jpegapp.c File Reference

#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "libavutil/error.h"
#include "libavutil/file_open.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/log.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "libavcodec/bsf.h"
#include "libavcodec/bsf_internal.h"
#include "libavcodec/bytestream.h"
#include "libavcodec/mjpeg.h"

Go to the source code of this file.

Data Structures
struct	JPEGAppContext

Macros
#define	JPEGAPP_MAX_RECORD   (16 * 1024 * 1024)
	Sidecar format (big-endian), one record per encoded JPEG packet:
#define	OFFSET(x)
#define	FLAGS   (AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_BSF_PARAM)

Functions
static int	jpeg_app_segment_len (const uint8_t *data, int size)
static int	jpegapp_validate_payload (const uint8_t *data, int size)
static int	jpegapp_init (AVBSFContext *ctx)
static int	jpegapp_read_record (AVBSFContext *ctx, int *out_size)
static int	jpegapp_filter (AVBSFContext *ctx, AVPacket *out)

Variables
static const AVOption	jpegapp_options []
static const AVClass	jpegapp_class
static enum AVCodecID	jpegapp_codec_ids []
const FFBitStreamFilter	ff_jpegapp_bsf

Macro Definition Documentation

JPEGAPP_MAX_RECORD

#define JPEGAPP_MAX_RECORD   (16 * 1024 * 1024)

Sidecar format (big-endian), one record per encoded JPEG packet:

u32be length u8 payload[length]

Payload is zero or more complete JPEG APP segments (APP0..APP15), each FF En + 16-bit length (length includes those two bytes). A zero length leaves the packet unchanged.

After SOI the payload is inserted. If it starts with APP0 and the two bytes immediately after SOI are an APP0 marker, that segment is dropped so the sidecar can replace it. An APP0 preceded by fill bytes or another segment is retained. An APP1-only payload keeps the encoder APP0: SOI, APP1, APP0, DQT, ...

A sidecar read or validation error stops further record consumption for this filter context. Flushing does not clear that error.

Definition at line 62 of file jpegapp.c.

Referenced by jpegapp_read_record().

OFFSET

#define OFFSET

(

x

)

Value:

offsetof(JPEGAppContext, x)

Definition at line 217 of file jpegapp.c.

FLAGS

#define FLAGS   (AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_BSF_PARAM)

Definition at line 218 of file jpegapp.c.

Function Documentation

jpeg_app_segment_len()

static int jpeg_app_segment_len ( const uint8_t * data, int size )

static

Definition at line 73 of file jpegapp.c.

Referenced by jpegapp_filter(), and jpegapp_validate_payload().

jpegapp_validate_payload()

static int jpegapp_validate_payload ( const uint8_t * data, int size )

static

Definition at line 85 of file jpegapp.c.

Referenced by jpegapp_read_record().

jpegapp_init()

static int jpegapp_init ( AVBSFContext * ctx )

static

Definition at line 98 of file jpegapp.c.

jpegapp_read_record()

static int jpegapp_read_record ( AVBSFContext * ctx, int * out_size )

static

Definition at line 112 of file jpegapp.c.

Referenced by jpegapp_filter().

jpegapp_filter()

static int jpegapp_filter ( AVBSFContext * ctx, AVPacket * out )

static

Definition at line 149 of file jpegapp.c.

Variable Documentation

jpegapp_options

const AVOption jpegapp_options[]

static

Initial value:

= {
    { "sidecar", "sidecar of u32be-length + APP-segment records", OFFSET(sidecar),
      AV_OPT_TYPE_BINARY, .flags = FLAGS },
    { NULL },
}

Definition at line 219 of file jpegapp.c.

jpegapp_class

const AVClass jpegapp_class

static

Initial value:

= {
    .class_name = "jpegapp",
    .item_name  = av_default_item_name,
    .option     = jpegapp_options,
    .version    = LIBAVUTIL_VERSION_INT,
}

Definition at line 225 of file jpegapp.c.

jpegapp_codec_ids

enum AVCodecID jpegapp_codec_ids[]

static

Initial value:

= {
    AV_CODEC_ID_MJPEG, AV_CODEC_ID_NONE,
}

Definition at line 232 of file jpegapp.c.

ff_jpegapp_bsf

const FFBitStreamFilter ff_jpegapp_bsf

Initial value:

= {
    .p.name         = "jpegapp",
    .p.codec_ids    = jpegapp_codec_ids,
    .p.priv_class   = &jpegapp_class,
    .priv_data_size = sizeof(JPEGAppContext),
    .init           = jpegapp_init,
    .filter         = jpegapp_filter,
}

Definition at line 236 of file jpegapp.c.