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jpeg: fix default quantization tables.

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Two elements in the luminance quantization table were wrong. So,
gst_jpeg_get_default_quantization_tables() now reconstructs tables
in zig-zag order from the standard ones (Tables K.1 and K.2).
This commit is contained in:
Gwenole Beauchesne 2012-08-02 18:27:48 +02:00
parent f88323857d
commit 0b3d75f14b
1 changed files with 55 additions and 34 deletions
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89
gst-libs/gst/codecparsers/gstjpegparser.c
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@ -83,40 +83,45 @@ ensure_debug_category (void)
} G_STMT_END
/* CCITT T.81, Annex K.1 Quantization tables for luminance and chrominance components */
/* only for 8-bit per sample image */
/* Table used to address an 8x8 matrix in zig-zag order */
/* *INDENT-OFF* */
static const GstJpegQuantTables default_quant_tables_zigzag = {
.quant_tables = {
/* luma */
{0, {0x10, 0x0b, 0x0c, 0x0e, 0x0c, 0x0a, 0x10, 0x0e,
0x0d, 0x0e, 0x12, 0x11, 0x10, 0x13, 0x18, 0x27,
0x1a, 0x18, 0x16, 0x16, 0x18, 0x31, 0x23, 0x25,
0x1d, 0x28, 0x3a, 0x33, 0x3d, 0x3c, 0x39, 0x33,
0x38, 0x37, 0x40, 0x48, 0x5c, 0x4e, 0x40, 0xa8,
0x57, 0x45, 0x37, 0x38, 0x50, 0x6d, 0xb5, 0x57,
0x5f, 0x62, 0x67, 0x68, 0x67, 0x3e, 0x4d, 0x71,
0x79, 0x70, 0x64, 0x78, 0x5c, 0x65, 0x67, 0x63}, TRUE},
/* chroma */
{0, {0x11, 0x12, 0x12, 0x18, 0x15, 0x18, 0x2f, 0x1a,
0x1a, 0x2f, 0x63, 0x42, 0x38, 0x42, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63}, TRUE},
/* chroma */
{0, {0x11, 0x12, 0x12, 0x18, 0x15, 0x18, 0x2f, 0x1a,
0x1a, 0x2f, 0x63, 0x42, 0x38, 0x42, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63}, TRUE},
{0,}
}
static const guint8 zigzag_index[64] = {
0, 1, 8, 16, 9, 2, 3, 10,
17, 24, 32, 25, 18, 11, 4, 5,
12, 19, 26, 33, 40, 48, 41, 34,
27, 20, 13, 6, 7, 14, 21, 28,
35, 42, 49, 56, 57, 50, 43, 36,
29, 22, 15, 23, 30, 37, 44, 51,
58, 59, 52, 45, 38, 31, 39, 46,
53, 60, 61, 54, 47, 55, 62, 63
};
/* *INDENT-ON* */
/* Table K.1 - Luminance quantization table */
/* *INDENT-OFF* */
static const guint8 default_luminance_quant_table[64] = {
16, 11, 10, 16, 24, 40, 51, 61,
12, 12, 14, 19, 26, 58, 60, 55,
14, 13, 16, 24, 40, 57, 69, 56,
14, 17, 22, 29, 51, 87, 80, 62,
18, 22, 37, 56, 68, 109, 103, 77,
24, 35, 55, 64, 81, 104, 113, 92,
49, 64, 78, 87, 103, 121, 120, 101,
72, 92, 95, 98, 112, 100, 103, 99
};
/* *INDENT-ON* */
/* Table K.2 - Chrominance quantization table */
/* *INDENT-OFF* */
static const guint8 default_chrominance_quant_table[64] = {
17, 18, 24, 47, 99, 99, 99, 99,
18, 21, 26, 66, 99, 99, 99, 99,
24, 26, 56, 99, 99, 99, 99, 99,
47, 66, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99
};
/* *INDENT-ON* */
@ -505,12 +510,28 @@ gst_jpeg_get_default_huffman_tables (GstJpegHuffmanTables * huf_tables)
sizeof (huf_tables->ac_tables[2]));
}
static void
build_quant_table (GstJpegQuantTable * quant_table, const guint8 values[64])
{
guint i;
for (i = 0; i < 64; i++)
quant_table->quant_table[i] = values[zigzag_index[i]];
quant_table->quant_precision = 0; /* Pq = 0 (8-bit precision) */
quant_table->valid = TRUE;
}
void
gst_jpeg_get_default_quantization_tables (GstJpegQuantTables * quant_tables)
{
g_assert (quant_tables);
memcpy (quant_tables, &default_quant_tables_zigzag, sizeof (*quant_tables));
build_quant_table (&quant_tables->quant_tables[0],
default_luminance_quant_table);
build_quant_table (&quant_tables->quant_tables[1],
default_chrominance_quant_table);
build_quant_table (&quant_tables->quant_tables[2],
default_chrominance_quant_table);
}
gboolean