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 "libavutil/intreadwrite.h"
23#include "libavutil/pixdesc.h"
24#include "avcodec.h"
25#include "rle.h"
26#include "targa.h"
27
28typedef struct TargaContext {
29    AVFrame picture;
30} TargaContext;
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 */
42static int targa_encode_rle(uint8_t *outbuf, int out_size, 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
62static int targa_encode_normal(uint8_t *outbuf, 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
77static int targa_encode_frame(AVCodecContext *avctx,
78                              unsigned char *outbuf,
79                              int buf_size, void *data){
80    AVFrame *p = data;
81    int bpp, picsize, datasize = -1;
82    uint8_t *out;
83
84    if(avctx->width > 0xffff || avctx->height > 0xffff) {
85        av_log(avctx, AV_LOG_ERROR, "image dimensions too large\n");
86        return AVERROR(EINVAL);
87    }
88    picsize = avpicture_get_size(avctx->pix_fmt, avctx->width, avctx->height);
89    if(buf_size < picsize + 45) {
90        av_log(avctx, AV_LOG_ERROR, "encoded frame too large\n");
91        return AVERROR(EINVAL);
92    }
93
94    p->pict_type= AV_PICTURE_TYPE_I;
95    p->key_frame= 1;
96
97    /* zero out the header and only set applicable fields */
98    memset(outbuf, 0, 12);
99    AV_WL16(outbuf+12, avctx->width);
100    AV_WL16(outbuf+14, avctx->height);
101    /* image descriptor byte: origin is always top-left, bits 0-3 specify alpha */
102    outbuf[17] = 0x20 | (avctx->pix_fmt == PIX_FMT_BGRA ? 8 : 0);
103
104    switch(avctx->pix_fmt) {
105    case PIX_FMT_GRAY8:
106        outbuf[2] = TGA_BW;      /* uncompressed grayscale image */
107        outbuf[16] = 8;          /* bpp */
108        break;
109    case PIX_FMT_RGB555LE:
110        outbuf[2] = TGA_RGB;     /* uncompresses true-color image */
111        outbuf[16] = 16;         /* bpp */
112        break;
113    case PIX_FMT_BGR24:
114        outbuf[2] = TGA_RGB;     /* uncompressed true-color image */
115        outbuf[16] = 24;         /* bpp */
116        break;
117    case PIX_FMT_BGRA:
118        outbuf[2] = TGA_RGB;     /* uncompressed true-color image */
119        outbuf[16] = 32;         /* bpp */
120        break;
121    default:
122        av_log(avctx, AV_LOG_ERROR, "Pixel format '%s' not supported.\n",
123               av_get_pix_fmt_name(avctx->pix_fmt));
124        return AVERROR(EINVAL);
125    }
126    bpp = outbuf[16] >> 3;
127
128    out = outbuf + 18;  /* skip past the header we just output */
129
130    /* try RLE compression */
131    if (avctx->coder_type != FF_CODER_TYPE_RAW)
132        datasize = targa_encode_rle(out, picsize, p, bpp, avctx->width, avctx->height);
133
134    /* if that worked well, mark the picture as RLE compressed */
135    if(datasize >= 0)
136        outbuf[2] |= 8;
137
138    /* if RLE didn't make it smaller, go back to no compression */
139    else datasize = targa_encode_normal(out, p, bpp, avctx->width, avctx->height);
140
141    out += datasize;
142
143    /* The standard recommends including this section, even if we don't use
144     * any of the features it affords. TODO: take advantage of the pixel
145     * aspect ratio and encoder ID fields available? */
146    memcpy(out, "\0\0\0\0\0\0\0\0TRUEVISION-XFILE.", 26);
147
148    return out + 26 - outbuf;
149}
150
151static av_cold int targa_encode_init(AVCodecContext *avctx)
152{
153    TargaContext *s = avctx->priv_data;
154
155    avcodec_get_frame_defaults(&s->picture);
156    s->picture.key_frame= 1;
157    avctx->coded_frame= &s->picture;
158
159    return 0;
160}
161
162AVCodec ff_targa_encoder = {
163    .name = "targa",
164    .type = AVMEDIA_TYPE_VIDEO,
165    .id = CODEC_ID_TARGA,
166    .priv_data_size = sizeof(TargaContext),
167    .init = targa_encode_init,
168    .encode = targa_encode_frame,
169    .pix_fmts= (const enum PixelFormat[]){PIX_FMT_BGR24, PIX_FMT_BGRA, PIX_FMT_RGB555LE, PIX_FMT_GRAY8, PIX_FMT_NONE},
170    .long_name= NULL_IF_CONFIG_SMALL("Truevision Targa image"),
171};
172