blob: 666c6b73510411de75b6ee44e96af90e390e5828
| 1 | /* |
| 2 | * QuickTime palette handling |
| 3 | * Copyright (c) 2001 Fabrice Bellard |
| 4 | * Copyright (c) 2009 Baptiste Coudurier <baptiste dot coudurier at gmail dot com> |
| 5 | * Copyright (c) 2015 Mats Peterson |
| 6 | * |
| 7 | * This file is part of FFmpeg. |
| 8 | * |
| 9 | * FFmpeg is free software; you can redistribute it and/or |
| 10 | * modify it under the terms of the GNU Lesser General Public |
| 11 | * License as published by the Free Software Foundation; either |
| 12 | * version 2.1 of the License, or (at your option) any later version. |
| 13 | * |
| 14 | * FFmpeg is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 17 | * Lesser General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU Lesser General Public |
| 20 | * License along with FFmpeg; if not, write to the Free Software |
| 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 22 | */ |
| 23 | |
| 24 | #include <stdio.h> |
| 25 | #include <stdint.h> |
| 26 | |
| 27 | #include "avformat.h" |
| 28 | #include "libavutil/intreadwrite.h" |
| 29 | #include "qtpalette.h" |
| 30 | |
| 31 | int ff_get_qtpalette(int codec_id, AVIOContext *pb, uint32_t *palette) |
| 32 | { |
| 33 | int tmp, bit_depth, color_table_id, greyscale, i; |
| 34 | |
| 35 | avio_seek(pb, 82, SEEK_CUR); |
| 36 | |
| 37 | /* Get the bit depth and greyscale state */ |
| 38 | tmp = avio_rb16(pb); |
| 39 | bit_depth = tmp & 0x1F; |
| 40 | greyscale = tmp & 0x20; |
| 41 | |
| 42 | /* Get the color table ID */ |
| 43 | color_table_id = avio_rb16(pb); |
| 44 | |
| 45 | /* Do not create a greyscale palette for Cinepak */ |
| 46 | if (greyscale && codec_id == AV_CODEC_ID_CINEPAK) |
| 47 | return 0; |
| 48 | |
| 49 | /* If the depth is 1, 2, 4, or 8 bpp, file is palettized. */ |
| 50 | if ((bit_depth == 1 || bit_depth == 2 || bit_depth == 4 || bit_depth == 8)) { |
| 51 | uint32_t color_count, color_start, color_end; |
| 52 | uint32_t a, r, g, b; |
| 53 | |
| 54 | /* Ignore the greyscale bit for 1-bit video and sample |
| 55 | * descriptions containing a color table. */ |
| 56 | if (greyscale && bit_depth > 1 && color_table_id) { |
| 57 | int color_index, color_dec; |
| 58 | /* compute the greyscale palette */ |
| 59 | color_count = 1 << bit_depth; |
| 60 | color_index = 255; |
| 61 | color_dec = 256 / (color_count - 1); |
| 62 | for (i = 0; i < color_count; i++) { |
| 63 | r = g = b = color_index; |
| 64 | palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | (b); |
| 65 | color_index -= color_dec; |
| 66 | if (color_index < 0) |
| 67 | color_index = 0; |
| 68 | } |
| 69 | } else if (color_table_id) { |
| 70 | /* The color table ID is non-zero. Interpret this as |
| 71 | * being -1, which means use the default Macintosh |
| 72 | * color table */ |
| 73 | const uint8_t *color_table; |
| 74 | color_count = 1 << bit_depth; |
| 75 | if (bit_depth == 1) |
| 76 | color_table = ff_qt_default_palette_2; |
| 77 | else if (bit_depth == 2) |
| 78 | color_table = ff_qt_default_palette_4; |
| 79 | else if (bit_depth == 4) |
| 80 | color_table = ff_qt_default_palette_16; |
| 81 | else |
| 82 | color_table = ff_qt_default_palette_256; |
| 83 | for (i = 0; i < color_count; i++) { |
| 84 | r = color_table[i * 3 + 0]; |
| 85 | g = color_table[i * 3 + 1]; |
| 86 | b = color_table[i * 3 + 2]; |
| 87 | palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | (b); |
| 88 | } |
| 89 | } else { |
| 90 | /* The color table ID is 0; the color table is in the sample |
| 91 | * description */ |
| 92 | color_start = avio_rb32(pb); |
| 93 | avio_rb16(pb); /* color table flags */ |
| 94 | color_end = avio_rb16(pb); |
| 95 | if ((color_start <= 255) && (color_end <= 255)) { |
| 96 | for (i = color_start; i <= color_end; i++) { |
| 97 | /* each A, R, G, or B component is 16 bits; |
| 98 | * only use the top 8 bits */ |
| 99 | a = avio_r8(pb); |
| 100 | avio_r8(pb); |
| 101 | r = avio_r8(pb); |
| 102 | avio_r8(pb); |
| 103 | g = avio_r8(pb); |
| 104 | avio_r8(pb); |
| 105 | b = avio_r8(pb); |
| 106 | avio_r8(pb); |
| 107 | palette[i] = (a << 24 ) | (r << 16) | (g << 8) | (b); |
| 108 | } |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | return 1; |
| 113 | } |
| 114 | |
| 115 | return 0; |
| 116 | } |
| 117 |