1/*
2 * Micrsoft RLE Video Decoder
3 * Copyright (C) 2003 the ffmpeg project
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 * MS RLE Video Decoder by Mike Melanson (melanson@pcisys.net)
25 * For more information about the MS RLE format, visit:
26 *   http://www.pcisys.net/~melanson/codecs/
27 *
28 * The MS RLE decoder outputs PAL8 colorspace data.
29 *
30 * Note that this decoder expects the palette colors from the end of the
31 * BITMAPINFO header passed through palctrl.
32 */
33
34#include <stdio.h>
35#include <stdlib.h>
36#include <string.h>
37
38#include "avcodec.h"
39#include "dsputil.h"
40#include "msrledec.h"
41
42typedef struct MsrleContext {
43    AVCodecContext *avctx;
44    AVFrame frame;
45
46    const unsigned char *buf;
47    int size;
48
49} MsrleContext;
50
51static av_cold int msrle_decode_init(AVCodecContext *avctx)
52{
53    MsrleContext *s = avctx->priv_data;
54
55    s->avctx = avctx;
56
57    switch (avctx->bits_per_coded_sample) {
58    case 4:
59    case 8:
60        avctx->pix_fmt = PIX_FMT_PAL8;
61        break;
62    case 24:
63        avctx->pix_fmt = PIX_FMT_BGR24;
64        break;
65    default:
66        av_log(avctx, AV_LOG_ERROR, "unsupported bits per sample\n");
67        return -1;
68    }
69
70    s->frame.data[0] = NULL;
71
72    return 0;
73}
74
75static int msrle_decode_frame(AVCodecContext *avctx,
76                              void *data, int *data_size,
77                              AVPacket *avpkt)
78{
79    const uint8_t *buf = avpkt->data;
80    int buf_size = avpkt->size;
81    MsrleContext *s = avctx->priv_data;
82    int istride = FFALIGN(avctx->width*avctx->bits_per_coded_sample, 32) / 8;
83
84    s->buf = buf;
85    s->size = buf_size;
86
87    s->frame.reference = 1;
88    s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
89    if (avctx->reget_buffer(avctx, &s->frame)) {
90        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
91        return -1;
92    }
93
94    if (s->avctx->palctrl) {
95        /* make the palette available */
96        memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
97        if (s->avctx->palctrl->palette_changed) {
98            s->frame.palette_has_changed = 1;
99            s->avctx->palctrl->palette_changed = 0;
100        }
101    }
102
103    /* FIXME how to correctly detect RLE ??? */
104    if (avctx->height * istride == avpkt->size) { /* assume uncompressed */
105        int linesize = avctx->width * avctx->bits_per_coded_sample / 8;
106        uint8_t *ptr = s->frame.data[0];
107        uint8_t *buf = avpkt->data + (avctx->height-1)*istride;
108        int i, j;
109
110        for (i = 0; i < avctx->height; i++) {
111            if (avctx->bits_per_coded_sample == 4) {
112                for (j = 0; j < avctx->width - 1; j += 2) {
113                    ptr[j+0] = buf[j>>1] >> 4;
114                    ptr[j+1] = buf[j>>1] & 0xF;
115                }
116                if (avctx->width & 1)
117                    ptr[j+0] = buf[j>>1] >> 4;
118            } else {
119                memcpy(ptr, buf, linesize);
120            }
121            buf -= istride;
122            ptr += s->frame.linesize[0];
123        }
124    } else {
125        ff_msrle_decode(avctx, (AVPicture*)&s->frame, avctx->bits_per_coded_sample, buf, buf_size);
126    }
127
128    *data_size = sizeof(AVFrame);
129    *(AVFrame*)data = s->frame;
130
131    /* report that the buffer was completely consumed */
132    return buf_size;
133}
134
135static av_cold int msrle_decode_end(AVCodecContext *avctx)
136{
137    MsrleContext *s = avctx->priv_data;
138
139    /* release the last frame */
140    if (s->frame.data[0])
141        avctx->release_buffer(avctx, &s->frame);
142
143    return 0;
144}
145
146AVCodec msrle_decoder = {
147    "msrle",
148    AVMEDIA_TYPE_VIDEO,
149    CODEC_ID_MSRLE,
150    sizeof(MsrleContext),
151    msrle_decode_init,
152    NULL,
153    msrle_decode_end,
154    msrle_decode_frame,
155    CODEC_CAP_DR1,
156    .long_name= NULL_IF_CONFIG_SMALL("Microsoft RLE"),
157};
158