FFmpeg
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graphparser.c
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86 * @param filt_ctx put here a filter context in case of successful creation and configuration, NULL otherwise.
88 * @param index an index which is supposed to be unique for each filter instance added to the filtergraph
Definition: start.py:1
void * av_mallocz(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:205
external API header
memory handling functions
void avfilter_inout_free(AVFilterInOut **inout)
Free the supplied list of AVFilterInOut and set *inout to NULL.
Definition: graphparser.c:175
struct AVFilterInOut * next
next input/input in the list, NULL if this is the last
Definition: avfilter.h:1134
Definition: avisynth_c.h:503
char * scale_sws_opts
sws options to use for the auto-inserted scale filters
Definition: avfilter.h:1002
void av_freep(void *arg)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc() and set the pointer ...
Definition: mem.c:198
int avfilter_link(AVFilterContext *src, unsigned srcpad, AVFilterContext *dst, unsigned dstpad)
Link two filters together.
Definition: avfilter.c:114
static void insert_inout(AVFilterInOut **inouts, AVFilterInOut *element)
Definition: graphparser.c:202
the mask is usually to keep the same permissions Filters should remove permissions on reference they give to output whenever necessary It can be automatically done by setting the rej_perms field on the output pad Here are a few guidelines corresponding to common then the filter should push the output frames on the output link immediately As an exception to the previous rule if the input frame is enough to produce several output frames then the filter needs output only at least one per link The additional frames can be left buffered in the filter
Definition: filter_design.txt:201
int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters, AVFilterInOut **inputs, AVFilterInOut **outputs)
Add a graph described by a string to a graph.
Definition: graphparser.c:379
static int parse_inputs(const char **buf, AVFilterInOut **curr_inputs, AVFilterInOut **open_outputs, void *log_ctx)
Definition: graphparser.c:268
void av_free(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc(). ...
Definition: mem.c:183
static AVFilterInOut * extract_inout(const char *label, AVFilterInOut **links)
Definition: graphparser.c:185
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 This method is called when a frame is wanted on an output For an input
Definition: filter_design.txt:216
size_t av_strlcpy(char *dst, const char *src, size_t size)
Copy the string src to dst, but no more than size - 1 bytes, and null-terminate dst.
Definition: avstring.c:82
char * av_get_token(const char **buf, const char *term)
Unescape the given string until a non escaped terminating char, and return the token corresponding to...
Definition: avstring.c:148
Definition: avfilter.h:991
AVFilterContext * filter_ctx
filter context associated to this input/output
Definition: avfilter.h:1128
int avfilter_init_str(AVFilterContext *filter, const char *args)
Initialize a filter with the supplied parameters.
Definition: avfilter.c:715
static int parse_sws_flags(const char **buf, AVFilterGraph *graph)
Definition: graphparser.c:356
static void append_inout(AVFilterInOut **inouts, AVFilterInOut **element)
Definition: graphparser.c:208
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFilterBuffer structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Buffer references ownership and permissions
static int parse_filter(AVFilterContext **filt_ctx, const char **buf, AVFilterGraph *graph, int index, void *log_ctx)
Parse a string of the form FILTER_NAME[=PARAMS], and create a corresponding filter instance which is ...
Definition: graphparser.c:152
static int parse_outputs(const char **buf, AVFilterInOut **curr_inputs, AVFilterInOut **open_inputs, AVFilterInOut **open_outputs, void *log_ctx)
Definition: graphparser.c:308
AVFilterInOut * avfilter_inout_alloc(void)
Allocate a single AVFilterInOut entry.
Definition: graphparser.c:170
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFilterBuffer structure Format for each input and each output links
Definition: filter_design.txt:12
static int create_filter(AVFilterContext **filt_ctx, AVFilterGraph *ctx, int index, const char *filt_name, const char *args, void *log_ctx)
Create an instance of a filter, initialize and insert it in the filtergraph in *ctx.
Definition: graphparser.c:94
static int link_filter(AVFilterContext *src, int srcpad, AVFilterContext *dst, int dstpad, void *log_ctx)
Link two filters together.
Definition: graphparser.c:37
AVFilterContext * avfilter_graph_alloc_filter(AVFilterGraph *graph, const AVFilter *filter, const char *name)
Create a new filter instance in a filter graph.
Definition: avfiltergraph.c:140
static char * parse_link_name(const char **buf, void *log_ctx)
Parse the name of a link, which has the format "[linkname]".
Definition: graphparser.c:58
static int link_filter_inouts(AVFilterContext *filt_ctx, AVFilterInOut **curr_inputs, AVFilterInOut **open_inputs, void *log_ctx)
Definition: graphparser.c:220
AVFilter * avfilter_get_by_name(const char *name)
Get a filter definition matching the given name.
Definition: avfilter.c:391
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 inputs
Definition: filter_design.txt:216
int avfilter_graph_parse(AVFilterGraph *graph, const char *filters, AVFilterInOut **open_inputs_ptr, AVFilterInOut **open_outputs_ptr, void *log_ctx)
Add a graph described by a string to a graph.
Definition: graphparser.c:447
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