PeerStreamer

/*

 * Miro VideoXL codec

 * Copyright (c) 2004 Konstantin Shishkov

 *

 * 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 xl.c

 * Miro VideoXL codec.

 */

#include "avcodec.h"

#include "mpegvideo.h"

typedef struct VideoXLContext{

    AVCodecContext *avctx;

    AVFrame pic;

} VideoXLContext;

const int xl_table[32] = {

   0,   1,   2,   3,   4,   5,   6,   7,

   8,   9,  12,  15,  20,  25,  34,  46,

  64,  82,  94, 103, 108, 113, 116, 119,

 120, 121, 122, 123, 124, 125, 126, 127};

static int decode_frame(AVCodecContext *avctx,

                        void *data, int *data_size,

                        uint8_t *buf, int buf_size)

{

    VideoXLContext * const a = avctx->priv_data;

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

    uint8_t *Y, *U, *V;

    int i, j;

    int stride;

    uint32_t val;

    int y0, y1, y2, y3, c0, c1;

    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;

    Y = a->pic.data[0];

    U = a->pic.data[1];

    V = a->pic.data[2];

    stride = avctx->width - 4;

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

        /* lines are stored in reversed order */

        buf += stride;

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

            /* value is stored in LE dword with word swapped */

            val = LE_32(buf);

            buf -= 4;

            val = ((val >> 16) & 0xFFFF) | ((val & 0xFFFF) << 16);

            if(!j)

                y0 = (val & 0x1F) << 2;

            else

                y0 = y3 + xl_table[val & 0x1F];

            val >>= 5;

            y1 = y0 + xl_table[val & 0x1F];

            val >>= 5;

            y2 = y1 + xl_table[val & 0x1F];

            val >>= 6; /* align to word */

            y3 = y2 + xl_table[val & 0x1F];

            val >>= 5;

            if(!j)

                c0 = (val & 0x1F) << 2;

            else

                c0 += xl_table[val & 0x1F];

            val >>= 5;

            if(!j)

                c1 = (val & 0x1F) << 2;

            else

                c1 += xl_table[val & 0x1F];

            Y[j + 0] = y0 << 1;

            Y[j + 1] = y1 << 1;

            Y[j + 2] = y2 << 1;

            Y[j + 3] = y3 << 1;

            U[j >> 2] = c0 << 1;

            V[j >> 2] = c1 << 1;

        }

        buf += avctx->width + 4;

        Y += a->pic.linesize[0];

        U += a->pic.linesize[1];

        V += a->pic.linesize[2];

    }

    *data_size = sizeof(AVFrame);

    *(AVFrame*)data = a->pic;

    return buf_size;

}

static int decode_init(AVCodecContext *avctx){

//    VideoXLContext * const a = avctx->priv_data;

    avctx->pix_fmt= PIX_FMT_YUV411P;

    return 0;

}

AVCodec xl_decoder = {

    "xl",

    CODEC_TYPE_VIDEO,

    CODEC_ID_VIXL,

    sizeof(VideoXLContext),

    decode_init,

    NULL,

    NULL,

    decode_frame,

    CODEC_CAP_DR1,

};