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
26typedef 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 */
40static 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
60static 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
75static 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
143static 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
154AVCodec targa_encoder = {
155    .name = "targa",
156    .type = AVMEDIA_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};
164