gst_jpeg_parse ()

gboolean
gst_jpeg_parse (GstJpegSegment *seg,
                const guint8 *data,
                gsize size,
                guint offset);

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.

Since: 1.6

gst_jpeg_segment_parse_frame_header ()

gboolean
gst_jpeg_segment_parse_frame_header (const GstJpegSegment *segment,
                                     GstJpegFrameHdr *frame_hdr);

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.

Since: 1.6

gst_jpeg_segment_parse_scan_header ()

gboolean
gst_jpeg_segment_parse_scan_header (const GstJpegSegment *segment,
                                    GstJpegScanHdr *scan_hdr);

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.

Since: 1.6

gst_jpeg_segment_parse_huffman_table ()

gboolean
gst_jpeg_segment_parse_huffman_table (const GstJpegSegment *segment,
                                      GstJpegHuffmanTables *huff_tables);

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;

Since: 1.6

gst_jpeg_segment_parse_quantization_table ()

gboolean
gst_jpeg_segment_parse_quantization_table
                               (const GstJpegSegment *segment,
                                GstJpegQuantTables *quant_tables);

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.

Since: 1.6

gst_jpeg_segment_parse_restart_interval ()

gboolean
gst_jpeg_segment_parse_restart_interval
                               (const GstJpegSegment *segment,
                                guint *interval);

The caller must make sure there is enough data for the whole segment available.

Since: 1.6

gst_jpeg_get_default_quantization_tables ()

void
gst_jpeg_get_default_quantization_tables
                               (GstJpegQuantTables *quant_tables);

gst_jpeg_get_default_huffman_tables ()

void
gst_jpeg_get_default_huffman_tables (GstJpegHuffmanTables *huff_tables);

Fills in huf_tables with the default AC/DC Huffman tables, as specified by the JPEG standard.

Since: 1.6

GST_JPEG_MAX_FRAME_COMPONENTS

#define GST_JPEG_MAX_FRAME_COMPONENTS   256

Maximum number of image components in a frame (Nf).

Since: 1.6

GST_JPEG_MAX_SCAN_COMPONENTS

#define GST_JPEG_MAX_SCAN_COMPONENTS    4

Maximum number of image components in a scan (Ns).

Since: 1.6

GST_JPEG_MAX_QUANT_ELEMENTS

#define GST_JPEG_MAX_QUANT_ELEMENTS     64

Number of elements in the quantization table.

Since: 1.6

GST_JPEG_MARKER_SOF_MIN

#define GST_JPEG_MARKER_SOF_MIN GST_JPEG_MARKER_SOF0

GST_JPEG_MARKER_SOF_MAX

#define GST_JPEG_MARKER_SOF_MAX GST_JPEG_MARKER_SOF15

GST_JPEG_MARKER_APP_MIN

#define GST_JPEG_MARKER_APP_MIN GST_JPEG_MARKER_APP0

GST_JPEG_MARKER_APP_MAX

#define GST_JPEG_MARKER_APP_MAX GST_JPEG_MARKER_APP15

GST_JPEG_MARKER_RST_MIN

#define GST_JPEG_MARKER_RST_MIN GST_JPEG_MARKER_RST0

GST_JPEG_MARKER_RST_MAX

#define GST_JPEG_MARKER_RST_MAX GST_JPEG_MARKER_RST7

enum GstJpegEntropyCodingMode

JPEG entropy coding mode.

Since: 1.6

enum GstJpegProfile

JPEG encoding processes.

Since: 1.6

struct GstJpegSegment

struct GstJpegSegment {
  GstJpegMarker marker;
  const guint8 *data;
  guint offset;
  gssize size;
};

A structure that contains the type of a segment, its offset and its size.

Since: 1.6

struct GstJpegFrameHdr

struct GstJpegFrameHdr {
  guint8 sample_precision;              /* 2 .. 16      */
  guint16 width;                        /* 1 .. 65535   */
  guint16 height;                       /* 0 .. 65535   */
  guint8 num_components;                /* 1 .. 255     */
  GstJpegFrameComponent components[GST_JPEG_MAX_FRAME_COMPONENTS];
};

Frame header.

Since: 1.6

struct GstJpegFrameComponent

struct GstJpegFrameComponent {
  guint8 identifier;                    /* 0 .. 255     */
  guint8 horizontal_factor;             /* 1 .. 4       */
  guint8 vertical_factor;               /* 1 .. 4       */
  guint8 quant_table_selector;          /* 0 .. 3       */
};

Component-specification parameters.

Since: 1.6

struct GstJpegScanHdr

struct GstJpegScanHdr {
  guint8 num_components;                /* 1 .. 4       */
  GstJpegScanComponent components[GST_JPEG_MAX_SCAN_COMPONENTS];
};

Scan header.

Since: 1.6

struct GstJpegScanComponent

struct GstJpegScanComponent {
    guint8 component_selector;          /* 0 .. 255     */
    guint8 dc_selector;                 /* 0 .. 3       */
    guint8 ac_selector;                 /* 0 .. 3       */
};

Component-specification parameters.

Since: 1.6

struct GstJpegHuffmanTables

struct GstJpegHuffmanTables {
  GstJpegHuffmanTable dc_tables[GST_JPEG_MAX_SCAN_COMPONENTS];
  GstJpegHuffmanTable ac_tables[GST_JPEG_MAX_SCAN_COMPONENTS];
};

Helper data structure that holds all AC/DC Huffman tables used to decode an image.

Since: 1.6

struct GstJpegHuffmanTable

struct GstJpegHuffmanTable {
  guint8 huf_bits[16];
  guint8 huf_values[256];
  gboolean valid;
};

Huffman table.

Since: 1.6

struct GstJpegQuantTable

struct GstJpegQuantTable {
  guint8 quant_precision;
  guint16 quant_table[GST_JPEG_MAX_QUANT_ELEMENTS];
  gboolean valid;
};

Quantization table.

Since: 1.6