Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / rl2.c
1 /*
2 * RL2 Video Decoder
3 * Copyright (C) 2008 Sascha Sommer (saschasommer@freenet.de)
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 * RL2 Video Decoder
25 * @author Sascha Sommer (saschasommer@freenet.de)
26 * @see http://wiki.multimedia.cx/index.php?title=RL2
27 */
28
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32
33 #include "libavutil/internal.h"
34 #include "libavutil/intreadwrite.h"
35 #include "libavutil/mem.h"
36 #include "avcodec.h"
37 #include "internal.h"
38
39
40 #define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr count, palette
41
42 typedef struct Rl2Context {
43 AVCodecContext *avctx;
44
45 uint16_t video_base; ///< initial drawing offset
46 uint32_t clr_count; ///< number of used colors (currently unused)
47 uint8_t *back_frame; ///< background frame
48 uint32_t palette[AVPALETTE_COUNT];
49 } Rl2Context;
50
51 /**
52 * Run Length Decode a single 320x200 frame
53 * @param s rl2 context
54 * @param in input buffer
55 * @param size input buffer size
56 * @param out output buffer
57 * @param stride stride of the output buffer
58 * @param video_base offset of the rle data inside the frame
59 */
60 static void rl2_rle_decode(Rl2Context *s, const uint8_t *in, int size,
61 uint8_t *out, int stride, int video_base)
62 {
63 int base_x = video_base % s->avctx->width;
64 int base_y = video_base / s->avctx->width;
65 int stride_adj = stride - s->avctx->width;
66 int i;
67 const uint8_t *back_frame = s->back_frame;
68 const uint8_t *in_end = in + size;
69 const uint8_t *out_end = out + stride * s->avctx->height;
70 uint8_t *line_end;
71
72 /** copy start of the background frame */
73 for (i = 0; i <= base_y; i++) {
74 if (s->back_frame)
75 memcpy(out, back_frame, s->avctx->width);
76 out += stride;
77 back_frame += s->avctx->width;
78 }
79 back_frame += base_x - s->avctx->width;
80 line_end = out - stride_adj;
81 out += base_x - stride;
82
83 /** decode the variable part of the frame */
84 while (in < in_end) {
85 uint8_t val = *in++;
86 int len = 1;
87 if (val >= 0x80) {
88 if (in >= in_end)
89 break;
90 len = *in++;
91 if (!len)
92 break;
93 }
94
95 if (len >= out_end - out)
96 break;
97
98 if (s->back_frame)
99 val |= 0x80;
100 else
101 val &= ~0x80;
102
103 while (len--) {
104 *out++ = (val == 0x80) ? *back_frame : val;
105 back_frame++;
106 if (out == line_end) {
107 out += stride_adj;
108 line_end += stride;
109 if (len >= out_end - out)
110 break;
111 }
112 }
113 }
114
115 /** copy the rest from the background frame */
116 if (s->back_frame) {
117 while (out < out_end) {
118 memcpy(out, back_frame, line_end - out);
119 back_frame += line_end - out;
120 out = line_end + stride_adj;
121 line_end += stride;
122 }
123 }
124 }
125
126
127 /**
128 * Initialize the decoder
129 * @param avctx decoder context
130 * @return 0 success, -1 on error
131 */
132 static av_cold int rl2_decode_init(AVCodecContext *avctx)
133 {
134 Rl2Context *s = avctx->priv_data;
135 int back_size;
136 int i;
137
138 s->avctx = avctx;
139 avctx->pix_fmt = AV_PIX_FMT_PAL8;
140
141 /** parse extra data */
142 if (!avctx->extradata || avctx->extradata_size < EXTRADATA1_SIZE) {
143 av_log(avctx, AV_LOG_ERROR, "invalid extradata size\n");
144 return AVERROR(EINVAL);
145 }
146
147 /** get frame_offset */
148 s->video_base = AV_RL16(&avctx->extradata[0]);
149 s->clr_count = AV_RL32(&avctx->extradata[2]);
150
151 if (s->video_base >= avctx->width * avctx->height) {
152 av_log(avctx, AV_LOG_ERROR, "invalid video_base\n");
153 return AVERROR_INVALIDDATA;
154 }
155
156 /** initialize palette */
157 for (i = 0; i < AVPALETTE_COUNT; i++)
158 s->palette[i] = 0xFFU << 24 | AV_RB24(&avctx->extradata[6 + i * 3]);
159
160 /** decode background frame if present */
161 back_size = avctx->extradata_size - EXTRADATA1_SIZE;
162
163 if (back_size > 0) {
164 uint8_t *back_frame = av_mallocz(avctx->width*avctx->height);
165 if (!back_frame)
166 return AVERROR(ENOMEM);
167 rl2_rle_decode(s, avctx->extradata + EXTRADATA1_SIZE, back_size,
168 back_frame, avctx->width, 0);
169 s->back_frame = back_frame;
170 }
171 return 0;
172 }
173
174
175 static int rl2_decode_frame(AVCodecContext *avctx,
176 void *data, int *got_frame,
177 AVPacket *avpkt)
178 {
179 AVFrame *frame = data;
180 const uint8_t *buf = avpkt->data;
181 int ret, buf_size = avpkt->size;
182 Rl2Context *s = avctx->priv_data;
183
184 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
185 return ret;
186
187 /** run length decode */
188 rl2_rle_decode(s, buf, buf_size, frame->data[0], frame->linesize[0],
189 s->video_base);
190
191 /** make the palette available on the way out */
192 memcpy(frame->data[1], s->palette, AVPALETTE_SIZE);
193
194 *got_frame = 1;
195
196 /** report that the buffer was completely consumed */
197 return buf_size;
198 }
199
200
201 /**
202 * Uninit decoder
203 * @param avctx decoder context
204 * @return 0 success, -1 on error
205 */
206 static av_cold int rl2_decode_end(AVCodecContext *avctx)
207 {
208 Rl2Context *s = avctx->priv_data;
209
210 av_freep(&s->back_frame);
211
212 return 0;
213 }
214
215
216 AVCodec ff_rl2_decoder = {
217 .name = "rl2",
218 .long_name = NULL_IF_CONFIG_SMALL("RL2 video"),
219 .type = AVMEDIA_TYPE_VIDEO,
220 .id = AV_CODEC_ID_RL2,
221 .priv_data_size = sizeof(Rl2Context),
222 .init = rl2_decode_init,
223 .close = rl2_decode_end,
224 .decode = rl2_decode_frame,
225 .capabilities = CODEC_CAP_DR1,
226 };