From: Aman Karmani <a...@tmm1.net>
Signed-off-by: Aman Karmani <a...@tmm1.net>
---
doc/bitstream_filters.texi | 11 +++++
libavcodec/Makefile | 2 +-
libavcodec/mpeg2_metadata_bsf.c | 80 +++++++++++++++++++++++++++++++++
3 files changed, 92 insertions(+), 1 deletion(-)
diff --git a/doc/bitstream_filters.texi b/doc/bitstream_filters.texi
index c63c20370f..c036d37403 100644
--- a/doc/bitstream_filters.texi
+++ b/doc/bitstream_filters.texi
@@ -537,6 +537,17 @@ Decompress non-standard compressed MP3 audio headers.
Modify metadata embedded in an MPEG-2 stream.
@table @option
+@item a53_cc
+Insert or remove user data containing A/53 closed captions.
+
+@table @samp
+@item pass
+@item insert
+@item remove
+@end table
+
+Default is pass.
+
@item display_aspect_ratio
Set the display aspect ratio in the stream.
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 1fb963f820..2a36a31ff2 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1227,7 +1227,7 @@ OBJS-$(CONFIG_MPEG4_UNPACK_BFRAMES_BSF) +=
mpeg4_unpack_bframes_bsf.o
OBJS-$(CONFIG_MOV2TEXTSUB_BSF) += movsub_bsf.o
OBJS-$(CONFIG_MP3_HEADER_DECOMPRESS_BSF) += mp3_header_decompress_bsf.o \
mpegaudiotabs.o
-OBJS-$(CONFIG_MPEG2_METADATA_BSF) += mpeg2_metadata_bsf.o
+OBJS-$(CONFIG_MPEG2_METADATA_BSF) += mpeg2_metadata_bsf.o cbs_misc.o
OBJS-$(CONFIG_NOISE_BSF) += noise_bsf.o
OBJS-$(CONFIG_NULL_BSF) += null_bsf.o
OBJS-$(CONFIG_OPUS_METADATA_BSF) += opus_metadata_bsf.o
diff --git a/libavcodec/mpeg2_metadata_bsf.c b/libavcodec/mpeg2_metadata_bsf.c
index 1aa6e02791..888bace6b2 100644
--- a/libavcodec/mpeg2_metadata_bsf.c
+++ b/libavcodec/mpeg2_metadata_bsf.c
@@ -23,6 +23,7 @@
#include "bsf_internal.h"
#include "cbs.h"
#include "cbs_bsf.h"
+#include "cbs_misc.h"
#include "cbs_mpeg2.h"
#include "mpeg12.h"
@@ -39,10 +40,79 @@ typedef struct MPEG2MetadataContext {
int colour_primaries;
int transfer_characteristics;
int matrix_coefficients;
+ int a53_cc;
int mpeg1_warned;
} MPEG2MetadataContext;
+static int mpeg2_metadata_handle_a53_cc(AVBSFContext *bsf,
+ AVPacket *pkt,
+ CodedBitstreamFragment *frag)
+{
+ MPEG2MetadataContext *ctx = bsf->priv_data;
+ int err, i;
+ uint8_t *a53_side_data = NULL;
+ size_t a53_side_data_size = 0;
+
+ if (ctx->a53_cc == BSF_ELEMENT_REMOVE || ctx->a53_cc ==
BSF_ELEMENT_EXTRACT) {
+ for (i = 0; i < frag->nb_units; i++) {
+ MPEG2RawUserData *ud;
+ A53UserData a53_ud;
+
+ if (frag->units[i].type != MPEG2_START_USER_DATA)
+ continue;
+ ud = frag->units[i].content;
+
+ err = ff_cbs_read_a53_user_data(ctx->common.output, &a53_ud,
ud->user_data,
+ ud->user_data_length);
+ if (err < 0) {
+ // Invalid or something completely different.
+ continue;
+ }
+ if (a53_ud.user_identifier != A53_USER_IDENTIFIER_ATSC ||
+ a53_ud.atsc.user_data_type_code !=
+ A53_USER_DATA_TYPE_CODE_CC_DATA) {
+ // Valid but something else (e.g. AFD).
+ continue;
+ }
+
+ if (ctx->a53_cc == BSF_ELEMENT_REMOVE) {
+ ff_cbs_delete_unit(frag, i);
+ --i;
+ break;
+ } else if(ctx->a53_cc == BSF_ELEMENT_EXTRACT) {
+ err = ff_cbs_write_a53_cc_side_data(ctx->common.output,
+ &a53_side_data,
+ &a53_side_data_size,
+ &a53_ud);
+ if (err < 0) {
+ av_log(bsf, AV_LOG_ERROR, "Failed to write "
+ "A/53 user data for packet side data.\n");
+ goto fail;
+ }
+
+ if (a53_side_data) {
+ err = av_packet_add_side_data(pkt, AV_PKT_DATA_A53_CC,
+ a53_side_data,
a53_side_data_size);
+ if (err) {
+ av_log(bsf, AV_LOG_ERROR, "Failed to attach extracted
A/53 "
+ "side data to packet.\n");
+ goto fail;
+ }
+ a53_side_data = NULL;
+ }
+ }
+ }
+ }
+
+ err = 0;
+
+fail:
+ av_freep(&a53_side_data);
+
+ return err;
+}
+
static int mpeg2_metadata_update_fragment(AVBSFContext *bsf,
AVPacket *pkt,
@@ -54,6 +124,13 @@ static int mpeg2_metadata_update_fragment(AVBSFContext *bsf,
MPEG2RawSequenceDisplayExtension *sde = NULL;
int i, se_pos;
+ if (pkt && ctx->a53_cc != BSF_ELEMENT_PASS) {
+ int err;
+ err = mpeg2_metadata_handle_a53_cc(bsf, pkt, frag);
+ if (err < 0)
+ return err;
+ }
+
for (i = 0; i < frag->nb_units; i++) {
if (frag->units[i].type == MPEG2_START_SEQUENCE_HEADER) {
sh = frag->units[i].content;
@@ -218,6 +295,9 @@ static const AVOption mpeg2_metadata_options[] = {
OFFSET(matrix_coefficients), AV_OPT_TYPE_INT,
{ .i64 = -1 }, -1, 255, FLAGS },
+ BSF_ELEMENT_OPTIONS_PIRE("a53_cc",
+ "A/53 Closed Captions in user data",
+ a53_cc, FLAGS),
{ NULL }
};
--
ffmpeg-codebot
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