the complete VOL */
            p_dec->fmt_out.i_extra = p_start - p_vol;
            p_dec->fmt_out.p_extra =
                realloc( p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
            memcpy( p_dec->fmt_out.p_extra, p_vol, p_dec->fmt_out.i_extra );
            m4v_VOLParse( p_dec, &p_dec->fmt_out,
                          p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );

            p_vol = NULL;
        }
        if( p_sys->b_vop )
        {
            /* Output the complete VOP we have */
            int     i_out = p_start - p_sys->p_buffer;
            block_t *p_out = block_New( p_dec, i_out );

            /* extract data */
            memcpy( p_out->p_buffer, p_sys->p_buffer, i_out );
            if( i_out < p_sys->i_buffer )
            {
                memmove( p_sys->p_buffer, &p_sys->p_buffer[i_out],
                         p_sys->i_buffer - i_out );
            }
            p_sys->i_buffer -= i_out;
            p_start -= i_out;

            p_out->i_flags = p_sys->i_flags;
            p_out->i_pts = p_sys->i_interpolated_pts;
            p_out->i_dts = p_sys->i_interpolated_dts;

            /* FIXME doesn't work when there is multiple VOP in one block */
            if( p_block->i_dts > p_sys->i_interpolated_dts )
            {
                p_out->i_length = p_block->i_dts - p_sys->i_interpolated_dts;
            }

            if( p_dec->fmt_out.i_extra > 0 )
            {
                block_ChainAppend( &p_chain_out, p_out );
            }
            else
            {