www.pudn.com > ffmpeg_src2007.rar > avs.c

/* 
 * AVS video decoder. 
 * Copyright (c) 2006  Aurelien Jacobs  
 * 
 * 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 St, Fifth Floor, Boston, MA  02110-1301  USA 
 */ 
 
#include "avcodec.h" 
#include "bitstream.h" 
 
 
typedef struct { 
    AVFrame picture; 
} avs_context_t; 
 
typedef enum { 
    AVS_VIDEO     = 0x01, 
    AVS_AUDIO     = 0x02, 
    AVS_PALETTE   = 0x03, 
    AVS_GAME_DATA = 0x04, 
} avs_block_type_t; 
 
typedef enum { 
    AVS_I_FRAME     = 0x00, 
    AVS_P_FRAME_3X3 = 0x01, 
    AVS_P_FRAME_2X2 = 0x02, 
    AVS_P_FRAME_2X3 = 0x03, 
} avs_video_sub_type_t; 
 
 
static int 
avs_decode_frame(AVCodecContext * avctx, 
                 void *data, int *data_size, uint8_t * buf, int buf_size) 
{ 
    avs_context_t *const avs = avctx->priv_data; 
    AVFrame *picture = data; 
    AVFrame *const p = (AVFrame *) & avs->picture; 
    uint8_t *table, *vect, *out; 
    int i, j, x, y, stride, vect_w = 3, vect_h = 3; 
    int sub_type; 
    avs_block_type_t type; 
    GetBitContext change_map; 
 
    if (avctx->reget_buffer(avctx, p)) { 
        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); 
        return -1; 
    } 
    p->reference = 1; 
    p->pict_type = FF_P_TYPE; 
    p->key_frame = 0; 
 
    out = avs->picture.data[0]; 
    stride = avs->picture.linesize[0]; 
 
    sub_type = buf[0]; 
    type = buf[1]; 
    buf += 4; 
 
    if (type == AVS_PALETTE) { 
        int first, last; 
        uint32_t *pal = (uint32_t *) avs->picture.data[1]; 
 
        first = LE_16(buf); 
        last = first + LE_16(buf + 2); 
        buf += 4; 
        for (i=first; ipict_type = FF_I_TYPE; 
        p->key_frame = 1; 
    case AVS_P_FRAME_3X3: 
        vect_w = 3; 
        vect_h = 3; 
        break; 
 
    case AVS_P_FRAME_2X2: 
        vect_w = 2; 
        vect_h = 2; 
        break; 
 
    case AVS_P_FRAME_2X3: 
        vect_w = 2; 
        vect_h = 3; 
        break; 
 
    default: 
      return -1; 
    } 
 
    table = buf + (256 * vect_w * vect_h); 
    if (sub_type != AVS_I_FRAME) { 
        int map_size = ((318 / vect_w + 7) / 8) * (198 / vect_h); 
        init_get_bits(&change_map, table, map_size); 
        table += map_size; 
    } 
 
    for (y=0; y<198; y+=vect_h) { 
        for (x=0; x<318; x+=vect_w) { 
            if (sub_type == AVS_I_FRAME || get_bits1(&change_map)) { 
                vect = &buf[*table++ * (vect_w * vect_h)]; 
                for (j=0; jpicture; 
    *data_size = sizeof(AVPicture); 
 
    return buf_size; 
} 
 
static int avs_decode_init(AVCodecContext * avctx) 
{ 
    avctx->pix_fmt = PIX_FMT_PAL8; 
    return 0; 
} 
 
AVCodec avs_decoder = { 
    "avs", 
    CODEC_TYPE_VIDEO, 
    CODEC_ID_AVS, 
    sizeof(avs_context_t), 
    avs_decode_init, 
    NULL, 
    NULL, 
    avs_decode_frame, 
    CODEC_CAP_DR1, 
};