cinepak.c

video linux conference

/*****************************************************************************
 * cinepak.c: cinepak video decoder
 *****************************************************************************
 * Copyright (C) 1999-2001 VideoLAN
 * $Id: cinepak.c 10101 2005-03-02 16:47:31Z robux4 $
 *
 * Authors: 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>

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
static int  OpenDecoder ( vlc_object_t * );
static void CloseDecoder( vlc_object_t * );

vlc_module_begin();
    set_description( _("Cinepak video decoder") );
    set_capability( "decoder", 100 );
    set_category( CAT_INPUT );
    set_subcategory( SUBCAT_INPUT_VCODEC );
    set_callbacks( OpenDecoder, CloseDecoder );
vlc_module_end();


/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
#define CINEPAK_MAXSTRIP 32

typedef struct
{
    uint8_t i_y[4];
    uint8_t i_u, i_v;

} cinepak_codebook_t;

typedef struct
{
    int b_grayscale; /* force to grayscale */

    int i_width;
    int i_height;

    int i_stride_x;
    int i_stride_y;

    uint8_t *p_y, *p_u, *p_v;

    int i_stride[3]; /* our 3 planes */
    int i_lines[3];
    uint8_t *p_pix[3];

    cinepak_codebook_t codebook_v1[CINEPAK_MAXSTRIP][256];
    cinepak_codebook_t codebook_v4[CINEPAK_MAXSTRIP][256];

} cinepak_context_t;

/*****************************************************************************
 * decoder_sys_t : decoder descriptor
 *****************************************************************************/
struct decoder_sys_t
{
    /*
     * Cinepak properties
     */
    cinepak_context_t context;
};

static picture_t *DecodeBlock ( decoder_t *, block_t ** );

static int cinepak_decode_frame( cinepak_context_t *, int, uint8_t * );

/*****************************************************************************
 * OpenDecoder: probe the decoder and return score
 *****************************************************************************
 * Tries to launch a decoder and return score so that the interface is able
 * to chose.
 *****************************************************************************/
static int OpenDecoder( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t*)p_this;
    decoder_sys_t *p_sys;
    vlc_value_t val;

    if( p_dec->fmt_in.i_codec != VLC_FOURCC('c','v','i','d') &&
        p_dec->fmt_in.i_codec != VLC_FOURCC('C','V','I','D') )
    {
        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->context, 0, sizeof( cinepak_context_t ) );

    var_Create( p_dec, "grayscale", VLC_VAR_BOOL | VLC_VAR_DOINHERIT );
    var_Get( p_dec, "grayscale", &val );
    p_sys->context.b_grayscale = val.b_bool;

    p_dec->pf_decode_video = DecodeBlock;

    msg_Dbg( p_dec, "cinepak decoder started" );

    return VLC_SUCCESS;
}

/****************************************************************************
 * DecodeBlock: the whole thing
 ****************************************************************************
 * This function must be fed with whole frames.
 ****************************************************************************/
static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    int i_status, i_plane;
    uint8_t *p_dst, *p_src;
    picture_t *p_pic;
    block_t *p_block;

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

    i_status = cinepak_decode_frame( &p_sys->context, p_block->i_buffer,
                                     p_block->p_buffer );
    if( i_status < 0 )
    {
        msg_Warn( p_dec, "cannot decode one frame (%d bytes)",
                  p_block->i_buffer );
        block_Release( p_block );
        return NULL;
    }

    p_dec->fmt_out.video.i_width = p_sys->context.i_width;
    p_dec->fmt_out.video.i_height = p_sys->context.i_height;
    p_dec->fmt_out.video.i_aspect = p_sys->context.i_width
        * VOUT_ASPECT_FACTOR / p_sys->context.i_height;
    p_dec->fmt_out.i_codec = VLC_FOURCC('I','4','2','0');

    /* Get a new picture */
    if( ( p_pic = p_dec->pf_vout_buffer_new( p_dec ) ) )
    {
        for( i_plane = 0; i_plane < 3; i_plane++ )
        {
            int i_line, i_lines;

            p_dst = p_pic->p[i_plane].p_pixels;
            p_src = p_sys->context.p_pix[i_plane];

            i_lines = __MIN( p_sys->context.i_lines[i_plane],
                             p_pic->p[i_plane].i_visible_lines );
            for( i_line = 0; i_line < i_lines; i_line++ )
            {
                memcpy( p_dst, p_src,
                        __MIN( p_pic->p[i_plane].i_pitch,
                               p_sys->context.i_stride[i_plane] ) );
                p_dst += p_pic->p[i_plane].i_pitch;
                p_src += p_sys->context.i_stride[i_plane];
            }
        }

        p_pic->date = p_block->i_pts ? p_block->i_pts : p_block->i_dts;
    }

    block_Release( p_block );
    return p_pic;
}

/*****************************************************************************
 * CloseDecoder: decoder destruction
 *****************************************************************************/
static void CloseDecoder( vlc_object_t *p_this )
{
    decoder_t     *p_dec = (decoder_t *)p_this;
    decoder_sys_t *p_sys = p_dec->p_sys;
    int i;

    msg_Dbg( p_dec, "cinepak decoder stopped" );

    for( i = 0; i < 3; i++ )
    {
        if( p_sys->context.p_pix[i] ) free( p_sys->context.p_pix[i] );
    }

    free( p_sys );
}

/*****************************************************************************
 * local Functions
 *****************************************************************************/

#define GET2BYTES( p ) \
    GetWBE( p ); p+= 2;
/* FIXME */
#define GET3BYTES( p ) \
    (GetDWBE( p ) >> 8); p+= 3;

#define GET4BYTES( p ) \
    GetDWBE( p ); p+= 4;

#define FREE( p ) \
    if( p ) free( p )

static void cinepak_LoadCodebook( cinepak_codebook_t *p_codebook,
                                  uint8_t *p_data, int b_grayscale )
{
    int i, i_y[4], i_u, i_v, i_Cb, i_Cr;
    int i_uv;
#define SCALEBITS 12
#define FIX( x ) ( (int)( (x) * ( 1L << SCALEBITS ) + 0.5 ) )

    for( i = 0; i < 4; i++ )
    {
        i_y[i] = (uint8_t)( *(p_data++) );
    }
    if( b_grayscale )
    {
        i_u  = (int8_t)( *(p_data++) );
        i_v  = (int8_t)( *(p_data++) );
    }
    else
    {
        i_u  = 0;
        i_v  = 0;
    }

    /*
          | Y  |   | 1 -0.0655  0.0110 | | CY |
          | Cb | = | 0  1.1656 -0.0062 | | CU |
          | Cr |   | 0  0.0467  1.4187 | | CV |
     */
    i_uv = ( FIX( -0.0655 ) * i_u + FIX( 0.0110 ) * i_v ) >> SCALEBITS;
    for( i = 0; i < 4; i++ )
    {
        i_y[i] += i_uv;
    }
    i_Cb  = ( FIX( 1.1656 ) * i_u + FIX( -0.0062 ) * i_v ) >> SCALEBITS;
    i_Cr  = ( FIX( 0.0467 ) * i_u + FIX(  1.4187 ) * i_v ) >> SCALEBITS;

    for( i = 0; i < 4; i++ )
    {
        p_codebook->i_y[i] = __MIN( __MAX( 0, i_y[i] ), 255 );
    }
    p_codebook->i_u  = __MIN( __MAX( 0, i_Cb + 128 ), 255 );
    p_codebook->i_v  = __MIN( __MAX( 0, i_Cr + 128 ), 255 );

#undef FIX
#undef SCALEBITS
}

static void cinepak_Getv4( cinepak_context_t *p_context,
                           int i_strip, int i_x, int i_y,
                           int i_x2, int i_y2, uint8_t *p_data )
{
    uint8_t i_index[4];
    int i,j;

    uint8_t *p_dst_y, *p_dst_u, *p_dst_v;
#define PIX_SET_Y( x, y, v ) \
    p_dst_y[(x) + (y)* p_context->i_stride[0]] = (v);

#define PIX_SET_UV( i, p, x, y, v ) \
    p[(x) + (y)* (p_context->i_stride[i])] = (v);

    for( i = 0; i < 4; i++ )
    {
        i_index[i] = *(p_data++);
    }

    /* y plane */
    p_dst_y = p_context->p_pix[0] + p_context->i_stride[0] * i_y + i_x;
    p_dst_u = p_context->p_pix[1] + p_context->i_stride[1] * (i_y/2) + (i_x/2);
    p_dst_v = p_context->p_pix[2] + p_context->i_stride[2] * (i_y/2) + (i_x/2);

    for( i = 0; i < 2; i++ )
    {
        for( j = 0; j < 2; j ++ )
        {
            PIX_SET_Y( 2*j + 0, 2*i + 0,
                       p_context->codebook_v4[i_strip][i_index[j+2*i]].i_y[0]);
            PIX_SET_Y( 2*j + 1, 2*i + 0,
                       p_context->codebook_v4[i_strip][i_index[j+2*i]].i_y[1]);
            PIX_SET_Y( 2*j + 0, 2*i + 1,
                       p_context->codebook_v4[i_strip][i_index[j+2*i]].i_y[2]);
            PIX_SET_Y( 2*j + 1, 2*i + 1,
                       p_context->codebook_v4[i_strip][i_index[j+2*i]].i_y[3]);

            PIX_SET_UV( 1, p_dst_u, j, i,
                        p_context->codebook_v4[i_strip][i_index[j+2*i]].i_u );
            PIX_SET_UV( 2, p_dst_v, j, i,
                        p_context->codebook_v4[i_strip][i_index[j+2*i]].i_v );
        }
    }
#undef PIX_SET_Y
#undef PIX_SET_UV
}

static void cinepak_Getv1( cinepak_context_t *p_context,
                           int i_strip, int i_x,  int i_y,
                           int i_x2, int i_y2, uint8_t *p_data )
{
    uint8_t i_index;
    int i,j;

    uint8_t *p_dst_y, *p_dst_u, *p_dst_v;
#define PIX_SET_Y( x, y, v ) \
    p_dst_y[(x) + (y)* p_context->i_stride[0]] = (v);

#define PIX_SET_UV( i,p, x, y, v ) \
    p[(x) + (y)* (p_context->i_stride[i])] = (v);

    i_index = *(p_data++);

    /* y plane */
    p_dst_y = p_context->p_pix[0] + p_context->i_stride[0] * i_y + i_x;
    p_dst_u = p_context->p_pix[1] + p_context->i_stride[1] * (i_y/2) + (i_x/2);
    p_dst_v = p_context->p_pix[2] + p_context->i_stride[2] * (i_y/2) + (i_x/2);

    for( i = 0; i < 2; i++ )
    {
        for( j = 0; j < 2; j ++ )
        {
            PIX_SET_Y( 2*j + 0, 2*i + 0,
                       p_context->codebook_v1[i_strip][i_index].i_y[2*i+j] );
            PIX_SET_Y( 2*j + 1, 2*i + 0,
                       p_context->codebook_v1[i_strip][i_index].i_y[2*i+j] );
            PIX_SET_Y( 2*j + 0, 2*i + 1,
                       p_context->codebook_v1[i_strip][i_index].i_y[2*i+j] );