avfilter/f_cue: add cue and acue filters

To delay filtering until a given wallclock timestamp.

Signed-off-by: Marton Balint <cus@passwd.hu>

1 files changed, 182 insertions, 0 deletions

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 */