Libav
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 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 
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 
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 
77 static int targa_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
78  const AVFrame *p, int *got_packet)
79 {
80  int bpp, picsize, datasize = -1, ret;
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_packet(pkt, picsize + 45)) < 0) {
89  av_log(avctx, AV_LOG_ERROR, "encoded frame too large\n");
90  return ret;
91  }
92 
93  /* zero out the header and only set applicable fields */
94  memset(pkt->data, 0, 12);
95  AV_WL16(pkt->data+12, avctx->width);
96  AV_WL16(pkt->data+14, avctx->height);
97  /* image descriptor byte: origin is always top-left, bits 0-3 specify alpha */
98  pkt->data[17] = 0x20 | (avctx->pix_fmt == AV_PIX_FMT_BGRA ? 8 : 0);
99 
100  switch(avctx->pix_fmt) {
101  case AV_PIX_FMT_GRAY8:
102  pkt->data[2] = TGA_BW; /* uncompressed grayscale image */
103  pkt->data[16] = 8; /* bpp */
104  break;
105  case AV_PIX_FMT_RGB555LE:
106  pkt->data[2] = TGA_RGB; /* uncompresses true-color image */
107  pkt->data[16] = 16; /* bpp */
108  break;
109  case AV_PIX_FMT_BGR24:
110  pkt->data[2] = TGA_RGB; /* uncompressed true-color image */
111  pkt->data[16] = 24; /* bpp */
112  break;
113  case AV_PIX_FMT_BGRA:
114  pkt->data[2] = TGA_RGB; /* uncompressed true-color image */
115  pkt->data[16] = 32; /* bpp */
116  break;
117  default:
118  av_log(avctx, AV_LOG_ERROR, "Pixel format '%s' not supported.\n",
119  av_get_pix_fmt_name(avctx->pix_fmt));
120  return AVERROR(EINVAL);
121  }
122  bpp = pkt->data[16] >> 3;
123 
124  out = pkt->data + 18; /* skip past the header we just output */
125 
126  /* try RLE compression */
127  if (avctx->coder_type != FF_CODER_TYPE_RAW)
128  datasize = targa_encode_rle(out, picsize, p, bpp, avctx->width, avctx->height);
129 
130  /* if that worked well, mark the picture as RLE compressed */
131  if(datasize >= 0)
132  pkt->data[2] |= 8;
133 
134  /* if RLE didn't make it smaller, go back to no compression */
135  else datasize = targa_encode_normal(out, p, bpp, avctx->width, avctx->height);
136 
137  out += datasize;
138 
139  /* The standard recommends including this section, even if we don't use
140  * any of the features it affords. TODO: take advantage of the pixel
141  * aspect ratio and encoder ID fields available? */
142  memcpy(out, "\0\0\0\0\0\0\0\0TRUEVISION-XFILE.", 26);
143 
144  pkt->size = out + 26 - pkt->data;
145  pkt->flags |= AV_PKT_FLAG_KEY;
146  *got_packet = 1;
147 
148  return 0;
149 }
150 
152 {
153  avctx->coded_frame = av_frame_alloc();
154  if (!avctx->coded_frame)
155  return AVERROR(ENOMEM);
156 
157  avctx->coded_frame->key_frame = 1;
159 
160  return 0;
161 }
162 
164 {
165  av_frame_free(&avctx->coded_frame);
166  return 0;
167 }
168 
170  .name = "targa",
171  .long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
172  .type = AVMEDIA_TYPE_VIDEO,
173  .id = AV_CODEC_ID_TARGA,
174  .init = targa_encode_init,
175  .close = targa_encode_close,
176  .encode2 = targa_encode_frame,
177  .pix_fmts = (const enum AVPixelFormat[]){
180  },
181 };