多媒体

开发平台：
MultiPlatform

dv.c：源码内容
							/*****************************************************************************
 * dv.c: a decoder for DV video
 *****************************************************************************
 * Copyright (C) 2002 VideoLAN
 * $Id: dv.c 6961 2004-03-05 17:34:23Z sam $
 *
 * Authors: Samuel Hocevar <sam@zoy.org>
 *
 * 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>
#undef vlc_error /*vlc_error is defined in the libdv headers, but not
                  * used in thes file */
#include <libdv/dv_types.h>
#include <libdv/dv.h>
/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int RunDecoder  ( decoder_fifo_t * );
static int OpenDecoder ( vlc_object_t * );
static vlc_fourcc_t GetFourCC   ( dv_sample_t );
/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
vlc_module_begin();
    set_description( _("DV video decoder") );
    set_capability( "decoder", 70 );
    set_callbacks( OpenDecoder, NULL );
vlc_module_end();
/*****************************************************************************
 * OpenDecoder: probe the decoder and return score
 *****************************************************************************
 * The fourcc format for DV is "dvsd"
 *****************************************************************************/
static int OpenDecoder ( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t*)p_this;
    if( p_dec->fmt_in.i_codec != VLC_FOURCC('d','v','s','d') )
    {
        return VLC_EGENERIC;
    }
    p_dec->pf_run = RunDecoder;
    return VLC_SUCCESS;
}
/*****************************************************************************
 * RunDecoder: this function is called just after the thread is created
 *****************************************************************************/
static int RunDecoder ( decoder_fifo_t *p_fifo )
{
    uint8_t *p_buffer;
    pes_packet_t *p_pes = NULL;
    unsigned int i_data = 120000;
    int i_aspect;
    bit_stream_t    bit_stream;
    dv_decoder_t *  p_decoder;
    vout_thread_t * p_vout;
    p_buffer = malloc( i_data );
    if( !p_buffer )
    {
        msg_Err( p_fifo, "out of memory" );
        p_fifo->b_error = 1;
        DecoderError( p_fifo );
        return -1;
    }
    p_decoder = dv_decoder_new( TRUE, FALSE, FALSE );
    if( !p_decoder )
    {
        msg_Err( p_fifo, "cannot start DV decoder" );
        free( p_buffer );
        p_fifo->b_error = 1;
        DecoderError( p_fifo );
        return -1;
    }
    if( InitBitstream( &bit_stream, p_fifo, NULL, NULL ) != VLC_SUCCESS )
    {
        msg_Err( p_fifo, "cannot initialize bitstream" );
        free( p_buffer );
        p_fifo->b_error = 1;
        DecoderError( p_fifo );
        return -1;
    }
    /* Fill the buffer */
    GetChunk( &bit_stream, p_buffer, i_data );
    while( !p_fifo->b_die && !p_fifo->b_error )
    {
        /* Parsing the beginning of the stream */
        if( dv_parse_header( p_decoder, p_buffer ) < 0 )
        {
            msg_Err(p_fifo, "parse error");
            p_fifo->b_error = 1;
            break;
        }
        if( dv_format_wide( p_decoder ) )
        {
            msg_Dbg( p_fifo, "aspect ratio is 4:3" );
            i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
        }
        else if( dv_format_normal( p_decoder ) )
        {
            msg_Dbg( p_fifo, "aspect ratio is 16:9" );
            i_aspect = VOUT_ASPECT_FACTOR * 4/3;//16 / 9;
        }
        else
        {
            msg_Dbg( p_fifo, "aspect is square pixels" );
            i_aspect = VOUT_ASPECT_FACTOR
                        * p_decoder->width / p_decoder->height;
        }
        if( p_decoder->frame_size <= i_data )
        {
            /* XXX: what to do? */
            i_data = p_decoder->frame_size;
        }
        else
        {
            p_buffer = realloc( p_buffer, p_decoder->frame_size );
        }
        /* Don't trust the sucker */
        //p_decoder->quality = p_decoder->video->quality;
        p_decoder->quality = DV_QUALITY_BEST;
        p_decoder->prev_frame_decoded = 0;
        /* Spawn a video output if there is none. First we look amongst our
         * children, then we look for any other vout that might be available */
        p_vout = vout_Request( p_fifo, NULL,
                               p_decoder->width, p_decoder->height,
                               GetFourCC( p_decoder->sampling ), i_aspect );
        /* Main loop */
        while( !p_fifo->b_die && !p_fifo->b_error )
        {
            mtime_t i_pts = 0;
            GetChunk( &bit_stream, p_buffer + i_data,
                                   p_decoder->frame_size - i_data );
            i_data = p_decoder->frame_size;
            if( p_pes )
            {
                input_DeletePES( p_fifo->p_packets_mgt, p_pes );
            }
            input_ExtractPES( p_fifo, &p_pes );
            if( p_pes )
            {
                /* Don't trust the sucker */
                //i_pts = p_pes->i_pts + DEFAULT_PTS_DELAY;
                i_pts = mdate() + DEFAULT_PTS_DELAY;
            }
            if( p_fifo->b_die || p_fifo->b_error )
            {
                break;
            }
            if( dv_parse_header( p_decoder, p_buffer ) > 0 )
            {
                msg_Warn(p_fifo, "size changed");
            }
            if( p_vout && ( !p_decoder->prev_frame_decoded
                             || dv_frame_changed( p_decoder ) ) )
            {
                picture_t *p_pic;
                uint8_t *pixels[3];
                int pitches[3], i;
                while( !(p_pic = vout_CreatePicture( p_vout, 0, 0, 0 ) ) )
                {
                    if( p_fifo->b_die || p_fifo->b_error )
                    {
                        break;
                    }
                    msleep( VOUT_OUTMEM_SLEEP );
                }
                if( !p_pic )
                {
                    break;
                }
                for( i = 0 ; i < p_pic->i_planes ; i++ )
                {
                    pixels[i] = p_pic->p[i].p_pixels;
                    pitches[i] = p_pic->p[i].i_pitch;
                }
                dv_decode_full_frame( p_decoder, p_buffer,
                                      e_dv_color_yuv, pixels, pitches );
                p_decoder->prev_frame_decoded = 1;
                vout_DatePicture( p_vout, p_pic, i_pts );
                vout_DisplayPicture( p_vout, p_pic );
            }
            i_data = 0;
        }
        vout_Request( p_fifo, p_vout, 0, 0, 0, 0 );
    }
    if( p_pes )
    {
        input_DeletePES( p_fifo->p_packets_mgt, p_pes );
    }
    free( p_buffer );
    CloseBitstream( &bit_stream );
    if( p_fifo->b_error )
    {
        DecoderError( p_fifo );
        return -1;
    }
    return 0;
}
static vlc_fourcc_t GetFourCC( dv_sample_t x )
{
    switch( x )
    {
        case e_dv_sample_411: return VLC_FOURCC('Y','U','Y','2');
        case e_dv_sample_420: return VLC_FOURCC('Y','U','Y','2');
        case e_dv_sample_422: return VLC_FOURCC('Y','U','Y','2');
        default: return 0;
    }
}

						