/*
* Copyright (c) 2011 Stefano Sabatini
*
* 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
*/
/**
* @file
* filter for selecting which frame passes in the filterchain
*/
#include "libavutil/avstring.h"
#include "libavutil/eval.h"
#include "libavutil/fifo.h"
#include "libavutil/internal.h"
#include "libavutil/opt.h"
#include "avfilter.h"
#include "audio.h"
#include "formats.h"
#include "internal.h"
#include "video.h"
#if CONFIG_AVCODEC
#include "libavcodec/dsputil.h"
#endif
static const char *const var_names[] = {
"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",
"PICT_TYPE_I",
"PICT_TYPE_P",
"PICT_TYPE_B",
"PICT_TYPE_S",
"PICT_TYPE_SI",
"PICT_TYPE_SP",
"PICT_TYPE_BI",
"interlace_type", ///< the frame interlace type
"PROGRESSIVE",
"TOPFIRST",
"BOTTOMFIRST",
"consumed_samples_n",///< number of samples consumed by the filter (only audio)
"samples_n", ///< number of samples in the current frame (only audio)
"sample_rate", ///< sample rate (only audio)
"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
"scene",
NULL
};
enum var_name {
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_I,
VAR_P,
VAR_B,
VAR_S,
VAR_SI,
VAR_SP,
VAR_BI,
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_CONSUMED_SAMPLES_N,
VAR_SAMPLES_N,
VAR_SAMPLE_RATE,
VAR_N,
VAR_SELECTED_N,
VAR_PREV_SELECTED_N,
VAR_KEY,
VAR_POS,
VAR_SCENE,
VAR_VARS_NB
};
typedef struct {
const AVClass *class;
char *expr_str;
AVExpr *expr;
double var_values[VAR_VARS_NB];
int do_scene_detect; ///< 1 if the expression requires scene detection variables, 0 otherwise
#if CONFIG_AVCODEC
AVCodecContext *avctx; ///< codec context required for the DSPContext (scene detect only)
DSPContext c; ///< context providing optimized SAD methods (scene detect only)
double prev_mafd; ///< previous MAFD (scene detect only)
#endif
AVFrame *prev_picref; ///< previous frame (scene detect only)
double select;
int select_out; ///< mark the selected output pad index
int nb_outputs;
} SelectContext;
#define OFFSET(x) offsetof(SelectContext, x)
#define DEFINE_OPTIONS(filt_name, FLAGS) \
static const AVOption filt_name##_options[] = { \
{ "expr", "set an expression to use for selecting frames", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "1" }, .flags=FLAGS }, \
{ "e", "set an expression to use for selecting frames", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "1" }, .flags=FLAGS }, \
{ "outputs", "set the number of outputs", OFFSET(nb_outputs), AV_OPT_TYPE_INT, {.i64 = 1}, 1, INT_MAX, .flags=FLAGS }, \
{ "n", "set the number of outputs", OFFSET(nb_outputs), AV_OPT_TYPE_INT, {.i64 = 1}, 1, INT_MAX, .flags=FLAGS }, \
{ NULL } \
}
static int request_frame(AVFilterLink *outlink);
static av_cold int init(AVFilterContext *ctx)
{
SelectContext *select = ctx->priv;
int i, 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
->do_scene_detect
= !!strstr(select
->expr_str
, "scene");
for (i = 0; i < select->nb_outputs; i++) {
AVFilterPad pad = { 0 };
pad.name = av_asprintf("output%d", i);
if (!pad.name)
return AVERROR(ENOMEM);
pad.type = ctx->filter->inputs[0].type;
pad.request_frame = request_frame;
ff_insert_outpad(ctx, i, &pad);
}
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_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_PREV_T] = NAN;
select->var_values[VAR_START_PTS] = NAN;
select->var_values[VAR_START_T] = NAN;
select->var_values[VAR_I] = AV_PICTURE_TYPE_I;
select->var_values[VAR_P] = AV_PICTURE_TYPE_P;
select->var_values[VAR_B] = AV_PICTURE_TYPE_B;
select->var_values[VAR_SI] = AV_PICTURE_TYPE_SI;
select->var_values[VAR_SP] = AV_PICTURE_TYPE_SP;
select->var_values[VAR_BI] = AV_PICTURE_TYPE_BI;
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_PICT_TYPE_BI] = AV_PICTURE_TYPE_BI;
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;
select->var_values[VAR_PICT_TYPE] = NAN;
select->var_values[VAR_INTERLACE_TYPE] = NAN;
select->var_values[VAR_SCENE] = NAN;
select->var_values[VAR_CONSUMED_SAMPLES_N] = NAN;
select->var_values[VAR_SAMPLES_N] = NAN;
select->var_values[VAR_SAMPLE_RATE] =
inlink->type == AVMEDIA_TYPE_AUDIO ? inlink->sample_rate : NAN;
#if CONFIG_AVCODEC
if (select->do_scene_detect) {
select->avctx = avcodec_alloc_context3(NULL);
if (!select->avctx)
return AVERROR(ENOMEM);
avpriv_dsputil_init(&select->c, select->avctx);
}
#endif
return 0;
}
#if CONFIG_AVCODEC
static double get_scene_score(AVFilterContext *ctx, AVFrame *frame)
{
double ret = 0;
SelectContext *select = ctx->priv;
AVFrame *prev_picref = select->prev_picref;
if (prev_picref &&
frame->height == prev_picref->height &&
frame->width == prev_picref->width &&
frame->linesize[0] == prev_picref->linesize[0]) {
int x, y, nb_sad = 0;
int64_t sad = 0;
double mafd, diff;
uint8_t *p1 = frame->data[0];
uint8_t *p2 = prev_picref->data[0];
const int linesize = frame->linesize[0];
for (y = 0; y < frame->height - 8; y += 8) {
for (x = 0; x < frame->width*3 - 8; x += 8) {
sad += select->c.sad[1](select, p1 + x, p2 + x,
linesize, 8);
nb_sad += 8 * 8;
}
p1 += 8 * linesize;
p2 += 8 * linesize;
}
emms_c();
mafd = nb_sad ? sad / nb_sad : 0;
diff
= fabs(mafd
- select
->prev_mafd
); ret = av_clipf(FFMIN(mafd, diff) / 100., 0, 1);
select->prev_mafd = mafd;
av_frame_free(&prev_picref);
}
select->prev_picref = av_frame_clone(frame);
return ret;
}
#endif
#define D2TS(d) (isnan(d) ? AV_NOPTS_VALUE : (int64_t)(d))
#define TS2D(ts) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts))
static void 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_N ] = inlink->frame_count;
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_POS] = av_frame_get_pkt_pos(frame) == -1 ? NAN : av_frame_get_pkt_pos(frame);
switch (inlink->type) {
case AVMEDIA_TYPE_AUDIO:
select->var_values[VAR_SAMPLES_N] = frame->nb_samples;
break;
case AVMEDIA_TYPE_VIDEO:
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;
#if CONFIG_AVCODEC
if (select->do_scene_detect) {
char buf[32];
select->var_values[VAR_SCENE] = get_scene_score(ctx, frame);
// TODO: document metadata
snprintf(buf
, sizeof(buf
), "%f", select
->var_values
[VAR_SCENE
]); av_dict_set(avpriv_frame_get_metadatap(frame), "lavfi.scene_score", buf, 0);
}
#endif
break;
}
select->select = res = av_expr_eval(select->expr, select->var_values, NULL);
av_log(inlink->dst, AV_LOG_DEBUG,
"n:%f pts:%f t:%f key:%d",
select->var_values[VAR_N],
select->var_values[VAR_PTS],
select->var_values[VAR_T],
(int)select->var_values[VAR_KEY]);
switch (inlink->type) {
case AVMEDIA_TYPE_VIDEO:
av_log(inlink->dst, AV_LOG_DEBUG, " interlace_type:%c pict_type:%c scene:%f",
select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_P ? 'P' :
select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_T ? 'T' :
select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_B ? 'B' : '?',
av_get_picture_type_char(select->var_values[VAR_PICT_TYPE]),
select->var_values[VAR_SCENE]);
break;
case AVMEDIA_TYPE_AUDIO:
av_log(inlink->dst, AV_LOG_DEBUG, " samples_n:%d consumed_samples_n:%d",
(int)select->var_values[VAR_SAMPLES_N],
(int)select->var_values[VAR_CONSUMED_SAMPLES_N]);
break;
}
if (res == 0) {
select->select_out = -1; /* drop */
} else if (isnan(res) || res < 0) {
select->select_out = 0; /* first output */
} else {
select->select_out = FFMIN(ceilf(res)-1, select->nb_outputs-1); /* other outputs */
}
av_log(inlink->dst, AV_LOG_DEBUG, " -> select:%f select_out:%d\n", res, select->select_out);
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;
if (inlink->type == AVMEDIA_TYPE_AUDIO)
select->var_values[VAR_CONSUMED_SAMPLES_N] += frame->nb_samples;
}
select->var_values[VAR_PREV_PTS] = select->var_values[VAR_PTS];
select->var_values[VAR_PREV_T] = select->var_values[VAR_T];
}
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
{
AVFilterContext *ctx = inlink->dst;
SelectContext *select = ctx->priv;
select_frame(ctx, frame);
if (select->select)
return ff_filter_frame(ctx->outputs[select->select_out], 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];
int out_no = FF_OUTLINK_IDX(outlink);
do {
int ret = ff_request_frame(inlink);
if (ret < 0)
return ret;
} while (select->select_out != out_no);
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
SelectContext *select = ctx->priv;
int i;
av_expr_free(select->expr);
select->expr = NULL;
for (i = 0; i < ctx->nb_outputs; i++)
av_freep(&ctx->output_pads[i].name);
#if CONFIG_AVCODEC
if (select->do_scene_detect) {
av_frame_free(&select->prev_picref);
if (select->avctx) {
avcodec_close(select->avctx);
av_freep(&select->avctx);
}
}
#endif
}
static int query_formats(AVFilterContext *ctx)
{
SelectContext *select = ctx->priv;
if (!select->do_scene_detect) {
return ff_default_query_formats(ctx);
} else {
static const enum AVPixelFormat pix_fmts[] = {
AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
AV_PIX_FMT_NONE
};
ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
}
return 0;
}
#if CONFIG_ASELECT_FILTER
DEFINE_OPTIONS(aselect, AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM);
AVFILTER_DEFINE_CLASS(aselect);
static av_cold int aselect_init(AVFilterContext *ctx)
{
SelectContext *select = ctx->priv;
int ret;
if ((ret = init(ctx)) < 0)
return ret;
if (select->do_scene_detect) {
av_log(ctx, AV_LOG_ERROR, "Scene detection is ignored in aselect filter\n");
return AVERROR(EINVAL);
}
return 0;
}
static const AVFilterPad avfilter_af_aselect_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.config_props = config_input,
.filter_frame = filter_frame,
},
{ NULL }
};
AVFilter avfilter_af_aselect = {
.name = "aselect",
.description = NULL_IF_CONFIG_SMALL("Select audio frames to pass in output."),
.init = aselect_init,
.uninit = uninit,
.priv_size = sizeof(SelectContext),
.inputs = avfilter_af_aselect_inputs,
.priv_class = &aselect_class,
.flags = AVFILTER_FLAG_DYNAMIC_OUTPUTS,
};
#endif /* CONFIG_ASELECT_FILTER */
#if CONFIG_SELECT_FILTER
DEFINE_OPTIONS(select, AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM);
AVFILTER_DEFINE_CLASS(select);
static av_cold int select_init(AVFilterContext *ctx)
{
SelectContext *select = ctx->priv;
int ret;
if ((ret = init(ctx)) < 0)
return ret;
if (select->do_scene_detect && !CONFIG_AVCODEC) {
av_log(ctx, AV_LOG_ERROR, "Scene detection is not available without libavcodec.\n");
return AVERROR(EINVAL);
}
return 0;
}
static const AVFilterPad avfilter_vf_select_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_input,
.filter_frame = filter_frame,
},
{ NULL }
};
AVFilter avfilter_vf_select = {
.name = "select",
.description = NULL_IF_CONFIG_SMALL("Select video frames to pass in output."),
.init = select_init,
.uninit = uninit,
.query_formats = query_formats,
.priv_size = sizeof(SelectContext),
.priv_class = &select_class,
.inputs = avfilter_vf_select_inputs,
.flags = AVFILTER_FLAG_DYNAMIC_OUTPUTS,
};
#endif /* CONFIG_SELECT_FILTER */