1/*
2 * Dxtory decoder
3 *
4 * Copyright (c) 2011 Konstantin Shishkov
5 *
6 * This file is part of Libav.
7 *
8 * Libav is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * Libav is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#include "avcodec.h"
24#include "libavutil/intreadwrite.h"
25
26static av_cold int decode_init(AVCodecContext *avctx)
27{
28    avctx->pix_fmt     = PIX_FMT_YUV420P;
29    avctx->coded_frame = avcodec_alloc_frame();
30    if (!avctx->coded_frame)
31        return AVERROR(ENOMEM);
32
33    return 0;
34}
35
36static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
37                        AVPacket *avpkt)
38{
39    int h, w;
40    AVFrame *pic = avctx->coded_frame;
41    const uint8_t *src = avpkt->data;
42    uint8_t *Y1, *Y2, *U, *V;
43    int ret;
44
45    if (pic->data[0])
46        avctx->release_buffer(avctx, pic);
47
48    if (avpkt->size < avctx->width * avctx->height * 3 / 2 + 16) {
49        av_log(avctx, AV_LOG_ERROR, "packet too small\n");
50        return AVERROR_INVALIDDATA;
51    }
52
53    pic->reference = 0;
54    if ((ret = avctx->get_buffer(avctx, pic)) < 0)
55        return ret;
56
57    pic->pict_type = AV_PICTURE_TYPE_I;
58    pic->key_frame = 1;
59
60    if (AV_RL32(src) != 0x01000002) {
61        av_log_ask_for_sample(avctx, "Unknown frame header %X\n", AV_RL32(src));
62        return AVERROR_PATCHWELCOME;
63    }
64    src += 16;
65
66    Y1 = pic->data[0];
67    Y2 = pic->data[0] + pic->linesize[0];
68    U  = pic->data[1];
69    V  = pic->data[2];
70    for (h = 0; h < avctx->height; h += 2) {
71        for (w = 0; w < avctx->width; w += 2) {
72            AV_WN16A(Y1 + w, AV_RN16A(src));
73            AV_WN16A(Y2 + w, AV_RN16A(src + 2));
74            U[w >> 1] = src[4] + 0x80;
75            V[w >> 1] = src[5] + 0x80;
76            src += 6;
77        }
78        Y1 += pic->linesize[0] << 1;
79        Y2 += pic->linesize[0] << 1;
80        U  += pic->linesize[1];
81        V  += pic->linesize[2];
82    }
83
84    *data_size      = sizeof(AVFrame);
85    *(AVFrame*)data = *pic;
86
87    return avpkt->size;
88}
89
90static av_cold int decode_close(AVCodecContext *avctx)
91{
92    AVFrame *pic = avctx->coded_frame;
93    if (pic->data[0])
94        avctx->release_buffer(avctx, pic);
95    av_freep(&avctx->coded_frame);
96
97    return 0;
98}
99
100AVCodec ff_dxtory_decoder = {
101    .name           = "dxtory",
102    .long_name      = NULL_IF_CONFIG_SMALL("Dxtory"),
103    .type           = AVMEDIA_TYPE_VIDEO,
104    .id             = CODEC_ID_DXTORY,
105    .init           = decode_init,
106    .close          = decode_close,
107    .decode         = decode_frame,
108    .capabilities   = CODEC_CAP_DR1,
109};
110