PeerStreamer

/*

 * ATI VCR1 codec

 * Copyright (c) 2003 Michael Niedermayer

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file vcr1.c

 * ati vcr1 codec.

 */

#include "avcodec.h"

#include "mpegvideo.h"

//#undef NDEBUG

//#include <assert.h>

typedef struct VCR1Context{

    AVCodecContext *avctx;

    AVFrame picture;

    int delta[16];

    int offset[4];

} VCR1Context;

static int decode_frame(AVCodecContext *avctx,

                        void *data, int *data_size,

                        uint8_t *buf, int buf_size)

{

    VCR1Context * const a = avctx->priv_data;

    AVFrame *picture = data;

    AVFrame * const p= (AVFrame*)&a->picture;

    uint8_t *bytestream= buf;

    int i, x, y;

    if(p->data[0])

        avctx->release_buffer(avctx, p);

    p->reference= 0;

    if(avctx->get_buffer(avctx, p) < 0){

        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

        return -1;

    }

    p->pict_type= I_TYPE;

    p->key_frame= 1;

    for(i=0; i<16; i++){

        a->delta[i]= *(bytestream++);

        bytestream++;

    }

    for(y=0; y<avctx->height; y++){

        int offset;

        uint8_t *luma= &a->picture.data[0][ y*a->picture.linesize[0] ];

        if((y&3) == 0){

            uint8_t *cb= &a->picture.data[1][ (y>>2)*a->picture.linesize[1] ];

            uint8_t *cr= &a->picture.data[2][ (y>>2)*a->picture.linesize[2] ];

            for(i=0; i<4; i++)

                a->offset[i]= *(bytestream++);

            offset= a->offset[0] - a->delta[ bytestream[2]&0xF ];

            for(x=0; x<avctx->width; x+=4){

                luma[0]=( offset += a->delta[ bytestream[2]&0xF ]);

                luma[1]=( offset += a->delta[ bytestream[2]>>4  ]);

                luma[2]=( offset += a->delta[ bytestream[0]&0xF ]);

                luma[3]=( offset += a->delta[ bytestream[0]>>4  ]);

                luma += 4;

                *(cb++) = bytestream[3];

                *(cr++) = bytestream[1];

                bytestream+= 4;

            }

        }else{

            offset= a->offset[y&3] - a->delta[ bytestream[2]&0xF ];

            for(x=0; x<avctx->width; x+=8){

                luma[0]=( offset += a->delta[ bytestream[2]&0xF ]);

                luma[1]=( offset += a->delta[ bytestream[2]>>4  ]);

                luma[2]=( offset += a->delta[ bytestream[3]&0xF ]);

                luma[3]=( offset += a->delta[ bytestream[3]>>4  ]);

                luma[4]=( offset += a->delta[ bytestream[0]&0xF ]);

                luma[5]=( offset += a->delta[ bytestream[0]>>4  ]);

                luma[6]=( offset += a->delta[ bytestream[1]&0xF ]);

                luma[7]=( offset += a->delta[ bytestream[1]>>4  ]);

                luma += 8;

                bytestream+= 4;

            }

        }

    }

    *picture= *(AVFrame*)&a->picture;

    *data_size = sizeof(AVPicture);

    emms_c();

    return buf_size;

}

#if 0

static int encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){

    VCR1Context * const a = avctx->priv_data;

    AVFrame *pict = data;

    AVFrame * const p= (AVFrame*)&a->picture;

    int size;

    int mb_x, mb_y;

    *p = *pict;

    p->pict_type= I_TYPE;

    p->key_frame= 1;

    emms_c();

    align_put_bits(&a->pb);

    while(get_bit_count(&a->pb)&31)

        put_bits(&a->pb, 8, 0);

    size= get_bit_count(&a->pb)/32;

    return size*4;

}

#endif

static void common_init(AVCodecContext *avctx){

    VCR1Context * const a = avctx->priv_data;

    avctx->coded_frame= (AVFrame*)&a->picture;

    a->avctx= avctx;

}

static int decode_init(AVCodecContext *avctx){

    common_init(avctx);

    avctx->pix_fmt= PIX_FMT_YUV410P;

    return 0;

}

#if 0

static int encode_init(AVCodecContext *avctx){

    common_init(avctx);

    return 0;

}

#endif

AVCodec vcr1_decoder = {

    "vcr1",

    CODEC_TYPE_VIDEO,

    CODEC_ID_VCR1,

    sizeof(VCR1Context),

    decode_init,

    NULL,

    NULL,

    decode_frame,

    CODEC_CAP_DR1,

};

#if 0

#ifdef CONFIG_ENCODERS

AVCodec vcr1_encoder = {

    "vcr1",

    CODEC_TYPE_VIDEO,

    CODEC_ID_VCR1,

    sizeof(VCR1Context),

    encode_init,

    encode_frame,

    //encode_end,

};

#endif //CONFIG_ENCODERS

#endif