gstreamer/gst-libs/gst/codecparsers/gstjpegparser.c
Gwenole Beauchesne f88323857d jpeg: compute default Huffman tables.
... instead of having them pre-calculated. This saves around 1.5 KB
of data in the DSO but requires gst_jpeg_get_default_huffman_tables()
to do more work. Though, the client application may have to call that
function at most once, only.
2012-08-02 15:17:57 +02:00

589 lines
21 KiB
C

/*
* gstjpegparser.c - JPEG parser
*
* Copyright (C) 2011-2012 Intel Corporation
*
* This library 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.
*
* This library 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 this library; if not, write to the Free
* Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
#include <string.h>
#include <gst/base/gstbytereader.h>
#include "gstjpegparser.h"
#ifndef GST_DISABLE_GST_DEBUG
#define GST_CAT_DEFAULT ensure_debug_category()
static GstDebugCategory *
ensure_debug_category (void)
{
static gsize cat_gonce = 0;
if (g_once_init_enter (&cat_gonce)) {
gsize cat_done;
cat_done = (gsize) _gst_debug_category_new ("codecparsers_jpeg", 0,
"GstJpegCodecParser");
g_once_init_leave (&cat_gonce, cat_done);
}
return (GstDebugCategory *) cat_gonce;
}
#else
#define ensure_debug_category() /* NOOP */
#endif /* GST_DISABLE_GST_DEBUG */
#define DEBUG_PRINT_COMMENT 0
#define READ_UINT8(reader, val) G_STMT_START { \
if (!gst_byte_reader_get_uint8 ((reader), &(val))) { \
GST_WARNING ("failed to read uint8"); \
goto failed; \
} \
} G_STMT_END
#define READ_UINT16(reader, val) G_STMT_START { \
if (!gst_byte_reader_get_uint16_be ((reader), &(val))) { \
GST_WARNING ("failed to read uint16"); \
goto failed; \
} \
} G_STMT_END
#define READ_BYTES(reader, buf, length) G_STMT_START { \
const guint8 *vals; \
if (!gst_byte_reader_get_data (reader, length, &vals)) { \
GST_WARNING ("failed to read bytes, size:%d", length); \
goto failed; \
} \
memcpy (buf, vals, length); \
} G_STMT_END
#define U_READ_UINT8(reader, val) G_STMT_START { \
(val) = gst_byte_reader_get_uint8_unchecked(reader); \
} G_STMT_END
#define U_READ_UINT16(reader, val) G_STMT_START { \
(val) = gst_byte_reader_get_uint16_be_unchecked(reader); \
} G_STMT_END
/* CCITT T.81, Annex K.1 Quantization tables for luminance and chrominance components */
/* only for 8-bit per sample image */
/* *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,}
}
};
/* *INDENT-ON* */
typedef struct _GstJpegHuffmanTableEntry GstJpegHuffmanTableEntry;
struct _GstJpegHuffmanTableEntry
{
guint8 value; /* category */
guint8 length; /* code length in bits */
};
/* Table K.3 - Table for luminance DC coefficient differences */
static const GstJpegHuffmanTableEntry default_luminance_dc_table[] = {
{0x00, 2}, {0x01, 3}, {0x02, 3}, {0x03, 3}, {0x04, 3}, {0x05, 3},
{0x06, 4}, {0x07, 5}, {0x08, 6}, {0x09, 7}, {0x0a, 8}, {0x0b, 9}
};
/* Table K.4 - Table for chrominance DC coefficient differences */
static const GstJpegHuffmanTableEntry default_chrominance_dc_table[] = {
{0x00, 2}, {0x01, 2}, {0x02, 2}, {0x03, 3}, {0x04, 4}, {0x05, 5},
{0x06, 6}, {0x07, 7}, {0x08, 8}, {0x09, 9}, {0x0a, 10}, {0x0b, 11}
};
/* Table K.5 - Table for luminance AC coefficients */
/* *INDENT-OFF* */
static const GstJpegHuffmanTableEntry default_luminance_ac_table[] = {
{0x00, 4}, {0x01, 2}, {0x02, 2}, {0x03, 3}, {0x04, 4}, {0x05, 5},
{0x06, 7}, {0x07, 8}, {0x08, 10}, {0x09, 16}, {0x0a, 16}, {0x11, 4},
{0x12, 5}, {0x13, 7}, {0x14, 9}, {0x15, 11}, {0x16, 16}, {0x17, 16},
{0x18, 16}, {0x19, 16}, {0x1a, 16}, {0x21, 5}, {0x22, 8}, {0x23, 10},
{0x24, 12}, {0x25, 16}, {0x26, 16}, {0x27, 16}, {0x28, 16}, {0x29, 16},
{0x2a, 16}, {0x31, 6}, {0x32, 9}, {0x33, 12}, {0x34, 16}, {0x35, 16},
{0x36, 16}, {0x37, 16}, {0x38, 16}, {0x39, 16}, {0x3a, 16}, {0x41, 6},
{0x42, 10}, {0x43, 16}, {0x44, 16}, {0x45, 16}, {0x46, 16}, {0x47, 16},
{0x48, 16}, {0x49, 16}, {0x4a, 16}, {0x51, 7}, {0x52, 11}, {0x53, 16},
{0x54, 16}, {0x55, 16}, {0x56, 16}, {0x57, 16}, {0x58, 16}, {0x59, 16},
{0x5a, 16}, {0x61, 7}, {0x62, 12}, {0x63, 16}, {0x64, 16}, {0x65, 16},
{0x66, 16}, {0x67, 16}, {0x68, 16}, {0x69, 16}, {0x6a, 16}, {0x71, 8},
{0x72, 12}, {0x73, 16}, {0x74, 16}, {0x75, 16}, {0x76, 16}, {0x77, 16},
{0x78, 16}, {0x79, 16}, {0x7a, 16}, {0x81, 9}, {0x82, 15}, {0x83, 16},
{0x84, 16}, {0x85, 16}, {0x86, 16}, {0x87, 16}, {0x88, 16}, {0x89, 16},
{0x8a, 16}, {0x91, 9}, {0x92, 16}, {0x93, 16}, {0x94, 16}, {0x95, 16},
{0x96, 16}, {0x97, 16}, {0x98, 16}, {0x99, 16}, {0x9a, 16}, {0xa1, 9},
{0xa2, 16}, {0xa3, 16}, {0xa4, 16}, {0xa5, 16}, {0xa6, 16}, {0xa7, 16},
{0xa8, 16}, {0xa9, 16}, {0xaa, 16}, {0xb1, 10}, {0xb2, 16}, {0xb3, 16},
{0xb4, 16}, {0xb5, 16}, {0xb6, 16}, {0xb7, 16}, {0xb8, 16}, {0xb9, 16},
{0xba, 16}, {0xc1, 10}, {0xc2, 16}, {0xc3, 16}, {0xc4, 16}, {0xc5, 16},
{0xc6, 16}, {0xc7, 16}, {0xc8, 16}, {0xc9, 16}, {0xca, 16}, {0xd1, 11},
{0xd2, 16}, {0xd3, 16}, {0xd4, 16}, {0xd5, 16}, {0xd6, 16}, {0xd7, 16},
{0xd8, 16}, {0xd9, 16}, {0xda, 16}, {0xe1, 16}, {0xe2, 16}, {0xe3, 16},
{0xe4, 16}, {0xe5, 16}, {0xe6, 16}, {0xe7, 16}, {0xe8, 16}, {0xe9, 16},
{0xea, 16}, {0xf0, 11}, {0xf1, 16}, {0xf2, 16}, {0xf3, 16}, {0xf4, 16},
{0xf5, 16}, {0xf6, 16}, {0xf7, 16}, {0xf8, 16}, {0xf9, 16}, {0xfa, 16}
};
/* *INDENT-ON* */
/* Table K.6 - Table for chrominance AC coefficients */
/* *INDENT-OFF* */
static const GstJpegHuffmanTableEntry default_chrominance_ac_table[] = {
{0x00, 2}, {0x01, 2}, {0x02, 3}, {0x03, 4}, {0x04, 5}, {0x05, 5},
{0x06, 6}, {0x07, 7}, {0x08, 9}, {0x09, 10}, {0x0a, 12}, {0x11, 4},
{0x12, 6}, {0x13, 8}, {0x14, 9}, {0x15, 11}, {0x16, 12}, {0x17, 16},
{0x18, 16}, {0x19, 16}, {0x1a, 16}, {0x21, 5}, {0x22, 8}, {0x23, 10},
{0x24, 12}, {0x25, 15}, {0x26, 16}, {0x27, 16}, {0x28, 16}, {0x29, 16},
{0x2a, 16}, {0x31, 5}, {0x32, 8}, {0x33, 10}, {0x34, 12}, {0x35, 16},
{0x36, 16}, {0x37, 16}, {0x38, 16}, {0x39, 16}, {0x3a, 16}, {0x41, 6},
{0x42, 9}, {0x43, 16}, {0x44, 16}, {0x45, 16}, {0x46, 16}, {0x47, 16},
{0x48, 16}, {0x49, 16}, {0x4a, 16}, {0x51, 6}, {0x52, 10}, {0x53, 16},
{0x54, 16}, {0x55, 16}, {0x56, 16}, {0x57, 16}, {0x58, 16}, {0x59, 16},
{0x5a, 16}, {0x61, 7}, {0x62, 11}, {0x63, 16}, {0x64, 16}, {0x65, 16},
{0x66, 16}, {0x67, 16}, {0x68, 16}, {0x69, 16}, {0x6a, 16}, {0x71, 7},
{0x72, 11}, {0x73, 16}, {0x74, 16}, {0x75, 16}, {0x76, 16}, {0x77, 16},
{0x78, 16}, {0x79, 16}, {0x7a, 16}, {0x81, 8}, {0x82, 16}, {0x83, 16},
{0x84, 16}, {0x85, 16}, {0x86, 16}, {0x87, 16}, {0x88, 16}, {0x89, 16},
{0x8a, 16}, {0x91, 9}, {0x92, 16}, {0x93, 16}, {0x94, 16}, {0x95, 16},
{0x96, 16}, {0x97, 16}, {0x98, 16}, {0x99, 16}, {0x9a, 16}, {0xa1, 9},
{0xa2, 16}, {0xa3, 16}, {0xa4, 16}, {0xa5, 16}, {0xa6, 16}, {0xa7, 16},
{0xa8, 16}, {0xa9, 16}, {0xaa, 16}, {0xb1, 9}, {0xb2, 16}, {0xb3, 16},
{0xb4, 16}, {0xb5, 16}, {0xb6, 16}, {0xb7, 16}, {0xb8, 16}, {0xb9, 16},
{0xba, 16}, {0xc1, 9}, {0xc2, 16}, {0xc3, 16}, {0xc4, 16}, {0xc5, 16},
{0xc6, 16}, {0xc7, 16}, {0xc8, 16}, {0xc9, 16}, {0xca, 16}, {0xd1, 11},
{0xd2, 16}, {0xd3, 16}, {0xd4, 16}, {0xd5, 16}, {0xd6, 16}, {0xd7, 16},
{0xd8, 16}, {0xd9, 16}, {0xda, 16}, {0xe1, 14}, {0xe2, 16}, {0xe3, 16},
{0xe4, 16}, {0xe5, 16}, {0xe6, 16}, {0xe7, 16}, {0xe8, 16}, {0xe9, 16},
{0xea, 16}, {0xf0, 10}, {0xf1, 15}, {0xf2, 16}, {0xf3, 16}, {0xf4, 16},
{0xf5, 16}, {0xf6, 16}, {0xf7, 16}, {0xf8, 16}, {0xf9, 16}, {0xfa, 16}
};
/* *INDENT-ON* */
static inline gboolean
jpeg_parse_to_next_marker (GstByteReader * br, guint8 * marker)
{
gint ofs;
ofs = gst_jpeg_scan_for_marker_code (br->data, br->size, br->byte);
if (ofs < 0)
return FALSE;
if (marker)
*marker = br->data[ofs + 1];
gst_byte_reader_skip (br, ofs - br->byte + 2);
return TRUE;
}
gint
gst_jpeg_scan_for_marker_code (const guint8 * data, gsize size, guint offset)
{
guint i;
g_return_val_if_fail (data != NULL, -1);
g_return_val_if_fail (size > offset, -1);
for (i = offset; i < size - 1;) {
if (data[i] != 0xff)
i++;
else {
const guint8 v = data[i + 1];
if (v >= 0xc0 && v <= 0xfe)
return i;
i += 2;
}
}
return -1;
}
gboolean
gst_jpeg_parse_frame_hdr (GstJpegFrameHdr * frame_hdr,
const guint8 * data, gsize size, guint offset)
{
GstByteReader br;
guint16 length;
guint8 val;
guint i;
g_return_val_if_fail (frame_hdr != NULL, FALSE);
g_return_val_if_fail (data != NULL, FALSE);
g_return_val_if_fail (size > offset, FALSE);
size -= offset;
gst_byte_reader_init (&br, &data[offset], size);
g_return_val_if_fail (size >= 8, FALSE);
U_READ_UINT16 (&br, length); /* Lf */
g_return_val_if_fail (size >= length, FALSE);
U_READ_UINT8 (&br, frame_hdr->sample_precision);
U_READ_UINT16 (&br, frame_hdr->height);
U_READ_UINT16 (&br, frame_hdr->width);
U_READ_UINT8 (&br, frame_hdr->num_components);
g_return_val_if_fail (frame_hdr->num_components <=
GST_JPEG_MAX_SCAN_COMPONENTS, FALSE);
length -= 8;
g_return_val_if_fail (length >= 3 * frame_hdr->num_components, FALSE);
for (i = 0; i < frame_hdr->num_components; i++) {
U_READ_UINT8 (&br, frame_hdr->components[i].identifier);
U_READ_UINT8 (&br, val);
frame_hdr->components[i].horizontal_factor = (val >> 4) & 0x0F;
frame_hdr->components[i].vertical_factor = (val & 0x0F);
U_READ_UINT8 (&br, frame_hdr->components[i].quant_table_selector);
g_return_val_if_fail ((frame_hdr->components[i].horizontal_factor <= 4 &&
frame_hdr->components[i].vertical_factor <= 4 &&
frame_hdr->components[i].quant_table_selector < 4), FALSE);
length -= 3;
}
g_assert (length == 0);
return TRUE;
}
gboolean
gst_jpeg_parse_scan_hdr (GstJpegScanHdr * scan_hdr,
const guint8 * data, gsize size, guint offset)
{
GstByteReader br;
guint16 length;
guint8 val;
guint i;
g_return_val_if_fail (scan_hdr != NULL, FALSE);
g_return_val_if_fail (data != NULL, FALSE);
g_return_val_if_fail (size > offset, FALSE);
size -= offset;
gst_byte_reader_init (&br, &data[offset], size);
g_return_val_if_fail (size >= 3, FALSE);
U_READ_UINT16 (&br, length); /* Ls */
g_return_val_if_fail (size >= length, FALSE);
U_READ_UINT8 (&br, scan_hdr->num_components);
g_return_val_if_fail (scan_hdr->num_components <=
GST_JPEG_MAX_SCAN_COMPONENTS, FALSE);
length -= 3;
g_return_val_if_fail (length >= 2 * scan_hdr->num_components, FALSE);
for (i = 0; i < scan_hdr->num_components; i++) {
U_READ_UINT8 (&br, scan_hdr->components[i].component_selector);
U_READ_UINT8 (&br, val);
scan_hdr->components[i].dc_selector = (val >> 4) & 0x0F;
scan_hdr->components[i].ac_selector = val & 0x0F;
g_return_val_if_fail ((scan_hdr->components[i].dc_selector < 4 &&
scan_hdr->components[i].ac_selector < 4), FALSE);
length -= 2;
}
/* FIXME: Ss, Se, Ah, Al */
g_assert (length == 3);
return TRUE;
}
gboolean
gst_jpeg_parse_huffman_table (GstJpegHuffmanTables * huf_tables,
const guint8 * data, gsize size, guint offset)
{
GstByteReader br;
GstJpegHuffmanTable *huf_table;
guint16 length;
guint8 val, table_class, table_index;
guint32 value_count;
guint i;
g_return_val_if_fail (huf_tables != NULL, FALSE);
g_return_val_if_fail (data != NULL, FALSE);
g_return_val_if_fail (size > offset, FALSE);
size -= offset;
gst_byte_reader_init (&br, &data[offset], size);
g_return_val_if_fail (size >= 2, FALSE);
U_READ_UINT16 (&br, length); /* Lh */
g_return_val_if_fail (size >= length, FALSE);
while (gst_byte_reader_get_remaining (&br)) {
U_READ_UINT8 (&br, val);
table_class = ((val >> 4) & 0x0F);
table_index = (val & 0x0F);
g_return_val_if_fail (table_index < GST_JPEG_MAX_SCAN_COMPONENTS, FALSE);
if (table_class == 0) {
huf_table = &huf_tables->dc_tables[table_index];
} else {
huf_table = &huf_tables->ac_tables[table_index];
}
READ_BYTES (&br, huf_table->huf_bits, 16);
value_count = 0;
for (i = 0; i < 16; i++)
value_count += huf_table->huf_bits[i];
READ_BYTES (&br, huf_table->huf_values, value_count);
huf_table->valid = TRUE;
}
return TRUE;
failed:
return FALSE;
}
gboolean
gst_jpeg_parse_quant_table (GstJpegQuantTables * quant_tables,
const guint8 * data, gsize size, guint offset)
{
GstByteReader br;
GstJpegQuantTable *quant_table;
guint16 length;
guint8 val, table_index;
guint i;
g_return_val_if_fail (quant_tables != NULL, FALSE);
g_return_val_if_fail (data != NULL, FALSE);
g_return_val_if_fail (size > offset, FALSE);
size -= offset;
gst_byte_reader_init (&br, &data[offset], size);
g_return_val_if_fail (size >= 2, FALSE);
U_READ_UINT16 (&br, length); /* Lq */
g_return_val_if_fail (size >= length, FALSE);
while (gst_byte_reader_get_remaining (&br)) {
U_READ_UINT8 (&br, val);
table_index = (val & 0x0f);
g_return_val_if_fail (table_index < GST_JPEG_MAX_SCAN_COMPONENTS, FALSE);
quant_table = &quant_tables->quant_tables[table_index];
quant_table->quant_precision = ((val >> 4) & 0x0f);
g_return_val_if_fail (gst_byte_reader_get_remaining (&br) >=
GST_JPEG_MAX_QUANT_ELEMENTS * (1 + ! !quant_table->quant_precision),
FALSE);
for (i = 0; i < GST_JPEG_MAX_QUANT_ELEMENTS; i++) {
if (!quant_table->quant_precision) { /* 8-bit values */
U_READ_UINT8 (&br, val);
quant_table->quant_table[i] = val;
} else { /* 16-bit values */
U_READ_UINT16 (&br, quant_table->quant_table[i]);
}
}
quant_table->valid = TRUE;
}
return TRUE;
}
gboolean
gst_jpeg_parse_restart_interval (guint * interval,
const guint8 * data, gsize size, guint offset)
{
GstByteReader br;
guint16 length, val;
g_return_val_if_fail (interval != NULL, FALSE);
g_return_val_if_fail (data != NULL, FALSE);
g_return_val_if_fail (size > offset, FALSE);
size -= offset;
gst_byte_reader_init (&br, &data[offset], size);
g_return_val_if_fail (size >= 4, FALSE);
U_READ_UINT16 (&br, length); /* Lr */
g_return_val_if_fail (size >= length, FALSE);
U_READ_UINT16 (&br, val);
*interval = val;
return TRUE;
}
static int
compare_huffman_table_entry (const void *a, const void *b)
{
const GstJpegHuffmanTableEntry *const e1 = *(GstJpegHuffmanTableEntry **) a;
const GstJpegHuffmanTableEntry *const e2 = *(GstJpegHuffmanTableEntry **) b;
if (e1->length == e2->length)
return (gint) e1->value - (gint) e2->value;
return (gint) e1->length - (gint) e2->length;
}
static void
build_huffman_table (GstJpegHuffmanTable * huf_table,
const GstJpegHuffmanTableEntry * entries, guint num_entries)
{
const GstJpegHuffmanTableEntry *sorted_entries[256];
guint i, j, n;
g_assert (num_entries <= G_N_ELEMENTS (sorted_entries));
for (i = 0; i < num_entries; i++)
sorted_entries[i] = &entries[i];
qsort (sorted_entries, num_entries, sizeof (sorted_entries[0]),
compare_huffman_table_entry);
for (i = 0, j = 1, n = 0; i < num_entries; i++) {
const GstJpegHuffmanTableEntry *const e = sorted_entries[i];
if (e->length != j) {
huf_table->huf_bits[j++ - 1] = n;
for (; j < e->length; j++)
huf_table->huf_bits[j - 1] = 0;
n = 0;
}
huf_table->huf_values[i] = e->value;
n++;
}
for (; j < G_N_ELEMENTS (huf_table->huf_bits); j++)
huf_table->huf_bits[j] = 0;
for (; i < G_N_ELEMENTS (huf_table->huf_values); i++)
huf_table->huf_values[i] = 0;
huf_table->valid = TRUE;
}
void
gst_jpeg_get_default_huffman_tables (GstJpegHuffmanTables * huf_tables)
{
g_assert (huf_tables);
/* Build DC tables */
build_huffman_table (&huf_tables->dc_tables[0], default_luminance_dc_table,
G_N_ELEMENTS (default_luminance_dc_table));
build_huffman_table (&huf_tables->dc_tables[1], default_chrominance_dc_table,
G_N_ELEMENTS (default_chrominance_dc_table));
memcpy (&huf_tables->dc_tables[2], &huf_tables->dc_tables[1],
sizeof (huf_tables->dc_tables[2]));
/* Build AC tables */
build_huffman_table (&huf_tables->ac_tables[0], default_luminance_ac_table,
G_N_ELEMENTS (default_luminance_ac_table));
build_huffman_table (&huf_tables->ac_tables[1], default_chrominance_ac_table,
G_N_ELEMENTS (default_chrominance_ac_table));
memcpy (&huf_tables->ac_tables[2], &huf_tables->ac_tables[1],
sizeof (huf_tables->ac_tables[2]));
}
void
gst_jpeg_get_default_quantization_tables (GstJpegQuantTables * quant_tables)
{
g_assert (quant_tables);
memcpy (quant_tables, &default_quant_tables_zigzag, sizeof (*quant_tables));
}
gboolean
gst_jpeg_parse (GstJpegMarkerSegment * seg,
const guint8 * data, gsize size, guint offset)
{
GstByteReader br;
guint16 length;
g_return_val_if_fail (seg != NULL, FALSE);
if (size <= offset) {
GST_DEBUG ("failed to parse from offset %u, buffer is too small", offset);
return FALSE;
}
size -= offset;
gst_byte_reader_init (&br, &data[offset], size);
if (!jpeg_parse_to_next_marker (&br, &seg->marker)) {
GST_DEBUG ("failed to find marker code");
return FALSE;
}
seg->offset = offset + gst_byte_reader_get_pos (&br);
seg->size = -1;
/* Try to find end of segment */
switch (seg->marker) {
case GST_JPEG_MARKER_SOI:
case GST_JPEG_MARKER_EOI:
fixed_size_segment:
seg->size = 2;
break;
case (GST_JPEG_MARKER_SOF_MIN + 0): /* Lf */
case (GST_JPEG_MARKER_SOF_MIN + 1): /* Lf */
case (GST_JPEG_MARKER_SOF_MIN + 2): /* Lf */
case (GST_JPEG_MARKER_SOF_MIN + 3): /* Lf */
case (GST_JPEG_MARKER_SOF_MIN + 9): /* Lf */
case (GST_JPEG_MARKER_SOF_MIN + 10): /* Lf */
case (GST_JPEG_MARKER_SOF_MIN + 11): /* Lf */
case GST_JPEG_MARKER_SOS: /* Ls */
case GST_JPEG_MARKER_DQT: /* Lq */
case GST_JPEG_MARKER_DHT: /* Lh */
case GST_JPEG_MARKER_DAC: /* La */
case GST_JPEG_MARKER_DRI: /* Lr */
case GST_JPEG_MARKER_COM: /* Lc */
case GST_JPEG_MARKER_DNL: /* Ld */
variable_size_segment:
READ_UINT16 (&br, length);
seg->size = length;
break;
default:
/* Application data segment length (Lp) */
if (seg->marker >= GST_JPEG_MARKER_APP_MIN &&
seg->marker <= GST_JPEG_MARKER_APP_MAX)
goto variable_size_segment;
/* Restart markers (fixed size, two bytes only) */
if (seg->marker >= GST_JPEG_MARKER_RST_MIN &&
seg->marker <= GST_JPEG_MARKER_RST_MAX)
goto fixed_size_segment;
/* Fallback: scan for next marker */
if (!jpeg_parse_to_next_marker (&br, NULL))
goto failed;
seg->size = gst_byte_reader_get_pos (&br) - seg->offset;
break;
}
return TRUE;
failed:
return FALSE;
}