FFmpeg/libavfilter/dualinput.c
2013-05-27 20:32:28 +02:00

160 lines
5.4 KiB
C

/*
* 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 MAIN 0
#define SECOND 1
#include "dualinput.h"
#include "libavutil/timestamp.h"
static int try_filter_frame(FFDualInputContext *s,
AVFilterContext *ctx, AVFrame *mainpic)
{
int ret;
/* Discard obsolete second frames: if there is a next second frame with pts
* before the main frame, we can drop the current second. */
while (1) {
AVFrame *next_overpic = ff_bufqueue_peek(&s->queue[SECOND], 0);
if (!next_overpic && s->second_eof && !s->repeatlast) {
av_frame_free(&s->second_frame);
break;
}
if (!next_overpic || av_compare_ts(next_overpic->pts, ctx->inputs[SECOND]->time_base,
mainpic->pts, ctx->inputs[MAIN]->time_base) > 0)
break;
ff_bufqueue_get(&s->queue[SECOND]);
av_frame_free(&s->second_frame);
s->second_frame = next_overpic;
}
/* If there is no next frame and no EOF and the second frame is before
* the main frame, we can not know yet if it will be superseded. */
if (!s->queue[SECOND].available && !s->second_eof &&
(!s->second_frame || av_compare_ts(s->second_frame->pts, ctx->inputs[SECOND]->time_base,
mainpic->pts, ctx->inputs[MAIN]->time_base) < 0))
return AVERROR(EAGAIN);
/* At this point, we know that the current second frame extends to the
* time of the main frame. */
av_dlog(ctx, "main_pts:%s main_pts_time:%s",
av_ts2str(mainpic->pts), av_ts2timestr(mainpic->pts, &ctx->inputs[MAIN]->time_base));
if (s->second_frame)
av_dlog(ctx, " second_pts:%s second_pts_time:%s",
av_ts2str(s->second_frame->pts), av_ts2timestr(s->second_frame->pts, &ctx->inputs[SECOND]->time_base));
av_dlog(ctx, "\n");
if (s->second_frame && !ctx->is_disabled)
mainpic = s->process(ctx, mainpic, s->second_frame);
ret = ff_filter_frame(ctx->outputs[0], mainpic);
av_assert1(ret != AVERROR(EAGAIN));
s->frame_requested = 0;
return ret;
}
static int try_filter_next_frame(FFDualInputContext *s, AVFilterContext *ctx)
{
AVFrame *next_mainpic = ff_bufqueue_peek(&s->queue[MAIN], 0);
int ret;
if (!next_mainpic)
return AVERROR(EAGAIN);
if ((ret = try_filter_frame(s, ctx, next_mainpic)) == AVERROR(EAGAIN))
return ret;
ff_bufqueue_get(&s->queue[MAIN]);
return ret;
}
static int flush_frames(FFDualInputContext *s, AVFilterContext *ctx)
{
int ret;
while (!(ret = try_filter_next_frame(s, ctx)));
return ret == AVERROR(EAGAIN) ? 0 : ret;
}
int ff_dualinput_filter_frame_main(FFDualInputContext *s,
AVFilterLink *inlink, AVFrame *in)
{
AVFilterContext *ctx = inlink->dst;
int ret;
if ((ret = flush_frames(s, ctx)) < 0)
return ret;
if ((ret = try_filter_frame(s, ctx, in)) < 0) {
if (ret != AVERROR(EAGAIN))
return ret;
ff_bufqueue_add(ctx, &s->queue[MAIN], in);
}
if (!s->second_frame)
return 0;
flush_frames(s, ctx);
return 0;
}
int ff_dualinput_filter_frame_second(FFDualInputContext *s,
AVFilterLink *inlink, AVFrame *in)
{
AVFilterContext *ctx = inlink->dst;
int ret;
if ((ret = flush_frames(s, ctx)) < 0)
return ret;
ff_bufqueue_add(ctx, &s->queue[SECOND], in);
ret = try_filter_next_frame(s, ctx);
return ret == AVERROR(EAGAIN) ? 0 : ret;
}
int ff_dualinput_request_frame(FFDualInputContext *s, AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
int input, ret;
if (!try_filter_next_frame(s, ctx))
return 0;
s->frame_requested = 1;
while (s->frame_requested) {
/* TODO if we had a frame duration, we could guess more accurately */
input = !s->second_eof && (s->queue[MAIN].available ||
s->queue[SECOND].available < 2) ?
SECOND : MAIN;
ret = ff_request_frame(ctx->inputs[input]);
/* EOF on main is reported immediately */
if (ret == AVERROR_EOF && input == SECOND) {
s->second_eof = 1;
if (s->shortest)
return ret;
if ((ret = try_filter_next_frame(s, ctx)) != AVERROR(EAGAIN))
return ret;
ret = 0; /* continue requesting frames on main */
}
if (ret < 0)
return ret;
}
return 0;
}
void ff_dualinput_uninit(FFDualInputContext *s)
{
av_frame_free(&s->second_frame);
ff_bufqueue_discard_all(&s->queue[MAIN]);
ff_bufqueue_discard_all(&s->queue[SECOND]);
}