image.c

uclinux 下的vlc播放器源代码

/*****************************************************************************
 * image.c : wrapper for image reading/writing facilities
 *****************************************************************************
 * Copyright (C) 2004 the VideoLAN team
 * $Id: image.c 16767 2006-09-21 14:32:45Z hartman $
 *
 * Author: 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.
 *****************************************************************************/

/**
 * \file
 * This file contains the functions to handle the image_handler_t type
 */

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#include <ctype.h>
#include <vlc/vlc.h>
#include <vlc/decoder.h>
#include <vlc_filter.h>
#include <vlc_image.h>
#include <vlc_stream.h>
#include <charset.h>

static picture_t *ImageRead( image_handler_t *, block_t *,
                             video_format_t *, video_format_t * );
static picture_t *ImageReadUrl( image_handler_t *, const char *,
                                video_format_t *, video_format_t * );
static block_t *ImageWrite( image_handler_t *, picture_t *,
                            video_format_t *, video_format_t * );
static int ImageWriteUrl( image_handler_t *, picture_t *,
                          video_format_t *, video_format_t *, const char * );

static picture_t *ImageConvert( image_handler_t *, picture_t *,
                                video_format_t *, video_format_t * );
static picture_t *ImageFilter( image_handler_t *, picture_t *,
                               video_format_t *, const char *psz_module );

static decoder_t *CreateDecoder( vlc_object_t *, video_format_t * );
static void DeleteDecoder( decoder_t * );
static encoder_t *CreateEncoder( vlc_object_t *, video_format_t *,
                                 video_format_t * );
static void DeleteEncoder( encoder_t * );
static filter_t *CreateFilter( vlc_object_t *, es_format_t *,
                               video_format_t *, const char * );
static void DeleteFilter( filter_t * );

static vlc_fourcc_t Ext2Fourcc( const char * );
/*static const char *Fourcc2Ext( vlc_fourcc_t );*/

/**
 * Create an image_handler_t instance
 *
 */
image_handler_t *__image_HandlerCreate( vlc_object_t *p_this )
{
    image_handler_t *p_image = malloc( sizeof(image_handler_t) );

    memset( p_image, 0, sizeof(image_handler_t) );
    p_image->p_parent = p_this;

    p_image->pf_read = ImageRead;
    p_image->pf_read_url = ImageReadUrl;
    p_image->pf_write = ImageWrite;
    p_image->pf_write_url = ImageWriteUrl;
    p_image->pf_convert = ImageConvert;
    p_image->pf_filter = ImageFilter;

    return p_image;
}

/**
 * Delete the image_handler_t instance
 *
 */
void image_HandlerDelete( image_handler_t *p_image )
{
    if( !p_image ) return;

    if( p_image->p_dec ) DeleteDecoder( p_image->p_dec );
    if( p_image->p_enc ) DeleteEncoder( p_image->p_enc );
    if( p_image->p_filter ) DeleteFilter( p_image->p_filter );

    free( p_image );
    p_image = NULL;
}

/**
 * Read an image
 *
 */

static picture_t *ImageRead( image_handler_t *p_image, block_t *p_block,
                             video_format_t *p_fmt_in,
                             video_format_t *p_fmt_out )
{
    picture_t *p_pic = NULL, *p_tmp;

    /* Check if we can reuse the current decoder */
    if( p_image->p_dec &&
        p_image->p_dec->fmt_in.i_codec != p_fmt_in->i_chroma )
    {
        DeleteDecoder( p_image->p_dec );
        p_image->p_dec = 0;
    }

    /* Start a decoder */
    if( !p_image->p_dec )
    {
        p_image->p_dec = CreateDecoder( p_image->p_parent, p_fmt_in );
        if( !p_image->p_dec ) return NULL;
    }

    p_block->i_pts = p_block->i_dts = mdate();
    while( (p_tmp = p_image->p_dec->pf_decode_video( p_image->p_dec, &p_block ))
             != NULL )
    {
        if ( p_pic != NULL )
            p_pic->pf_release( p_pic );
        p_pic = p_tmp;
    }

    if( p_pic == NULL )
    {
        msg_Warn( p_image->p_parent, "no image decoded" );
        return 0;
    }

    if( !p_fmt_out->i_chroma )
        p_fmt_out->i_chroma = p_image->p_dec->fmt_out.video.i_chroma;
    if( !p_fmt_out->i_width && p_fmt_out->i_height )
        p_fmt_out->i_width = p_fmt_out->i_height
                              * p_image->p_dec->fmt_out.video.i_aspect
                              / VOUT_ASPECT_FACTOR;
    if( !p_fmt_out->i_height && p_fmt_out->i_width )
        p_fmt_out->i_height = p_fmt_out->i_width * VOUT_ASPECT_FACTOR
                               / p_image->p_dec->fmt_out.video.i_aspect;
    if( !p_fmt_out->i_width )
        p_fmt_out->i_width = p_image->p_dec->fmt_out.video.i_width;
    if( !p_fmt_out->i_height )
        p_fmt_out->i_height = p_image->p_dec->fmt_out.video.i_height;

    /* Check if we need chroma conversion or resizing */
    if( p_image->p_dec->fmt_out.video.i_chroma != p_fmt_out->i_chroma ||
        p_image->p_dec->fmt_out.video.i_width != p_fmt_out->i_width ||
        p_image->p_dec->fmt_out.video.i_height != p_fmt_out->i_height )
    {
        if( p_image->p_filter )
        if( p_image->p_filter->fmt_in.video.i_chroma !=
            p_image->p_dec->fmt_out.video.i_chroma ||
            p_image->p_filter->fmt_out.video.i_chroma != p_fmt_out->i_chroma )
        {
            /* We need to restart a new filter */
            DeleteFilter( p_image->p_filter );
            p_image->p_filter = 0;
        }

        /* Start a filter */
        if( !p_image->p_filter )
        {
            p_image->p_filter =
                CreateFilter( p_image->p_parent, &p_image->p_dec->fmt_out,
                              p_fmt_out, NULL );

            if( !p_image->p_filter )
            {
                p_pic->pf_release( p_pic );
                return NULL;
            }
        }
        else
        {
            /* Filters should handle on-the-fly size changes */
            p_image->p_filter->fmt_in = p_image->p_dec->fmt_out;
            p_image->p_filter->fmt_out = p_image->p_dec->fmt_out;
            p_image->p_filter->fmt_out.i_codec = p_fmt_out->i_chroma;
            p_image->p_filter->fmt_out.video = *p_fmt_out;
        }

        p_pic = p_image->p_filter->pf_video_filter( p_image->p_filter, p_pic );
        *p_fmt_out = p_image->p_filter->fmt_out.video;
    }
    else *p_fmt_out = p_image->p_dec->fmt_out.video;

    return p_pic;
}

static picture_t *ImageReadUrl( image_handler_t *p_image, const char *psz_url,
                                video_format_t *p_fmt_in,
                                video_format_t *p_fmt_out )
{
    block_t *p_block;
    picture_t *p_pic;
    stream_t *p_stream = NULL;
    int i_size;

    p_stream = stream_UrlNew( p_image->p_parent, psz_url );

    if( !p_stream )
    {
        msg_Dbg( p_image->p_parent, "could not open %s for reading",
                 psz_url );
        return NULL;
    }

    i_size = stream_Size( p_stream );

    p_block = block_New( p_image->p_parent, i_size );

    stream_Read( p_stream, p_block->p_buffer, i_size );
    stream_Delete( p_stream );

    if( !p_fmt_in->i_chroma )
    {
        /* Try to guess format from file name */
        p_fmt_in->i_chroma = Ext2Fourcc( psz_url );
    }

    p_pic = ImageRead( p_image, p_block, p_fmt_in, p_fmt_out );

    return p_pic;
}

/**
 * Write an image
 *
 */

void PicRelease( picture_t *p_pic ){};

static block_t *ImageWrite( image_handler_t *p_image, picture_t *p_pic,
                            video_format_t *p_fmt_in,
                            video_format_t *p_fmt_out )
{
    block_t *p_block;
    void (*pf_release)( picture_t * );

    /* Check if we can reuse the current encoder */
    if( p_image->p_enc &&
        ( p_image->p_enc->fmt_out.i_codec != p_fmt_out->i_chroma ||
          p_image->p_enc->fmt_out.video.i_width != p_fmt_out->i_width ||
          p_image->p_enc->fmt_out.video.i_height != p_fmt_out->i_height ) )
    {
        DeleteEncoder( p_image->p_enc );
        p_image->p_enc = 0;
    }

    /* Start an encoder */
    if( !p_image->p_enc )
    {
        p_image->p_enc = CreateEncoder( p_image->p_parent,
                                        p_fmt_in, p_fmt_out );
        if( !p_image->p_enc ) return NULL;
    }

    /* Check if we need chroma conversion or resizing */
    if( p_image->p_enc->fmt_in.video.i_chroma != p_fmt_in->i_chroma ||
        p_image->p_enc->fmt_in.video.i_width != p_fmt_in->i_width ||
        p_image->p_enc->fmt_in.video.i_height != p_fmt_in->i_height )
    {
        picture_t *p_tmp_pic;

        if( p_image->p_filter )
        if( p_image->p_filter->fmt_in.video.i_chroma != p_fmt_in->i_chroma ||
            p_image->p_filter->fmt_out.video.i_chroma !=
            p_image->p_enc->fmt_in.video.i_chroma )
        {
            /* We need to restart a new filter */
            DeleteFilter( p_image->p_filter );
            p_image->p_filter = 0;
        }

        /* Start a filter */
        if( !p_image->p_filter )
        {
            es_format_t fmt_in;
            es_format_Init( &fmt_in, VIDEO_ES, p_fmt_in->i_chroma );
            fmt_in.video = *p_fmt_in;

            p_image->p_filter =
                CreateFilter( p_image->p_parent, &fmt_in,
                              &p_image->p_enc->fmt_in.video, NULL );

            if( !p_image->p_filter )
            {
                return NULL;
            }
        }
        else
        {
            /* Filters should handle on-the-fly size changes */
            p_image->p_filter->fmt_in.i_codec = p_fmt_in->i_chroma;
            p_image->p_filter->fmt_out.video = *p_fmt_in;
            p_image->p_filter->fmt_out.i_codec =p_image->p_enc->fmt_in.i_codec;
            p_image->p_filter->fmt_out.video = p_image->p_enc->fmt_in.video;
        }

        pf_release = p_pic->pf_release;
        p_pic->pf_release = PicRelease; /* Small hack */
        p_tmp_pic =
            p_image->p_filter->pf_video_filter( p_image->p_filter, p_pic );
        p_pic->pf_release = pf_release;

        p_block = p_image->p_enc->pf_encode_video( p_image->p_enc, p_tmp_pic );

        p_image->p_filter->pf_vout_buffer_del( p_image->p_filter, p_tmp_pic );
    }
    else
    {
        p_block = p_image->p_enc->pf_encode_video( p_image->p_enc, p_pic );
    }

    if( !p_block )
    {
        msg_Dbg( p_image->p_parent, "no image encoded" );
        return 0;
    }

    return p_block;
}

static int ImageWriteUrl( image_handler_t *p_image, picture_t *p_pic,
                          video_format_t *p_fmt_in, video_format_t *p_fmt_out,
                          const char *psz_url )
{
    block_t *p_block;
    FILE *file;

    if( !p_fmt_out->i_chroma )
    {
        /* Try to guess format from file name */
        p_fmt_out->i_chroma = Ext2Fourcc( psz_url );
    }

    file = utf8_fopen( psz_url, "wb" );
    if( !file )
    {
        msg_Dbg( p_image->p_parent, "could not open file %s for writing",
                 psz_url );
        return VLC_EGENERIC;
    }

    p_block = ImageWrite( p_image, p_pic, p_fmt_in, p_fmt_out );

    if( p_block )
    {
        fwrite( p_block->p_buffer, sizeof(char), p_block->i_buffer, file );
        block_Release( p_block );
    }

    fclose( file );

    return p_block ? VLC_SUCCESS : VLC_EGENERIC;
}

/**
 * Convert an image to a different format
 *
 */

static picture_t *ImageConvert( image_handler_t *p_image, picture_t *p_pic,
                                video_format_t *p_fmt_in,
                                video_format_t *p_fmt_out )
{
    void (*pf_release)( picture_t * );
    picture_t *p_pif;

    if( !p_fmt_out->i_width && !p_fmt_out->i_height &&
        p_fmt_out->i_sar_num && p_fmt_out->i_sar_den &&
        p_fmt_out->i_sar_num * p_fmt_in->i_sar_den !=
        p_fmt_out->i_sar_den * p_fmt_in->i_sar_num )
    {
        p_fmt_out->i_width =
            p_fmt_in->i_sar_num * (int64_t)p_fmt_out->i_sar_den *
            p_fmt_in->i_width / p_fmt_in->i_sar_den / p_fmt_out->i_sar_num;
        p_fmt_out->i_visible_width =
            p_fmt_in->i_sar_num * (int64_t)p_fmt_out->i_sar_den *
            p_fmt_in->i_visible_width / p_fmt_in->i_sar_den /
            p_fmt_out->i_sar_num;