[FFmpeg-devel] [PATCH] avfilter/f_cue: add cue and acue filters
Marton Balint
cus at passwd.hu
Sat Aug 25 21:35:01 EEST 2018
To delay filtering until a given wallclock timestamp.
Signed-off-by: Marton Balint <cus at passwd.hu>
---
doc/filters.texi | 36 ++++++++++
libavfilter/Makefile | 2 +
libavfilter/allfilters.c | 2 +
libavfilter/f_cue.c | 182 +++++++++++++++++++++++++++++++++++++++++++++++
libavfilter/version.h | 2 +-
5 files changed, 223 insertions(+), 1 deletion(-)
create mode 100644 libavfilter/f_cue.c
diff --git a/doc/filters.texi b/doc/filters.texi
index 32c95b591c..79eec0c808 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -551,6 +551,11 @@ Set LFO range.
Set LFO rate.
@end table
+ at section acue
+
+Delay audio filtering until a given wallclock timestamp. See the @ref{cue}
+filter.
+
@section adeclick
Remove impulsive noise from input audio.
@@ -6987,6 +6992,37 @@ indicates 'never reset', and returns the largest area encountered during
playback.
@end table
+ at anchor{cue}
+ at section cue
+
+Delay video filtering until a given wallclock timestamp. The filter first
+passes on @option{preroll} amount of frames, then it buffers at most
+ at option{buffer} amount of frames and waits for the cue. After reaching the cue
+it forwards the buffered frames and also any subsequent frames coming in its
+input.
+
+The filter can be used synchronize the output of multiple ffmpeg processes for
+realtime output devices like decklink. By putting the delay in the filtering
+chain and pre-buffering frames the process can pass on data to output almost
+immediately after the target wallclock timestamp is reached.
+
+Perfect frame accuracy cannot be guaranteed, but the result is good enough for
+some use cases.
+
+ at table @option
+
+ at item cue
+The cue timestamp expressed in a UNIX timestamp in microseconds. Default is 0.
+
+ at item preroll
+The duration of content to pass on as preroll expressed in seconds. Default is 0.
+
+ at item buffer
+The maximum duration of content to buffer before waiting for the cue expressed
+in seconds. Default is 0.
+
+ at end table
+
@anchor{curves}
@section curves
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index e5d3a57af7..37a06e0ec0 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -36,6 +36,7 @@ OBJS-$(CONFIG_ACONTRAST_FILTER) += af_acontrast.o
OBJS-$(CONFIG_ACOPY_FILTER) += af_acopy.o
OBJS-$(CONFIG_ACROSSFADE_FILTER) += af_afade.o
OBJS-$(CONFIG_ACRUSHER_FILTER) += af_acrusher.o
+OBJS-$(CONFIG_ACUE_FILTER) += f_cue.o
OBJS-$(CONFIG_ADECLICK_FILTER) += af_adeclick.o
OBJS-$(CONFIG_ADECLIP_FILTER) += af_adeclick.o
OBJS-$(CONFIG_ADELAY_FILTER) += af_adelay.o
@@ -178,6 +179,7 @@ OBJS-$(CONFIG_COREIMAGE_FILTER) += vf_coreimage.o
OBJS-$(CONFIG_COVER_RECT_FILTER) += vf_cover_rect.o lavfutils.o
OBJS-$(CONFIG_CROP_FILTER) += vf_crop.o
OBJS-$(CONFIG_CROPDETECT_FILTER) += vf_cropdetect.o
+OBJS-$(CONFIG_CUE_FILTER) += f_cue.o
OBJS-$(CONFIG_CURVES_FILTER) += vf_curves.o
OBJS-$(CONFIG_DATASCOPE_FILTER) += vf_datascope.o
OBJS-$(CONFIG_DCTDNOIZ_FILTER) += vf_dctdnoiz.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 9732ae5345..6c6d0f43f0 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -27,6 +27,7 @@ extern AVFilter ff_af_abench;
extern AVFilter ff_af_acompressor;
extern AVFilter ff_af_acontrast;
extern AVFilter ff_af_acopy;
+extern AVFilter ff_af_acue;
extern AVFilter ff_af_acrossfade;
extern AVFilter ff_af_acrusher;
extern AVFilter ff_af_adeclick;
@@ -167,6 +168,7 @@ extern AVFilter ff_vf_coreimage;
extern AVFilter ff_vf_cover_rect;
extern AVFilter ff_vf_crop;
extern AVFilter ff_vf_cropdetect;
+extern AVFilter ff_vf_cue;
extern AVFilter ff_vf_curves;
extern AVFilter ff_vf_datascope;
extern AVFilter ff_vf_dctdnoiz;
diff --git a/libavfilter/f_cue.c b/libavfilter/f_cue.c
new file mode 100644
index 0000000000..732b5e218a
--- /dev/null
+++ b/libavfilter/f_cue.c
@@ -0,0 +1,182 @@
+/*
+ * Copyright (c) 2018 Marton Balint
+ *
+ * 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
+ */
+
+#include "libavutil/opt.h"
+#include "libavutil/time.h"
+#include "avfilter.h"
+#include "filters.h"
+#include "framequeue.h"
+#include "internal.h"
+
+typedef struct CueContext {
+ const AVClass *class;
+ int64_t first_pts;
+ int64_t cue;
+ int64_t preroll;
+ int64_t buffer;
+ int status;
+ FFFrameQueue queue;
+} CueContext;
+
+static av_cold int init(AVFilterContext *ctx)
+{
+ CueContext *s = ctx->priv;
+ ff_framequeue_init(&s->queue, &ctx->graph->internal->frame_queues);
+ return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ CueContext *s = ctx->priv;
+ ff_framequeue_free(&s->queue);
+}
+
+static int activate(AVFilterContext *ctx)
+{
+ AVFilterLink *inlink = ctx->inputs[0];
+ AVFilterLink *outlink = ctx->outputs[0];
+ CueContext *s = ctx->priv;
+ int64_t pts;
+ AVFrame *frame = NULL;
+
+ FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
+
+ if (s->status < 3 || s->status == 5) {
+ int ret = ff_inlink_consume_frame(inlink, &frame);
+ if (ret < 0)
+ return ret;
+ if (frame)
+ pts = av_rescale_q(frame->pts, inlink->time_base, AV_TIME_BASE_Q);
+ }
+
+ if (!s->status && frame) {
+ s->first_pts = pts;
+ s->status++;
+ }
+ if (s->status == 1 && frame) {
+ if (pts - s->first_pts < s->preroll)
+ return ff_filter_frame(outlink, frame);
+ s->first_pts = pts;
+ s->status++;
+ }
+ if (s->status == 2 && frame) {
+ int ret = ff_framequeue_add(&s->queue, frame);
+ if (ret < 0) {
+ av_frame_free(&frame);
+ return ret;
+ }
+ frame = NULL;
+ if (!(pts - s->first_pts < s->buffer && (av_gettime() - s->cue) < 0))
+ s->status++;
+ }
+ if (s->status == 3) {
+ int64_t diff;
+ while ((diff = (av_gettime() - s->cue)) < 0)
+ av_usleep(av_clip(-diff / 2, 100, 1000000));
+ s->status++;
+ }
+ if (s->status == 4) {
+ if (ff_framequeue_queued_frames(&s->queue))
+ return ff_filter_frame(outlink, ff_framequeue_take(&s->queue));
+ s->status++;
+ }
+ if (s->status == 5 && frame)
+ return ff_filter_frame(outlink, frame);
+
+ FF_FILTER_FORWARD_STATUS(inlink, outlink);
+ FF_FILTER_FORWARD_WANTED(outlink, inlink);
+
+ return FFERROR_NOT_READY;
+}
+
+#define OFFSET(x) offsetof(CueContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
+static const AVOption options[] = {
+ { "cue", "cue unix timestamp in microseconds", OFFSET(cue), AV_OPT_TYPE_INT64, { .i64 = 0 }, 0, INT64_MAX, FLAGS },
+ { "preroll", "preroll duration in seconds", OFFSET(preroll), AV_OPT_TYPE_DURATION, { .i64 = 0 }, 0, INT64_MAX, FLAGS },
+ { "buffer", "buffer duration in seconds", OFFSET(buffer), AV_OPT_TYPE_DURATION, { .i64 = 0 }, 0, INT64_MAX, FLAGS },
+ { NULL }
+};
+
+#if CONFIG_CUE_FILTER
+#define cue_options options
+AVFILTER_DEFINE_CLASS(cue);
+
+static const AVFilterPad cue_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+ { NULL }
+};
+
+static const AVFilterPad cue_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+ { NULL }
+};
+
+AVFilter ff_vf_cue = {
+ .name = "cue",
+ .description = NULL_IF_CONFIG_SMALL("Delay filtering to match a cue."),
+ .priv_size = sizeof(CueContext),
+ .priv_class = &cue_class,
+ .init = init,
+ .uninit = uninit,
+ .inputs = cue_inputs,
+ .outputs = cue_outputs,
+ .activate = activate,
+};
+#endif /* CONFIG_CUE_FILTER */
+
+#if CONFIG_ACUE_FILTER
+#define acue_options options
+AVFILTER_DEFINE_CLASS(acue);
+
+static const AVFilterPad acue_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO,
+ },
+ { NULL }
+};
+
+static const AVFilterPad acue_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO,
+ },
+ { NULL }
+};
+
+AVFilter ff_af_acue = {
+ .name = "acue",
+ .description = NULL_IF_CONFIG_SMALL("Delay filtering to match a cue."),
+ .priv_size = sizeof(CueContext),
+ .priv_class = &acue_class,
+ .init = init,
+ .uninit = uninit,
+ .inputs = acue_inputs,
+ .outputs = acue_outputs,
+ .activate = activate,
+};
+#endif /* CONFIG_ACUE_FILTER */
diff --git a/libavfilter/version.h b/libavfilter/version.h
index 0ac3a2f3a9..2ff2b6a318 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -30,7 +30,7 @@
#include "libavutil/version.h"
#define LIBAVFILTER_VERSION_MAJOR 7
-#define LIBAVFILTER_VERSION_MINOR 26
+#define LIBAVFILTER_VERSION_MINOR 27
#define LIBAVFILTER_VERSION_MICRO 100
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
--
2.16.4
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