2 * Microsoft RLE decoder
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
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"
33 static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
36 unsigned char rle_code;
37 unsigned char extra_byte, odd_pixel;
38 unsigned char stream_byte;
40 int line = avctx->height - 1;
43 while (line >= 0 && pixel_ptr <= avctx->width) {
44 if (bytestream2_get_bytes_left(gb) <= 0) {
45 av_log(avctx, AV_LOG_ERROR,
46 "MS RLE: bytestream overrun, %dx%d left\n",
47 avctx->width - pixel_ptr, line);
48 return AVERROR_INVALIDDATA;
50 rle_code = stream_byte = bytestream2_get_byteu(gb);
52 /* fetch the next byte to see how to handle escape code */
53 stream_byte = bytestream2_get_byte(gb);
54 if (stream_byte == 0) {
55 /* line is done, goto the next one */
58 } else if (stream_byte == 1) {
61 } else if (stream_byte == 2) {
62 /* reposition frame decode coordinates */
63 stream_byte = bytestream2_get_byte(gb);
64 pixel_ptr += stream_byte;
65 stream_byte = bytestream2_get_byte(gb);
67 // copy pixels from encoded stream
68 odd_pixel = stream_byte & 1;
69 rle_code = (stream_byte + 1) / 2;
70 extra_byte = rle_code & 0x01;
71 if (pixel_ptr + 2*rle_code - odd_pixel > avctx->width ||
72 bytestream2_get_bytes_left(gb) < rle_code) {
73 av_log(avctx, AV_LOG_ERROR,
74 "MS RLE: frame/stream ptr just went out of bounds (copy)\n");
75 return AVERROR_INVALIDDATA;
78 for (i = 0; i < rle_code; i++) {
79 if (pixel_ptr >= avctx->width)
81 stream_byte = bytestream2_get_byteu(gb);
82 pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte >> 4;
84 if (i + 1 == rle_code && odd_pixel)
86 if (pixel_ptr >= avctx->width)
88 pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte & 0x0F;
92 // if the RLE code is odd, skip a byte in the stream
94 bytestream2_skip(gb, 1);
97 // decode a run of data
98 if (pixel_ptr + rle_code > avctx->width + 1) {
99 av_log(avctx, AV_LOG_ERROR,
100 "MS RLE: frame ptr just went out of bounds (run) %d %d %d\n", pixel_ptr, rle_code, avctx->width);
101 return AVERROR_INVALIDDATA;
103 stream_byte = bytestream2_get_byte(gb);
104 for (i = 0; i < rle_code; i++) {
105 if (pixel_ptr >= avctx->width)
108 pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte >> 4;
110 pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte & 0x0F;
116 /* one last sanity check on the way out */
117 if (bytestream2_get_bytes_left(gb)) {
118 av_log(avctx, AV_LOG_ERROR,
119 "MS RLE: ended frame decode with %d bytes left over\n",
120 bytestream2_get_bytes_left(gb));
121 return AVERROR_INVALIDDATA;
128 static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic,
129 int depth, GetByteContext *gb)
131 uint8_t *output, *output_end;
132 int p1, p2, line=avctx->height - 1, pos=0, i;
135 unsigned int width= FFABS(pic->linesize[0]) / (depth >> 3);
137 output = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
138 output_end = output + FFABS(pic->linesize[0]);
140 while (bytestream2_get_bytes_left(gb) > 0) {
141 p1 = bytestream2_get_byteu(gb);
142 if(p1 == 0) { //Escape code
143 p2 = bytestream2_get_byte(gb);
144 if(p2 == 0) { //End-of-line
146 if (bytestream2_get_be16(gb) == 1) { // end-of-picture
149 av_log(avctx, AV_LOG_ERROR,
150 "Next line is beyond picture bounds (%d bytes left)\n",
151 bytestream2_get_bytes_left(gb));
152 return AVERROR_INVALIDDATA;
155 output = pic->data[0] + line * pic->linesize[0];
156 output_end = output + FFABS(pic->linesize[0]);
159 } else if(p2 == 1) { //End-of-picture
161 } else if(p2 == 2) { //Skip
162 p1 = bytestream2_get_byte(gb);
163 p2 = bytestream2_get_byte(gb);
166 if (line < 0 || pos >= width){
167 av_log(avctx, AV_LOG_ERROR, "Skip beyond picture bounds\n");
170 output = pic->data[0] + line * pic->linesize[0] + pos * (depth >> 3);
171 output_end = pic->data[0] + line * pic->linesize[0] + FFABS(pic->linesize[0]);
175 if (output + p2 * (depth >> 3) > output_end) {
176 bytestream2_skip(gb, 2 * (depth >> 3));
178 } else if (bytestream2_get_bytes_left(gb) < p2 * (depth >> 3)) {
179 av_log(avctx, AV_LOG_ERROR, "bytestream overrun\n");
180 return AVERROR_INVALIDDATA;
183 if ((depth == 8) || (depth == 24)) {
184 bytestream2_get_bufferu(gb, output, p2 * (depth >> 3));
185 output += p2 * (depth >> 3);
187 // RLE8 copy is actually padded - and runs are not!
188 if(depth == 8 && (p2 & 1)) {
189 bytestream2_skip(gb, 1);
191 } else if (depth == 16) {
192 for(i = 0; i < p2; i++) {
193 *(uint16_t*)output = bytestream2_get_le16u(gb);
196 } else if (depth == 32) {
197 for(i = 0; i < p2; i++) {
198 *(uint32_t*)output = bytestream2_get_le32u(gb);
203 } else { //run of pixels
204 uint8_t pix[3]; //original pixel
205 if (output + p1 * (depth >> 3) > output_end)
210 pix[0] = bytestream2_get_byte(gb);
211 memset(output, pix[0], p1);
215 pix16 = bytestream2_get_le16(gb);
216 for(i = 0; i < p1; i++) {
217 *(uint16_t*)output = pix16;
222 pix[0] = bytestream2_get_byte(gb);
223 pix[1] = bytestream2_get_byte(gb);
224 pix[2] = bytestream2_get_byte(gb);
225 for(i = 0; i < p1; i++) {
232 pix32 = bytestream2_get_le32(gb);
233 for(i = 0; i < p1; i++) {
234 *(uint32_t*)output = pix32;
243 av_log(avctx, AV_LOG_WARNING, "MS RLE warning: no end-of-picture code\n");
248 int ff_msrle_decode(AVCodecContext *avctx, AVPicture *pic,
249 int depth, GetByteContext *gb)
253 return msrle_decode_pal4(avctx, pic, gb);
258 return msrle_decode_8_16_24_32(avctx, pic, depth, gb);
260 av_log(avctx, AV_LOG_ERROR, "Unknown depth %d\n", depth);