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Data Structures | Macros | Functions | Variables
gifdec.c File Reference

GIF demuxer. More...

#include "avformat.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/opt.h"
#include "internal.h"
#include "libavcodec/gif.h"

Go to the source code of this file.

Data Structures

struct  GIFDemuxContext
 

Macros

#define GIF_DEFAULT_DELAY   10
 Major web browsers display gifs at ~10-15fps when rate is not explicitly set or have too low values.
 
#define GIF_MIN_DELAY   2
 By default delay values less than this threshold considered to be invalid.
 

Functions

static int gif_probe (AVProbeData *p)
 
static int resync (AVIOContext *pb)
 
static int gif_read_header (AVFormatContext *s)
 
static int gif_skip_subblocks (AVIOContext *pb)
 
static int gif_read_ext (AVFormatContext *s)
 
static int gif_read_packet (AVFormatContext *s, AVPacket *pkt)
 

Variables

static const AVOption options []
 
static const AVClass demuxer_class
 
AVInputFormat ff_gif_demuxer
 

Detailed Description

GIF demuxer.

Definition in file gifdec.c.

Macro Definition Documentation

#define GIF_DEFAULT_DELAY   10

Major web browsers display gifs at ~10-15fps when rate is not explicitly set or have too low values.

We assume default rate to be 10. Default delay = 100hundredths of second / 10fps = 10hos per frame.

Definition at line 54 of file gifdec.c.

#define GIF_MIN_DELAY   2

By default delay values less than this threshold considered to be invalid.

Definition at line 58 of file gifdec.c.

Function Documentation

static int gif_probe ( AVProbeData p)
static

Definition at line 60 of file gifdec.c.

static int resync ( AVIOContext pb)
static

Definition at line 73 of file gifdec.c.

Referenced by gif_read_header(), gif_read_packet(), and nut_read_packet().

static int gif_read_header ( AVFormatContext s)
static

Definition at line 86 of file gifdec.c.

static int gif_skip_subblocks ( AVIOContext pb)
static

Definition at line 122 of file gifdec.c.

Referenced by gif_read_ext(), and gif_read_packet().

static int gif_read_ext ( AVFormatContext s)
static

Definition at line 134 of file gifdec.c.

Referenced by gif_read_packet().

static int gif_read_packet ( AVFormatContext s,
AVPacket pkt 
)
static

Definition at line 167 of file gifdec.c.

Variable Documentation

const AVOption options[]
static
Initial value:
= {
{ "min_delay" , "minimum valid delay between frames (in hundredths of second)", 0x42 , AV_OPT_TYPE_INT, {.i64 = GIF_MIN_DELAY} , 0, 100 * 60, AV_OPT_FLAG_DECODING_PARAM },
{ "default_delay", "default delay between frames (in hundredths of second)" , 0x42, AV_OPT_TYPE_INT, {.i64 = GIF_DEFAULT_DELAY}, 0, 100 * 60, AV_OPT_FLAG_DECODING_PARAM },
{ NULL },
}

Definition at line 279 of file gifdec.c.

const AVClass demuxer_class
static
Initial value:
= {
.class_name = "GIF demuxer",
.item_name = av_default_item_name,
.option = options,
}

Definition at line 285 of file gifdec.c.

AVInputFormat ff_gif_demuxer
Initial value:
= {
.name = "gif",
.long_name = NULL_IF_CONFIG_SMALL("CompuServe Graphics Interchange Format (GIF)"),
.priv_data_size = sizeof(GIFDemuxContext),
.priv_class = &demuxer_class,
}

Definition at line 293 of file gifdec.c.