FFmpeg
pcx.c
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1 /*
2  * PC Paintbrush PCX (.pcx) image decoder
3  * Copyright (c) 2007, 2008 Ivo van Poorten
4  *
5  * This decoder does not support CGA palettes. I am unable to find samples
6  * and Netpbm cannot generate them.
7  *
8  * This file is part of FFmpeg.
9  *
10  * FFmpeg is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU Lesser General Public
12  * License as published by the Free Software Foundation; either
13  * version 2.1 of the License, or (at your option) any later version.
14  *
15  * FFmpeg is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18  * Lesser General Public License for more details.
19  *
20  * You should have received a copy of the GNU Lesser General Public
21  * License along with FFmpeg; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23  */
24 
25 #include "avcodec.h"
26 #include "bytestream.h"
27 #include "codec_internal.h"
28 #include "decode.h"
29 #include "get_bits.h"
30 
31 #define PCX_HEADER_SIZE 128
32 
34  uint8_t *dst,
35  unsigned int bytes_per_scanline,
36  int compressed)
37 {
38  unsigned int i = 0;
39  unsigned char run, value;
40 
41  if (bytestream2_get_bytes_left(gb) < 1)
42  return AVERROR_INVALIDDATA;
43 
44  if (compressed) {
45  while (i < bytes_per_scanline && bytestream2_get_bytes_left(gb)>0) {
46  run = 1;
47  value = bytestream2_get_byte(gb);
48  if (value >= 0xc0 && bytestream2_get_bytes_left(gb)>0) {
49  run = value & 0x3f;
50  value = bytestream2_get_byte(gb);
51  }
52  while (i < bytes_per_scanline && run--)
53  dst[i++] = value;
54  }
55  } else {
56  bytestream2_get_buffer(gb, dst, bytes_per_scanline);
57  }
58  return 0;
59 }
60 
61 static void pcx_palette(GetByteContext *gb, uint32_t *dst, int pallen)
62 {
63  int i;
64 
65  pallen = FFMIN(pallen, bytestream2_get_bytes_left(gb) / 3);
66  for (i = 0; i < pallen; i++)
67  *dst++ = 0xFF000000 | bytestream2_get_be24u(gb);
68  if (pallen < 256)
69  memset(dst, 0, (256 - pallen) * sizeof(*dst));
70 }
71 
72 static int pcx_decode_frame(AVCodecContext *avctx, AVFrame *p,
73  int *got_frame, AVPacket *avpkt)
74 {
75  GetByteContext gb;
76  int compressed, xmin, ymin, xmax, ymax;
77  int ret;
78  unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
79  bytes_per_scanline;
80  uint8_t *ptr, *scanline;
81 
82  if (avpkt->size < PCX_HEADER_SIZE) {
83  av_log(avctx, AV_LOG_ERROR, "Packet too small\n");
84  return AVERROR_INVALIDDATA;
85  }
86 
87  bytestream2_init(&gb, avpkt->data, avpkt->size);
88 
89  if (bytestream2_get_byteu(&gb) != 0x0a || bytestream2_get_byteu(&gb) > 5) {
90  av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
91  return AVERROR_INVALIDDATA;
92  }
93 
94  compressed = bytestream2_get_byteu(&gb);
95  bits_per_pixel = bytestream2_get_byteu(&gb);
96  xmin = bytestream2_get_le16u(&gb);
97  ymin = bytestream2_get_le16u(&gb);
98  xmax = bytestream2_get_le16u(&gb);
99  ymax = bytestream2_get_le16u(&gb);
100  avctx->sample_aspect_ratio.num = bytestream2_get_le16u(&gb);
101  avctx->sample_aspect_ratio.den = bytestream2_get_le16u(&gb);
102 
103  if (xmax < xmin || ymax < ymin) {
104  av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
105  return AVERROR_INVALIDDATA;
106  }
107 
108  w = xmax - xmin + 1;
109  h = ymax - ymin + 1;
110 
111  bytestream2_skipu(&gb, 49);
112  nplanes = bytestream2_get_byteu(&gb);
113  bytes_per_line = bytestream2_get_le16u(&gb);
114  bytes_per_scanline = nplanes * bytes_per_line;
115 
116  if (bytes_per_scanline < (w * bits_per_pixel * nplanes + 7) / 8 ||
117  (!compressed && bytes_per_scanline > bytestream2_get_bytes_left(&gb) / h)) {
118  av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
119  return AVERROR_INVALIDDATA;
120  }
121 
122  switch ((nplanes << 8) + bits_per_pixel) {
123  case 0x0308:
124  avctx->pix_fmt = AV_PIX_FMT_RGB24;
125  break;
126  case 0x0108:
127  case 0x0104:
128  case 0x0102:
129  case 0x0101:
130  case 0x0401:
131  case 0x0301:
132  case 0x0201:
133  avctx->pix_fmt = AV_PIX_FMT_PAL8;
134  break;
135  default:
136  av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
137  return AVERROR_INVALIDDATA;
138  }
139 
140  bytestream2_skipu(&gb, 60);
141 
142  if ((ret = ff_set_dimensions(avctx, w, h)) < 0)
143  return ret;
144 
145  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
146  return ret;
147 
149 
150  ptr = p->data[0];
151  stride = p->linesize[0];
152 
153  scanline = av_malloc(bytes_per_scanline + AV_INPUT_BUFFER_PADDING_SIZE);
154  if (!scanline)
155  return AVERROR(ENOMEM);
156 
157  if (nplanes == 3 && bits_per_pixel == 8) {
158  for (y = 0; y < h; y++) {
159  ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
160  if (ret < 0)
161  goto end;
162 
163  for (x = 0; x < w; x++) {
164  ptr[3 * x] = scanline[x];
165  ptr[3 * x + 1] = scanline[x + bytes_per_line];
166  ptr[3 * x + 2] = scanline[x + (bytes_per_line << 1)];
167  }
168 
169  ptr += stride;
170  }
171  } else if (nplanes == 1 && bits_per_pixel == 8) {
172  int palstart = avpkt->size - 769;
173 
174  if (avpkt->size < 769) {
175  av_log(avctx, AV_LOG_ERROR, "File is too short\n");
176  ret = avctx->err_recognition & AV_EF_EXPLODE ?
177  AVERROR_INVALIDDATA : avpkt->size;
178  goto end;
179  }
180 
181  for (y = 0; y < h; y++, ptr += stride) {
182  ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
183  if (ret < 0)
184  goto end;
185  memcpy(ptr, scanline, w);
186  }
187 
188  if (bytestream2_tell(&gb) != palstart) {
189  av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
190  bytestream2_seek(&gb, palstart, SEEK_SET);
191  }
192  if (bytestream2_get_byte(&gb) != 12) {
193  av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
194  ret = avctx->err_recognition & AV_EF_EXPLODE ?
195  AVERROR_INVALIDDATA : avpkt->size;
196  goto end;
197  }
198  } else if (nplanes == 1) { /* all packed formats, max. 16 colors */
200 
201  for (y = 0; y < h; y++) {
202  init_get_bits8(&s, scanline, bytes_per_scanline);
203 
204  ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
205  if (ret < 0)
206  goto end;
207 
208  for (x = 0; x < w; x++)
209  ptr[x] = get_bits(&s, bits_per_pixel);
210  ptr += stride;
211  }
212  } else { /* planar, 4, 8 or 16 colors */
213  int i;
214 
215  for (y = 0; y < h; y++) {
216  ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
217  if (ret < 0)
218  goto end;
219 
220  for (x = 0; x < w; x++) {
221  int m = 0x80 >> (x & 7), v = 0;
222  for (i = nplanes - 1; i >= 0; i--) {
223  v <<= 1;
224  v += !!(scanline[i * bytes_per_line + (x >> 3)] & m);
225  }
226  ptr[x] = v;
227  }
228  ptr += stride;
229  }
230  }
231 
232  ret = bytestream2_tell(&gb);
233  if (nplanes == 1 && bits_per_pixel == 8) {
234  pcx_palette(&gb, (uint32_t *)p->data[1], 256);
235  ret += 256 * 3;
236  } else if (bits_per_pixel * nplanes == 1) {
237  AV_WN32A(p->data[1] , 0xFF000000);
238  AV_WN32A(p->data[1]+4, 0xFFFFFFFF);
239  } else if (bits_per_pixel < 8) {
240  bytestream2_seek(&gb, 16, SEEK_SET);
241  pcx_palette(&gb, (uint32_t *)p->data[1], 16);
242  }
243 
244  *got_frame = 1;
245 
246 end:
247  av_free(scanline);
248  return ret;
249 }
250 
252  .p.name = "pcx",
253  CODEC_LONG_NAME("PC Paintbrush PCX image"),
254  .p.type = AVMEDIA_TYPE_VIDEO,
255  .p.id = AV_CODEC_ID_PCX,
257  .p.capabilities = AV_CODEC_CAP_DR1,
258 };
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
AV_EF_EXPLODE
#define AV_EF_EXPLODE
abort decoding on minor error detection
Definition: defs.h:51
ff_pcx_decoder
const FFCodec ff_pcx_decoder
Definition: pcx.c:251
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
GetByteContext
Definition: bytestream.h:33
AVCodecContext::err_recognition
int err_recognition
Error recognition; may misdetect some more or less valid parts as errors.
Definition: avcodec.h:1351
bytestream2_skipu
static av_always_inline void bytestream2_skipu(GetByteContext *g, unsigned int size)
Definition: bytestream.h:174
bytestream2_seek
static av_always_inline int bytestream2_seek(GetByteContext *g, int offset, int whence)
Definition: bytestream.h:212
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
w
uint8_t w
Definition: llviddspenc.c:38
AVPacket::data
uint8_t * data
Definition: packet.h:374
FFCodec
Definition: codec_internal.h:119
AV_WN32A
#define AV_WN32A(p, v)
Definition: intreadwrite.h:538
ff_set_dimensions
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Check that the provided frame dimensions are valid and set them on the codec context.
Definition: utils.c:91
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:346
PCX_HEADER_SIZE
#define PCX_HEADER_SIZE
Definition: pcx.c:31
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:30
get_bits
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:123
GetBitContext
Definition: get_bits.h:61
pcx_palette
static void pcx_palette(GetByteContext *gb, uint32_t *dst, int pallen)
Definition: pcx.c:61
AVRational::num
int num
Numerator.
Definition: rational.h:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
init_get_bits8
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:667
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:298
s
#define s(width, name)
Definition: cbs_vp9.c:256
decode.h
get_bits.h
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:264
run
uint8_t run
Definition: svq3.c:203
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
bytestream2_get_buffer
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:267
bytestream2_get_bytes_left
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:158
bytestream2_tell
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:192
AVFrame::pict_type
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:422
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1450
AV_PIX_FMT_RGB24
@ AV_PIX_FMT_RGB24
packed RGB 8:8:8, 24bpp, RGBRGB...
Definition: pixfmt.h:68
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:375
codec_internal.h
AV_CODEC_ID_PCX
@ AV_CODEC_ID_PCX
Definition: codec_id.h:161
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
pcx_rle_decode
static int pcx_rle_decode(GetByteContext *gb, uint8_t *dst, unsigned int bytes_per_scanline, int compressed)
Definition: pcx.c:33
value
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default value
Definition: writing_filters.txt:86
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:211
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:608
avcodec.h
stride
#define stride
Definition: h264pred_template.c:537
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
ret
ret
Definition: filter_design.txt:187
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: defs.h:40
AVCodecContext
main external API structure.
Definition: avcodec.h:398
AVRational::den
int den
Denominator.
Definition: rational.h:60
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
av_free
#define av_free(p)
Definition: tableprint_vlc.h:33
AVPacket
This structure stores compressed data.
Definition: packet.h:351
bytestream.h
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:370
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
h
h
Definition: vp9dsp_template.c:2038
pcx_decode_frame
static int pcx_decode_frame(AVCodecContext *avctx, AVFrame *p, int *got_frame, AVPacket *avpkt)
Definition: pcx.c:72
AVCodecContext::sample_aspect_ratio
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown) That is the width of a pixel divided by the height of the pixel.
Definition: avcodec.h:768