FFmpeg/libavcodec/targaenc.c
2013-11-16 17:46:51 +01:00

182 lines
5.6 KiB
C

/*
* Targa (.tga) image encoder
* Copyright (c) 2007 Bobby Bingham
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <string.h>
#include "libavutil/internal.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/pixdesc.h"
#include "avcodec.h"
#include "internal.h"
#include "rle.h"
#include "targa.h"
/**
* RLE compress the image, with maximum size of out_size
* @param outbuf Output buffer
* @param out_size Maximum output size
* @param pic Image to compress
* @param bpp Bytes per pixel
* @param w Image width
* @param h Image height
* @return Size of output in bytes, or -1 if larger than out_size
*/
static int targa_encode_rle(uint8_t *outbuf, int out_size, const AVFrame *pic,
int bpp, int w, int h)
{
int y,ret;
uint8_t *out;
out = outbuf;
for(y = 0; y < h; y ++) {
ret = ff_rle_encode(out, out_size, pic->data[0] + pic->linesize[0] * y, bpp, w, 0x7f, 0, -1, 0);
if(ret == -1){
return -1;
}
out+= ret;
out_size -= ret;
}
return out - outbuf;
}
static int targa_encode_normal(uint8_t *outbuf, const AVFrame *pic, int bpp, int w, int h)
{
int i, n = bpp * w;
uint8_t *out = outbuf;
uint8_t *ptr = pic->data[0];
for(i=0; i < h; i++) {
memcpy(out, ptr, n);
out += n;
ptr += pic->linesize[0];
}
return out - outbuf;
}
static int targa_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
const AVFrame *p, int *got_packet)
{
int bpp, picsize, datasize = -1, ret;
uint8_t *out;
if(avctx->width > 0xffff || avctx->height > 0xffff) {
av_log(avctx, AV_LOG_ERROR, "image dimensions too large\n");
return AVERROR(EINVAL);
}
picsize = avpicture_get_size(avctx->pix_fmt, avctx->width, avctx->height);
if ((ret = ff_alloc_packet(pkt, picsize + 45)) < 0) {
av_log(avctx, AV_LOG_ERROR, "encoded frame too large\n");
return ret;
}
/* zero out the header and only set applicable fields */
memset(pkt->data, 0, 12);
AV_WL16(pkt->data+12, avctx->width);
AV_WL16(pkt->data+14, avctx->height);
/* image descriptor byte: origin is always top-left, bits 0-3 specify alpha */
pkt->data[17] = 0x20 | (avctx->pix_fmt == AV_PIX_FMT_BGRA ? 8 : 0);
switch(avctx->pix_fmt) {
case AV_PIX_FMT_GRAY8:
pkt->data[2] = TGA_BW; /* uncompressed grayscale image */
pkt->data[16] = 8; /* bpp */
break;
case AV_PIX_FMT_RGB555LE:
pkt->data[2] = TGA_RGB; /* uncompresses true-color image */
pkt->data[16] = 16; /* bpp */
break;
case AV_PIX_FMT_BGR24:
pkt->data[2] = TGA_RGB; /* uncompressed true-color image */
pkt->data[16] = 24; /* bpp */
break;
case AV_PIX_FMT_BGRA:
pkt->data[2] = TGA_RGB; /* uncompressed true-color image */
pkt->data[16] = 32; /* bpp */
break;
default:
av_log(avctx, AV_LOG_ERROR, "Pixel format '%s' not supported.\n",
av_get_pix_fmt_name(avctx->pix_fmt));
return AVERROR(EINVAL);
}
bpp = pkt->data[16] >> 3;
out = pkt->data + 18; /* skip past the header we just output */
/* try RLE compression */
if (avctx->coder_type != FF_CODER_TYPE_RAW)
datasize = targa_encode_rle(out, picsize, p, bpp, avctx->width, avctx->height);
/* if that worked well, mark the picture as RLE compressed */
if(datasize >= 0)
pkt->data[2] |= 8;
/* if RLE didn't make it smaller, go back to no compression */
else datasize = targa_encode_normal(out, p, bpp, avctx->width, avctx->height);
out += datasize;
/* The standard recommends including this section, even if we don't use
* any of the features it affords. TODO: take advantage of the pixel
* aspect ratio and encoder ID fields available? */
memcpy(out, "\0\0\0\0\0\0\0\0TRUEVISION-XFILE.", 26);
pkt->size = out + 26 - pkt->data;
pkt->flags |= AV_PKT_FLAG_KEY;
*got_packet = 1;
return 0;
}
static av_cold int targa_encode_init(AVCodecContext *avctx)
{
avctx->coded_frame = av_frame_alloc();
if (!avctx->coded_frame)
return AVERROR(ENOMEM);
avctx->coded_frame->key_frame = 1;
avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
return 0;
}
static av_cold int targa_encode_close(AVCodecContext *avctx)
{
av_frame_free(&avctx->coded_frame);
return 0;
}
AVCodec ff_targa_encoder = {
.name = "targa",
.long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_TARGA,
.init = targa_encode_init,
.close = targa_encode_close,
.encode2 = targa_encode_frame,
.pix_fmts = (const enum AVPixelFormat[]){
AV_PIX_FMT_BGR24, AV_PIX_FMT_BGRA, AV_PIX_FMT_RGB555LE, AV_PIX_FMT_GRAY8,
AV_PIX_FMT_NONE
},
};