Libav
pcxenc.c
Go to the documentation of this file.
1 /*
2  * PC Paintbrush PCX (.pcx) image encoder
3  * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
29 #include "avcodec.h"
30 #include "bytestream.h"
31 #include "internal.h"
32 
33 static const uint32_t monoblack_pal[16] = { 0x000000, 0xFFFFFF };
34 
36 {
37  avctx->coded_frame = av_frame_alloc();
38  if (!avctx->coded_frame)
39  return AVERROR(ENOMEM);
40 
42  avctx->coded_frame->key_frame = 1;
43 
44  return 0;
45 }
46 
48 {
49  av_frame_free(&avctx->coded_frame);
50  return 0;
51 }
52 
63 static int pcx_rle_encode( uint8_t *dst, int dst_size,
64  const uint8_t *src, int src_plane_size, int nplanes)
65 {
66  int p;
67  const uint8_t *dst_start = dst;
68 
69  // check worst-case upper bound on dst_size
70  if (dst_size < 2LL * src_plane_size * nplanes || src_plane_size <= 0)
71  return -1;
72 
73  for (p = 0; p < nplanes; p++) {
74  int count = 1;
75  const uint8_t *src_plane = src + p;
76  const uint8_t *src_plane_end = src_plane + src_plane_size * nplanes;
77  uint8_t prev = *src_plane;
78  src_plane += nplanes;
79 
80  for (; ; src_plane += nplanes) {
81  if (src_plane < src_plane_end && *src_plane == prev && count < 0x3F) {
82  // current byte is same as prev
83  ++count;
84  } else {
85  // output prev * count
86  if (count != 1 || prev >= 0xC0)
87  *dst++ = 0xC0 | count;
88  *dst++ = prev;
89 
90  if (src_plane == src_plane_end)
91  break;
92 
93  // start new run
94  count = 1;
95  prev = *src_plane;
96  }
97  }
98  }
99 
100  return dst - dst_start;
101 }
102 
103 static int pcx_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
104  const AVFrame *frame, int *got_packet)
105 {
106  const uint8_t *buf_end;
107  uint8_t *buf;
108 
109  int bpp, nplanes, i, y, line_bytes, written, ret, max_pkt_size;
110  const uint32_t *pal = NULL;
111  const uint8_t *src;
112 
113  if (avctx->width > 65535 || avctx->height > 65535) {
114  av_log(avctx, AV_LOG_ERROR, "image dimensions do not fit in 16 bits\n");
115  return -1;
116  }
117 
118  switch (avctx->pix_fmt) {
119  case AV_PIX_FMT_RGB24:
120  bpp = 8;
121  nplanes = 3;
122  break;
123  case AV_PIX_FMT_RGB8:
124  case AV_PIX_FMT_BGR8:
127  case AV_PIX_FMT_GRAY8:
128  case AV_PIX_FMT_PAL8:
129  bpp = 8;
130  nplanes = 1;
131  pal = (uint32_t *)frame->data[1];
132  break;
134  bpp = 1;
135  nplanes = 1;
136  pal = monoblack_pal;
137  break;
138  default:
139  av_log(avctx, AV_LOG_ERROR, "unsupported pixfmt\n");
140  return -1;
141  }
142 
143  line_bytes = (avctx->width * bpp + 7) >> 3;
144  line_bytes = (line_bytes + 1) & ~1;
145 
146  max_pkt_size = 128 + avctx->height * 2 * line_bytes * nplanes + (pal ? 256*3 + 1 : 0);
147  if ((ret = ff_alloc_packet(pkt, max_pkt_size)) < 0) {
148  av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", max_pkt_size);
149  return ret;
150  }
151  buf = pkt->data;
152  buf_end = pkt->data + pkt->size;
153 
154  bytestream_put_byte(&buf, 10); // manufacturer
155  bytestream_put_byte(&buf, 5); // version
156  bytestream_put_byte(&buf, 1); // encoding
157  bytestream_put_byte(&buf, bpp); // bits per pixel per plane
158  bytestream_put_le16(&buf, 0); // x min
159  bytestream_put_le16(&buf, 0); // y min
160  bytestream_put_le16(&buf, avctx->width - 1); // x max
161  bytestream_put_le16(&buf, avctx->height - 1); // y max
162  bytestream_put_le16(&buf, 0); // horizontal DPI
163  bytestream_put_le16(&buf, 0); // vertical DPI
164  for (i = 0; i < 16; i++)
165  bytestream_put_be24(&buf, pal ? pal[i] : 0);// palette (<= 16 color only)
166  bytestream_put_byte(&buf, 0); // reserved
167  bytestream_put_byte(&buf, nplanes); // number of planes
168  bytestream_put_le16(&buf, line_bytes); // scanline plane size in bytes
169 
170  while (buf - pkt->data < 128)
171  *buf++= 0;
172 
173  src = frame->data[0];
174 
175  for (y = 0; y < avctx->height; y++) {
176  if ((written = pcx_rle_encode(buf, buf_end - buf,
177  src, line_bytes, nplanes)) < 0) {
178  av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
179  return -1;
180  }
181  buf += written;
182  src += frame->linesize[0];
183  }
184 
185  if (nplanes == 1 && bpp == 8) {
186  if (buf_end - buf < 257) {
187  av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
188  return -1;
189  }
190  bytestream_put_byte(&buf, 12);
191  for (i = 0; i < 256; i++) {
192  bytestream_put_be24(&buf, pal[i]);
193  }
194  }
195 
196  pkt->size = buf - pkt->data;
197  pkt->flags |= AV_PKT_FLAG_KEY;
198  *got_packet = 1;
199 
200  return 0;
201 }
202 
204  .name = "pcx",
205  .long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
206  .type = AVMEDIA_TYPE_VIDEO,
207  .id = AV_CODEC_ID_PCX,
208  .init = pcx_encode_init,
209  .close = pcx_encode_close,
210  .encode2 = pcx_encode_frame,
211  .pix_fmts = (const enum AVPixelFormat[]){
217  },
218 };
This structure describes decoded (raw) audio or video data.
Definition: frame.h:135
packed RGB 8:8:8, 24bpp, RGBRGB...
Definition: pixfmt.h:67
AVFrame * coded_frame
the picture in the bitstream
Definition: avcodec.h:2532
int size
Definition: avcodec.h:974
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1254
AVCodec.
Definition: avcodec.h:2796
packed RGB 1:2:1, 8bpp, (msb)1B 2G 1R(lsb)
Definition: pixfmt.h:88
uint8_t
#define av_cold
Definition: attributes.h:66
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:57
8 bit with PIX_FMT_RGB32 palette
Definition: pixfmt.h:76
uint8_t * data
Definition: avcodec.h:973
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1019
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
#define AVERROR(e)
Definition: error.h:43
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:69
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:150
static int pcx_rle_encode(uint8_t *dst, int dst_size, const uint8_t *src, int src_plane_size, int nplanes)
PCX run-length encoder.
Definition: pcxenc.c:63
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:169
const char * name
Name of the codec implementation.
Definition: avcodec.h:2803
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:979
static av_cold int pcx_encode_close(AVCodecContext *avctx)
Definition: pcxenc.c:47
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:196
packed RGB 1:2:1, 8bpp, (msb)1R 2G 1B(lsb)
Definition: pixfmt.h:91
int width
picture width / height.
Definition: avcodec.h:1224
static int pcx_encode_frame(AVCodecContext *avctx, AVPacket *pkt, const AVFrame *frame, int *got_packet)
Definition: pcxenc.c:103
int ff_alloc_packet(AVPacket *avpkt, int size)
Check AVPacket size and/or allocate data.
Definition: utils.c:1245
NULL
Definition: eval.c:55
packed RGB 3:3:2, 8bpp, (msb)2B 3G 3R(lsb)
Definition: pixfmt.h:86
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:153
main external API structure.
Definition: avcodec.h:1050
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:141
Y , 1bpp, 0 is black, 1 is white, in each byte pixels are ordered from the msb to the lsb...
Definition: pixfmt.h:75
Y , 8bpp.
Definition: pixfmt.h:73
common internal api header.
packed RGB 3:3:2, 8bpp, (msb)2R 3G 3B(lsb)
Definition: pixfmt.h:89
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:191
static const uint32_t monoblack_pal[16]
Definition: pcxenc.c:33
static av_cold int pcx_encode_init(AVCodecContext *avctx)
Definition: pcxenc.c:35
AVPixelFormat
Pixel format.
Definition: pixfmt.h:63
This structure stores compressed data.
Definition: avcodec.h:950
AVCodec ff_pcx_encoder
Definition: pcxenc.c:203