/*
* Filters implementation helper functions
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVFILTER_FILTERS_H
#define AVFILTER_FILTERS_H
/**
* Filters implementation helper functions
*/
#include "avfilter.h"
#include "internal.h"
/**
* Special return code when activate() did not do anything.
*/
#define FFERROR_NOT_READY FFERRTAG('N','R','D','Y')
/**
* Mark a filter ready and schedule it for activation.
*
* This is automatically done when something happens to the filter (queued
* frame, status change, request on output).
* Filters implementing the activate callback can call it directly to
* perform one more round of processing later.
* It is also useful for filters reacting to external or asynchronous
* events.
*/
void ff_filter_set_ready(AVFilterContext *filter, unsigned priority);
/**
* Process the commands queued in the link up to the time of the frame.
* Commands will trigger the process_command() callback.
* @return >= 0 or AVERROR code.
*/
int ff_inlink_process_commands(AVFilterLink *link, const AVFrame *frame);
/**
* Evaluate the timeline expression of the link for the time and properties
* of the frame.
* @return >0 if enabled, 0 if disabled
* @note It does not update link->dst->is_disabled.
*/
int ff_inlink_evaluate_timeline_at_frame(AVFilterLink *link, const AVFrame *frame);
/**
* Test if a frame is available on the link.
* @return >0 if a frame is available
*/
int ff_inlink_check_available_frame(AVFilterLink *link);
/**
* Test if enough samples are available on the link.
* @return >0 if enough samples are available
* @note on EOF and error, min becomes 1
*/
int ff_inlink_check_available_samples(AVFilterLink *link, unsigned min);
/**
* Take a frame from the link's FIFO and update the link's stats.
*
* If ff_inlink_check_available_frame() was previously called, the
* preferred way of expressing it is "av_assert1(ret);" immediately after
* ff_inlink_consume_frame(). Negative error codes must still be checked.
*
* @note May trigger process_command() and/or update is_disabled.
* @return >0 if a frame is available,
* 0 and set rframe to NULL if no frame available,
* or AVERROR code
*/
int ff_inlink_consume_frame(AVFilterLink *link, AVFrame **rframe);
/**
* Take samples from the link's FIFO and update the link's stats.
*
* If ff_inlink_check_available_samples() was previously called, the
* preferred way of expressing it is "av_assert1(ret);" immediately after
* ff_inlink_consume_samples(). Negative error codes must still be checked.
*
* @note May trigger process_command() and/or update is_disabled.
* @return >0 if a frame is available,
* 0 and set rframe to NULL if no frame available,
* or AVERROR code
*/
int ff_inlink_consume_samples(AVFilterLink *link, unsigned min, unsigned max,
AVFrame **rframe);
/**
* Make sure a frame is writable.
* This is similar to av_frame_make_writable() except it uses the link's
* buffer allocation callback, and therefore allows direct rendering.
*/
int ff_inlink_make_frame_writable(AVFilterLink *link, AVFrame **rframe);
/**
* Test and acknowledge the change of status on the link.
*
* Status means EOF or an error condition; a change from the normal (0)
* status to a non-zero status can be queued in a filter's input link, it
* becomes relevant after the frames queued in the link's FIFO are
* processed. This function tests if frames are still queued and if a queued
* status change has not yet been processed. In that case it performs basic
* treatment (updating the link's timestamp) and returns a positive value to
* let the filter do its own treatments (flushing...).
*
* Filters implementing the activate callback should call this function when
* they think it might succeed (usually after checking unsuccessfully for a
* queued frame).
* Filters implementing the filter_frame and request_frame callbacks do not
* need to call that since the same treatment happens in ff_filter_frame().
*
* @param[out] rstatus new or current status
* @param[out] rpts current timestamp of the link in link time base
* @return >0 if status changed, <0 if status already acked, 0 otherwise
*/
int ff_inlink_acknowledge_status(AVFilterLink *link, int *rstatus, int64_t *rpts);
/**
* Mark that a frame is wanted on the link.
* Unlike ff_filter_frame(), it must not be called when the link has a
* non-zero status, and thus does not acknowledge it.
* Also it cannot fail.
*/
void ff_inlink_request_frame(AVFilterLink *link);
/**
* Set the status on an input link.
* Also discard all frames in the link's FIFO.
*/
void ff_inlink_set_status(AVFilterLink *link, int status);
/**
* Test if a frame is wanted on an output link.
*/
static inline int ff_outlink_frame_wanted(AVFilterLink *link)
{
return link->frame_wanted_out;
}
/**
* Get the status on an output link.
*/
int ff_outlink_get_status(AVFilterLink *link);
/**
* Set the status field of a link from the source filter.
* The pts should reflect the timestamp of the status change,
* in link time base and relative to the frames timeline.
* In particular, for AVERROR_EOF, it should reflect the
* end time of the last frame.
*/
static inline void ff_outlink_set_status(AVFilterLink *link, int status, int64_t pts)
{
ff_avfilter_link_set_in_status(link, status, pts);
}
/**
* Forward the status on an output link to an input link.
* If the status is set, it will discard all queued frames and this macro
* will return immediately.
*/
#define FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink) do { \
int ret = ff_outlink_get_status(outlink); \
if (ret) { \
ff_inlink_set_status(inlink, ret); \
return 0; \
} \
} while (0)
/**
* Forward the status on an output link to all input links.
* If the status is set, it will discard all queued frames and this macro
* will return immediately.
*/
#define FF_FILTER_FORWARD_STATUS_BACK_ALL(outlink, filter) do { \
int ret = ff_outlink_get_status(outlink); \
if (ret) { \
unsigned i; \
for (i = 0; i < filter->nb_inputs; i++) \
ff_inlink_set_status(filter->inputs[i], ret); \
return 0; \
} \
} while (0)
/**
* Acknowledge the status on an input link and forward it to an output link.
* If the status is set, this macro will return immediately.
*/
#define FF_FILTER_FORWARD_STATUS(inlink, outlink) do { \
int status; \
int64_t pts; \
if (ff_inlink_acknowledge_status(inlink, &status, &pts)) { \
ff_outlink_set_status(outlink, status, pts); \
return 0; \
} \
} while (0)
/**
* Acknowledge the status on an input link and forward it to an output link.
* If the status is set, this macro will return immediately.
*/
#define FF_FILTER_FORWARD_STATUS_ALL(inlink, filter) do { \
int status; \
int64_t pts; \
if (ff_inlink_acknowledge_status(inlink, &status, &pts)) { \
unsigned i; \
for (i = 0; i < filter->nb_outputs; i++) \
ff_outlink_set_status(filter->outputs[i], status, pts); \
return 0; \
} \
} while (0)
/**
* Forward the frame_wanted_out flag from an output link to an input link.
* If the flag is set, this macro will return immediately.
*/
#define FF_FILTER_FORWARD_WANTED(outlink, inlink) do { \
if (ff_outlink_frame_wanted(outlink)) { \
ff_inlink_request_frame(inlink); \
return 0; \
} \
} while (0)
#endif /* AVFILTER_FILTERS_H */