| /* |
| * huffyuv codec for libavcodec |
| * |
| * Copyright (c) 2002-2014 Michael Niedermayer <michaelni@gmx.at> |
| * |
| * see https://multimedia.cx/huffyuv.txt for a description of |
| * the algorithm used |
| * |
| * 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 |
| */ |
| |
| /** |
| * @file |
| * huffyuv codec for libavcodec. |
| */ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include "libavutil/error.h" |
| #include "libavutil/log.h" |
| #include "libavutil/macros.h" |
| |
| #include "huffyuv.h" |
| |
| int ff_huffyuv_generate_bits_table(uint32_t *dst, const uint8_t *len_table, int n) |
| { |
| int lens[33] = { 0 }; |
| uint32_t codes[33]; |
| |
| for (int i = 0; i < n; i++) |
| lens[len_table[i]]++; |
| |
| codes[32] = 0; |
| for (int i = FF_ARRAY_ELEMS(lens) - 1; i > 0; i--) { |
| if ((lens[i] + codes[i]) & 1) { |
| av_log(NULL, AV_LOG_ERROR, "Error generating huffman table\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| codes[i - 1] = (lens[i] + codes[i]) >> 1; |
| } |
| for (int i = 0; i < n; i++) { |
| if (len_table[i]) |
| dst[i] = codes[len_table[i]]++; |
| } |
| return 0; |
| } |