FFmpeg  2.1.1
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. More...
 
#define GIF_MIN_DELAY   2
 By default delay values less than this threshold considered to be invalid. More...
 

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 61 of file gifdec.c.

#define GIF_MIN_DELAY   2

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

Definition at line 65 of file gifdec.c.

Function Documentation

static int gif_probe ( AVProbeData p)
static

Definition at line 67 of file gifdec.c.

static int resync ( AVIOContext pb)
static

Definition at line 80 of file gifdec.c.

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

static int gif_read_header ( AVFormatContext s)
static

Definition at line 93 of file gifdec.c.

static int gif_skip_subblocks ( AVIOContext pb)
static

Definition at line 129 of file gifdec.c.

Referenced by gif_read_ext(), and gif_read_packet().

static int gif_read_ext ( AVFormatContext s)
static

Definition at line 141 of file gifdec.c.

Referenced by gif_read_packet().

static int gif_read_packet ( AVFormatContext s,
AVPacket pkt 
)
static

Definition at line 195 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 },
{ "ignore_loop" , "ignore loop setting (netscape extension)" , 0x42 , AV_OPT_TYPE_INT, {.i64 = 1} , 0, 1, AV_OPT_FLAG_DECODING_PARAM },
{ NULL },
}
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
Definition: opt.h:284
#define GIF_DEFAULT_DELAY
Major web browsers display gifs at ~10-15fps when rate is not explicitly set or have too low values...
Definition: gifdec.c:61
#define GIF_MIN_DELAY
By default delay values less than this threshold considered to be invalid.
Definition: gifdec.c:65

Definition at line 310 of file gifdec.c.

const AVClass demuxer_class
static
Initial value:
= {
.class_name = "GIF demuxer",
.item_name = av_default_item_name,
.option = options,
}
#define LIBAVUTIL_VERSION_INT
Definition: avcodec.h:820
const char * av_default_item_name(void *ctx)
Return the context name.
Definition: log.c:145
const OptionDef options[]
Definition: ffserver.c:4682

Definition at line 317 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,
}
static int gif_read_header(AVFormatContext *s)
Definition: gifdec.c:93
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:151
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:355
static const AVClass demuxer_class
Definition: gifdec.c:317
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:54
static int gif_probe(AVProbeData *p)
Definition: gifdec.c:67
static int gif_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: gifdec.c:195
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:592
static int read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: libcdio.c:114
static int flags
Definition: cpu.c:45

Definition at line 325 of file gifdec.c.