/* * AVS video decoder. * Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org> * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "avcodec.h" #include "get_bits.h" #include "internal.h" typedef struct { 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, void *data, 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 *picture = 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; if ((ret = ff_reget_buffer(avctx, p)) < 0) { av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); return ret; } p->pict_type = AV_PICTURE_TYPE_P; p->key_frame = 0; 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); 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->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 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; } AVCodec ff_avs_decoder = { .name = "avs", .long_name = NULL_IF_CONFIG_SMALL("AVS (Audio Video Standard) video"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_AVS, .priv_data_size = sizeof(AvsContext), .init = avs_decode_init, .decode = avs_decode_frame, .close = avs_decode_end, .capabilities = CODEC_CAP_DR1, };