3 * Copyright (C) 2008 Sascha Sommer (saschasommer@freenet.de)
5 * This file is part of FFmpeg.
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.
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.
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
25 * @author Sascha Sommer (saschasommer@freenet.de)
26 * @see http://wiki.multimedia.cx/index.php?title=RL2
33 #include "libavutil/internal.h"
34 #include "libavutil/intreadwrite.h"
35 #include "libavutil/mem.h"
40 #define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr count, palette
42 typedef struct Rl2Context {
43 AVCodecContext *avctx;
46 uint16_t video_base; ///< initial drawing offset
47 uint32_t clr_count; ///< number of used colors (currently unused)
48 uint8_t *back_frame; ///< background frame
49 uint32_t palette[AVPALETTE_COUNT];
53 * Run Length Decode a single 320x200 frame
54 * @param s rl2 context
55 * @param in input buffer
56 * @param size input buffer size
57 * @param out output buffer
58 * @param stride stride of the output buffer
59 * @param video_base offset of the rle data inside the frame
61 static void rl2_rle_decode(Rl2Context *s, const uint8_t *in, int size,
62 uint8_t *out, int stride, int video_base)
64 int base_x = video_base % s->avctx->width;
65 int base_y = video_base / s->avctx->width;
66 int stride_adj = stride - s->avctx->width;
68 const uint8_t *back_frame = s->back_frame;
69 const uint8_t *in_end = in + size;
70 const uint8_t *out_end = out + stride * s->avctx->height;
73 /** copy start of the background frame */
74 for (i = 0; i <= base_y; i++) {
76 memcpy(out, back_frame, s->avctx->width);
78 back_frame += s->avctx->width;
80 back_frame += base_x - s->avctx->width;
81 line_end = out - stride_adj;
82 out += base_x - stride;
84 /** decode the variable part of the frame */
96 if (len >= out_end - out)
105 *out++ = (val == 0x80) ? *back_frame : val;
107 if (out == line_end) {
110 if (len >= out_end - out)
116 /** copy the rest from the background frame */
118 while (out < out_end) {
119 memcpy(out, back_frame, line_end - out);
120 back_frame += line_end - out;
121 out = line_end + stride_adj;
129 * Initialize the decoder
130 * @param avctx decoder context
131 * @return 0 success, -1 on error
133 static av_cold int rl2_decode_init(AVCodecContext *avctx)
135 Rl2Context *s = avctx->priv_data;
140 avctx->pix_fmt = AV_PIX_FMT_PAL8;
141 avcodec_get_frame_defaults(&s->frame);
143 /** parse extra data */
144 if (!avctx->extradata || avctx->extradata_size < EXTRADATA1_SIZE) {
145 av_log(avctx, AV_LOG_ERROR, "invalid extradata size\n");
146 return AVERROR(EINVAL);
149 /** get frame_offset */
150 s->video_base = AV_RL16(&avctx->extradata[0]);
151 s->clr_count = AV_RL32(&avctx->extradata[2]);
153 if (s->video_base >= avctx->width * avctx->height) {
154 av_log(avctx, AV_LOG_ERROR, "invalid video_base\n");
155 return AVERROR_INVALIDDATA;
158 /** initialize palette */
159 for (i = 0; i < AVPALETTE_COUNT; i++)
160 s->palette[i] = 0xFFU << 24 | AV_RB24(&avctx->extradata[6 + i * 3]);
162 /** decode background frame if present */
163 back_size = avctx->extradata_size - EXTRADATA1_SIZE;
166 uint8_t *back_frame = av_mallocz(avctx->width*avctx->height);
168 return AVERROR(ENOMEM);
169 rl2_rle_decode(s, avctx->extradata + EXTRADATA1_SIZE, back_size,
170 back_frame, avctx->width, 0);
171 s->back_frame = back_frame;
177 static int rl2_decode_frame(AVCodecContext *avctx,
178 void *data, int *got_frame,
181 const uint8_t *buf = avpkt->data;
182 int ret, buf_size = avpkt->size;
183 Rl2Context *s = avctx->priv_data;
185 if (s->frame.data[0])
186 avctx->release_buffer(avctx, &s->frame);
189 s->frame.reference = 0;
190 if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
191 av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
195 /** run length decode */
196 rl2_rle_decode(s, buf, buf_size, s->frame.data[0], s->frame.linesize[0],
199 /** make the palette available on the way out */
200 memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
203 *(AVFrame*)data = s->frame;
205 /** report that the buffer was completely consumed */
212 * @param avctx decoder context
213 * @return 0 success, -1 on error
215 static av_cold int rl2_decode_end(AVCodecContext *avctx)
217 Rl2Context *s = avctx->priv_data;
219 if (s->frame.data[0])
220 avctx->release_buffer(avctx, &s->frame);
222 av_free(s->back_frame);
228 AVCodec ff_rl2_decoder = {
230 .type = AVMEDIA_TYPE_VIDEO,
231 .id = AV_CODEC_ID_RL2,
232 .priv_data_size = sizeof(Rl2Context),
233 .init = rl2_decode_init,
234 .close = rl2_decode_end,
235 .decode = rl2_decode_frame,
236 .capabilities = CODEC_CAP_DR1,
237 .long_name = NULL_IF_CONFIG_SMALL("RL2 video"),