1/*
2 * Silicon Graphics RLE 8-bit video decoder
3 * Copyright (c) 2012 Peter Ross
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 * Silicon Graphics RLE 8-bit video decoder
25 * @note Data is packed in rbg323 with rle, contained in mv or mov.
26 * The algorithm and pixfmt are subtly different from SGI images.
27 */
28
29#include "libavutil/common.h"
30
31#include "avcodec.h"
32#include "internal.h"
33
34typedef struct SGIRLEContext {
35    AVFrame *frame;
36} SGIRLEContext;
37
38static av_cold int sgirle_decode_init(AVCodecContext *avctx)
39{
40    SGIRLEContext *s = avctx->priv_data;
41    avctx->pix_fmt = AV_PIX_FMT_BGR8;
42    s->frame = av_frame_alloc();
43    if (!s->frame)
44        return AVERROR(ENOMEM);
45    return 0;
46}
47
48/**
49 * Convert SGI RBG323 pixel into AV_PIX_FMT_BGR8
50 * SGI RGB data is packed as 8bpp, (msb)3R 2B 3G(lsb)
51 */
52#define RBG323_TO_BGR8(x) ((((x) << 3) & 0xC0) |                                \
53                           (((x) << 3) & 0x38) |                                \
54                           (((x) >> 5) & 7))
55static av_always_inline
56void rbg323_to_bgr8(uint8_t *dst, const uint8_t *src, int size)
57{
58    int i;
59    for (i = 0; i < size; i++)
60        dst[i] = RBG323_TO_BGR8(src[i]);
61}
62
63/**
64 * @param[out] dst Destination buffer
65 * @param[in] src  Source buffer
66 * @param src_size Source buffer size (bytes)
67 * @param width    Width of destination buffer (pixels)
68 * @param height   Height of destination buffer (pixels)
69 * @param linesize Line size of destination buffer (bytes)
70 *
71 * @return <0 on error
72 */
73static int decode_sgirle8(AVCodecContext *avctx, uint8_t *dst,
74                          const uint8_t *src, int src_size,
75                          int width, int height, ptrdiff_t linesize)
76{
77    const uint8_t *src_end = src + src_size;
78    int x = 0, y = 0;
79
80#define INC_XY(n)                                                             \
81    x += n;                                                                   \
82    if (x >= width) {                                                         \
83        y++;                                                                  \
84        if (y >= height)                                                      \
85            return 0;                                                         \
86        x = 0;                                                                \
87    }
88
89    while (src_end - src >= 2) {
90        uint8_t v = *src++;
91        if (v > 0 && v < 0xC0) {
92            do {
93                int length = FFMIN(v, width - x);
94                if (length <= 0)
95                    break;
96                memset(dst + y * linesize + x, RBG323_TO_BGR8(*src), length);
97                INC_XY(length);
98                v -= length;
99            } while (v > 0);
100            src++;
101        } else if (v >= 0xC1) {
102            v -= 0xC0;
103            do {
104                int length = FFMIN3(v, width - x, src_end - src);
105                if (src_end - src < length || length <= 0)
106                    break;
107                rbg323_to_bgr8(dst + y * linesize + x, src, length);
108                INC_XY(length);
109                src += length;
110                v   -= length;
111            } while (v > 0);
112        } else {
113            avpriv_request_sample(avctx, "opcode %d", v);
114            return AVERROR_PATCHWELCOME;
115        }
116    }
117    return 0;
118}
119
120static int sgirle_decode_frame(AVCodecContext *avctx, void *data,
121                               int *got_frame, AVPacket *avpkt)
122{
123    SGIRLEContext *s = avctx->priv_data;
124    int ret;
125
126    if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
127        return ret;
128
129    ret = decode_sgirle8(avctx, s->frame->data[0], avpkt->data, avpkt->size,
130                         avctx->width, avctx->height, s->frame->linesize[0]);
131    if (ret < 0)
132        return ret;
133
134    *got_frame = 1;
135    if ((ret = av_frame_ref(data, s->frame)) < 0)
136        return ret;
137
138    return avpkt->size;
139}
140
141static av_cold int sgirle_decode_end(AVCodecContext *avctx)
142{
143    SGIRLEContext *s = avctx->priv_data;
144
145    av_frame_free(&s->frame);
146
147    return 0;
148}
149
150AVCodec ff_sgirle_decoder = {
151    .name           = "sgirle",
152    .long_name      = NULL_IF_CONFIG_SMALL("Silicon Graphics RLE 8-bit video"),
153    .type           = AVMEDIA_TYPE_VIDEO,
154    .id             = AV_CODEC_ID_SGIRLE,
155    .priv_data_size = sizeof(SGIRLEContext),
156    .init           = sgirle_decode_init,
157    .close          = sgirle_decode_end,
158    .decode         = sgirle_decode_frame,
159    .capabilities   = CODEC_CAP_DR1,
160};
161