THis filter can correct certain issues seen from upstream sources
where the cc_count is not properly set or the CEA-608 tuples are
not at the start of the payload as expected.
Make use of the ccfifo to extract and immediately repack the CEA-708
side data, thereby removing any extra padding and ensuring the 608
tuples are at the front of the payload.
Signed-off-by: Devin Heitmueller <dheitmuel...@ltnglobal.com>
---
doc/filters.texi | 10 +++++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_ccrepack.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 114 insertions(+)
create mode 100644 libavfilter/vf_ccrepack.c
diff --git a/doc/filters.texi b/doc/filters.texi
index 9a0fe9c..d425081 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -9070,6 +9070,16 @@ Only deinterlace frames marked as interlaced.
The default value is @code{all}.
@end table
+@section ccrepack
+
+Repack CEA-708 closed captioning side data
+
+This filter fixes various issues seen with commerical encoders
+related to upstream malformed CEA-708 payloads, specifically
+incorrect number of tuples (wrong cc_count for the target FPS),
+and incorrect ordering of tuples (i.e. the CEA-608 tuples are not at
+the first entries in the payload).
+
@section cas
Apply Contrast Adaptive Sharpen filter to video stream.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 68c8f14..7c2195f 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -214,6 +214,7 @@ OBJS-$(CONFIG_BOXBLUR_OPENCL_FILTER) +=
vf_avgblur_opencl.o opencl.o \
opencl/avgblur.o boxblur.o
OBJS-$(CONFIG_BWDIF_FILTER) += vf_bwdif.o yadif_common.o
OBJS-$(CONFIG_CAS_FILTER) += vf_cas.o
+OBJS-$(CONFIG_CCREPACK_FILTER) += vf_ccrepack.o
OBJS-$(CONFIG_CHROMABER_VULKAN_FILTER) += vf_chromaber_vulkan.o vulkan.o
vulkan_filter.o
OBJS-$(CONFIG_CHROMAHOLD_FILTER) += vf_chromakey.o
OBJS-$(CONFIG_CHROMAKEY_FILTER) += vf_chromakey.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 6994124..ee2ac17 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -198,6 +198,7 @@ extern const AVFilter ff_vf_boxblur;
extern const AVFilter ff_vf_boxblur_opencl;
extern const AVFilter ff_vf_bwdif;
extern const AVFilter ff_vf_cas;
+extern const AVFilter ff_vf_ccrepack;
extern const AVFilter ff_vf_chromaber_vulkan;
extern const AVFilter ff_vf_chromahold;
extern const AVFilter ff_vf_chromakey;
diff --git a/libavfilter/vf_ccrepack.c b/libavfilter/vf_ccrepack.c
new file mode 100644
index 0000000..e3fd67f
--- /dev/null
+++ b/libavfilter/vf_ccrepack.c
@@ -0,0 +1,102 @@
+/*
+ * CEA-708 Closed Caption Repacker
+ * Copyright (c) 2023 LTN Global Communications
+ *
+ * Author: Devin Heitmueller <dheitmuel...@ltnglobal.com>
+ *
+ * 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
+ */
+
+/*
+ * Repackage CEA-708 arrays, which deals with incorrect cc_count for a given
+ * output framerate, and incorrect 708 padding.
+ *
+ * See CEA CEA-10-A "EIA-708-B Implementation Guidance", Section 26.5
+ * "Grouping DTVCC Data Within user_data() Structure"
+ */
+
+#include "avfilter.h"
+#include "internal.h"
+#include "ccfifo.h"
+#include "libavutil/opt.h"
+
+typedef struct CCRepackContext
+{
+ const AVClass *class;
+ AVCCFifo *cc_fifo;
+} CCRepackContext;
+
+static const AVOption ccrepack_options[] = {
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(ccrepack);
+
+static int config_input(AVFilterLink *link)
+{
+ CCRepackContext *ctx = link->dst->priv;
+
+ if (!(ctx->cc_fifo = ff_ccfifo_alloc(link->frame_rate, ctx))) {
+ av_log(ctx, AV_LOG_ERROR, "Failure to setup CC FIFO queue\n");
+ return AVERROR(ENOMEM);
+ }
+
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
+{
+ CCRepackContext *ctx = inlink->dst->priv;
+ AVFilterLink *outlink = inlink->dst->outputs[0];
+
+ ff_ccfifo_extract(ctx->cc_fifo, frame);
+ ff_ccfifo_inject(ctx->cc_fifo, frame);
+
+ return ff_filter_frame(outlink, frame);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ CCRepackContext *s = ctx->priv;
+ ff_ccfifo_freep(&s->cc_fifo);
+}
+
+static const AVFilterPad avfilter_vf_ccrepack_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .filter_frame = filter_frame,
+ .config_props = config_input,
+ },
+};
+
+static const AVFilterPad avfilter_vf_ccrepack_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+};
+
+AVFilter ff_vf_ccrepack = {
+ .name = "ccrepack",
+ .description = NULL_IF_CONFIG_SMALL("Repack CEA-708 closed caption
metadata"),
+ .uninit = uninit,
+ .priv_size = sizeof(CCRepackContext),
+ .priv_class = &ccrepack_class,
+ FILTER_INPUTS(avfilter_vf_ccrepack_inputs),
+ FILTER_OUTPUTS(avfilter_vf_ccrepack_outputs),
+};
--
1.8.3.1
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
