1 /*
2 * Microsoft 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
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34
35 #include "avcodec.h"
36 #include "internal.h"
37 #include "msrledec.h"
38 #include "libavutil/imgutils.h"
39
40 typedef struct MsrleContext {
41 AVCodecContext *avctx;
42 AVFrame *frame;
43
44 GetByteContext gb;
45
46 uint32_t pal[256];
47 } MsrleContext;
48
msrle_decode_init(AVCodecContext * avctx)49 static av_cold int msrle_decode_init(AVCodecContext *avctx)
50 {
51 MsrleContext *s = avctx->priv_data;
52 int i;
53
54 s->avctx = avctx;
55
56 switch (avctx->bits_per_coded_sample) {
57 case 1:
58 avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
59 break;
60 case 4:
61 case 8:
62 avctx->pix_fmt = AV_PIX_FMT_PAL8;
63 break;
64 case 24:
65 avctx->pix_fmt = AV_PIX_FMT_BGR24;
66 break;
67 default:
68 av_log(avctx, AV_LOG_ERROR, "unsupported bits per sample\n");
69 return AVERROR_INVALIDDATA;
70 }
71
72 s->frame = av_frame_alloc();
73 if (!s->frame)
74 return AVERROR(ENOMEM);
75
76 if (avctx->extradata_size >= 4)
77 for (i = 0; i < FFMIN(avctx->extradata_size, AVPALETTE_SIZE)/4; i++)
78 s->pal[i] = 0xFFU<<24 | AV_RL32(avctx->extradata+4*i);
79
80 return 0;
81 }
82
msrle_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)83 static int msrle_decode_frame(AVCodecContext *avctx,
84 void *data, int *got_frame,
85 AVPacket *avpkt)
86 {
87 const uint8_t *buf = avpkt->data;
88 int buf_size = avpkt->size;
89 MsrleContext *s = avctx->priv_data;
90 int istride = FFALIGN(avctx->width*avctx->bits_per_coded_sample, 32) / 8;
91 int ret;
92
93 if (buf_size < 2) //Minimally a end of picture code should be there
94 return AVERROR_INVALIDDATA;
95
96 if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
97 return ret;
98
99 if (avctx->bits_per_coded_sample > 1 && avctx->bits_per_coded_sample <= 8) {
100 buffer_size_t size;
101 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &size);
102
103 if (pal && size == AVPALETTE_SIZE) {
104 s->frame->palette_has_changed = 1;
105 memcpy(s->pal, pal, AVPALETTE_SIZE);
106 } else if (pal) {
107 av_log(avctx, AV_LOG_ERROR, "Palette size %d is wrong\n", size);
108 }
109 /* make the palette available */
110 memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
111 }
112
113 /* FIXME how to correctly detect RLE ??? */
114 if (avctx->height * istride == avpkt->size) { /* assume uncompressed */
115 int linesize = av_image_get_linesize(avctx->pix_fmt, avctx->width, 0);
116 uint8_t *ptr = s->frame->data[0];
117 uint8_t *buf = avpkt->data + (avctx->height-1)*istride;
118 int i, j;
119
120 if (linesize < 0)
121 return linesize;
122
123 for (i = 0; i < avctx->height; i++) {
124 if (avctx->bits_per_coded_sample == 4) {
125 for (j = 0; j < avctx->width - 1; j += 2) {
126 ptr[j+0] = buf[j>>1] >> 4;
127 ptr[j+1] = buf[j>>1] & 0xF;
128 }
129 if (avctx->width & 1)
130 ptr[j+0] = buf[j>>1] >> 4;
131 } else {
132 memcpy(ptr, buf, linesize);
133 }
134 buf -= istride;
135 ptr += s->frame->linesize[0];
136 }
137 } else {
138 bytestream2_init(&s->gb, buf, buf_size);
139 ff_msrle_decode(avctx, s->frame, avctx->bits_per_coded_sample, &s->gb);
140 }
141
142 if ((ret = av_frame_ref(data, s->frame)) < 0)
143 return ret;
144
145 *got_frame = 1;
146
147 /* report that the buffer was completely consumed */
148 return buf_size;
149 }
150
msrle_decode_flush(AVCodecContext * avctx)151 static void msrle_decode_flush(AVCodecContext *avctx)
152 {
153 MsrleContext *s = avctx->priv_data;
154
155 av_frame_unref(s->frame);
156 }
157
msrle_decode_end(AVCodecContext * avctx)158 static av_cold int msrle_decode_end(AVCodecContext *avctx)
159 {
160 MsrleContext *s = avctx->priv_data;
161
162 /* release the last frame */
163 av_frame_free(&s->frame);
164
165 return 0;
166 }
167
168 AVCodec ff_msrle_decoder = {
169 .name = "msrle",
170 .long_name = NULL_IF_CONFIG_SMALL("Microsoft RLE"),
171 .type = AVMEDIA_TYPE_VIDEO,
172 .id = AV_CODEC_ID_MSRLE,
173 .priv_data_size = sizeof(MsrleContext),
174 .init = msrle_decode_init,
175 .close = msrle_decode_end,
176 .decode = msrle_decode_frame,
177 .flush = msrle_decode_flush,
178 .capabilities = AV_CODEC_CAP_DR1,
179 };
180