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targaenc.c
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1 /*
2  * Targa (.tga) image encoder
3  * Copyright (c) 2007 Bobby Bingham
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 #include <string.h>
23 
24 #include "libavutil/internal.h"
25 #include "libavutil/intreadwrite.h"
26 #include "libavutil/pixdesc.h"
27 #include "avcodec.h"
28 #include "internal.h"
29 #include "rle.h"
30 #include "targa.h"
31 
32 typedef struct TargaContext {
34 } TargaContext;
35 
36 /**
37  * RLE compress the image, with maximum size of out_size
38  * @param outbuf Output buffer
39  * @param out_size Maximum output size
40  * @param pic Image to compress
41  * @param bpp Bytes per pixel
42  * @param w Image width
43  * @param h Image height
44  * @return Size of output in bytes, or -1 if larger than out_size
45  */
46 static int targa_encode_rle(uint8_t *outbuf, int out_size, const AVFrame *pic,
47  int bpp, int w, int h)
48 {
49  int y,ret;
50  uint8_t *out;
51 
52  out = outbuf;
53 
54  for(y = 0; y < h; y ++) {
55  ret = ff_rle_encode(out, out_size, pic->data[0] + pic->linesize[0] * y, bpp, w, 0x7f, 0, -1, 0);
56  if(ret == -1){
57  return -1;
58  }
59  out+= ret;
60  out_size -= ret;
61  }
62 
63  return out - outbuf;
64 }
65 
66 static int targa_encode_normal(uint8_t *outbuf, const AVFrame *pic, int bpp, int w, int h)
67 {
68  int i, n = bpp * w;
69  uint8_t *out = outbuf;
70  uint8_t *ptr = pic->data[0];
71 
72  for(i=0; i < h; i++) {
73  memcpy(out, ptr, n);
74  out += n;
75  ptr += pic->linesize[0];
76  }
77 
78  return out - outbuf;
79 }
80 
82  const AVFrame *p, int *got_packet)
83 {
84  int bpp, picsize, datasize = -1, ret, i;
85  uint8_t *out;
86 
87  if(avctx->width > 0xffff || avctx->height > 0xffff) {
88  av_log(avctx, AV_LOG_ERROR, "image dimensions too large\n");
89  return AVERROR(EINVAL);
90  }
91  picsize = avpicture_get_size(avctx->pix_fmt, avctx->width, avctx->height);
92  if ((ret = ff_alloc_packet2(avctx, pkt, picsize + 45)) < 0)
93  return ret;
94 
95  /* zero out the header and only set applicable fields */
96  memset(pkt->data, 0, 12);
97  AV_WL16(pkt->data+12, avctx->width);
98  AV_WL16(pkt->data+14, avctx->height);
99  /* image descriptor byte: origin is always top-left, bits 0-3 specify alpha */
100  pkt->data[17] = 0x20 | (avctx->pix_fmt == AV_PIX_FMT_BGRA ? 8 : 0);
101 
102  out = pkt->data + 18; /* skip past the header we write */
103 
105  switch(avctx->pix_fmt) {
106  case AV_PIX_FMT_PAL8: {
107  int pal_bpp = 24; /* Only write 32bit palette if there is transparency information */
108  for (i = 0; i < 256; i++)
109  if (AV_RN32(p->data[1] + 4 * i) >> 24 != 0xFF) {
110  pal_bpp = 32;
111  break;
112  }
113  pkt->data[1] = 1; /* palette present */
114  pkt->data[2] = TGA_PAL; /* uncompressed palettised image */
115  pkt->data[6] = 1; /* palette contains 256 entries */
116  pkt->data[7] = pal_bpp; /* palette contains pal_bpp bit entries */
117  pkt->data[16] = 8; /* bpp */
118  for (i = 0; i < 256; i++)
119  if (pal_bpp == 32) {
120  AV_WL32(pkt->data + 18 + 4 * i, *(uint32_t *)(p->data[1] + i * 4));
121  } else {
122  AV_WL24(pkt->data + 18 + 3 * i, *(uint32_t *)(p->data[1] + i * 4));
123  }
124  out += 32 * pal_bpp; /* skip past the palette we just output */
125  break;
126  }
127  case AV_PIX_FMT_GRAY8:
128  pkt->data[2] = TGA_BW; /* uncompressed grayscale image */
129  avctx->bits_per_coded_sample = 0x28;
130  pkt->data[16] = 8; /* bpp */
131  break;
132  case AV_PIX_FMT_RGB555LE:
133  pkt->data[2] = TGA_RGB; /* uncompressed true-color image */
134  avctx->bits_per_coded_sample =
135  pkt->data[16] = 16; /* bpp */
136  break;
137  case AV_PIX_FMT_BGR24:
138  pkt->data[2] = TGA_RGB; /* uncompressed true-color image */
139  pkt->data[16] = 24; /* bpp */
140  break;
141  case AV_PIX_FMT_BGRA:
142  pkt->data[2] = TGA_RGB; /* uncompressed true-color image */
143  pkt->data[16] = 32; /* bpp */
144  break;
145  default:
146  av_log(avctx, AV_LOG_ERROR, "Pixel format '%s' not supported.\n",
147  av_get_pix_fmt_name(avctx->pix_fmt));
148  return AVERROR(EINVAL);
149  }
150  bpp = pkt->data[16] >> 3;
151 
152  /* try RLE compression */
153  if (avctx->coder_type != FF_CODER_TYPE_RAW)
154  datasize = targa_encode_rle(out, picsize, p, bpp, avctx->width, avctx->height);
155 
156  /* if that worked well, mark the picture as RLE compressed */
157  if(datasize >= 0)
158  pkt->data[2] |= TGA_RLE;
159 
160  /* if RLE didn't make it smaller, go back to no compression */
161  else datasize = targa_encode_normal(out, p, bpp, avctx->width, avctx->height);
162 
163  out += datasize;
164 
165  /* The standard recommends including this section, even if we don't use
166  * any of the features it affords. TODO: take advantage of the pixel
167  * aspect ratio and encoder ID fields available? */
168  memcpy(out, "\0\0\0\0\0\0\0\0TRUEVISION-XFILE.", 26);
169 
170  pkt->size = out + 26 - pkt->data;
171  pkt->flags |= AV_PKT_FLAG_KEY;
172  *got_packet = 1;
173 
174  return 0;
175 }
176 
178 {
179  TargaContext *s = avctx->priv_data;
180 
182  s->picture.key_frame= 1;
184  avctx->coded_frame= &s->picture;
185 
186  return 0;
187 }
188 
190  .name = "targa",
191  .type = AVMEDIA_TYPE_VIDEO,
192  .id = AV_CODEC_ID_TARGA,
193  .priv_data_size = sizeof(TargaContext),
195  .encode2 = targa_encode_frame,
196  .pix_fmts = (const enum AVPixelFormat[]){
199  },
200  .long_name= NULL_IF_CONFIG_SMALL("Truevision Targa image"),
201 };