[FFmpeg-devel] [PATCH] lavfi: add arandorder filter
Nicolas George
nicolas.george at normalesup.org
Wed Dec 14 21:45:14 CET 2011
This filter has two inputs, two outputs and just copies the samples from one
to the other. But it does it in a random order, possibly buffering several
buffers of samples in the middle.
The purpose is to help stress-testing filters with several inputs.
Signed-off-by: Nicolas George <nicolas.george at normalesup.org>
---
I do not know whether it deserves to be committed in the public repository,
but I had to write it, so I should make it available to other developers if
they happen to need it.
Regards,
--
Nicolas George
libavfilter/Makefile | 1 +
libavfilter/af_arandorder.c | 155 +++++++++++++++++++++++++++++++++++++++++++
libavfilter/allfilters.c | 1 +
3 files changed, 157 insertions(+), 0 deletions(-)
create mode 100644 libavfilter/af_arandorder.c
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index a6fd18f..a04fd15 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -26,6 +26,7 @@ OBJS-$(CONFIG_AVCODEC) += avcodec.o
OBJS-$(CONFIG_ACONVERT_FILTER) += af_aconvert.o
OBJS-$(CONFIG_AFORMAT_FILTER) += af_aformat.o
OBJS-$(CONFIG_ANULL_FILTER) += af_anull.o
+OBJS-$(CONFIG_ARANDORDER_FILTER) += af_arandorder.o
OBJS-$(CONFIG_ARESAMPLE_FILTER) += af_aresample.o
OBJS-$(CONFIG_ASHOWINFO_FILTER) += af_ashowinfo.o
OBJS-$(CONFIG_EARWAX_FILTER) += af_earwax.o
diff --git a/libavfilter/af_arandorder.c b/libavfilter/af_arandorder.c
new file mode 100644
index 0000000..573f387
--- /dev/null
+++ b/libavfilter/af_arandorder.c
@@ -0,0 +1,155 @@
+/*
+ * Copyright (C) 2011 Nicolas George <nicolas.george at normalesup.org>
+ *
+ * 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 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
+ */
+
+/**
+ * @file
+ * Random reordering filter
+ */
+
+#include <stdlib.h>
+#include "libavcodec/avcodec.h"
+#include "libavutil/avstring.h"
+#include "libswresample/swresample.h" // only for SWR_CH_MAX
+#include "avfilter.h"
+#include "internal.h"
+
+#define QUEUE_SIZE 16
+
+struct arandorder_context {
+ unsigned rand_state;
+ struct {
+ AVFilterBufferRef *buf[QUEUE_SIZE];
+ unsigned t, n;
+ } queue[2];
+ int req[2];
+};
+
+static inline int next_out(struct arandorder_context *ar)
+{
+ return !!(ar->rand_state & 0x80000000);
+}
+
+static av_cold int init(AVFilterContext *ctx, const char *args0, void *opaque)
+{
+ struct arandorder_context *ar = ctx->priv;
+
+ ar->rand_state = MKTAG('R','A','N','D') * 42;
+ return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ avfilter_set_common_sample_formats(ctx, avfilter_make_all_formats(AVMEDIA_TYPE_AUDIO));
+ avfilter_set_common_packing_formats(ctx, avfilter_make_all_packing_formats());
+ avfilter_set_common_channel_layouts(ctx, avfilter_make_all_channel_layouts());
+ return 0;
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+ return 0;
+}
+
+static void send_next(AVFilterContext *ctx)
+{
+ struct arandorder_context *ar = ctx->priv;
+ int id;
+
+ while (1) {
+ id = next_out(ar);
+ if (!ar->queue[id].n)
+ break;
+ avfilter_filter_samples(ctx->outputs[id], ar->queue[id].buf[ar->queue[id].t]);
+ ar->queue[id].n--;
+ ar->queue[id].t = (ar->queue[id].t + 1) % QUEUE_SIZE;
+ ar->rand_state = ar->rand_state * 1664525 + 1013904223;
+ if (ar->req[id])
+ ar->req[id]--;
+ }
+ for (id = 0; id < 2; id++) {
+ if (ar->queue[id].n == QUEUE_SIZE) {
+ avfilter_filter_samples(ctx->outputs[id], ar->queue[id].buf[ar->queue[id].t]);
+ ar->queue[id].n--;
+ ar->queue[id].t = (ar->queue[id].t + 1) % QUEUE_SIZE;
+ if (ar->req[id])
+ ar->req[id]--;
+ }
+ }
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ struct arandorder_context *ar = ctx->priv;
+ int id = outlink == ctx->outputs[1];
+ int i;
+
+ if (id == next_out(ar) && ar->queue[id].n) {
+ send_next(ctx);
+ return 0;
+ }
+ ar->req[id]++;
+ while (ar->req[id])
+ for (i = 0; i < 2; i++)
+ if (!ar->queue[i].n)
+ avfilter_request_frame(ctx->inputs[i]);
+ return 0;
+}
+
+static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)
+{
+ AVFilterContext *ctx = inlink->dst;
+ struct arandorder_context *ar = ctx->priv;
+ int id = inlink == ctx->inputs[1];
+
+ ar->queue[id].buf[(ar->queue[id].t + ar->queue[id].n++) % QUEUE_SIZE] = insamples;
+ send_next(ctx);
+}
+
+AVFilter avfilter_af_arandorder = {
+ .name = "arandorder",
+ .description = NULL_IF_CONFIG_SMALL("Copy two streams of audio data in a random order"),
+ .priv_size = sizeof(struct arandorder_context),
+ .init = init,
+ .query_formats = query_formats,
+
+ .inputs = (const AVFilterPad[]) {
+ { .name = "in1",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .filter_samples = filter_samples,
+ .min_perms = AV_PERM_READ, },
+ { .name = "in2",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .filter_samples = filter_samples,
+ .min_perms = AV_PERM_READ, },
+ { .name = NULL}
+ },
+ .outputs = (const AVFilterPad[]) {
+ { .name = "out1",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .config_props = config_output,
+ .request_frame = request_frame, },
+ { .name = "out2",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .config_props = config_output,
+ .request_frame = request_frame, },
+ { .name = NULL}
+ },
+};
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index fb50a3a..94cfa40 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -37,6 +37,7 @@ void avfilter_register_all(void)
REGISTER_FILTER (ACONVERT, aconvert, af);
REGISTER_FILTER (AFORMAT, aformat, af);
REGISTER_FILTER (ANULL, anull, af);
+ REGISTER_FILTER (ARANDORDER, arandorder, af);
REGISTER_FILTER (ARESAMPLE, aresample, af);
REGISTER_FILTER (ASHOWINFO, ashowinfo, af);
REGISTER_FILTER (EARWAX, earwax, af);
--
1.7.7.3
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