FFmpeg/libavfilter/framesync.c
Nicolas George 3b64e3ea45 lavf/framesync: detect EOF immediately.
Fix an infinite loop in forward_status_change().
2016-12-24 13:18:02 +01:00

344 lines
9.9 KiB
C

/*
* Copyright (c) 2013 Nicolas George
*
* 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
*/
#define FF_INTERNAL_FIELDS 1
#include "framequeue.h"
#include "libavutil/avassert.h"
#include "avfilter.h"
#include "bufferqueue.h"
#include "framesync.h"
#include "internal.h"
#define OFFSET(member) offsetof(FFFrameSync, member)
static const char *framesync_name(void *ptr)
{
return "framesync";
}
static const AVClass framesync_class = {
.version = LIBAVUTIL_VERSION_INT,
.class_name = "framesync",
.item_name = framesync_name,
.category = AV_CLASS_CATEGORY_FILTER,
.option = NULL,
.parent_log_context_offset = OFFSET(parent),
};
enum {
STATE_BOF,
STATE_RUN,
STATE_EOF,
};
int ff_framesync_init(FFFrameSync *fs, void *parent, unsigned nb_in)
{
fs->class = &framesync_class;
fs->parent = parent;
fs->nb_in = nb_in;
fs->in = av_calloc(nb_in, sizeof(*fs->in));
if (!fs->in)
return AVERROR(ENOMEM);
return 0;
}
static void framesync_sync_level_update(FFFrameSync *fs)
{
unsigned i, level = 0;
for (i = 0; i < fs->nb_in; i++)
if (fs->in[i].state != STATE_EOF)
level = FFMAX(level, fs->in[i].sync);
av_assert0(level <= fs->sync_level);
if (level < fs->sync_level)
av_log(fs, AV_LOG_VERBOSE, "Sync level %u\n", level);
if (level)
fs->sync_level = level;
else
fs->eof = 1;
}
int ff_framesync_configure(FFFrameSync *fs)
{
unsigned i;
int64_t gcd, lcm;
if (!fs->time_base.num) {
for (i = 0; i < fs->nb_in; i++) {
if (fs->in[i].sync) {
if (fs->time_base.num) {
gcd = av_gcd(fs->time_base.den, fs->in[i].time_base.den);
lcm = (fs->time_base.den / gcd) * fs->in[i].time_base.den;
if (lcm < AV_TIME_BASE / 2) {
fs->time_base.den = lcm;
fs->time_base.num = av_gcd(fs->time_base.num,
fs->in[i].time_base.num);
} else {
fs->time_base.num = 1;
fs->time_base.den = AV_TIME_BASE;
break;
}
} else {
fs->time_base = fs->in[i].time_base;
}
}
}
if (!fs->time_base.num) {
av_log(fs, AV_LOG_ERROR, "Impossible to set time base\n");
return AVERROR(EINVAL);
}
av_log(fs, AV_LOG_VERBOSE, "Selected %d/%d time base\n",
fs->time_base.num, fs->time_base.den);
}
for (i = 0; i < fs->nb_in; i++)
fs->in[i].pts = fs->in[i].pts_next = AV_NOPTS_VALUE;
fs->sync_level = UINT_MAX;
framesync_sync_level_update(fs);
return 0;
}
static void framesync_advance(FFFrameSync *fs)
{
int latest;
unsigned i;
int64_t pts;
if (fs->eof)
return;
while (!fs->frame_ready) {
latest = -1;
for (i = 0; i < fs->nb_in; i++) {
if (!fs->in[i].have_next) {
if (latest < 0 || fs->in[i].pts < fs->in[latest].pts)
latest = i;
}
}
if (latest >= 0) {
fs->in_request = latest;
break;
}
pts = fs->in[0].pts_next;
for (i = 1; i < fs->nb_in; i++)
if (fs->in[i].pts_next < pts)
pts = fs->in[i].pts_next;
if (pts == INT64_MAX) {
fs->eof = 1;
break;
}
for (i = 0; i < fs->nb_in; i++) {
if (fs->in[i].pts_next == pts ||
(fs->in[i].before == EXT_INFINITY &&
fs->in[i].state == STATE_BOF)) {
av_frame_free(&fs->in[i].frame);
fs->in[i].frame = fs->in[i].frame_next;
fs->in[i].pts = fs->in[i].pts_next;
fs->in[i].frame_next = NULL;
fs->in[i].pts_next = AV_NOPTS_VALUE;
fs->in[i].have_next = 0;
fs->in[i].state = fs->in[i].frame ? STATE_RUN : STATE_EOF;
if (fs->in[i].sync == fs->sync_level && fs->in[i].frame)
fs->frame_ready = 1;
if (fs->in[i].state == STATE_EOF &&
fs->in[i].after == EXT_STOP)
fs->eof = 1;
}
}
if (fs->eof)
fs->frame_ready = 0;
if (fs->frame_ready)
for (i = 0; i < fs->nb_in; i++)
if ((fs->in[i].state == STATE_BOF &&
fs->in[i].before == EXT_STOP))
fs->frame_ready = 0;
fs->pts = pts;
}
}
static int64_t framesync_pts_extrapolate(FFFrameSync *fs, unsigned in,
int64_t pts)
{
/* Possible enhancement: use the link's frame rate */
return pts + 1;
}
static void framesync_inject_frame(FFFrameSync *fs, unsigned in, AVFrame *frame)
{
int64_t pts;
av_assert0(!fs->in[in].have_next);
if (frame) {
pts = av_rescale_q(frame->pts, fs->in[in].time_base, fs->time_base);
frame->pts = pts;
} else {
pts = fs->in[in].state != STATE_RUN || fs->in[in].after == EXT_INFINITY
? INT64_MAX : framesync_pts_extrapolate(fs, in, fs->in[in].pts);
fs->in[in].sync = 0;
framesync_sync_level_update(fs);
}
fs->in[in].frame_next = frame;
fs->in[in].pts_next = pts;
fs->in[in].have_next = 1;
}
int ff_framesync_add_frame(FFFrameSync *fs, unsigned in, AVFrame *frame)
{
av_assert1(in < fs->nb_in);
if (!fs->in[in].have_next)
framesync_inject_frame(fs, in, frame);
else
ff_bufqueue_add(fs, &fs->in[in].queue, frame);
return 0;
}
void ff_framesync_next(FFFrameSync *fs)
{
unsigned i;
av_assert0(!fs->frame_ready);
for (i = 0; i < fs->nb_in; i++)
if (!fs->in[i].have_next && fs->in[i].queue.available)
framesync_inject_frame(fs, i, ff_bufqueue_get(&fs->in[i].queue));
fs->frame_ready = 0;
framesync_advance(fs);
}
void ff_framesync_drop(FFFrameSync *fs)
{
fs->frame_ready = 0;
}
int ff_framesync_get_frame(FFFrameSync *fs, unsigned in, AVFrame **rframe,
unsigned get)
{
AVFrame *frame;
unsigned need_copy = 0, i;
int64_t pts_next;
int ret;
if (!fs->in[in].frame) {
*rframe = NULL;
return 0;
}
frame = fs->in[in].frame;
if (get) {
/* Find out if we need to copy the frame: is there another sync
stream, and do we know if its current frame will outlast this one? */
pts_next = fs->in[in].have_next ? fs->in[in].pts_next : INT64_MAX;
for (i = 0; i < fs->nb_in && !need_copy; i++)
if (i != in && fs->in[i].sync &&
(!fs->in[i].have_next || fs->in[i].pts_next < pts_next))
need_copy = 1;
if (need_copy) {
if (!(frame = av_frame_clone(frame)))
return AVERROR(ENOMEM);
if ((ret = av_frame_make_writable(frame)) < 0) {
av_frame_free(&frame);
return ret;
}
} else {
fs->in[in].frame = NULL;
}
fs->frame_ready = 0;
}
*rframe = frame;
return 0;
}
void ff_framesync_uninit(FFFrameSync *fs)
{
unsigned i;
for (i = 0; i < fs->nb_in; i++) {
av_frame_free(&fs->in[i].frame);
av_frame_free(&fs->in[i].frame_next);
ff_bufqueue_discard_all(&fs->in[i].queue);
}
av_freep(&fs->in);
}
int ff_framesync_process_frame(FFFrameSync *fs, unsigned all)
{
int ret, count = 0;
av_assert0(fs->on_event);
while (1) {
ff_framesync_next(fs);
if (fs->eof || !fs->frame_ready)
break;
if ((ret = fs->on_event(fs)) < 0)
return ret;
ff_framesync_drop(fs);
count++;
if (!all)
break;
}
if (!count && fs->eof)
return AVERROR_EOF;
return count;
}
int ff_framesync_filter_frame(FFFrameSync *fs, AVFilterLink *inlink,
AVFrame *in)
{
int ret;
if ((ret = ff_framesync_process_frame(fs, 1)) < 0)
return ret;
if ((ret = ff_framesync_add_frame(fs, FF_INLINK_IDX(inlink), in)) < 0)
return ret;
if ((ret = ff_framesync_process_frame(fs, 0)) < 0)
return ret;
return 0;
}
int ff_framesync_request_frame(FFFrameSync *fs, AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
int input, ret, i;
if ((ret = ff_framesync_process_frame(fs, 0)) < 0)
return ret;
if (ret > 0)
return 0;
if (fs->eof)
return AVERROR_EOF;
input = fs->in_request;
/* Detect status change early */
for (i = 0; i < fs->nb_in; i++)
if (!ff_framequeue_queued_frames(&ctx->inputs[i]->fifo) &&
ctx->inputs[i]->status_in && !ctx->inputs[i]->status_out)
input = i;
ret = ff_request_frame(ctx->inputs[input]);
if (ret == AVERROR_EOF) {
if ((ret = ff_framesync_add_frame(fs, input, NULL)) < 0)
return ret;
if ((ret = ff_framesync_process_frame(fs, 0)) < 0)
return ret;
ret = 0;
}
return ret;
}