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 "libavutil/mem.h"
26 #include "avcodec.h"
27 #include "bytestream.h"
28 #include "codec_internal.h"
29 #include "decode.h"
30 #include "get_bits.h"
31 
32 #define PCX_HEADER_SIZE 128
33 
35  uint8_t *dst,
36  unsigned int bytes_per_scanline,
37  int compressed)
38 {
39  unsigned int i = 0;
40  unsigned char run, value;
41 
42  if (bytestream2_get_bytes_left(gb) < 1)
43  return AVERROR_INVALIDDATA;
44 
45  if (compressed) {
46  while (i < bytes_per_scanline && bytestream2_get_bytes_left(gb)>0) {
47  run = 1;
48  value = bytestream2_get_byte(gb);
49  if (value >= 0xc0 && bytestream2_get_bytes_left(gb)>0) {
50  run = value & 0x3f;
51  value = bytestream2_get_byte(gb);
52  }
53  while (i < bytes_per_scanline && run--)
54  dst[i++] = value;
55  }
56  } else {
57  bytestream2_get_buffer(gb, dst, bytes_per_scanline);
58  }
59  return 0;
60 }
61 
62 static void pcx_palette(GetByteContext *gb, uint32_t *dst, int pallen)
63 {
64  int i;
65 
66  pallen = FFMIN(pallen, bytestream2_get_bytes_left(gb) / 3);
67  for (i = 0; i < pallen; i++)
68  *dst++ = 0xFF000000 | bytestream2_get_be24u(gb);
69  if (pallen < 256)
70  memset(dst, 0, (256 - pallen) * sizeof(*dst));
71 }
72 
73 static int pcx_decode_frame(AVCodecContext *avctx, AVFrame *p,
74  int *got_frame, AVPacket *avpkt)
75 {
76  GetByteContext gb;
77  int compressed, xmin, ymin, xmax, ymax;
78  int ret;
79  unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, y, x,
80  bytes_per_scanline;
81  uint8_t *ptr, *scanline;
82  ptrdiff_t stride;
83 
84  if (avpkt->size < PCX_HEADER_SIZE) {
85  av_log(avctx, AV_LOG_ERROR, "Packet too small\n");
86  return AVERROR_INVALIDDATA;
87  }
88 
89  bytestream2_init(&gb, avpkt->data, avpkt->size);
90 
91  if (bytestream2_get_byteu(&gb) != 0x0a || bytestream2_get_byteu(&gb) > 5) {
92  av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
93  return AVERROR_INVALIDDATA;
94  }
95 
96  compressed = bytestream2_get_byteu(&gb);
97  bits_per_pixel = bytestream2_get_byteu(&gb);
98  xmin = bytestream2_get_le16u(&gb);
99  ymin = bytestream2_get_le16u(&gb);
100  xmax = bytestream2_get_le16u(&gb);
101  ymax = bytestream2_get_le16u(&gb);
102  avctx->sample_aspect_ratio.num = bytestream2_get_le16u(&gb);
103  avctx->sample_aspect_ratio.den = bytestream2_get_le16u(&gb);
104 
105  if (xmax < xmin || ymax < ymin) {
106  av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
107  return AVERROR_INVALIDDATA;
108  }
109 
110  w = xmax - xmin + 1;
111  h = ymax - ymin + 1;
112 
113  bytestream2_skipu(&gb, 49);
114  nplanes = bytestream2_get_byteu(&gb);
115  bytes_per_line = bytestream2_get_le16u(&gb);
116  bytes_per_scanline = nplanes * bytes_per_line;
117 
118  if (bytes_per_scanline < (w * bits_per_pixel * nplanes + 7) / 8 ||
119  (!compressed && bytes_per_scanline > bytestream2_get_bytes_left(&gb) / h)) {
120  av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
121  return AVERROR_INVALIDDATA;
122  }
123 
124  switch ((nplanes << 8) + bits_per_pixel) {
125  case 0x0308:
126  avctx->pix_fmt = AV_PIX_FMT_RGB24;
127  break;
128  case 0x0108:
129  case 0x0104:
130  case 0x0102:
131  case 0x0101:
132  case 0x0401:
133  case 0x0301:
134  case 0x0201:
135  avctx->pix_fmt = AV_PIX_FMT_PAL8;
136  break;
137  default:
138  av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
139  return AVERROR_INVALIDDATA;
140  }
141 
142  bytestream2_skipu(&gb, 60);
143 
144  if ((ret = ff_set_dimensions(avctx, w, h)) < 0)
145  return ret;
146 
147  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
148  return ret;
149 
151 
152  ptr = p->data[0];
153  stride = p->linesize[0];
154 
155  scanline = av_malloc(bytes_per_scanline + AV_INPUT_BUFFER_PADDING_SIZE);
156  if (!scanline)
157  return AVERROR(ENOMEM);
158 
159  if (nplanes == 3 && bits_per_pixel == 8) {
160  for (y = 0; y < h; y++) {
161  ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
162  if (ret < 0)
163  goto end;
164 
165  for (x = 0; x < w; x++) {
166  ptr[3 * x] = scanline[x];
167  ptr[3 * x + 1] = scanline[x + bytes_per_line];
168  ptr[3 * x + 2] = scanline[x + (bytes_per_line << 1)];
169  }
170 
171  ptr += stride;
172  }
173  } else if (nplanes == 1 && bits_per_pixel == 8) {
174  int palstart = avpkt->size - 769;
175 
176  if (avpkt->size < 769) {
177  av_log(avctx, AV_LOG_ERROR, "File is too short\n");
178  ret = avctx->err_recognition & AV_EF_EXPLODE ?
179  AVERROR_INVALIDDATA : avpkt->size;
180  goto end;
181  }
182 
183  for (y = 0; y < h; y++, ptr += stride) {
184  ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
185  if (ret < 0)
186  goto end;
187  memcpy(ptr, scanline, w);
188  }
189 
190  if (bytestream2_tell(&gb) != palstart) {
191  av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
192  bytestream2_seek(&gb, palstart, SEEK_SET);
193  }
194  if (bytestream2_get_byte(&gb) != 12) {
195  av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
196  ret = avctx->err_recognition & AV_EF_EXPLODE ?
197  AVERROR_INVALIDDATA : avpkt->size;
198  goto end;
199  }
200  } else if (nplanes == 1) { /* all packed formats, max. 16 colors */
202 
203  for (y = 0; y < h; y++) {
204  init_get_bits8(&s, scanline, bytes_per_scanline);
205 
206  ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
207  if (ret < 0)
208  goto end;
209 
210  for (x = 0; x < w; x++)
211  ptr[x] = get_bits(&s, bits_per_pixel);
212  ptr += stride;
213  }
214  } else { /* planar, 4, 8 or 16 colors */
215  int i;
216 
217  for (y = 0; y < h; y++) {
218  ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
219  if (ret < 0)
220  goto end;
221 
222  for (x = 0; x < w; x++) {
223  int m = 0x80 >> (x & 7), v = 0;
224  for (i = nplanes - 1; i >= 0; i--) {
225  v <<= 1;
226  v += !!(scanline[i * bytes_per_line + (x >> 3)] & m);
227  }
228  ptr[x] = v;
229  }
230  ptr += stride;
231  }
232  }
233 
234  ret = bytestream2_tell(&gb);
235  if (nplanes == 1 && bits_per_pixel == 8) {
236  pcx_palette(&gb, (uint32_t *)p->data[1], 256);
237  ret += 256 * 3;
238  } else if (bits_per_pixel * nplanes == 1) {
239  AV_WN32A(p->data[1] , 0xFF000000);
240  AV_WN32A(p->data[1]+4, 0xFFFFFFFF);
241  } else if (bits_per_pixel < 8) {
242  bytestream2_seek(&gb, 16, SEEK_SET);
243  pcx_palette(&gb, (uint32_t *)p->data[1], 16);
244  }
245 
246  *got_frame = 1;
247 
248 end:
249  av_free(scanline);
250  return ret;
251 }
252 
254  .p.name = "pcx",
255  CODEC_LONG_NAME("PC Paintbrush PCX image"),
256  .p.type = AVMEDIA_TYPE_VIDEO,
257  .p.id = AV_CODEC_ID_PCX,
259  .p.capabilities = AV_CODEC_CAP_DR1,
260 };
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:253
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:1420
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:374
w
uint8_t w
Definition: llviddspenc.c:38
AVPacket::data
uint8_t * data
Definition: packet.h:533
FFCodec
Definition: codec_internal.h:126
AV_WN32A
#define AV_WN32A(p, v)
Definition: intreadwrite.h:532
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:94
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:395
PCX_HEADER_SIZE
#define PCX_HEADER_SIZE
Definition: pcx.c:32
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:335
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:130
GetBitContext
Definition: get_bits.h:108
pcx_palette
static void pcx_palette(GetByteContext *gb, uint32_t *dst, int pallen)
Definition: pcx.c:62
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:545
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:286
s
#define s(width, name)
Definition: cbs_vp9.c:198
decode.h
get_bits.h
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:271
run
uint8_t run
Definition: svq3.c:204
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:279
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:476
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1575
AV_PIX_FMT_RGB24
@ AV_PIX_FMT_RGB24
packed RGB 8:8:8, 24bpp, RGBRGB...
Definition: pixfmt.h:75
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:534
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:256
pcx_rle_decode
static int pcx_rle_decode(GetByteContext *gb, uint8_t *dst, unsigned int bytes_per_scanline, int compressed)
Definition: pcx.c:34
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:194
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:657
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:84
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:445
AVRational::den
int den
Denominator.
Definition: rational.h:60
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
mem.h
av_free
#define av_free(p)
Definition: tableprint_vlc.h:33
AVPacket
This structure stores compressed data.
Definition: packet.h:510
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:419
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:73
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:642