LCOV - code coverage report
Current view: top level - libavcodec - rle.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 26 27 96.3 %
Date: 2017-12-17 04:34:43 Functions: 2 2 100.0 %

          Line data    Source code
       1             : /*
       2             :  * RLE 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/common.h"
      23             : 
      24             : #include "avcodec.h"
      25             : #include "rle.h"
      26             : 
      27      239474 : int ff_rle_count_pixels(const uint8_t *start, int len, int bpp, int same)
      28             : {
      29             :     const uint8_t *pos;
      30      239474 :     int count = 1;
      31             : 
      32     9354597 :     for (pos = start + bpp; count < FFMIN(127, len); pos += bpp, count++) {
      33     9285053 :         if (same != !memcmp(pos - bpp, pos, bpp)) {
      34      268613 :             if (!same) {
      35             :                 /* if bpp == 1, then 0 1 1 0 is more efficiently encoded as a
      36             :                  * single raw block of pixels. For larger bpp, RLE is as good
      37             :                  * or better */
      38      129548 :                 if (bpp == 1 && count + 1 < FFMIN(127, len) && *pos != *(pos + 1))
      39       98683 :                     continue;
      40             : 
      41             :                 /* if RLE can encode the next block better than as a raw block,
      42             :                  * back up and leave _all_ the identical pixels for RLE */
      43       30865 :                 count--;
      44             :             }
      45      169930 :             break;
      46             :         }
      47             :     }
      48             : 
      49      239474 :     return count;
      50             : }
      51             : 
      52        7488 : int ff_rle_encode(uint8_t *outbuf, int out_size, const uint8_t *ptr, int bpp,
      53             :                   int w, int add_rep, int xor_rep, int add_raw, int xor_raw)
      54             : {
      55             :     int count, x;
      56        7488 :     uint8_t *out = outbuf;
      57             : 
      58       60989 :     for (x = 0; x < w; x += count) {
      59             :         /* see if we can encode the next set of pixels with RLE */
      60       53514 :         if ((count = ff_rle_count_pixels(ptr, w - x, bpp, 1)) > 1) {
      61        5546 :             if (out + bpp + 1 > outbuf + out_size)
      62           0 :                 return -1;
      63             : 
      64        5546 :             *out++ = (count ^ xor_rep) + add_rep;
      65        5546 :             memcpy(out, ptr, bpp);
      66        5546 :             out += bpp;
      67             :         } else {
      68             :             /* fall back on uncompressed */
      69       47968 :             count = ff_rle_count_pixels(ptr, w - x, bpp, 0);
      70       47968 :             if (out + bpp * count >= outbuf + out_size)
      71          13 :                 return -1;
      72             : 
      73       47955 :             *out++ = (count ^ xor_raw) + add_raw;
      74       47955 :             memcpy(out, ptr, bpp * count);
      75       47955 :             out += bpp * count;
      76             :         }
      77             : 
      78       53501 :         ptr += count * bpp;
      79             :     }
      80             : 
      81        7475 :     return out - outbuf;
      82             : }

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