int ff_get_qtpalette(int codec_id, AVIOContext *pb, uint32_t *palette) { int tmp, bit_depth, color_table_id, greyscale, i; avio_seek(pb, 82, SEEK_CUR); /* Get the bit depth and greyscale state */ tmp = avio_rb16(pb); bit_depth = tmp & 0x1F; greyscale = tmp & 0x20; /* Get the color table ID */ color_table_id = avio_rb16(pb); /* Do not create a greyscale palette for Cinepak */ if (greyscale && codec_id == AV_CODEC_ID_CINEPAK) return 0; /* If the depth is 1, 2, 4, or 8 bpp, file is palettized. */ if ((bit_depth == 1 || bit_depth == 2 || bit_depth == 4 || bit_depth == 8)) { int color_count, color_start, color_end; uint32_t a, r, g, b; /* Ignore the greyscale bit for 1-bit video and sample * descriptions containing a color table. */ if (greyscale && bit_depth > 1 && color_table_id) { int color_index, color_dec; /* compute the greyscale palette */ color_count = 1 << bit_depth; color_index = 255; color_dec = 256 / (color_count - 1); for (i = 0; i < color_count; i++) { r = g = b = color_index; palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | (b); color_index -= color_dec; if (color_index < 0) color_index = 0; } } else if (color_table_id) { /* The color table ID is non-zero. Interpret this as * being -1, which means use the default Macintosh * color table */ const uint8_t *color_table; color_count = 1 << bit_depth; if (bit_depth == 1) color_table = ff_qt_default_palette_2; else if (bit_depth == 2) color_table = ff_qt_default_palette_4; else if (bit_depth == 4) color_table = ff_qt_default_palette_16; else color_table = ff_qt_default_palette_256; for (i = 0; i < color_count; i++) { r = color_table[i * 3 + 0]; g = color_table[i * 3 + 1]; b = color_table[i * 3 + 2]; palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | (b); } } else { /* The color table ID is 0; the color table is in the sample * description */ color_start = avio_rb32(pb); avio_rb16(pb); /* color table flags */ color_end = avio_rb16(pb); if ((color_start <= 255) && (color_end <= 255)) { for (i = color_start; i <= color_end; i++) { /* each A, R, G, or B component is 16 bits; * only use the top 8 bits */ a = avio_r8(pb); avio_r8(pb); r = avio_r8(pb); avio_r8(pb); g = avio_r8(pb); avio_r8(pb); b = avio_r8(pb); avio_r8(pb); palette[i] = (a << 24 ) | (r << 16) | (g << 8) | (b); } } } return 1; } return 0; }