libavfilter/vf_fps: Rewrite using activate callback

The old version of the filter had a problem where it would queue up
all of the duplicate frames required to fill a timestamp gap in a
single call to filter_frame. In problematic files - I've hit this in
webcam streams with large gaps due to network issues - this will queue
up a potentially huge number of frames. (I've seen it trigger the Linux
OOM-killer on particularly large pts gaps.)

This revised version of the filter using the activate callback will
generate at most 1 frame each time it is called.
pull/281/head
Calvin Walton 7 years ago committed by Nicolas George
parent 2f147588f7
commit e4edc567a0
  1. 342
      libavfilter/vf_fps.c

@ -2,6 +2,7 @@
* Copyright 2007 Bobby Bingham * Copyright 2007 Bobby Bingham
* Copyright 2012 Robert Nagy <ronag89 gmail com> * Copyright 2012 Robert Nagy <ronag89 gmail com>
* Copyright 2012 Anton Khirnov <anton khirnov net> * Copyright 2012 Anton Khirnov <anton khirnov net>
* Copyright 2018 Calvin Walton <calvin.walton@kepstin.ca>
* *
* This file is part of FFmpeg. * This file is part of FFmpeg.
* *
@ -28,17 +29,12 @@
#include <float.h> #include <float.h>
#include <stdint.h> #include <stdint.h>
#include "libavutil/common.h" #include "libavutil/avassert.h"
#include "libavutil/fifo.h"
#include "libavutil/mathematics.h" #include "libavutil/mathematics.h"
#include "libavutil/opt.h" #include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#define FF_INTERNAL_FIELDS 1
#include "framequeue.h"
#include "avfilter.h" #include "avfilter.h"
#include "filters.h"
#include "internal.h" #include "internal.h"
#include "video.h"
enum EOFAction { enum EOFAction {
EOF_ACTION_ROUND, EOF_ACTION_ROUND,
@ -49,18 +45,27 @@ enum EOFAction {
typedef struct FPSContext { typedef struct FPSContext {
const AVClass *class; const AVClass *class;
AVFifoBuffer *fifo; ///< store frames until we get two successive timestamps
/* timestamps in input timebase */
int64_t first_pts; ///< pts of the first frame that arrived on this filter
double start_time; ///< pts, in seconds, of the expected first frame double start_time; ///< pts, in seconds, of the expected first frame
AVRational framerate; ///< target framerate AVRational framerate; ///< target framerate
int rounding; ///< AVRounding method for timestamps int rounding; ///< AVRounding method for timestamps
int eof_action; ///< action performed for last frame in FIFO int eof_action; ///< action performed for last frame in FIFO
/* Set during outlink configuration */
int64_t in_pts_off; ///< input frame pts offset for start_time handling
int64_t out_pts_off; ///< output frame pts offset for start_time handling
/* Runtime state */
int status; ///< buffered input status
int64_t status_pts; ///< buffered input status timestamp
AVFrame *frames[2]; ///< buffered frames
int frames_count; ///< number of buffered frames
int64_t next_pts; ///< pts of the next frame to output
/* statistics */ /* statistics */
int cur_frame_out; ///< number of times current frame has been output
int frames_in; ///< number of frames on input int frames_in; ///< number of frames on input
int frames_out; ///< number of frames on output int frames_out; ///< number of frames on output
int dup; ///< number of frames duplicated int dup; ///< number of frames duplicated
@ -91,31 +96,51 @@ static av_cold int init(AVFilterContext *ctx)
{ {
FPSContext *s = ctx->priv; FPSContext *s = ctx->priv;
if (!(s->fifo = av_fifo_alloc_array(2, sizeof(AVFrame*)))) s->status_pts = AV_NOPTS_VALUE;
return AVERROR(ENOMEM); s->next_pts = AV_NOPTS_VALUE;
s->first_pts = AV_NOPTS_VALUE;
av_log(ctx, AV_LOG_VERBOSE, "fps=%d/%d\n", s->framerate.num, s->framerate.den); av_log(ctx, AV_LOG_VERBOSE, "fps=%d/%d\n", s->framerate.num, s->framerate.den);
return 0; return 0;
} }
static void flush_fifo(AVFifoBuffer *fifo) /* Remove the first frame from the buffer, returning it */
static AVFrame *shift_frame(AVFilterContext *ctx, FPSContext *s)
{ {
while (av_fifo_size(fifo)) { AVFrame *frame;
AVFrame *tmp;
av_fifo_generic_read(fifo, &tmp, sizeof(tmp), NULL); /* Must only be called when there are frames in the buffer */
av_frame_free(&tmp); av_assert1(s->frames_count > 0);
frame = s->frames[0];
s->frames[0] = s->frames[1];
s->frames[1] = NULL;
s->frames_count--;
/* Update statistics counters */
s->frames_out += s->cur_frame_out;
if (s->cur_frame_out > 1) {
av_log(ctx, AV_LOG_DEBUG, "Duplicated frame with pts %"PRId64" %d times\n",
frame->pts, s->cur_frame_out - 1);
s->dup += s->cur_frame_out - 1;
} else if (s->cur_frame_out == 0) {
av_log(ctx, AV_LOG_DEBUG, "Dropping frame with pts %"PRId64"\n",
frame->pts);
s->drop++;
} }
s->cur_frame_out = 0;
return frame;
} }
static av_cold void uninit(AVFilterContext *ctx) static av_cold void uninit(AVFilterContext *ctx)
{ {
FPSContext *s = ctx->priv; FPSContext *s = ctx->priv;
if (s->fifo) {
s->drop += av_fifo_size(s->fifo) / sizeof(AVFrame*); AVFrame *frame;
flush_fifo(s->fifo);
av_fifo_freep(&s->fifo); while (s->frames_count > 0) {
frame = shift_frame(ctx, s);
av_frame_free(&frame);
} }
av_log(ctx, AV_LOG_VERBOSE, "%d frames in, %d frames out; %d frames dropped, " av_log(ctx, AV_LOG_VERBOSE, "%d frames in, %d frames out; %d frames dropped, "
@ -124,198 +149,187 @@ static av_cold void uninit(AVFilterContext *ctx)
static int config_props(AVFilterLink* link) static int config_props(AVFilterLink* link)
{ {
FPSContext *s = link->src->priv; AVFilterContext *ctx = link->src;
AVFilterLink *inlink = ctx->inputs[0];
FPSContext *s = ctx->priv;
link->time_base = av_inv_q(s->framerate); link->time_base = av_inv_q(s->framerate);
link->frame_rate= s->framerate; link->frame_rate= s->framerate;
link->w = link->src->inputs[0]->w; link->w = link->src->inputs[0]->w;
link->h = link->src->inputs[0]->h; link->h = link->src->inputs[0]->h;
/* Calculate the input and output pts offsets for start_time */
if (s->start_time != DBL_MAX && s->start_time != AV_NOPTS_VALUE) {
double first_pts = s->start_time * AV_TIME_BASE;
if (first_pts < INT64_MIN || first_pts > INT64_MAX) {
av_log(ctx, AV_LOG_ERROR, "Start time %f cannot be represented in internal time base\n",
s->start_time);
return AVERROR(EINVAL);
}
s->in_pts_off = av_rescale_q_rnd(first_pts, AV_TIME_BASE_Q, inlink->time_base,
s->rounding | AV_ROUND_PASS_MINMAX);
s->out_pts_off = av_rescale_q_rnd(first_pts, AV_TIME_BASE_Q, link->time_base,
s->rounding | AV_ROUND_PASS_MINMAX);
s->next_pts = s->out_pts_off;
av_log(ctx, AV_LOG_VERBOSE, "Set first pts to (in:%"PRId64" out:%"PRId64") from start time %f\n",
s->in_pts_off, s->out_pts_off, s->start_time);
}
return 0; return 0;
} }
static int request_frame(AVFilterLink *outlink) /* Read a frame from the input and save it in the buffer */
static int read_frame(AVFilterContext *ctx, FPSContext *s, AVFilterLink *inlink, AVFilterLink *outlink)
{ {
AVFilterContext *ctx = outlink->src; AVFrame *frame;
FPSContext *s = ctx->priv;
int ret; int ret;
int64_t in_pts;
ret = ff_request_frame(ctx->inputs[0]); /* Must only be called when we have buffer room available */
av_assert1(s->frames_count < 2);
/* flush the fifo */ ret = ff_inlink_consume_frame(inlink, &frame);
if (ret == AVERROR_EOF && av_fifo_size(s->fifo)) { /* Caller must have run ff_inlink_check_available_frame first */
int i; av_assert1(ret);
for (i = 0; av_fifo_size(s->fifo); i++) { if (ret < 0)
AVFrame *buf;
av_fifo_generic_read(s->fifo, &buf, sizeof(buf), NULL);
if (av_fifo_size(s->fifo)) {
buf->pts = av_rescale_q(s->first_pts, ctx->inputs[0]->time_base,
outlink->time_base) + s->frames_out;
if ((ret = ff_filter_frame(outlink, buf)) < 0)
return ret;
s->frames_out++;
} else {
/* This is the last frame, we may have to duplicate it to match
* the last frame duration */
int j;
int eof_rounding = (s->eof_action == EOF_ACTION_PASS) ? AV_ROUND_UP : s->rounding;
int delta = av_rescale_q_rnd(ctx->inputs[0]->current_pts - s->first_pts,
ctx->inputs[0]->time_base,
outlink->time_base, eof_rounding) - s->frames_out;
av_log(ctx, AV_LOG_DEBUG, "EOF frames_out:%d delta:%d\n", s->frames_out, delta);
/* if the delta is equal to 1, it means we just need to output
* the last frame. Greater than 1 means we will need duplicate
* delta-1 frames */
if (delta > 0 ) {
for (j = 0; j < delta; j++) {
AVFrame *dup = av_frame_clone(buf);
av_log(ctx, AV_LOG_DEBUG, "Duplicating frame.\n");
dup->pts = av_rescale_q(s->first_pts, ctx->inputs[0]->time_base,
outlink->time_base) + s->frames_out;
if ((ret = ff_filter_frame(outlink, dup)) < 0)
return ret; return ret;
s->frames_out++; /* Convert frame pts to output timebase.
if (j > 0) s->dup++; * The dance with offsets is required to match the rounding behaviour of the
} * previous version of the fps filter when using the start_time option. */
av_frame_free(&buf); in_pts = frame->pts;
} else { frame->pts = s->out_pts_off + av_rescale_q_rnd(in_pts - s->in_pts_off,
/* for delta less or equal to 0, we should drop the frame, inlink->time_base, outlink->time_base,
* otherwise, we will have one or more extra frames */ s->rounding | AV_ROUND_PASS_MINMAX);
av_frame_free(&buf);
s->drop++;
}
}
}
return 0;
}
return ret;
}
static int write_to_fifo(AVFifoBuffer *fifo, AVFrame *buf) av_log(ctx, AV_LOG_DEBUG, "Read frame with in pts %"PRId64", out pts %"PRId64"\n",
{ in_pts, frame->pts);
int ret;
if (!av_fifo_space(fifo) && s->frames[s->frames_count++] = frame;
(ret = av_fifo_realloc2(fifo, 2*av_fifo_size(fifo)))) { s->frames_in++;
av_frame_free(&buf);
return ret;
}
av_fifo_generic_write(fifo, &buf, sizeof(buf), NULL); return 1;
return 0;
} }
static int filter_frame(AVFilterLink *inlink, AVFrame *buf) /* Write a frame to the output */
static int write_frame(AVFilterContext *ctx, FPSContext *s, AVFilterLink *outlink, int *again)
{ {
AVFilterContext *ctx = inlink->dst; AVFrame *frame;
FPSContext *s = ctx->priv;
AVFilterLink *outlink = ctx->outputs[0];
int64_t delta;
int i, ret;
s->frames_in++; av_assert1(s->frames_count == 2 || (s->status && s->frames_count == 1));
/* discard frames until we get the first timestamp */
if (s->first_pts == AV_NOPTS_VALUE) {
if (buf->pts != AV_NOPTS_VALUE) {
ret = write_to_fifo(s->fifo, buf);
if (ret < 0)
return ret;
if (s->start_time != DBL_MAX && s->start_time != AV_NOPTS_VALUE) { /* We haven't yet determined the pts of the first frame */
double first_pts = s->start_time * AV_TIME_BASE; if (s->next_pts == AV_NOPTS_VALUE) {
first_pts = FFMIN(FFMAX(first_pts, INT64_MIN), INT64_MAX); if (s->frames[0]->pts != AV_NOPTS_VALUE) {
s->first_pts = av_rescale_q(first_pts, AV_TIME_BASE_Q, s->next_pts = s->frames[0]->pts;
inlink->time_base); av_log(ctx, AV_LOG_VERBOSE, "Set first pts to %"PRId64"\n", s->next_pts);
av_log(ctx, AV_LOG_VERBOSE, "Set first pts to (in:%"PRId64" out:%"PRId64")\n",
s->first_pts, av_rescale_q(first_pts, AV_TIME_BASE_Q,
outlink->time_base));
} else {
s->first_pts = buf->pts;
}
} else { } else {
av_log(ctx, AV_LOG_WARNING, "Discarding initial frame(s) with no " av_log(ctx, AV_LOG_WARNING, "Discarding initial frame(s) with no "
"timestamp.\n"); "timestamp.\n");
av_frame_free(&buf); frame = shift_frame(ctx, s);
s->drop++; av_frame_free(&frame);
} *again = 1;
return 0; return 0;
} }
/* now wait for the next timestamp */
if (buf->pts == AV_NOPTS_VALUE || av_fifo_size(s->fifo) <= 0) {
return write_to_fifo(s->fifo, buf);
} }
/* number of output frames */ /* There are two conditions where we want to drop a frame:
delta = av_rescale_q_rnd(buf->pts - s->first_pts, inlink->time_base, * - If we have two buffered frames and the second frame is acceptable
outlink->time_base, s->rounding) - s->frames_out ; * as the next output frame, then drop the first buffered frame.
* - If we have status (EOF) set, drop frames when we hit the
* status timestamp. */
if ((s->frames_count == 2 && s->frames[1]->pts <= s->next_pts) ||
(s->status && s->status_pts <= s->next_pts)) {
frame = shift_frame(ctx, s);
av_frame_free(&frame);
*again = 1;
return 0;
if (delta < 1) { /* Output a copy of the first buffered frame */
/* drop everything buffered except the last */ } else {
int drop = av_fifo_size(s->fifo)/sizeof(AVFrame*); frame = av_frame_clone(s->frames[0]);
if (!frame)
return AVERROR(ENOMEM);
frame->pts = s->next_pts++;
av_log(ctx, AV_LOG_DEBUG, "Dropping %d frame(s).\n", drop); av_log(ctx, AV_LOG_DEBUG, "Writing frame with pts %"PRId64" to pts %"PRId64"\n",
s->drop += drop; s->frames[0]->pts, frame->pts);
s->cur_frame_out++;
flush_fifo(s->fifo); return ff_filter_frame(outlink, frame);
ret = write_to_fifo(s->fifo, buf); }
}
return ret; /* Convert status_pts to outlink timebase */
static void update_eof_pts(AVFilterContext *ctx, FPSContext *s, AVFilterLink *inlink, AVFilterLink *outlink, int64_t status_pts)
{
int eof_rounding = (s->eof_action == EOF_ACTION_PASS) ? AV_ROUND_UP : s->rounding;
s->status_pts = av_rescale_q_rnd(status_pts, inlink->time_base, outlink->time_base,
eof_rounding | AV_ROUND_PASS_MINMAX);
av_log(ctx, AV_LOG_DEBUG, "EOF is at pts %"PRId64"\n", s->status_pts);
} }
/* can output >= 1 frames */ static int activate(AVFilterContext *ctx)
for (i = 0; i < delta; i++) { {
AVFrame *buf_out; FPSContext *s = ctx->priv;
av_fifo_generic_read(s->fifo, &buf_out, sizeof(buf_out), NULL); AVFilterLink *inlink = ctx->inputs[0];
AVFilterLink *outlink = ctx->outputs[0];
int ret;
int again = 0;
int64_t status_pts;
/* duplicate the frame if needed */ FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
if (!av_fifo_size(s->fifo) && i < delta - 1) {
AVFrame *dup = av_frame_clone(buf_out);
av_log(ctx, AV_LOG_DEBUG, "Duplicating frame.\n"); /* No buffered status: normal operation */
if (dup) if (!s->status) {
ret = write_to_fifo(s->fifo, dup);
else
ret = AVERROR(ENOMEM);
if (ret < 0) { /* Read available input frames if we have room */
av_frame_free(&buf_out); while (s->frames_count < 2 && ff_inlink_check_available_frame(inlink)) {
av_frame_free(&buf); ret = read_frame(ctx, s, inlink, outlink);
if (ret < 0)
return ret; return ret;
} }
s->dup++; /* We do not yet have enough frames to produce output */
} if (s->frames_count < 2) {
/* Check if we've hit EOF (or otherwise that an error status is set) */
ret = ff_inlink_acknowledge_status(inlink, &s->status, &status_pts);
if (ret > 0)
update_eof_pts(ctx, s, inlink, outlink, status_pts);
buf_out->pts = av_rescale_q(s->first_pts, inlink->time_base, if (!ret) {
outlink->time_base) + s->frames_out; /* If someone wants us to output, we'd better ask for more input */
FF_FILTER_FORWARD_WANTED(outlink, inlink);
return 0;
}
}
}
if ((ret = ff_filter_frame(outlink, buf_out)) < 0) { /* Buffered frames are available, so generate an output frame */
av_frame_free(&buf); if (s->frames_count > 0) {
ret = write_frame(ctx, s, outlink, &again);
/* Couldn't generate a frame, so schedule us to perform another step */
if (again)
ff_filter_set_ready(ctx, 100);
return ret; return ret;
} }
s->frames_out++; /* No frames left, so forward the status */
if (s->status && s->frames_count == 0) {
ff_outlink_set_status(outlink, s->status, s->next_pts);
return 0;
} }
flush_fifo(s->fifo);
ret = write_to_fifo(s->fifo, buf); return FFERROR_NOT_READY;
return ret;
} }
static const AVFilterPad avfilter_vf_fps_inputs[] = { static const AVFilterPad avfilter_vf_fps_inputs[] = {
{ {
.name = "default", .name = "default",
.type = AVMEDIA_TYPE_VIDEO, .type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
}, },
{ NULL } { NULL }
}; };
@ -324,8 +338,7 @@ static const AVFilterPad avfilter_vf_fps_outputs[] = {
{ {
.name = "default", .name = "default",
.type = AVMEDIA_TYPE_VIDEO, .type = AVMEDIA_TYPE_VIDEO,
.request_frame = request_frame, .config_props = config_props,
.config_props = config_props
}, },
{ NULL } { NULL }
}; };
@ -337,6 +350,7 @@ AVFilter ff_vf_fps = {
.uninit = uninit, .uninit = uninit,
.priv_size = sizeof(FPSContext), .priv_size = sizeof(FPSContext),
.priv_class = &fps_class, .priv_class = &fps_class,
.activate = activate,
.inputs = avfilter_vf_fps_inputs, .inputs = avfilter_vf_fps_inputs,
.outputs = avfilter_vf_fps_outputs, .outputs = avfilter_vf_fps_outputs,
}; };

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