[FFmpeg-devel] [PATCH 2/5] h264_metadata: Add support for A/53 closed captions
Mark Thompson
sw at jkqxz.net
Sun Mar 25 20:41:34 EEST 2018
Allows insertion (from side data), extraction (to side data), and removal
of closed captions in SEI messages.
---
libavcodec/Makefile | 2 +-
libavcodec/h264_metadata_bsf.c | 138 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 139 insertions(+), 1 deletion(-)
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index aaef6c3ab8..cfde104055 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1044,7 +1044,7 @@ OBJS-$(CONFIG_DCA_CORE_BSF) += dca_core_bsf.o
OBJS-$(CONFIG_EXTRACT_EXTRADATA_BSF) += extract_extradata_bsf.o \
h2645_parse.o
OBJS-$(CONFIG_FILTER_UNITS_BSF) += filter_units_bsf.o
-OBJS-$(CONFIG_H264_METADATA_BSF) += h264_metadata_bsf.o
+OBJS-$(CONFIG_H264_METADATA_BSF) += h264_metadata_bsf.o cbs_misc.o
OBJS-$(CONFIG_H264_MP4TOANNEXB_BSF) += h264_mp4toannexb_bsf.o
OBJS-$(CONFIG_H264_REDUNDANT_PPS_BSF) += h264_redundant_pps_bsf.o
OBJS-$(CONFIG_HAPQA_EXTRACT_BSF) += hapqa_extract_bsf.o hap.o
diff --git a/libavcodec/h264_metadata_bsf.c b/libavcodec/h264_metadata_bsf.c
index 27053dbdcf..d79e6c0c87 100644
--- a/libavcodec/h264_metadata_bsf.c
+++ b/libavcodec/h264_metadata_bsf.c
@@ -24,6 +24,7 @@
#include "bsf.h"
#include "cbs.h"
#include "cbs_h264.h"
+#include "cbs_misc.h"
#include "h264.h"
#include "h264_sei.h"
@@ -74,6 +75,8 @@ typedef struct H264MetadataContext {
int display_orientation;
double rotate;
int flip;
+
+ int a53_cc;
} H264MetadataContext;
@@ -222,6 +225,8 @@ static int h264_metadata_filter(AVBSFContext *bsf, AVPacket *out)
int err, i, j, has_sps;
uint8_t *displaymatrix_side_data = NULL;
size_t displaymatrix_side_data_size = 0;
+ uint8_t *a53_side_data = NULL;
+ size_t a53_side_data_size = 0;
err = ff_bsf_get_packet(bsf, &in);
if (err < 0)
@@ -516,6 +521,116 @@ static int h264_metadata_filter(AVBSFContext *bsf, AVPacket *out)
}
}
+ if (ctx->a53_cc == INSERT) {
+ uint8_t *data;
+ int size;
+
+ data = av_packet_get_side_data(in, AV_PKT_DATA_A53_CC, &size);
+ if (data) {
+ A53UserData a53_ud;
+
+ err = ff_cbs_read_a53_cc_side_data(ctx->cbc, &a53_ud,
+ data, size);
+ if (err < 0) {
+ av_log(bsf, AV_LOG_WARNING, "Invalid A/53 closed captions "
+ "in packet side data dropped.\n");
+ } else {
+ H264RawSEIPayload payload = {
+ .payload_type = H264_SEI_TYPE_USER_DATA_REGISTERED,
+ };
+ H264RawSEIUserDataRegistered *udr =
+ &payload.payload.user_data_registered;
+ size_t size = 9 + 3 * a53_ud.atsc.cc_data.cc_count;
+
+ udr->data_ref = av_buffer_alloc(2 + size);
+ if (!udr->data_ref) {
+ err = AVERROR(ENOMEM);
+ goto fail;
+ }
+ udr->data = udr->data_ref->data;
+
+ udr->itu_t_t35_country_code = 181;
+ AV_WB16(udr->data, 49); // provider_code
+
+ err = ff_cbs_write_a53_user_data(ctx->cbc, udr->data + 2,
+ &size, &a53_ud);
+ if (err < 0) {
+ av_log(bsf, AV_LOG_ERROR, "Failed to write "
+ "A/53 user data.\n");
+ av_buffer_unref(&udr->data_ref);
+ goto fail;
+ }
+ udr->data_length = size + 2;
+
+ err = ff_cbs_h264_add_sei_message(ctx->cbc, au, &payload);
+ if (err < 0) {
+ av_log(bsf, AV_LOG_ERROR, "Failed to add A/53 user data "
+ "SEI message to access unit.\n");
+ av_buffer_unref(&udr->data_ref);
+ goto fail;
+ }
+ }
+ }
+
+ } else if (ctx->a53_cc == REMOVE || ctx->a53_cc == EXTRACT) {
+ for (i = 0; i < au->nb_units; i++) {
+ H264RawSEI *sei;
+ if (au->units[i].type != H264_NAL_SEI)
+ continue;
+ sei = au->units[i].content;
+
+ for (j = 0; j < sei->payload_count; j++) {
+ H264RawSEIUserDataRegistered *udr;
+ A53UserData a53_ud;
+
+ if (sei->payload[j].payload_type !=
+ H264_SEI_TYPE_USER_DATA_REGISTERED)
+ continue;
+ udr = &sei->payload[j].payload.user_data_registered;
+ if (udr->data_length < 6) {
+ // Can't be relevant.
+ continue;
+ }
+
+ err = ff_cbs_read_a53_user_data(ctx->cbc, &a53_ud,
+ udr->data + 2,
+ udr->data_length - 2);
+ 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 == REMOVE) {
+ err = ff_cbs_h264_delete_sei_message(ctx->cbc, au,
+ &au->units[i], j);
+ if (err < 0) {
+ av_log(bsf, AV_LOG_ERROR, "Failed to delete "
+ "A/53 CC SEI message.\n");
+ goto fail;
+ }
+ --i;
+ break;
+ } else if(ctx->a53_cc == EXTRACT) {
+ err = ff_cbs_write_a53_cc_side_data(ctx->cbc,
+ &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;
+ }
+ }
+ }
+ }
+ }
+
err = ff_cbs_write_packet(ctx->cbc, out, au);
if (err < 0) {
av_log(bsf, AV_LOG_ERROR, "Failed to write packet.\n");
@@ -537,6 +652,16 @@ static int h264_metadata_filter(AVBSFContext *bsf, AVPacket *out)
}
displaymatrix_side_data = NULL;
}
+ if (a53_side_data) {
+ err = av_packet_add_side_data(out, 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;
+ }
ctx->done_first_au = 1;
@@ -544,6 +669,7 @@ static int h264_metadata_filter(AVBSFContext *bsf, AVPacket *out)
fail:
ff_cbs_fragment_uninit(ctx->cbc, au);
av_freep(&displaymatrix_side_data);
+ av_freep(&a53_side_data);
if (err < 0)
av_packet_unref(out);
@@ -684,6 +810,18 @@ static const AVOption h264_metadata_options[] = {
0, AV_OPT_TYPE_CONST,
{ .i64 = FLIP_VERTICAL }, .flags = FLAGS, .unit = "flip" },
+ { "a53_cc", "A/53 Closed Captions in SEI NAL units",
+ OFFSET(a53_cc), AV_OPT_TYPE_INT,
+ { .i64 = PASS }, PASS, EXTRACT, FLAGS, "a53_cc" },
+ { "pass", NULL, 0, AV_OPT_TYPE_CONST,
+ { .i64 = PASS }, .flags = FLAGS, .unit = "a53_cc" },
+ { "insert", NULL, 0, AV_OPT_TYPE_CONST,
+ { .i64 = INSERT }, .flags = FLAGS, .unit = "a53_cc" },
+ { "remove", NULL, 0, AV_OPT_TYPE_CONST,
+ { .i64 = REMOVE }, .flags = FLAGS, .unit = "a53_cc" },
+ { "extract", NULL, 0, AV_OPT_TYPE_CONST,
+ { .i64 = EXTRACT }, .flags = FLAGS, .unit = "a53_cc" },
+
{ NULL }
};
--
2.16.1
More information about the ffmpeg-devel
mailing list