/* * AVS video decoder. * Copyright (c) 2006  Aurelien Jacobs <aurel@gnuage.org> * * 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 */ #include "avcodec.h"#include "codec_internal.h"#include "decode.h"#include "get_bits.h" typedef struct AvsContext {    AVFrame *frame;} AvsContext; typedef enum {    AVS_VIDEO     = 0x01,    AVS_AUDIO     = 0x02,    AVS_PALETTE   = 0x03,    AVS_GAME_DATA = 0x04,} AvsBlockType; typedef enum {    AVS_I_FRAME     = 0x00,    AVS_P_FRAME_3X3 = 0x01,    AVS_P_FRAME_2X2 = 0x02,    AVS_P_FRAME_2X3 = 0x03,} AvsVideoSubType;  static int avs_decode_frame(AVCodecContext * avctx, AVFrame *picture,                            int *got_frame, AVPacket *avpkt){    const uint8_t *buf = avpkt->data;    const uint8_t *buf_end = avpkt->data + avpkt->size;    int buf_size = avpkt->size;    AvsContext *const avs = avctx->priv_data;    AVFrame *const p =  avs->frame;    const uint8_t *table, *vect;    uint8_t *out;    int i, j, x, y, stride, ret, vect_w = 3, vect_h = 3;    AvsVideoSubType sub_type;    AvsBlockType type;    GetBitContext change_map = {0}; //init to silence warning     if ((ret = ff_reget_buffer(avctx, p, 0)) < 0)        return ret;    p->pict_type = AV_PICTURE_TYPE_P;    p->flags &= ~AV_FRAME_FLAG_KEY;     out    = p->data[0];    stride = p->linesize[0];     if (buf_end - buf < 4)        return AVERROR_INVALIDDATA;    sub_type = buf[0];    type = buf[1];    buf += 4;     if (type == AVS_PALETTE) {        int first, last;        uint32_t *pal = (uint32_t *) p->data[1];         first = AV_RL16(buf);        last = first + AV_RL16(buf + 2);        if (first >= 256 || last > 256 || buf_end - buf < 4 + 4 + 3 * (last - first))            return AVERROR_INVALIDDATA;        buf += 4;        for (i=first; i<last; i++, buf+=3) {            pal[i] = (buf[0] << 18) | (buf[1] << 10) | (buf[2] << 2);            pal[i] |= 0xFFU << 24 | (pal[i] >> 6) & 0x30303;        }         sub_type = buf[0];        type = buf[1];        buf += 4;    }     if (type != AVS_VIDEO)        return AVERROR_INVALIDDATA;     switch (sub_type) {    case AVS_I_FRAME:        p->pict_type = AV_PICTURE_TYPE_I;        p->flags |= AV_FRAME_FLAG_KEY;    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 AVERROR_INVALIDDATA;    }     if (buf_end - buf < 256 * vect_w * vect_h)        return AVERROR_INVALIDDATA;    table = buf + (256 * vect_w * vect_h);    if (sub_type != AVS_I_FRAME) {        int map_size = ((318 / vect_w + 7) / 8) * (198 / vect_h);        if (buf_end - table < map_size)            return AVERROR_INVALIDDATA;        init_get_bits(&change_map, table, map_size * 8);        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)) {                if (buf_end - table < 1)                    return AVERROR_INVALIDDATA;                vect = &buf[*table++ * (vect_w * vect_h)];                for (j=0; j<vect_w; j++) {                    out[(y + 0) * stride + x + j] = vect[(0 * vect_w) + j];                    out[(y + 1) * stride + x + j] = vect[(1 * vect_w) + j];                    if (vect_h == 3)                        out[(y + 2) * stride + x + j] =                            vect[(2 * vect_w) + j];                }            }        }        if (sub_type != AVS_I_FRAME)            align_get_bits(&change_map);    }     if ((ret = av_frame_ref(picture, p)) < 0)        return ret;    *got_frame = 1;     return buf_size;} static av_cold int avs_decode_init(AVCodecContext * avctx){    AvsContext *s = avctx->priv_data;     s->frame = av_frame_alloc();    if (!s->frame)        return AVERROR(ENOMEM);     avctx->pix_fmt = AV_PIX_FMT_PAL8;     return ff_set_dimensions(avctx, 318, 198);} static av_cold int avs_decode_end(AVCodecContext *avctx){    AvsContext *s = avctx->priv_data;    av_frame_free(&s->frame);    return 0;}  const FFCodec ff_avs_decoder = {    .p.name         = "avs",    CODEC_LONG_NAME("AVS (Audio Video Standard) video"),    .p.type         = AVMEDIA_TYPE_VIDEO,    .p.id           = AV_CODEC_ID_AVS,    .priv_data_size = sizeof(AvsContext),    .init           = avs_decode_init,    FF_CODEC_DECODE_CB(avs_decode_frame),    .close          = avs_decode_end,    .p.capabilities = AV_CODEC_CAP_DR1,};