PeerStreamer

/*

 * 8088flex TMV video decoder

 * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg 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 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg 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 FFmpeg; if not, write to the Free Software

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

 */

/**

 * 8088flex TMV video decoder

 * @file

 * @author Daniel Verkamp

 * @sa http://www.oldskool.org/pc/8088_Corruption

 */

#include "avcodec.h"

#include "cga_data.h"

typedef struct TMVContext {

    AVFrame pic;

} TMVContext;

static int tmv_decode_frame(AVCodecContext *avctx, void *data,

                            int *data_size, AVPacket *avpkt)

{

    TMVContext *tmv    = avctx->priv_data;

    const uint8_t *src = avpkt->data;

    uint8_t *dst;

    unsigned char_cols = avctx->width >> 3;

    unsigned char_rows = avctx->height >> 3;

    unsigned x, y, fg, bg, c;

    if (tmv->pic.data[0])

        avctx->release_buffer(avctx, &tmv->pic);

    if (avctx->get_buffer(avctx, &tmv->pic) < 0) {

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

        return -1;

    }

    if (avpkt->size < 2*char_rows*char_cols) {

        av_log(avctx, AV_LOG_ERROR,

               "Input buffer too small, truncated sample?\n");

        *data_size = 0;

        return -1;

    }

    tmv->pic.pict_type = AV_PICTURE_TYPE_I;

    tmv->pic.key_frame = 1;

    dst                = tmv->pic.data[0];

    tmv->pic.palette_has_changed = 1;

    memcpy(tmv->pic.data[1], ff_cga_palette, 16 * 4);

    for (y = 0; y < char_rows; y++) {

        for (x = 0; x < char_cols; x++) {

            c  = *src++;

            bg = *src  >> 4;

            fg = *src++ & 0xF;

            ff_draw_pc_font(dst + x * 8, tmv->pic.linesize[0],

                            ff_cga_font, 8, c, fg, bg);

        }

        dst += tmv->pic.linesize[0] * 8;

    }

    *data_size = sizeof(AVFrame);

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

    return avpkt->size;

}

static av_cold int tmv_decode_close(AVCodecContext *avctx)

{

    TMVContext *tmv = avctx->priv_data;

    if (tmv->pic.data[0])

        avctx->release_buffer(avctx, &tmv->pic);

    return 0;

}

AVCodec ff_tmv_decoder = {

    .name           = "tmv",

    .type           = AVMEDIA_TYPE_VIDEO,

    .id             = CODEC_ID_TMV,

    .priv_data_size = sizeof(TMVContext),

    .close          = tmv_decode_close,

    .decode         = tmv_decode_frame,

    .capabilities   = CODEC_CAP_DR1,

    .long_name      = NULL_IF_CONFIG_SMALL("8088flex TMV"),

};