FFmpeg
Data Structures | Macros | Enumerations | Functions
framesync.h File Reference
#include "bufferqueue.h"

Go to the source code of this file.

Data Structures

struct  FFFrameSyncIn
 Input stream structure. More...
 
struct  FFFrameSync
 Frame sync structure. More...
 

Macros

#define FRAMESYNC_DEFINE_CLASS(name, context, field)
 

Enumerations

enum  EOFAction {
  EOF_ACTION_REPEAT, EOF_ACTION_ENDALL, EOF_ACTION_PASS, EOF_ACTION_ROUND,
  EOF_ACTION_PASS, EOF_ACTION_NB
}
 
enum  FFFrameSyncExtMode { EXT_STOP, EXT_NULL, EXT_INFINITY }
 This API is intended as a helper for filters that have several video input and need to combine them somehow. More...
 

Functions

const AVClassff_framesync_get_class (void)
 Get the class for the framesync object. More...
 
void ff_framesync_preinit (FFFrameSync *fs)
 Pre-initialize a frame sync structure. More...
 
int ff_framesync_init (FFFrameSync *fs, AVFilterContext *parent, unsigned nb_in)
 Initialize a frame sync structure. More...
 
int ff_framesync_configure (FFFrameSync *fs)
 Configure a frame sync structure. More...
 
void ff_framesync_uninit (FFFrameSync *fs)
 Free all memory currently allocated. More...
 
int ff_framesync_get_frame (FFFrameSync *fs, unsigned in, AVFrame **rframe, unsigned get)
 Get the current frame in an input. More...
 
int ff_framesync_activate (FFFrameSync *fs)
 Examine the frames in the filter's input and try to produce output. More...
 
int ff_framesync_init_dualinput (FFFrameSync *fs, AVFilterContext *parent)
 Initialize a frame sync structure for dualinput. More...
 
int ff_framesync_dualinput_get (FFFrameSync *fs, AVFrame **f0, AVFrame **f1)
 
int ff_framesync_dualinput_get_writable (FFFrameSync *fs, AVFrame **f0, AVFrame **f1)
 Same as ff_framesync_dualinput_get(), but make sure that f0 is writable. More...
 

Macro Definition Documentation

#define FRAMESYNC_DEFINE_CLASS (   name,
  context,
  field 
)
Value:
static int name##_framesync_preinit(AVFilterContext *ctx) { \
context *s = ctx->priv; \
return 0; \
} \
static const AVClass *name##_child_class_next(const AVClass *prev) { \
} \
static void *name##_child_next(void *obj, void *prev) { \
context *s = obj; \
s->fs.class = ff_framesync_get_class(); /* FIXME */ \
return prev ? NULL : &s->field; \
} \
static const AVClass name##_class = { \
.item_name = av_default_item_name, \
.option = name##_options, \
.version = LIBAVUTIL_VERSION_INT, \
.category = AV_CLASS_CATEGORY_FILTER, \
.child_class_next = name##_child_class_next, \
.child_next = name##_child_next, \
}
#define NULL
Definition: coverity.c:32
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:191
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
const AVClass * ff_framesync_get_class(void)
Get the class for the framesync object.
Definition: framesync.c:64
void * priv
private data for use by the filter
Definition: avfilter.h:353
void ff_framesync_preinit(FFFrameSync *fs)
Pre-initialize a frame sync structure.
Definition: framesync.c:69
AVFormatContext * ctx
Definition: movenc.c:48
#define s(width, name)
Definition: cbs_vp9.c:257
Describe the class of an AVClass context structure.
Definition: log.h:67
An instance of a filter.
Definition: avfilter.h:338
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a it should return
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option keep it simple and lowercase description are in without and describe what they for example set the foo of the bar offset is the offset of the field in your local context
const char * name
Definition: opengl_enc.c:102

Definition at line 300 of file framesync.h.

Referenced by filter_frame().

Enumeration Type Documentation

enum EOFAction
Enumerator
EOF_ACTION_REPEAT 
EOF_ACTION_ENDALL 
EOF_ACTION_PASS 
EOF_ACTION_ROUND 
EOF_ACTION_PASS 
EOF_ACTION_NB 

Definition at line 26 of file framesync.h.

This API is intended as a helper for filters that have several video input and need to combine them somehow.

If the inputs have different or variable frame rate, getting the input frames to match requires a rather complex logic and a few user-tunable options.

In this API, when a set of synchronized input frames is ready to be procesed is called a frame event. Frame event can be generated in response to input frames on any or all inputs and the handling of situations where some stream extend beyond the beginning or the end of others can be configured.

The basic working of this API is the following: set the on_event callback, then call ff_framesync_activate() from the filter's activate callback. Stream extrapolation mode

Describe how the frames of a stream are extrapolated before the first one and after EOF to keep sync with possibly longer other streams.

Enumerator
EXT_STOP 

Completely stop all streams with this one.

EXT_NULL 

Ignore this stream and continue processing the other ones.

EXT_INFINITY 

Extend the frame to infinity.

Definition at line 60 of file framesync.h.

Function Documentation

const AVClass* ff_framesync_get_class ( void  )

Get the class for the framesync object.

Definition at line 64 of file framesync.c.

void ff_framesync_preinit ( FFFrameSync fs)

Pre-initialize a frame sync structure.

It sets the class pointer and inits the options to their default values. The entire structure is expected to be already set to 0. This step is optional, but necessary to use the options.

Definition at line 69 of file framesync.c.

Referenced by ff_framesync_init().

int ff_framesync_init ( FFFrameSync fs,
AVFilterContext parent,
unsigned  nb_in 
)

Initialize a frame sync structure.

The entire structure is expected to be already set to 0 or preinited.

Parameters
fsframe sync structure to initialize
parentparent AVFilterContext object
nb_innumber of inputs
Returns
>= 0 for success or a negative error code

Definition at line 77 of file framesync.c.

Referenced by config_output(), ff_framesync_init_dualinput(), init_framesync(), lut2_config_output(), and program_opencl_config_output().

int ff_framesync_configure ( FFFrameSync fs)

Configure a frame sync structure.

Must be called after all options are set but before all use.

Returns
>= 0 for success or a negative error code

Definition at line 117 of file framesync.c.

Referenced by config_output(), filter_frame(), init_framesync(), lut2_config_output(), overlay_opencl_config_output(), and program_opencl_config_output().

void ff_framesync_uninit ( FFFrameSync fs)

Free all memory currently allocated.

Definition at line 293 of file framesync.c.

Referenced by filter_frame(), overlay_opencl_uninit(), overlay_qsv_uninit(), program_opencl_uninit(), and uninit().

int ff_framesync_get_frame ( FFFrameSync fs,
unsigned  in,
AVFrame **  rframe,
unsigned  get 
)

Get the current frame in an input.

Parameters
fsframe sync structure
inindex of the input
rframeused to return the current frame (or NULL)
getif not zero, the calling code needs to get ownership of the returned frame; the current frame will either be duplicated or removed from the framesync structure

Definition at line 256 of file framesync.c.

Referenced by ff_framesync_dualinput_get(), overlay_opencl_blend(), process_frame(), and program_opencl_filter().

int ff_framesync_activate ( FFFrameSync fs)

Examine the frames in the filter's input and try to produce output.

This function can be the complete implementation of the activate method of a filter using framesync.

Definition at line 344 of file framesync.c.

Referenced by activate(), config_output(), filter_frame(), overlay_opencl_activate(), and program_opencl_activate().

int ff_framesync_init_dualinput ( FFFrameSync fs,
AVFilterContext parent 
)

Initialize a frame sync structure for dualinput.

Compared to generic framesync, dualinput assumes the first input is the main one and the filtering is performed on it. The first input will be the only one with sync set and generic timeline support will just pass it unchanged when disabled.

Equivalent to ff_framesync_init(fs, parent, 2) then setting the time base, sync and ext modes on the inputs.

Definition at line 361 of file framesync.c.

Referenced by config_output(), filter_frame(), and overlay_opencl_config_output().

int ff_framesync_dualinput_get ( FFFrameSync fs,
AVFrame **  f0,
AVFrame **  f1 
)
Parameters
f0used to return the main frame
f1used to return the second frame, or NULL if disabled
Returns
>=0 for success or AVERROR code
Note
The frame returned in f0 belongs to the caller (get = 1 in ff_framesync_get_frame()) while the frame returned in f1 is still owned by the framesync structure.

Definition at line 379 of file framesync.c.

Referenced by blend_frame_for_dualinput(), do_convolve(), do_psnr(), do_ssim(), do_vmaf(), ff_framesync_dualinput_get_writable(), and filter_frame().

int ff_framesync_dualinput_get_writable ( FFFrameSync fs,
AVFrame **  f0,
AVFrame **  f1 
)

Same as ff_framesync_dualinput_get(), but make sure that f0 is writable.

Definition at line 399 of file framesync.c.

Referenced by do_blend(), and load_apply_palette().