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Diffstat (limited to 'contrib/ffmpeg/libavcodec/targaenc.c')
| -rw-r--r-- | contrib/ffmpeg/libavcodec/targaenc.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/contrib/ffmpeg/libavcodec/targaenc.c b/contrib/ffmpeg/libavcodec/targaenc.c new file mode 100644 index 000000000..8b36e1d3d --- /dev/null +++ b/contrib/ffmpeg/libavcodec/targaenc.c @@ -0,0 +1,199 @@ +/* + * Targa (.tga) image encoder + * Copyright (c) 2007 Bobby Bingham + * + * This file is part of FFmpeg. + * + * FFmpeg 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. + * + * FFmpeg 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 FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + */ +#include "avcodec.h" + +/** + * Count up to 127 consecutive pixels which are either all the same or + * all differ from the previous and next pixels. + * @param start Pointer to the first pixel + * @param len Maximum number of pixels + * @param bpp Bytes per pixel + * @param same 1 if searching for identical pixel values. 0 for differing + * @return Number of matching consecutive pixels found + */ +static int count_pixels(uint8_t *start, int len, int bpp, int same) +{ + uint8_t *pos; + int count = 1; + + for(pos = start + bpp; count < FFMIN(128, len); pos += bpp, count ++) { + if(same != !memcmp(pos-bpp, pos, bpp)) { + if(!same) { + /* if bpp == 1, then 0 1 1 0 is more efficiently encoded as a single + * raw block of pixels. for larger bpp, RLE is as good or better */ + if(bpp == 1 && count + 1 < FFMIN(128, len) && *pos != *(pos+1)) + continue; + + /* if RLE can encode the next block better than as a raw block, + * back up and leave _all_ the identical pixels for RLE */ + count --; + } + break; + } + } + + return count; +} + +/** + * 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, AVFrame *pic, + int bpp, int w, int h) +{ + int count, x, y; + uint8_t *ptr, *line, *out; + + out = outbuf; + line = pic->data[0]; + + for(y = 0; y < h; y ++) { + ptr = line; + + for(x = 0; x < w; x += count) { + /* see if we can encode the next set of pixels with RLE */ + if((count = count_pixels(ptr, w-x, bpp, 1)) > 1) { + if(out + bpp + 1 > outbuf + out_size) return -1; + *out++ = 0x80 | (count - 1); + memcpy(out, ptr, bpp); + out += bpp; + } else { + /* fall back on uncompressed */ + count = count_pixels(ptr, w-x, bpp, 0); + *out++ = count - 1; + + if(out + bpp*count > outbuf + out_size) return -1; + memcpy(out, ptr, bpp * count); + out += bpp * count; + } + ptr += count * bpp; + } + + line += pic->linesize[0]; + } + + return out - outbuf; +} + +static int targa_encode_normal(uint8_t *outbuf, 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, + unsigned char *outbuf, + int buf_size, void *data){ + AVFrame *p = data; + int bpp, picsize, datasize; + uint8_t *out; + + if(avctx->width > 0xffff || avctx->height > 0xffff) { + av_log(avctx, AV_LOG_ERROR, "image dimensions too large\n"); + return -1; + } + picsize = avpicture_get_size(avctx->pix_fmt, avctx->width, avctx->height); + if(buf_size < picsize + 45) { + av_log(avctx, AV_LOG_ERROR, "encoded frame too large\n"); + return -1; + } + + p->pict_type= FF_I_TYPE; + p->key_frame= 1; + + /* zero out the header and only set applicable fields */ + memset(outbuf, 0, 11); + AV_WL16(outbuf+12, avctx->width); + AV_WL16(outbuf+14, avctx->height); + outbuf[17] = 0x20; /* origin is top-left. no alpha */ + + /* TODO: support alpha channel */ + switch(avctx->pix_fmt) { + case PIX_FMT_GRAY8: + outbuf[2] = 3; /* uncompressed grayscale image */ + outbuf[16] = 8; /* bpp */ + break; + case PIX_FMT_RGB555: + outbuf[2] = 2; /* uncompresses true-color image */ + outbuf[16] = 16; /* bpp */ + break; + case PIX_FMT_BGR24: + outbuf[2] = 2; /* uncompressed true-color image */ + outbuf[16] = 24; /* bpp */ + break; + default: + return -1; + } + bpp = outbuf[16] >> 3; + + out = outbuf + 18; /* skip past the header we just output */ + + /* try RLE compression */ + 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) + outbuf[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); + + return out + 26 - outbuf; +} + +static int targa_encode_init(AVCodecContext *avctx) +{ + return 0; +} + +AVCodec targa_encoder = { + .name = "targa", + .type = CODEC_TYPE_VIDEO, + .id = CODEC_ID_TARGA, + .priv_data_size = 0, + .init = targa_encode_init, + .encode = targa_encode_frame, + .pix_fmts= (enum PixelFormat[]){PIX_FMT_BGR24, PIX_FMT_RGB555, PIX_FMT_GRAY8, -1}, +}; |