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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 /**
33  * RLE compress the image, with maximum size of out_size
34  * @param outbuf Output buffer
35  * @param out_size Maximum output size
36  * @param pic Image to compress
37  * @param bpp Bytes per pixel
38  * @param w Image width
39  * @param h Image height
40  * @return Size of output in bytes, or -1 if larger than out_size
41  */
42 static int targa_encode_rle(uint8_t *outbuf, int out_size, const AVFrame *pic,
43  int bpp, int w, int h)
44 {
45  int y,ret;
46  uint8_t *out;
47 
48  out = outbuf;
49 
50  for(y = 0; y < h; y ++) {
51  ret = ff_rle_encode(out, out_size, pic->data[0] + pic->linesize[0] * y, bpp, w, 0x7f, 0, -1, 0);
52  if(ret == -1){
53  return -1;
54  }
55  out+= ret;
56  out_size -= ret;
57  }
58 
59  return out - outbuf;
60 }
61 
62 static int targa_encode_normal(uint8_t *outbuf, const AVFrame *pic, int bpp, int w, int h)
63 {
64  int i, n = bpp * w;
65  uint8_t *out = outbuf;
66  uint8_t *ptr = pic->data[0];
67 
68  for(i=0; i < h; i++) {
69  memcpy(out, ptr, n);
70  out += n;
71  ptr += pic->linesize[0];
72  }
73 
74  return out - outbuf;
75 }
76 
78  const AVFrame *p, int *got_packet)
79 {
80  int bpp, picsize, datasize = -1, ret, i;
81  uint8_t *out;
82 
83  if(avctx->width > 0xffff || avctx->height > 0xffff) {
84  av_log(avctx, AV_LOG_ERROR, "image dimensions too large\n");
85  return AVERROR(EINVAL);
86  }
87  picsize = avpicture_get_size(avctx->pix_fmt, avctx->width, avctx->height);
88  if ((ret = ff_alloc_packet2(avctx, pkt, picsize + 45)) < 0)
89  return ret;
90 
91  /* zero out the header and only set applicable fields */
92  memset(pkt->data, 0, 12);
93  AV_WL16(pkt->data+12, avctx->width);
94  AV_WL16(pkt->data+14, avctx->height);
95  /* image descriptor byte: origin is always top-left, bits 0-3 specify alpha */
96  pkt->data[17] = 0x20 | (avctx->pix_fmt == AV_PIX_FMT_BGRA ? 8 : 0);
97 
98  out = pkt->data + 18; /* skip past the header we write */
99 
101  switch(avctx->pix_fmt) {
102  case AV_PIX_FMT_PAL8: {
103  int pal_bpp = 24; /* Only write 32bit palette if there is transparency information */
104  for (i = 0; i < 256; i++)
105  if (AV_RN32(p->data[1] + 4 * i) >> 24 != 0xFF) {
106  pal_bpp = 32;
107  break;
108  }
109  pkt->data[1] = 1; /* palette present */
110  pkt->data[2] = TGA_PAL; /* uncompressed palettised image */
111  pkt->data[6] = 1; /* palette contains 256 entries */
112  pkt->data[7] = pal_bpp; /* palette contains pal_bpp bit entries */
113  pkt->data[16] = 8; /* bpp */
114  for (i = 0; i < 256; i++)
115  if (pal_bpp == 32) {
116  AV_WL32(pkt->data + 18 + 4 * i, *(uint32_t *)(p->data[1] + i * 4));
117  } else {
118  AV_WL24(pkt->data + 18 + 3 * i, *(uint32_t *)(p->data[1] + i * 4));
119  }
120  out += 32 * pal_bpp; /* skip past the palette we just output */
121  break;
122  }
123  case AV_PIX_FMT_GRAY8:
124  pkt->data[2] = TGA_BW; /* uncompressed grayscale image */
125  avctx->bits_per_coded_sample = 0x28;
126  pkt->data[16] = 8; /* bpp */
127  break;
128  case AV_PIX_FMT_RGB555LE:
129  pkt->data[2] = TGA_RGB; /* uncompressed true-color image */
130  avctx->bits_per_coded_sample =
131  pkt->data[16] = 16; /* bpp */
132  break;
133  case AV_PIX_FMT_BGR24:
134  pkt->data[2] = TGA_RGB; /* uncompressed true-color image */
135  pkt->data[16] = 24; /* bpp */
136  break;
137  case AV_PIX_FMT_BGRA:
138  pkt->data[2] = TGA_RGB; /* uncompressed true-color image */
139  pkt->data[16] = 32; /* bpp */
140  break;
141  default:
142  av_log(avctx, AV_LOG_ERROR, "Pixel format '%s' not supported.\n",
143  av_get_pix_fmt_name(avctx->pix_fmt));
144  return AVERROR(EINVAL);
145  }
146  bpp = pkt->data[16] >> 3;
147 
148  /* try RLE compression */
149  if (avctx->coder_type != FF_CODER_TYPE_RAW)
150  datasize = targa_encode_rle(out, picsize, p, bpp, avctx->width, avctx->height);
151 
152  /* if that worked well, mark the picture as RLE compressed */
153  if(datasize >= 0)
154  pkt->data[2] |= TGA_RLE;
155 
156  /* if RLE didn't make it smaller, go back to no compression */
157  else datasize = targa_encode_normal(out, p, bpp, avctx->width, avctx->height);
158 
159  out += datasize;
160 
161  /* The standard recommends including this section, even if we don't use
162  * any of the features it affords. TODO: take advantage of the pixel
163  * aspect ratio and encoder ID fields available? */
164  memcpy(out, "\0\0\0\0\0\0\0\0TRUEVISION-XFILE.", 26);
165 
166  pkt->size = out + 26 - pkt->data;
167  pkt->flags |= AV_PKT_FLAG_KEY;
168  *got_packet = 1;
169 
170  return 0;
171 }
172 
174 {
175  avctx->coded_frame = av_frame_alloc();
176  if (!avctx->coded_frame)
177  return AVERROR(ENOMEM);
178 
179  avctx->coded_frame->key_frame = 1;
181 
182  return 0;
183 }
184 
186 {
187  av_frame_free(&avctx->coded_frame);
188  return 0;
189 }
190 
192  .name = "targa",
193  .long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
194  .type = AVMEDIA_TYPE_VIDEO,
195  .id = AV_CODEC_ID_TARGA,
196  .init = targa_encode_init,
197  .close = targa_encode_close,
198  .encode2 = targa_encode_frame,
199  .pix_fmts = (const enum AVPixelFormat[]){
202  },
203 };