avdevice/decklink_enc: add support for playout of 608 captions in MOV files

Unlike other cases where the closed captions are embedded in the
video stream as MPEG-2 userdata or H.264 SEI data, with MOV files
the captions are often found on a separate "e608" subtitle track.

Add support for playout of such files, leveraging the new ccfifo
mechanism to ensure that they are embedded into VANC at the correct
rate (since e608 packets often contain batches of multiple 608 pairs).

Note this patch includes a new file named libavdevice/ccfifo.c, which
allows the ccfifo functionality in libavfilter to be reused even if
doing shared builds.  This is the same approach used for log2_tab.c.

Signed-off-by: Devin Heitmueller <dheitmueller@ltnglobal.com>
Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
This commit is contained in:
Devin Heitmueller 2023-05-05 15:09:07 -04:00 committed by Limin Wang
parent 0e12cdc69c
commit 9f4df9a535
5 changed files with 94 additions and 1 deletions

View File

@ -57,6 +57,7 @@ OBJS-$(CONFIG_LIBDC1394_INDEV) += libdc1394.o
# Objects duplicated from other libraries for shared builds # Objects duplicated from other libraries for shared builds
SHLIBOBJS-$(CONFIG_DECKLINK_INDEV) += reverse.o SHLIBOBJS-$(CONFIG_DECKLINK_INDEV) += reverse.o
SHLIBOBJS-$(CONFIG_DECKLINK_OUTDEV) += ccfifo.o
# Windows resource file # Windows resource file
SHLIBOBJS-$(HAVE_GNU_WINDRES) += avdeviceres.o SHLIBOBJS-$(HAVE_GNU_WINDRES) += avdeviceres.o

24
libavdevice/ccfifo.c Normal file
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@ -0,0 +1,24 @@
/*
* CEA-708 Closed Captioning FIFO
* Copyright (c) 2023 LTN Global Communications
*
* Author: Devin Heitmueller <dheitmueller@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
*/
#include "libavfilter/ccfifo.c"

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@ -31,6 +31,7 @@
extern "C" { extern "C" {
#include "libavcodec/packet_internal.h" #include "libavcodec/packet_internal.h"
#include "libavfilter/ccfifo.h"
} }
#include "libavutil/thread.h" #include "libavutil/thread.h"
#include "decklink_common_c.h" #include "decklink_common_c.h"
@ -112,6 +113,8 @@ struct decklink_ctx {
/* Capture buffer queue */ /* Capture buffer queue */
AVPacketQueue queue; AVPacketQueue queue;
AVCCFifo *cc_fifo; ///< closed captions
/* Streams present */ /* Streams present */
int audio; int audio;
int video; int video;

View File

@ -326,6 +326,25 @@ static int create_s337_payload(AVPacket *pkt, uint8_t **outbuf, int *outsize)
return 0; return 0;
} }
static int decklink_setup_subtitle(AVFormatContext *avctx, AVStream *st)
{
int ret = -1;
switch(st->codecpar->codec_id) {
#if CONFIG_LIBKLVANC
case AV_CODEC_ID_EIA_608:
/* No special setup required */
ret = 0;
break;
#endif
default:
av_log(avctx, AV_LOG_ERROR, "Unsupported subtitle codec specified\n");
break;
}
return ret;
}
av_cold int ff_decklink_write_trailer(AVFormatContext *avctx) av_cold int ff_decklink_write_trailer(AVFormatContext *avctx)
{ {
struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data; struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
@ -352,6 +371,7 @@ av_cold int ff_decklink_write_trailer(AVFormatContext *avctx)
klvanc_context_destroy(ctx->vanc_ctx); klvanc_context_destroy(ctx->vanc_ctx);
#endif #endif
ff_ccfifo_freep(&ctx->cc_fifo);
av_freep(&cctx->ctx); av_freep(&cctx->ctx);
return 0; return 0;
@ -503,6 +523,21 @@ out:
free(afd_words); free(afd_words);
} }
/* Parse any EIA-608 subtitles sitting on the queue, and write packet side data
that will later be handled by construct_cc... */
static void parse_608subs(AVFormatContext *avctx, struct decklink_ctx *ctx, AVPacket *pkt)
{
size_t cc_size = ff_ccfifo_getoutputsize(ctx->cc_fifo);
uint8_t *cc_data;
if (!ff_ccfifo_ccdetected(ctx->cc_fifo))
return;
cc_data = av_packet_new_side_data(pkt, AV_PKT_DATA_A53_CC, cc_size);
if (cc_data)
ff_ccfifo_injectbytes(ctx->cc_fifo, cc_data, cc_size);
}
static int decklink_construct_vanc(AVFormatContext *avctx, struct decklink_ctx *ctx, static int decklink_construct_vanc(AVFormatContext *avctx, struct decklink_ctx *ctx,
AVPacket *pkt, decklink_frame *frame, AVPacket *pkt, decklink_frame *frame,
AVStream *st) AVStream *st)
@ -513,6 +548,7 @@ static int decklink_construct_vanc(AVFormatContext *avctx, struct decklink_ctx *
if (!ctx->supports_vanc) if (!ctx->supports_vanc)
return 0; return 0;
parse_608subs(avctx, ctx, pkt);
construct_cc(avctx, ctx, pkt, &vanc_lines); construct_cc(avctx, ctx, pkt, &vanc_lines);
construct_afd(avctx, ctx, pkt, &vanc_lines, st); construct_afd(avctx, ctx, pkt, &vanc_lines, st);
@ -704,6 +740,16 @@ static int decklink_write_audio_packet(AVFormatContext *avctx, AVPacket *pkt)
return ret; return ret;
} }
static int decklink_write_subtitle_packet(AVFormatContext *avctx, AVPacket *pkt)
{
struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
struct decklink_ctx *ctx = (struct decklink_ctx *)cctx->ctx;
ff_ccfifo_extractbytes(ctx->cc_fifo, pkt->data, pkt->size);
return 0;
}
extern "C" { extern "C" {
av_cold int ff_decklink_write_header(AVFormatContext *avctx) av_cold int ff_decklink_write_header(AVFormatContext *avctx)
@ -768,12 +814,29 @@ av_cold int ff_decklink_write_header(AVFormatContext *avctx)
} else if (c->codec_type == AVMEDIA_TYPE_VIDEO) { } else if (c->codec_type == AVMEDIA_TYPE_VIDEO) {
if (decklink_setup_video(avctx, st)) if (decklink_setup_video(avctx, st))
goto error; goto error;
} else if (c->codec_type == AVMEDIA_TYPE_SUBTITLE) {
if (decklink_setup_subtitle(avctx, st))
goto error;
} else { } else {
av_log(avctx, AV_LOG_ERROR, "Unsupported stream type.\n"); av_log(avctx, AV_LOG_ERROR, "Unsupported stream type.\n");
goto error; goto error;
} }
} }
for (n = 0; n < avctx->nb_streams; n++) {
AVStream *st = avctx->streams[n];
AVCodecParameters *c = st->codecpar;
if(c->codec_type == AVMEDIA_TYPE_SUBTITLE)
avpriv_set_pts_info(st, 64, ctx->bmd_tb_num, ctx->bmd_tb_den);
}
if (!(ctx->cc_fifo = ff_ccfifo_alloc(av_make_q(ctx->bmd_tb_den, ctx->bmd_tb_num), avctx))) {
av_log(ctx, AV_LOG_ERROR, "Failure to setup CC FIFO queue\n");
ret = AVERROR(ENOMEM);
goto error;
}
return 0; return 0;
error: error:
@ -789,6 +852,8 @@ int ff_decklink_write_packet(AVFormatContext *avctx, AVPacket *pkt)
return decklink_write_video_packet(avctx, pkt); return decklink_write_video_packet(avctx, pkt);
else if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) else if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)
return decklink_write_audio_packet(avctx, pkt); return decklink_write_audio_packet(avctx, pkt);
else if (st->codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE)
return decklink_write_subtitle_packet(avctx, pkt);
return AVERROR(EIO); return AVERROR(EIO);
} }

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@ -77,7 +77,7 @@ const FFOutputFormat ff_decklink_muxer = {
.p.long_name = NULL_IF_CONFIG_SMALL("Blackmagic DeckLink output"), .p.long_name = NULL_IF_CONFIG_SMALL("Blackmagic DeckLink output"),
.p.audio_codec = AV_CODEC_ID_PCM_S16LE, .p.audio_codec = AV_CODEC_ID_PCM_S16LE,
.p.video_codec = AV_CODEC_ID_WRAPPED_AVFRAME, .p.video_codec = AV_CODEC_ID_WRAPPED_AVFRAME,
.p.subtitle_codec = AV_CODEC_ID_NONE, .p.subtitle_codec = AV_CODEC_ID_EIA_608,
.p.flags = AVFMT_NOFILE, .p.flags = AVFMT_NOFILE,
.p.priv_class = &decklink_muxer_class, .p.priv_class = &decklink_muxer_class,
.get_device_list = ff_decklink_list_output_devices, .get_device_list = ff_decklink_list_output_devices,