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gstreamer/gst-libs/gst/codecparsers/gstjpegparser.c
Tim-Philipp Müller b6411ae74c libs: fix API export/import and 'inconsistent linkage' on MSVC 
For each lib we build export its own API in headers when we're
building it, otherwise import the API from the headers.

This fixes linker warnings on Windows when building with MSVC.

The problem was that we had defined all GST_*_API decorators
unconditionally to GST_EXPORT. This was intentional and only
supposed to be temporary, but caused linker warnings because
we tell the linker that we want to export all symbols even
those from externall DLLs, and when the linker notices that
they were in external DLLS and not present locally it warns.

What we need to do when building each library is: export
the library's own symbols and import all other symbols. To
this end we define e.g. BUILDING_GST_FOO and then we define
the GST_FOO_API decorator either to export or to import
symbols depending on whether BUILDING_GST_FOO is set or not.
That way external users of each library API automatically
get the import.

While we're at it, add new GST_API_EXPORT in config.h and use
that for GST_*_API decorators instead of GST_EXPORT.

The right export define depends on the toolchain and whether
we're using -fvisibility=hidden or not, so it's better to set it
to the right thing directly than hard-coding a compiler whitelist
in the public header.

We put the export define into config.h instead of passing it via the
command line to the compiler because it might contain spaces and brackets
and in the autotools scenario we'd have to pass that through multiple
layers of plumbing and Makefile/shell escaping and we're just not going
to be *that* lucky.

The export define is only used if we're compiling our lib, not by external
users of the lib headers, so it's not a problem to put it into config.h

Also, this means all .c files of libs need to include config.h
to get the export marker defined, so fix up a few that didn't
include config.h.

This commit depends on a common submodule commit that makes gst-glib-gen.mak
add an #include "config.h" to generated enum/marshal .c files for the
autotools build.

https://bugzilla.gnome.org/show_bug.cgi?id=797185
2018-09-24 14:45:56 +01:00

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/* GStreamer JPEG parser
* Copyright (C) 2011-2012 Intel Corporation
* Copyright (C) 2015 Tim-Philipp Müller <tim@centricular.com>
*
* 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
*/
/**
* SECTION:gstjpegparser
* @title: GstJpegParser
* @short_description: Convenience library for JPEG bitstream parsing.
*
* Provides useful functions for parsing JPEG images
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include <stdlib.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
/* Table used to address an 8x8 matrix in zig-zag order */
/* *INDENT-OFF* */
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* */
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 gint gst_jpeg_scan_for_marker_code (const guint8 * data, gsize size,
guint offset);
static inline gboolean
jpeg_parse_to_next_marker (GstByteReader * br, GstJpegMarker * marker)
{
gint ofs;
ofs = gst_jpeg_scan_for_marker_code (br->data, br->size, br->byte);
if (ofs < 0)
return FALSE;
if (marker)
*marker = (GstJpegMarker) br->data[ofs + 1];
gst_byte_reader_skip_unchecked (br, ofs - br->byte);
return TRUE;
}
/* gst_jpeg_scan_for_marker_code:
* @data: The data to parse
* @size: The size of @data
* @offset: The offset from which to start parsing
*
* Scans the JPEG bitstream contained in @data for the next marker
* code. If found, the function returns an offset to the marker code,
* including the 0xff prefix code but excluding any extra fill bytes.
*
* Returns: offset to the marker code if found, or -1 if not found.
*/
static gint
gst_jpeg_scan_for_marker_code (const guint8 * data, gsize size, guint offset)
{
guint i;
i = offset + 1;
while (i < size) {
const guint8 v = data[i];
if (v < 0xc0)
i += 2;
else if (v < 0xff && data[i - 1] == 0xff)
return i - 1;
else
i++;
}
return -1;
}
/**
* gst_jpeg_segment_parse_frame_header:
* @segment: the JPEG segment
* @frame_hdr: (out): The #GstJpegFrameHdr structure to fill in
*
* Parses the @frame_hdr JPEG frame header structure members from @segment.
*
* The caller must make sure there is enough data for the whole segment
* available.
*
* Returns: TRUE if the frame header was correctly parsed.
*
* Since: 1.6
*/
gboolean
gst_jpeg_segment_parse_frame_header (const GstJpegSegment * segment,
GstJpegFrameHdr * frame_hdr)
{
GstByteReader br;
guint8 val;
guint i;
g_return_val_if_fail (segment != NULL, FALSE);
g_return_val_if_fail (frame_hdr != NULL, FALSE);
if (segment->size < 8)
return FALSE;
gst_byte_reader_init (&br, segment->data + segment->offset, segment->size);
gst_byte_reader_skip_unchecked (&br, 2);
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);
if (frame_hdr->num_components > GST_JPEG_MAX_SCAN_COMPONENTS)
return FALSE;
if (gst_byte_reader_get_remaining (&br) < 3 * frame_hdr->num_components)
return 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);
if (frame_hdr->components[i].horizontal_factor > 4
|| frame_hdr->components[i].vertical_factor > 4
|| frame_hdr->components[i].quant_table_selector >= 4)
return FALSE;
}
if (gst_byte_reader_get_remaining (&br) > 0)
GST_DEBUG ("data left at end of frame header segment");
return TRUE;
}
/**
* gst_jpeg_segment_parse_scan_header:
* @segment: the JPEG segment
* @scan_hdr: (out): The #GstJpegScanHdr structure to fill in
*
* Parses the @scan_hdr JPEG scan header structure members from @segment.
*
* The caller must make sure there is enough data for the whole segment
* available.
*
* Returns: TRUE if the scan header was correctly parsed
*
* Since: 1.6
*/
gboolean
gst_jpeg_segment_parse_scan_header (const GstJpegSegment * segment,
GstJpegScanHdr * scan_hdr)
{
GstByteReader br;
guint8 val;
guint i;
g_return_val_if_fail (segment != NULL, FALSE);
g_return_val_if_fail (scan_hdr != NULL, FALSE);
gst_byte_reader_init (&br, segment->data + segment->offset, segment->size);
if (segment->size < 3)
return FALSE;
gst_byte_reader_skip_unchecked (&br, 2);
U_READ_UINT8 (&br, scan_hdr->num_components);
if (scan_hdr->num_components > GST_JPEG_MAX_SCAN_COMPONENTS)
return FALSE;
if (gst_byte_reader_get_remaining (&br) < 2 * scan_hdr->num_components)
return 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;
if (scan_hdr->components[i].dc_selector >= 4
|| scan_hdr->components[i].ac_selector >= 4)
return FALSE;
}
if (gst_byte_reader_get_remaining (&br) < 3)
return FALSE;
/* FIXME: Ss, Se, Ah, Al */
gst_byte_reader_skip_unchecked (&br, 3);
if (gst_byte_reader_get_remaining (&br) > 0)
GST_DEBUG ("data left at end of scan header segment");
return TRUE;
}
/**
* gst_jpeg_segment_parse_huffman_table:
* @segment: the JPEG segment
* @huff_tables: (out): The #GstJpegHuffmanTables structure to fill in
*
* Parses the JPEG Huffman table structure members from @segment.
*
* The caller must make sure there is enough data for the whole segment
* available.
*
* Note: @huf_tables represents the complete set of possible Huffman
* tables. However, the parser will only write to the Huffman table
* specified by the table destination identifier (Th). While doing so,
* the @valid flag of the specified Huffman table will also be set to
* %TRUE;
*
* Returns: TRUE if the Huffman table was correctly parsed.
*
* Since: 1.6
*/
gboolean
gst_jpeg_segment_parse_huffman_table (const GstJpegSegment * segment,
GstJpegHuffmanTables * huff_tables)
{
GstByteReader br;
GstJpegHuffmanTable *huf_table;
guint8 val, table_class, table_index;
guint32 value_count;
guint i;
g_return_val_if_fail (segment != NULL, FALSE);
g_return_val_if_fail (huff_tables != NULL, FALSE);
if (segment->size < 2)
return FALSE;
gst_byte_reader_init (&br, segment->data + segment->offset, segment->size);
gst_byte_reader_skip_unchecked (&br, 2);
while (gst_byte_reader_get_remaining (&br) > 0) {
U_READ_UINT8 (&br, val);
table_class = ((val >> 4) & 0x0F);
table_index = (val & 0x0F);
if (table_index >= GST_JPEG_MAX_SCAN_COMPONENTS)
return FALSE;
if (table_class == 0) {
huf_table = &huff_tables->dc_tables[table_index];
} else {
huf_table = &huff_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;
}
/**
* gst_jpeg_segment_parse_quantization_table:
* @segment: the JPEG segment
* @quant_tables: (out): The #GstJpegQuantTables structure to fill in
*
* Parses the JPEG quantization table structure members from @segment.
*
* The caller must make sure there is enough data for the whole segment
* available.
*
* Note: @quant_tables represents the complete set of possible
* quantization tables. However, the parser will only write to the
* quantization table specified by the table destination identifier
* (Tq). While doing so, the @valid flag of the specified quantization
* table will also be set to %TRUE.
*
* Returns: TRUE if the quantization table was correctly parsed.
*
* Since: 1.6
*/
gboolean
gst_jpeg_segment_parse_quantization_table (const GstJpegSegment * segment,
GstJpegQuantTables * quant_tables)
{
GstByteReader br;
GstJpegQuantTable *quant_table;
guint8 val, table_index;
guint i;
g_return_val_if_fail (segment != NULL, FALSE);
g_return_val_if_fail (quant_tables != NULL, FALSE);
if (segment->size < 2)
return FALSE;
gst_byte_reader_init (&br, segment->data + segment->offset, segment->size);
gst_byte_reader_skip_unchecked (&br, 2);
while (gst_byte_reader_get_remaining (&br) > 0) {
guint8 element_size;
U_READ_UINT8 (&br, val);
table_index = (val & 0x0f);
if (table_index >= GST_JPEG_MAX_SCAN_COMPONENTS)
return FALSE;
quant_table = &quant_tables->quant_tables[table_index];
quant_table->quant_precision = ((val >> 4) & 0x0f);
element_size = (quant_table->quant_precision == 0) ? 1 : 2;
if (gst_byte_reader_get_remaining (&br) <
GST_JPEG_MAX_QUANT_ELEMENTS * element_size)
return 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;
}
/**
* gst_jpeg_segment_parse_restart_interval:
* @segment: the JPEG segment
* @interval: (out): The parsed restart interval value
*
* The caller must make sure there is enough data for the whole segment
* available.
*
* Returns: TRUE if the restart interval value was correctly parsed.
*
* Since: 1.6
*/
gboolean
gst_jpeg_segment_parse_restart_interval (const GstJpegSegment * segment,
guint * interval)
{
GstByteReader br;
guint16 val;
g_return_val_if_fail (segment != NULL, FALSE);
g_return_val_if_fail (interval != NULL, FALSE);
if (segment->size < 4)
return FALSE;
gst_byte_reader_init (&br, segment->data + segment->offset, segment->size);
gst_byte_reader_skip_unchecked (&br, 2);
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 ((void *) 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++;
}
huf_table->huf_bits[j - 1] = 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;
}
/**
* gst_jpeg_get_default_huffman_tables:
* @huf_tables: (out): The default DC/AC Huffman tables to fill in
*
* Fills in @huf_tables with the default AC/DC Huffman tables, as
* specified by the JPEG standard.
*
* Since: 1.6
*/
void
gst_jpeg_get_default_huffman_tables (GstJpegHuffmanTables * huf_tables)
{
g_return_if_fail (huf_tables != NULL);
/* 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]));
}
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;
}
/**
* gst_jpeg_get_default_quantization_table:
* @quant_tables: (out): The default luma/chroma quant-tables in zigzag mode
*
* Fills in @quant_tables with the default quantization tables, as
* specified by the JPEG standard.
*
* Since: 1.6
*/
void
gst_jpeg_get_default_quantization_tables (GstJpegQuantTables * quant_tables)
{
g_return_if_fail (quant_tables != NULL);
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);
}
/**
* gst_jpeg_parse:
* @segment: (out): pointer to a #GstJpegSegment structure to fill in
* @data: The data to parse
* @size: The size of @data
* @offset: The offset from which to start parsing
*
* Parses the JPEG bitstream contained in @data, and returns the
* detected segment as a #GstJpegSegment.
*
* Note that a valid segment may be returned with a length that exceeds
* the available data. It is up to the caller to make sure there's enough
* data available when parsing the segment.
*
* Returns: TRUE if a packet start code was found.
*
* Since: 1.6
*/
gboolean
gst_jpeg_parse (GstJpegSegment * segment,
const guint8 * data, gsize size, guint offset)
{
GstJpegSegment *seg = segment;
GstByteReader br;
guint16 length;
g_return_val_if_fail (seg != NULL, FALSE);
g_return_val_if_fail (data != 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;
}
gst_byte_reader_skip_unchecked (&br, 2);
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 = 0;
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;
}
seg->data = data;
return TRUE;
failed:
return FALSE;
}
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