3 * Copyright (C) 2008 Konstantin Shishkov
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
23 * @file libavcodec/msrledec.c
24 * MS RLE Decoder based on decoder by Mike Melanson and my own for TSCC
25 * For more information about the MS RLE format, visit:
26 * http://www.multimedia.cx/msrle.txt
29 #include "libavutil/intreadwrite.h"
32 #define FETCH_NEXT_STREAM_BYTE() \
33 if (stream_ptr >= data_size) \
35 av_log(avctx, AV_LOG_ERROR, " MS RLE: stream ptr just went out of bounds (1)\n"); \
38 stream_byte = data[stream_ptr++];
40 static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
41 const uint8_t *data, int data_size)
44 unsigned char rle_code;
45 unsigned char extra_byte, odd_pixel;
46 unsigned char stream_byte;
48 int row_dec = pic->linesize[0];
49 int row_ptr = (avctx->height - 1) * row_dec;
50 int frame_size = row_dec * avctx->height;
53 while (row_ptr >= 0) {
54 FETCH_NEXT_STREAM_BYTE();
55 rle_code = stream_byte;
57 /* fetch the next byte to see how to handle escape code */
58 FETCH_NEXT_STREAM_BYTE();
59 if (stream_byte == 0) {
60 /* line is done, goto the next one */
63 } else if (stream_byte == 1) {
66 } else if (stream_byte == 2) {
67 /* reposition frame decode coordinates */
68 FETCH_NEXT_STREAM_BYTE();
69 pixel_ptr += stream_byte;
70 FETCH_NEXT_STREAM_BYTE();
71 row_ptr -= stream_byte * row_dec;
73 // copy pixels from encoded stream
74 odd_pixel = stream_byte & 1;
75 rle_code = (stream_byte + 1) / 2;
76 extra_byte = rle_code & 0x01;
77 if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
79 av_log(avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
83 for (i = 0; i < rle_code; i++) {
84 if (pixel_ptr >= avctx->width)
86 FETCH_NEXT_STREAM_BYTE();
87 pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
89 if (i + 1 == rle_code && odd_pixel)
91 if (pixel_ptr >= avctx->width)
93 pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
97 // if the RLE code is odd, skip a byte in the stream
102 // decode a run of data
103 if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
105 av_log(avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
108 FETCH_NEXT_STREAM_BYTE();
109 for (i = 0; i < rle_code; i++) {
110 if (pixel_ptr >= avctx->width)
113 pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
115 pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
121 /* one last sanity check on the way out */
122 if (stream_ptr < data_size) {
123 av_log(avctx, AV_LOG_ERROR, " MS RLE: ended frame decode with bytes left over (%d < %d)\n",
124 stream_ptr, data_size);
132 static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic, int depth,
133 const uint8_t *data, int srcsize)
135 uint8_t *output, *output_end;
136 const uint8_t* src = data;
137 int p1, p2, line=avctx->height, pos=0, i;
138 uint16_t av_uninit(pix16);
139 uint32_t av_uninit(pix32);
141 output = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
142 output_end = pic->data[0] + (avctx->height) * pic->linesize[0];
143 while(src < data + srcsize) {
145 if(p1 == 0) { //Escape code
147 if(p2 == 0) { //End-of-line
148 output = pic->data[0] + (--line) * pic->linesize[0];
150 av_log(avctx, AV_LOG_ERROR, "Next line is beyond picture bounds\n");
155 } else if(p2 == 1) { //End-of-picture
157 } else if(p2 == 2) { //Skip
162 av_log(avctx, AV_LOG_ERROR, "Skip beyond picture bounds\n");
166 output = pic->data[0] + line * pic->linesize[0] + pos * (depth >> 3);
170 if (output + p2 * (depth >> 3) > output_end) {
171 src += p2 * (depth >> 3);
174 if ((depth == 8) || (depth == 24)) {
175 for(i = 0; i < p2 * (depth >> 3); i++) {
178 // RLE8 copy is actually padded - and runs are not!
179 if(depth == 8 && (p2 & 1)) {
182 } else if (depth == 16) {
183 for(i = 0; i < p2; i++) {
184 pix16 = AV_RL16(src);
186 *(uint16_t*)output = pix16;
189 } else if (depth == 32) {
190 for(i = 0; i < p2; i++) {
191 pix32 = AV_RL32(src);
193 *(uint32_t*)output = pix32;
198 } else { //Run of pixels
199 uint8_t pix[3]; //original pixel
201 case 8: pix[0] = *src++;
203 case 16: pix16 = AV_RL16(src);
206 case 24: pix[0] = *src++;
210 case 32: pix32 = AV_RL32(src);
214 if (output + p1 * (depth >> 3) > output_end)
216 for(i = 0; i < p1; i++) {
218 case 8: *output++ = pix[0];
220 case 16: *(uint16_t*)output = pix16;
223 case 24: *output++ = pix[0];
227 case 32: *(uint32_t*)output = pix32;
236 av_log(avctx, AV_LOG_WARNING, "MS RLE warning: no End-of-picture code\n");
241 int ff_msrle_decode(AVCodecContext *avctx, AVPicture *pic, int depth,
242 const uint8_t* data, int data_size)
246 return msrle_decode_pal4(avctx, pic, data, data_size);
251 return msrle_decode_8_16_24_32(avctx, pic, depth, data, data_size);
253 av_log(avctx, AV_LOG_ERROR, "Unknown depth %d\n", depth);