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 unsigned short video_base; ///< initial drawing offset
47 unsigned int clr_count; ///< number of used colors (currently unused)
48 unsigned char* back_frame; ///< background frame
49 unsigned int 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 unsigned char* in,int size,
62 unsigned char* out,int stride,int video_base){
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;
67 const unsigned char* back_frame = s->back_frame;
68 const unsigned char* in_end = in + size;
69 const unsigned char* out_end = out + stride * s->avctx->height;
70 unsigned char* line_end;
72 /** copy start of the background frame */
73 for(i=0;i<=base_y;i++){
75 memcpy(out,back_frame,s->avctx->width);
77 back_frame += s->avctx->width;
79 back_frame += base_x - s->avctx->width;
80 line_end = out - stride_adj;
81 out += base_x - stride;
83 /** decode the variable part of the frame */
85 unsigned char val = *in++;
95 if(len >= out_end - out)
104 *out++ = (val == 0x80)? *back_frame:val;
109 if(len >= out_end - out)
115 /** copy the rest from the background 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;
128 * Initialize the decoder
129 * @param avctx decoder context
130 * @return 0 success, -1 on error
132 static av_cold int rl2_decode_init(AVCodecContext *avctx)
134 Rl2Context *s = avctx->priv_data;
138 avctx->pix_fmt = AV_PIX_FMT_PAL8;
139 avcodec_get_frame_defaults(&s->frame);
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_INVALIDDATA;
147 /** get frame_offset */
148 s->video_base = AV_RL16(&avctx->extradata[0]);
149 s->clr_count = AV_RL32(&avctx->extradata[2]);
151 if(s->video_base >= avctx->width * avctx->height){
152 av_log(avctx, AV_LOG_ERROR, "invalid video_base\n");
153 return AVERROR_INVALIDDATA;
156 /** initialize palette */
157 for(i=0;i<AVPALETTE_COUNT;i++)
158 s->palette[i] = 0xFFU << 24 | AV_RB24(&avctx->extradata[6 + i * 3]);
160 /** decode background frame if present */
161 back_size = avctx->extradata_size - EXTRADATA1_SIZE;
164 unsigned char* back_frame = av_mallocz(avctx->width*avctx->height);
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;
175 static int rl2_decode_frame(AVCodecContext *avctx,
176 void *data, int *got_frame,
179 const uint8_t *buf = avpkt->data;
180 int buf_size = avpkt->size;
181 Rl2Context *s = avctx->priv_data;
185 avctx->release_buffer(avctx, &s->frame);
188 s->frame.reference= 0;
189 if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
190 av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
194 /** run length decode */
195 rl2_rle_decode(s,buf,buf_size,s->frame.data[0],s->frame.linesize[0],s->video_base);
197 /** make the palette available on the way out */
198 memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
201 *(AVFrame*)data = s->frame;
203 /** report that the buffer was completely consumed */
210 * @param avctx decoder context
211 * @return 0 success, -1 on error
213 static av_cold int rl2_decode_end(AVCodecContext *avctx)
215 Rl2Context *s = avctx->priv_data;
218 avctx->release_buffer(avctx, &s->frame);
220 av_free(s->back_frame);
226 AVCodec ff_rl2_decoder = {
228 .type = AVMEDIA_TYPE_VIDEO,
229 .id = AV_CODEC_ID_RL2,
230 .priv_data_size = sizeof(Rl2Context),
231 .init = rl2_decode_init,
232 .close = rl2_decode_end,
233 .decode = rl2_decode_frame,
234 .capabilities = CODEC_CAP_DR1,
235 .long_name = NULL_IF_CONFIG_SMALL("RL2 video"),