xref: /third_party/ffmpeg/libavcodec/xl.c (revision cabdff1a)
1/*
2 * Miro VideoXL codec
3 * Copyright (c) 2004 Konstantin Shishkov
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * Miro VideoXL codec.
25 */
26
27#include "libavutil/common.h"
28#include "libavutil/intreadwrite.h"
29#include "avcodec.h"
30#include "codec_internal.h"
31#include "internal.h"
32
33static const int xl_table[32] = {
34   0,   1,   2,   3,   4,   5,   6,   7,
35   8,   9,  12,  15,  20,  25,  34,  46,
36  64,  82,  94, 103, 108, 113, 116, 119,
37 120, 121, 122, 123, 124, 125, 126, 127
38};
39
40static int decode_frame(AVCodecContext *avctx, AVFrame *p,
41                        int *got_frame, AVPacket *avpkt)
42{
43    const uint8_t *buf = avpkt->data;
44    int buf_size       = avpkt->size;
45    uint8_t *Y, *U, *V;
46    int i, j, ret;
47    int stride;
48    uint32_t val;
49    int y0, y1, y2, y3 = 0, c0 = 0, c1 = 0;
50
51    if (avctx->width % 4) {
52        av_log(avctx, AV_LOG_ERROR, "width is not a multiple of 4\n");
53        return AVERROR_INVALIDDATA;
54    }
55    if (buf_size < avctx->width * avctx->height) {
56        av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
57        return AVERROR_INVALIDDATA;
58    }
59
60    if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
61        return ret;
62    p->pict_type = AV_PICTURE_TYPE_I;
63    p->key_frame = 1;
64
65    Y = p->data[0];
66    U = p->data[1];
67    V = p->data[2];
68
69    stride = avctx->width - 4;
70
71    for (i = 0; i < avctx->height; i++) {
72        /* lines are stored in reversed order */
73        buf += stride;
74
75        for (j = 0; j < avctx->width; j += 4) {
76            /* value is stored in LE dword with word swapped */
77            val  = AV_RL32(buf);
78            buf -= 4;
79            val  = ((val >> 16) & 0xFFFF) | ((val & 0xFFFF) << 16);
80
81            if (!j)
82                y0 = (val & 0x1F) << 2;
83            else
84                y0 = y3 + xl_table[val & 0x1F];
85            val >>= 5;
86            y1    = y0 + xl_table[val & 0x1F];
87            val >>= 5;
88            y2    = y1 + xl_table[val & 0x1F];
89            val >>= 6; /* align to word */
90            y3    = y2 + xl_table[val & 0x1F];
91            val >>= 5;
92            if (!j)
93                c0 = (val & 0x1F) << 2;
94            else
95                c0 += xl_table[val & 0x1F];
96            val >>= 5;
97            if (!j)
98                c1 = (val & 0x1F) << 2;
99            else
100                c1 += xl_table[val & 0x1F];
101
102            Y[j + 0] = y0 << 1;
103            Y[j + 1] = y1 << 1;
104            Y[j + 2] = y2 << 1;
105            Y[j + 3] = y3 << 1;
106
107            U[j >> 2] = c0 << 1;
108            V[j >> 2] = c1 << 1;
109        }
110
111        buf += avctx->width + 4;
112        Y   += p->linesize[0];
113        U   += p->linesize[1];
114        V   += p->linesize[2];
115    }
116
117    *got_frame = 1;
118
119    return buf_size;
120}
121
122static av_cold int decode_init(AVCodecContext *avctx)
123{
124    avctx->pix_fmt = AV_PIX_FMT_YUV411P;
125
126    return 0;
127}
128
129const FFCodec ff_xl_decoder = {
130    .p.name       = "xl",
131    .p.long_name  = NULL_IF_CONFIG_SMALL("Miro VideoXL"),
132    .p.type       = AVMEDIA_TYPE_VIDEO,
133    .p.id         = AV_CODEC_ID_VIXL,
134    .init         = decode_init,
135    FF_CODEC_DECODE_CB(decode_frame),
136    .p.capabilities = AV_CODEC_CAP_DR1,
137    .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
138};
139