libavcodec/targaenc.c

   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
  32 typedef struct TargaContext {
  33     AVFrame picture;
  34 } TargaContext;
  35
  36 /**
  37  * RLE compress the image, with maximum size of out_size
  38  * @param outbuf Output buffer
  39  * @param out_size Maximum output size
  40  * @param pic Image to compress
  41  * @param bpp Bytes per pixel
  42  * @param w Image width
  43  * @param h Image height
  44  * @return Size of output in bytes, or -1 if larger than out_size
  45  */
  46 static int targa_encode_rle(uint8_t *outbuf, int out_size, const AVFrame *pic,
  47                             int bpp, int w, int h)
  48 {
  49     int y,ret;
  50     uint8_t *out;
  51
  52     out = outbuf;
  53
  54     for(y = 0; y < h; y ++) {
  55         ret = ff_rle_encode(out, out_size, pic->data[0] + pic->linesize[0] * y, bpp, w, 0x7f, 0, -1, 0);
  56         if(ret == -1){
  57             return -1;
  58         }
  59         out+= ret;
  60         out_size -= ret;
  61     }
  62
  63     return out - outbuf;
  64 }
  65
  66 static int targa_encode_normal(uint8_t *outbuf, const AVFrame *pic, int bpp, int w, int h)
  67 {
  68     int i, n = bpp * w;
  69     uint8_t *out = outbuf;
  70     uint8_t *ptr = pic->data[0];
  71
  72     for(i=0; i < h; i++) {
  73         memcpy(out, ptr, n);
  74         out += n;
  75         ptr += pic->linesize[0];
  76     }
  77
  78     return out - outbuf;
  79 }
  80
  81 static int targa_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
  82                               const AVFrame *p, int *got_packet)
  83 {
  84     int bpp, picsize, datasize = -1, ret;
  85     uint8_t *out;
  86
  87     if(avctx->width > 0xffff || avctx->height > 0xffff) {
  88         av_log(avctx, AV_LOG_ERROR, "image dimensions too large\n");
  89         return AVERROR(EINVAL);
  90     }
  91     picsize = avpicture_get_size(avctx->pix_fmt, avctx->width, avctx->height);
  92     if ((ret = ff_alloc_packet(pkt, picsize + 45)) < 0) {
  93         av_log(avctx, AV_LOG_ERROR, "encoded frame too large\n");
  94         return ret;
  95     }
  96
  97     /* zero out the header and only set applicable fields */
  98     memset(pkt->data, 0, 12);
  99     AV_WL16(pkt->data+12, avctx->width);
 100     AV_WL16(pkt->data+14, avctx->height);
 101     /* image descriptor byte: origin is always top-left, bits 0-3 specify alpha */
 102     pkt->data[17] = 0x20 | (avctx->pix_fmt == AV_PIX_FMT_BGRA ? 8 : 0);
 103
 104     switch(avctx->pix_fmt) {
 105     case AV_PIX_FMT_GRAY8:
 106         pkt->data[2]  = TGA_BW;     /* uncompressed grayscale image */
 107         pkt->data[16] = 8;          /* bpp */
 108         break;
 109     case AV_PIX_FMT_RGB555LE:
 110         pkt->data[2]  = TGA_RGB;    /* uncompresses true-color image */
 111         pkt->data[16] = 16;         /* bpp */
 112         break;
 113     case AV_PIX_FMT_BGR24:
 114         pkt->data[2]  = TGA_RGB;    /* uncompressed true-color image */
 115         pkt->data[16] = 24;         /* bpp */
 116         break;
 117     case AV_PIX_FMT_BGRA:
 118         pkt->data[2]  = TGA_RGB;    /* uncompressed true-color image */
 119         pkt->data[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 = pkt->data[16] >> 3;
 127
 128     out = pkt->data + 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         pkt->data[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     pkt->size   = out + 26 - pkt->data;
 149     pkt->flags |= AV_PKT_FLAG_KEY;
 150     *got_packet = 1;
 151
 152     return 0;
 153 }
 154
 155 static av_cold int targa_encode_init(AVCodecContext *avctx)
 156 {
 157     TargaContext *s = avctx->priv_data;
 158
 159     avcodec_get_frame_defaults(&s->picture);
 160     s->picture.key_frame= 1;
 161     s->picture.pict_type = AV_PICTURE_TYPE_I;
 162     avctx->coded_frame= &s->picture;
 163
 164     return 0;
 165 }
 166
 167 AVCodec ff_targa_encoder = {
 168     .name           = "targa",
 169     .type           = AVMEDIA_TYPE_VIDEO,
 170     .id             = AV_CODEC_ID_TARGA,
 171     .priv_data_size = sizeof(TargaContext),
 172     .init           = targa_encode_init,
 173     .encode2        = targa_encode_frame,
 174     .pix_fmts       = (const enum AVPixelFormat[]){
 175         AV_PIX_FMT_BGR24, AV_PIX_FMT_BGRA, AV_PIX_FMT_RGB555LE, AV_PIX_FMT_GRAY8,
 176         AV_PIX_FMT_NONE
 177     },
 178     .long_name= NULL_IF_CONFIG_SMALL("Truevision Targa image"),
 179 };