f426b058bd1f3511d0148915fad37a9e2d36b024
[libav.git] / libavcodec / msrle.c
1 /*
2 * Micrsoft RLE Video Decoder
3 * Copyright (C) 2003 the ffmpeg project
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 "dsputil.h"
37 #include "msrledec.h"
38
39 typedef struct MsrleContext {
40 AVCodecContext *avctx;
41 AVFrame frame;
42
43 const unsigned char *buf;
44 int size;
45
46 uint32_t pal[256];
47 } MsrleContext;
48
49 static av_cold int msrle_decode_init(AVCodecContext *avctx)
50 {
51 MsrleContext *s = avctx->priv_data;
52
53 s->avctx = avctx;
54
55 switch (avctx->bits_per_coded_sample) {
56 case 4:
57 case 8:
58 avctx->pix_fmt = PIX_FMT_PAL8;
59 break;
60 case 24:
61 avctx->pix_fmt = PIX_FMT_BGR24;
62 break;
63 default:
64 av_log(avctx, AV_LOG_ERROR, "unsupported bits per sample\n");
65 return -1;
66 }
67
68 s->frame.data[0] = NULL;
69
70 return 0;
71 }
72
73 static int msrle_decode_frame(AVCodecContext *avctx,
74 void *data, int *data_size,
75 AVPacket *avpkt)
76 {
77 const uint8_t *buf = avpkt->data;
78 int buf_size = avpkt->size;
79 MsrleContext *s = avctx->priv_data;
80 int istride = FFALIGN(avctx->width*avctx->bits_per_coded_sample, 32) / 8;
81
82 s->buf = buf;
83 s->size = buf_size;
84
85 s->frame.reference = 1;
86 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
87 if (avctx->reget_buffer(avctx, &s->frame)) {
88 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
89 return -1;
90 }
91
92 if (avctx->bits_per_coded_sample <= 8) {
93 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
94
95 if (pal) {
96 s->frame.palette_has_changed = 1;
97 memcpy(s->pal, pal, AVPALETTE_SIZE);
98 }
99
100 /* make the palette available */
101 memcpy(s->frame.data[1], s->pal, AVPALETTE_SIZE);
102 }
103
104 /* FIXME how to correctly detect RLE ??? */
105 if (avctx->height * istride == avpkt->size) { /* assume uncompressed */
106 int linesize = avctx->width * avctx->bits_per_coded_sample / 8;
107 uint8_t *ptr = s->frame.data[0];
108 uint8_t *buf = avpkt->data + (avctx->height-1)*istride;
109 int i, j;
110
111 for (i = 0; i < avctx->height; i++) {
112 if (avctx->bits_per_coded_sample == 4) {
113 for (j = 0; j < avctx->width - 1; j += 2) {
114 ptr[j+0] = buf[j>>1] >> 4;
115 ptr[j+1] = buf[j>>1] & 0xF;
116 }
117 if (avctx->width & 1)
118 ptr[j+0] = buf[j>>1] >> 4;
119 } else {
120 memcpy(ptr, buf, linesize);
121 }
122 buf -= istride;
123 ptr += s->frame.linesize[0];
124 }
125 } else {
126 ff_msrle_decode(avctx, (AVPicture*)&s->frame, avctx->bits_per_coded_sample, buf, buf_size);
127 }
128
129 *data_size = sizeof(AVFrame);
130 *(AVFrame*)data = s->frame;
131
132 /* report that the buffer was completely consumed */
133 return buf_size;
134 }
135
136 static av_cold int msrle_decode_end(AVCodecContext *avctx)
137 {
138 MsrleContext *s = avctx->priv_data;
139
140 /* release the last frame */
141 if (s->frame.data[0])
142 avctx->release_buffer(avctx, &s->frame);
143
144 return 0;
145 }
146
147 AVCodec ff_msrle_decoder = {
148 "msrle",
149 AVMEDIA_TYPE_VIDEO,
150 CODEC_ID_MSRLE,
151 sizeof(MsrleContext),
152 msrle_decode_init,
153 NULL,
154 msrle_decode_end,
155 msrle_decode_frame,
156 CODEC_CAP_DR1,
157 .long_name= NULL_IF_CONFIG_SMALL("Microsoft RLE"),
158 };