mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-11-21 10:55:51 +02:00
351 lines
10 KiB
C
351 lines
10 KiB
C
/*
|
|
* Copyright (c) 2011 Stefano Sabatini
|
|
*
|
|
* This file is part of Libav.
|
|
*
|
|
* Libav 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.
|
|
*
|
|
* Libav 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 Libav; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* filter for selecting which frame passes in the filterchain
|
|
*/
|
|
|
|
#include "libavutil/eval.h"
|
|
#include "libavutil/fifo.h"
|
|
#include "libavutil/internal.h"
|
|
#include "libavutil/mathematics.h"
|
|
#include "libavutil/opt.h"
|
|
#include "avfilter.h"
|
|
#include "internal.h"
|
|
#include "video.h"
|
|
|
|
static const char *const var_names[] = {
|
|
"E", ///< Euler number
|
|
"PHI", ///< golden ratio
|
|
"PI", ///< Greek pi
|
|
|
|
"TB", ///< timebase
|
|
|
|
"pts", ///< original pts in the file of the frame
|
|
"start_pts", ///< first PTS in the stream, expressed in TB units
|
|
"prev_pts", ///< previous frame PTS
|
|
"prev_selected_pts", ///< previous selected frame PTS
|
|
|
|
"t", ///< first PTS in seconds
|
|
"start_t", ///< first PTS in the stream, expressed in seconds
|
|
"prev_t", ///< previous frame time
|
|
"prev_selected_t", ///< previously selected time
|
|
|
|
"pict_type", ///< the type of picture in the movie
|
|
"I",
|
|
"P",
|
|
"B",
|
|
"S",
|
|
"SI",
|
|
"SP",
|
|
"BI",
|
|
|
|
"interlace_type", ///< the frame interlace type
|
|
"PROGRESSIVE",
|
|
"TOPFIRST",
|
|
"BOTTOMFIRST",
|
|
|
|
"n", ///< frame number (starting from zero)
|
|
"selected_n", ///< selected frame number (starting from zero)
|
|
"prev_selected_n", ///< number of the last selected frame
|
|
|
|
"key", ///< tell if the frame is a key frame
|
|
"pos", ///< original position in the file of the frame
|
|
|
|
NULL
|
|
};
|
|
|
|
enum var_name {
|
|
VAR_E,
|
|
VAR_PHI,
|
|
VAR_PI,
|
|
|
|
VAR_TB,
|
|
|
|
VAR_PTS,
|
|
VAR_START_PTS,
|
|
VAR_PREV_PTS,
|
|
VAR_PREV_SELECTED_PTS,
|
|
|
|
VAR_T,
|
|
VAR_START_T,
|
|
VAR_PREV_T,
|
|
VAR_PREV_SELECTED_T,
|
|
|
|
VAR_PICT_TYPE,
|
|
VAR_PICT_TYPE_I,
|
|
VAR_PICT_TYPE_P,
|
|
VAR_PICT_TYPE_B,
|
|
VAR_PICT_TYPE_S,
|
|
VAR_PICT_TYPE_SI,
|
|
VAR_PICT_TYPE_SP,
|
|
VAR_PICT_TYPE_BI,
|
|
|
|
VAR_INTERLACE_TYPE,
|
|
VAR_INTERLACE_TYPE_P,
|
|
VAR_INTERLACE_TYPE_T,
|
|
VAR_INTERLACE_TYPE_B,
|
|
|
|
VAR_N,
|
|
VAR_SELECTED_N,
|
|
VAR_PREV_SELECTED_N,
|
|
|
|
VAR_KEY,
|
|
|
|
VAR_VARS_NB
|
|
};
|
|
|
|
#define FIFO_SIZE 8
|
|
|
|
typedef struct SelectContext {
|
|
const AVClass *class;
|
|
char *expr_str;
|
|
AVExpr *expr;
|
|
double var_values[VAR_VARS_NB];
|
|
double select;
|
|
int cache_frames;
|
|
AVFifoBuffer *pending_frames; ///< FIFO buffer of video frames
|
|
} SelectContext;
|
|
|
|
static av_cold int init(AVFilterContext *ctx)
|
|
{
|
|
SelectContext *select = ctx->priv;
|
|
int ret;
|
|
|
|
if ((ret = av_expr_parse(&select->expr, select->expr_str,
|
|
var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) {
|
|
av_log(ctx, AV_LOG_ERROR, "Error while parsing expression '%s'\n",
|
|
select->expr_str);
|
|
return ret;
|
|
}
|
|
|
|
select->pending_frames = av_fifo_alloc(FIFO_SIZE*sizeof(AVFrame*));
|
|
if (!select->pending_frames) {
|
|
av_log(ctx, AV_LOG_ERROR, "Failed to allocate pending frames buffer.\n");
|
|
return AVERROR(ENOMEM);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#define INTERLACE_TYPE_P 0
|
|
#define INTERLACE_TYPE_T 1
|
|
#define INTERLACE_TYPE_B 2
|
|
|
|
static int config_input(AVFilterLink *inlink)
|
|
{
|
|
SelectContext *select = inlink->dst->priv;
|
|
|
|
select->var_values[VAR_E] = M_E;
|
|
select->var_values[VAR_PHI] = M_PHI;
|
|
select->var_values[VAR_PI] = M_PI;
|
|
|
|
select->var_values[VAR_N] = 0.0;
|
|
select->var_values[VAR_SELECTED_N] = 0.0;
|
|
|
|
select->var_values[VAR_TB] = av_q2d(inlink->time_base);
|
|
|
|
select->var_values[VAR_PREV_PTS] = NAN;
|
|
select->var_values[VAR_PREV_SELECTED_PTS] = NAN;
|
|
select->var_values[VAR_PREV_SELECTED_T] = NAN;
|
|
select->var_values[VAR_START_PTS] = NAN;
|
|
select->var_values[VAR_START_T] = NAN;
|
|
|
|
select->var_values[VAR_PICT_TYPE_I] = AV_PICTURE_TYPE_I;
|
|
select->var_values[VAR_PICT_TYPE_P] = AV_PICTURE_TYPE_P;
|
|
select->var_values[VAR_PICT_TYPE_B] = AV_PICTURE_TYPE_B;
|
|
select->var_values[VAR_PICT_TYPE_SI] = AV_PICTURE_TYPE_SI;
|
|
select->var_values[VAR_PICT_TYPE_SP] = AV_PICTURE_TYPE_SP;
|
|
|
|
select->var_values[VAR_INTERLACE_TYPE_P] = INTERLACE_TYPE_P;
|
|
select->var_values[VAR_INTERLACE_TYPE_T] = INTERLACE_TYPE_T;
|
|
select->var_values[VAR_INTERLACE_TYPE_B] = INTERLACE_TYPE_B;;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define D2TS(d) (isnan(d) ? AV_NOPTS_VALUE : (int64_t)(d))
|
|
#define TS2D(ts) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts))
|
|
|
|
static int select_frame(AVFilterContext *ctx, AVFrame *frame)
|
|
{
|
|
SelectContext *select = ctx->priv;
|
|
AVFilterLink *inlink = ctx->inputs[0];
|
|
double res;
|
|
|
|
if (isnan(select->var_values[VAR_START_PTS]))
|
|
select->var_values[VAR_START_PTS] = TS2D(frame->pts);
|
|
if (isnan(select->var_values[VAR_START_T]))
|
|
select->var_values[VAR_START_T] = TS2D(frame->pts) * av_q2d(inlink->time_base);
|
|
|
|
select->var_values[VAR_PTS] = TS2D(frame->pts);
|
|
select->var_values[VAR_T ] = TS2D(frame->pts) * av_q2d(inlink->time_base);
|
|
select->var_values[VAR_PREV_PTS] = TS2D(frame->pts);
|
|
|
|
select->var_values[VAR_INTERLACE_TYPE] =
|
|
!frame->interlaced_frame ? INTERLACE_TYPE_P :
|
|
frame->top_field_first ? INTERLACE_TYPE_T : INTERLACE_TYPE_B;
|
|
select->var_values[VAR_PICT_TYPE] = frame->pict_type;
|
|
|
|
res = av_expr_eval(select->expr, select->var_values, NULL);
|
|
|
|
select->var_values[VAR_N] += 1.0;
|
|
|
|
if (res) {
|
|
select->var_values[VAR_PREV_SELECTED_N] = select->var_values[VAR_N];
|
|
select->var_values[VAR_PREV_SELECTED_PTS] = select->var_values[VAR_PTS];
|
|
select->var_values[VAR_PREV_SELECTED_T] = select->var_values[VAR_T];
|
|
select->var_values[VAR_SELECTED_N] += 1.0;
|
|
}
|
|
return res;
|
|
}
|
|
|
|
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
|
|
{
|
|
SelectContext *select = inlink->dst->priv;
|
|
|
|
select->select = select_frame(inlink->dst, frame);
|
|
if (select->select) {
|
|
/* frame was requested through poll_frame */
|
|
if (select->cache_frames) {
|
|
if (!av_fifo_space(select->pending_frames)) {
|
|
av_log(inlink->dst, AV_LOG_ERROR,
|
|
"Buffering limit reached, cannot cache more frames\n");
|
|
av_frame_free(&frame);
|
|
} else
|
|
av_fifo_generic_write(select->pending_frames, &frame,
|
|
sizeof(frame), NULL);
|
|
return 0;
|
|
}
|
|
return ff_filter_frame(inlink->dst->outputs[0], frame);
|
|
}
|
|
|
|
av_frame_free(&frame);
|
|
return 0;
|
|
}
|
|
|
|
static int request_frame(AVFilterLink *outlink)
|
|
{
|
|
AVFilterContext *ctx = outlink->src;
|
|
SelectContext *select = ctx->priv;
|
|
AVFilterLink *inlink = outlink->src->inputs[0];
|
|
select->select = 0;
|
|
|
|
if (av_fifo_size(select->pending_frames)) {
|
|
AVFrame *frame;
|
|
|
|
av_fifo_generic_read(select->pending_frames, &frame, sizeof(frame), NULL);
|
|
return ff_filter_frame(outlink, frame);
|
|
}
|
|
|
|
while (!select->select) {
|
|
int ret = ff_request_frame(inlink);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int poll_frame(AVFilterLink *outlink)
|
|
{
|
|
SelectContext *select = outlink->src->priv;
|
|
AVFilterLink *inlink = outlink->src->inputs[0];
|
|
int count, ret;
|
|
|
|
if (!av_fifo_size(select->pending_frames)) {
|
|
if ((count = ff_poll_frame(inlink)) <= 0)
|
|
return count;
|
|
/* request frame from input, and apply select condition to it */
|
|
select->cache_frames = 1;
|
|
while (count-- && av_fifo_space(select->pending_frames)) {
|
|
ret = ff_request_frame(inlink);
|
|
if (ret < 0)
|
|
break;
|
|
}
|
|
select->cache_frames = 0;
|
|
}
|
|
|
|
return av_fifo_size(select->pending_frames)/sizeof(AVFrame*);
|
|
}
|
|
|
|
static av_cold void uninit(AVFilterContext *ctx)
|
|
{
|
|
SelectContext *select = ctx->priv;
|
|
AVFrame *frame;
|
|
|
|
av_expr_free(select->expr);
|
|
select->expr = NULL;
|
|
|
|
while (select->pending_frames &&
|
|
av_fifo_generic_read(select->pending_frames, &frame, sizeof(frame), NULL) == sizeof(frame))
|
|
av_frame_free(&frame);
|
|
av_fifo_free(select->pending_frames);
|
|
select->pending_frames = NULL;
|
|
}
|
|
|
|
#define OFFSET(x) offsetof(SelectContext, x)
|
|
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM
|
|
static const AVOption options[] = {
|
|
{ "expr", "An expression to use for selecting frames", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "1" }, .flags = FLAGS },
|
|
{ NULL },
|
|
};
|
|
|
|
static const AVClass select_class = {
|
|
.class_name = "select",
|
|
.item_name = av_default_item_name,
|
|
.option = options,
|
|
.version = LIBAVUTIL_VERSION_INT,
|
|
};
|
|
|
|
static const AVFilterPad avfilter_vf_select_inputs[] = {
|
|
{
|
|
.name = "default",
|
|
.type = AVMEDIA_TYPE_VIDEO,
|
|
.get_video_buffer = ff_null_get_video_buffer,
|
|
.config_props = config_input,
|
|
.filter_frame = filter_frame,
|
|
},
|
|
{ NULL }
|
|
};
|
|
|
|
static const AVFilterPad avfilter_vf_select_outputs[] = {
|
|
{
|
|
.name = "default",
|
|
.type = AVMEDIA_TYPE_VIDEO,
|
|
.poll_frame = poll_frame,
|
|
.request_frame = request_frame,
|
|
},
|
|
{ NULL }
|
|
};
|
|
|
|
AVFilter ff_vf_select = {
|
|
.name = "select",
|
|
.description = NULL_IF_CONFIG_SMALL("Select frames to pass in output."),
|
|
.init = init,
|
|
.uninit = uninit,
|
|
|
|
.priv_size = sizeof(SelectContext),
|
|
.priv_class = &select_class,
|
|
|
|
.inputs = avfilter_vf_select_inputs,
|
|
.outputs = avfilter_vf_select_outputs,
|
|
};
|