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msrledec.c
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1 /*
2  * Microsoft RLE decoder
3  * Copyright (C) 2008 Konstantin Shishkov
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  * 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
27  */
28 
29 #include "libavutil/intreadwrite.h"
30 #include "avcodec.h"
31 #include "msrledec.h"
32 
33 static int msrle_decode_pal4(AVCodecContext *avctx, AVFrame *pic,
34  GetByteContext *gb)
35 {
36  unsigned char rle_code;
37  unsigned char extra_byte, odd_pixel;
38  unsigned char stream_byte;
39  int pixel_ptr = 0;
40  int line = avctx->height - 1;
41  int i;
42 
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;
49  }
50  rle_code = stream_byte = bytestream2_get_byteu(gb);
51  if (rle_code == 0) {
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 */
56  line--;
57  pixel_ptr = 0;
58  } else if (stream_byte == 1) {
59  /* decode is done */
60  return 0;
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);
66  avpriv_request_sample(avctx, "Unused stream byte %X", stream_byte);
67  } else {
68  // copy pixels from encoded stream
69  odd_pixel = stream_byte & 1;
70  rle_code = (stream_byte + 1) / 2;
71  extra_byte = rle_code & 0x01;
72  if (pixel_ptr + 2*rle_code - odd_pixel > avctx->width ||
73  bytestream2_get_bytes_left(gb) < rle_code) {
74  av_log(avctx, AV_LOG_ERROR,
75  "MS RLE: frame/stream ptr just went out of bounds (copy)\n");
76  return AVERROR_INVALIDDATA;
77  }
78 
79  for (i = 0; i < rle_code; i++) {
80  if (pixel_ptr >= avctx->width)
81  break;
82  stream_byte = bytestream2_get_byteu(gb);
83  pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte >> 4;
84  pixel_ptr++;
85  if (i + 1 == rle_code && odd_pixel)
86  break;
87  if (pixel_ptr >= avctx->width)
88  break;
89  pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte & 0x0F;
90  pixel_ptr++;
91  }
92 
93  // if the RLE code is odd, skip a byte in the stream
94  if (extra_byte)
95  bytestream2_skip(gb, 1);
96  }
97  } else {
98  // decode a run of data
99  if (pixel_ptr + rle_code > avctx->width + 1) {
100  av_log(avctx, AV_LOG_ERROR,
101  "MS RLE: frame ptr just went out of bounds (run) %d %d %d\n", pixel_ptr, rle_code, avctx->width);
102  return AVERROR_INVALIDDATA;
103  }
104  stream_byte = bytestream2_get_byte(gb);
105  for (i = 0; i < rle_code; i++) {
106  if (pixel_ptr >= avctx->width)
107  break;
108  if ((i & 1) == 0)
109  pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte >> 4;
110  else
111  pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte & 0x0F;
112  pixel_ptr++;
113  }
114  }
115  }
116 
117  /* one last sanity check on the way out */
118  if (bytestream2_get_bytes_left(gb)) {
119  av_log(avctx, AV_LOG_ERROR,
120  "MS RLE: ended frame decode with %d bytes left over\n",
122  return AVERROR_INVALIDDATA;
123  }
124 
125  return 0;
126 }
127 
128 
130  int depth, GetByteContext *gb)
131 {
132  uint8_t *output, *output_end;
133  int p1, p2, line=avctx->height - 1, pos=0, i;
134  uint16_t pix16;
135  uint32_t pix32;
136  unsigned int width= FFABS(pic->linesize[0]) / (depth >> 3);
137 
138  output = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
139  output_end = output + FFABS(pic->linesize[0]);
140 
141  while (bytestream2_get_bytes_left(gb) > 0) {
142  p1 = bytestream2_get_byteu(gb);
143  if(p1 == 0) { //Escape code
144  p2 = bytestream2_get_byte(gb);
145  if(p2 == 0) { //End-of-line
146  if (--line < 0) {
147  if (bytestream2_get_be16(gb) == 1) { // end-of-picture
148  return 0;
149  } else {
150  av_log(avctx, AV_LOG_ERROR,
151  "Next line is beyond picture bounds (%d bytes left)\n",
153  return AVERROR_INVALIDDATA;
154  }
155  }
156  output = pic->data[0] + line * pic->linesize[0];
157  output_end = output + FFABS(pic->linesize[0]);
158  pos = 0;
159  continue;
160  } else if(p2 == 1) { //End-of-picture
161  return 0;
162  } else if(p2 == 2) { //Skip
163  p1 = bytestream2_get_byte(gb);
164  p2 = bytestream2_get_byte(gb);
165  line -= p2;
166  pos += p1;
167  if (line < 0 || pos >= width){
168  av_log(avctx, AV_LOG_ERROR, "Skip beyond picture bounds\n");
169  return -1;
170  }
171  output = pic->data[0] + line * pic->linesize[0] + pos * (depth >> 3);
172  output_end = pic->data[0] + line * pic->linesize[0] + FFABS(pic->linesize[0]);
173  continue;
174  }
175  // Copy data
176  if (output + p2 * (depth >> 3) > output_end) {
177  bytestream2_skip(gb, 2 * (depth >> 3));
178  continue;
179  } else if (bytestream2_get_bytes_left(gb) < p2 * (depth >> 3)) {
180  av_log(avctx, AV_LOG_ERROR, "bytestream overrun\n");
181  return AVERROR_INVALIDDATA;
182  }
183 
184  if ((depth == 8) || (depth == 24)) {
185  bytestream2_get_bufferu(gb, output, p2 * (depth >> 3));
186  output += p2 * (depth >> 3);
187 
188  // RLE8 copy is actually padded - and runs are not!
189  if(depth == 8 && (p2 & 1)) {
190  bytestream2_skip(gb, 1);
191  }
192  } else if (depth == 16) {
193  for(i = 0; i < p2; i++) {
194  *(uint16_t*)output = bytestream2_get_le16u(gb);
195  output += 2;
196  }
197  } else if (depth == 32) {
198  for(i = 0; i < p2; i++) {
199  *(uint32_t*)output = bytestream2_get_le32u(gb);
200  output += 4;
201  }
202  }
203  pos += p2;
204  } else { //run of pixels
205  uint8_t pix[3]; //original pixel
206  if (output + p1 * (depth >> 3) > output_end)
207  continue;
208 
209  switch(depth){
210  case 8:
211  pix[0] = bytestream2_get_byte(gb);
212  memset(output, pix[0], p1);
213  output += p1;
214  break;
215  case 16:
216  pix16 = bytestream2_get_le16(gb);
217  for(i = 0; i < p1; i++) {
218  *(uint16_t*)output = pix16;
219  output += 2;
220  }
221  break;
222  case 24:
223  pix[0] = bytestream2_get_byte(gb);
224  pix[1] = bytestream2_get_byte(gb);
225  pix[2] = bytestream2_get_byte(gb);
226  for(i = 0; i < p1; i++) {
227  *output++ = pix[0];
228  *output++ = pix[1];
229  *output++ = pix[2];
230  }
231  break;
232  case 32:
233  pix32 = bytestream2_get_le32(gb);
234  for(i = 0; i < p1; i++) {
235  *(uint32_t*)output = pix32;
236  output += 4;
237  }
238  break;
239  }
240  pos += p1;
241  }
242  }
243 
244  av_log(avctx, AV_LOG_WARNING, "MS RLE warning: no end-of-picture code\n");
245  return 0;
246 }
247 
248 
250  int depth, GetByteContext *gb)
251 {
252  switch(depth){
253  case 4:
254  return msrle_decode_pal4(avctx, pic, gb);
255  case 8:
256  case 16:
257  case 24:
258  case 32:
259  return msrle_decode_8_16_24_32(avctx, pic, depth, gb);
260  default:
261  av_log(avctx, AV_LOG_ERROR, "Unknown depth %d\n", depth);
262  return -1;
263  }
264 }
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:180
int ff_msrle_decode(AVCodecContext *avctx, AVFrame *pic, int depth, GetByteContext *gb)
Decode stream in MS RLE format into frame.
Definition: msrledec.c:249
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
static av_always_inline unsigned int bytestream2_get_bufferu(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:273
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
uint8_t
static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVFrame *pic, int depth, GetByteContext *gb)
Definition: msrledec.c:129
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:164
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:154
Definition: graph2dot.c:48
int depth
Definition: v4l.c:62
int width
picture width / height.
Definition: avcodec.h:1826
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:211
main external API structure.
Definition: avcodec.h:1639
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:194
static int msrle_decode_pal4(AVCodecContext *avctx, AVFrame *pic, GetByteContext *gb)
Definition: msrledec.c:33
static int width