targeenc: fix rgb555 encoding on big endian systems.
[libav.git] / libavcodec / targaenc.c
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 "libavutil/intreadwrite.h"
23 #include "avcodec.h"
24 #include "rle.h"
25
26 typedef struct TargaContext {
27 AVFrame picture;
28 } TargaContext;
29
30 /**
31 * RLE compress the image, with maximum size of out_size
32 * @param outbuf Output buffer
33 * @param out_size Maximum output size
34 * @param pic Image to compress
35 * @param bpp Bytes per pixel
36 * @param w Image width
37 * @param h Image height
38 * @return Size of output in bytes, or -1 if larger than out_size
39 */
40 static int targa_encode_rle(uint8_t *outbuf, int out_size, AVFrame *pic,
41 int bpp, int w, int h)
42 {
43 int y,ret;
44 uint8_t *out;
45
46 out = outbuf;
47
48 for(y = 0; y < h; y ++) {
49 ret = ff_rle_encode(out, out_size, pic->data[0] + pic->linesize[0] * y, bpp, w, 0x7f, 0, -1, 0);
50 if(ret == -1){
51 return -1;
52 }
53 out+= ret;
54 out_size -= ret;
55 }
56
57 return out - outbuf;
58 }
59
60 static int targa_encode_normal(uint8_t *outbuf, AVFrame *pic, int bpp, int w, int h)
61 {
62 int i, n = bpp * w;
63 uint8_t *out = outbuf;
64 uint8_t *ptr = pic->data[0];
65
66 for(i=0; i < h; i++) {
67 memcpy(out, ptr, n);
68 out += n;
69 ptr += pic->linesize[0];
70 }
71
72 return out - outbuf;
73 }
74
75 static int targa_encode_frame(AVCodecContext *avctx,
76 unsigned char *outbuf,
77 int buf_size, void *data){
78 AVFrame *p = data;
79 int bpp, picsize, datasize = -1;
80 uint8_t *out;
81
82 if(avctx->width > 0xffff || avctx->height > 0xffff) {
83 av_log(avctx, AV_LOG_ERROR, "image dimensions too large\n");
84 return -1;
85 }
86 picsize = avpicture_get_size(avctx->pix_fmt, avctx->width, avctx->height);
87 if(buf_size < picsize + 45) {
88 av_log(avctx, AV_LOG_ERROR, "encoded frame too large\n");
89 return -1;
90 }
91
92 p->pict_type= FF_I_TYPE;
93 p->key_frame= 1;
94
95 /* zero out the header and only set applicable fields */
96 memset(outbuf, 0, 12);
97 AV_WL16(outbuf+12, avctx->width);
98 AV_WL16(outbuf+14, avctx->height);
99 outbuf[17] = 0x20; /* origin is top-left. no alpha */
100
101 /* TODO: support alpha channel */
102 switch(avctx->pix_fmt) {
103 case PIX_FMT_GRAY8:
104 outbuf[2] = 3; /* uncompressed grayscale image */
105 outbuf[16] = 8; /* bpp */
106 break;
107 case PIX_FMT_RGB555LE:
108 outbuf[2] = 2; /* uncompresses true-color image */
109 outbuf[16] = 16; /* bpp */
110 break;
111 case PIX_FMT_BGR24:
112 outbuf[2] = 2; /* uncompressed true-color image */
113 outbuf[16] = 24; /* bpp */
114 break;
115 default:
116 return -1;
117 }
118 bpp = outbuf[16] >> 3;
119
120 out = outbuf + 18; /* skip past the header we just output */
121
122 /* try RLE compression */
123 if (avctx->coder_type != FF_CODER_TYPE_RAW)
124 datasize = targa_encode_rle(out, picsize, p, bpp, avctx->width, avctx->height);
125
126 /* if that worked well, mark the picture as RLE compressed */
127 if(datasize >= 0)
128 outbuf[2] |= 8;
129
130 /* if RLE didn't make it smaller, go back to no compression */
131 else datasize = targa_encode_normal(out, p, bpp, avctx->width, avctx->height);
132
133 out += datasize;
134
135 /* The standard recommends including this section, even if we don't use
136 * any of the features it affords. TODO: take advantage of the pixel
137 * aspect ratio and encoder ID fields available? */
138 memcpy(out, "\0\0\0\0\0\0\0\0TRUEVISION-XFILE.", 26);
139
140 return out + 26 - outbuf;
141 }
142
143 static av_cold int targa_encode_init(AVCodecContext *avctx)
144 {
145 TargaContext *s = avctx->priv_data;
146
147 avcodec_get_frame_defaults(&s->picture);
148 s->picture.key_frame= 1;
149 avctx->coded_frame= &s->picture;
150
151 return 0;
152 }
153
154 AVCodec targa_encoder = {
155 .name = "targa",
156 .type = CODEC_TYPE_VIDEO,
157 .id = CODEC_ID_TARGA,
158 .priv_data_size = sizeof(TargaContext),
159 .init = targa_encode_init,
160 .encode = targa_encode_frame,
161 .pix_fmts= (const enum PixelFormat[]){PIX_FMT_BGR24, PIX_FMT_RGB555LE, PIX_FMT_GRAY8, PIX_FMT_NONE},
162 .long_name= NULL_IF_CONFIG_SMALL("Truevision Targa image"),
163 };