[FFmpeg-devel] [PATCH 1/3] lavc/pgs_frame_merge_bsf: add bsf to merge PGS segments
John Stebbins
jstebbins at jetheaddev.com
Fri Apr 17 02:06:06 EEST 2020
On Thu, 2020-04-16 at 15:59 -0700, John Stebbins wrote:
> On Thu, 2020-04-16 at 16:57 -0600, John Stebbins wrote:
> > Required to remux m2ts to mkv
> > ---
> > libavcodec/Makefile | 1 +
> > libavcodec/bitstream_filters.c | 1 +
> > libavcodec/pgs_frame_merge_bsf.c | 164
> > +++++++++++++++++++++++++++++++
> > 3 files changed, 166 insertions(+)
> > create mode 100644 libavcodec/pgs_frame_merge_bsf.c
> >
>
> Ugh! I forgot the version bump. Will get on that...
A question about this. I have 2 bsf submitted for review. Should I
just do a separate patch that updates the minor version once. Or do
you require it to be bumped with each change separately?
>
> > diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> > index c1c9a44f2b..c7d8fbebaa 100644
> > --- a/libavcodec/Makefile
> > +++ b/libavcodec/Makefile
> > @@ -1110,6 +1110,7 @@ OBJS-$(CONFIG_MP3_HEADER_DECOMPRESS_BSF) +=
> > mp3_header_decompress_bsf.o \
> > OBJS-$(CONFIG_MPEG2_METADATA_BSF) += mpeg2_metadata_bsf.o
> > OBJS-$(CONFIG_NOISE_BSF) += noise_bsf.o
> > OBJS-$(CONFIG_NULL_BSF) += null_bsf.o
> > +OBJS-$(CONFIG_PGS_FRAME_MERGE_BSF) += pgs_frame_merge_bsf.o
> > OBJS-$(CONFIG_PRORES_METADATA_BSF) += prores_metadata_bsf.o
> > OBJS-$(CONFIG_REMOVE_EXTRADATA_BSF) +=
> > remove_extradata_bsf.o
> > OBJS-$(CONFIG_TEXT2MOVSUB_BSF) += movsub_bsf.o
> > diff --git a/libavcodec/bitstream_filters.c
> > b/libavcodec/bitstream_filters.c
> > index 6b5ffe4d70..92619225f0 100644
> > --- a/libavcodec/bitstream_filters.c
> > +++ b/libavcodec/bitstream_filters.c
> > @@ -49,6 +49,7 @@ extern const AVBitStreamFilter
> > ff_mpeg4_unpack_bframes_bsf;
> > extern const AVBitStreamFilter ff_mov2textsub_bsf;
> > extern const AVBitStreamFilter ff_noise_bsf;
> > extern const AVBitStreamFilter ff_null_bsf;
> > +extern const AVBitStreamFilter ff_pgs_frame_merge_bsf;
> > extern const AVBitStreamFilter ff_prores_metadata_bsf;
> > extern const AVBitStreamFilter ff_remove_extradata_bsf;
> > extern const AVBitStreamFilter ff_text2movsub_bsf;
> > diff --git a/libavcodec/pgs_frame_merge_bsf.c
> > b/libavcodec/pgs_frame_merge_bsf.c
> > new file mode 100644
> > index 0000000000..d1bb3a60c2
> > --- /dev/null
> > +++ b/libavcodec/pgs_frame_merge_bsf.c
> > @@ -0,0 +1,164 @@
> > +/*
> > + * Copyright (c) 2020 John Stebbins <jstebbins.hb at gmail.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
> > + */
> > +
> > +/**
> > + * @file
> > + * This bitstream filter merges PGS subtitle packets containing
> > incomplete
> > + * set of segments into a single packet
> > + *
> > + * Packets already containing a complete set of segments will be
> > passed through
> > + * unchanged.
> > + */
> > +
> > +#include "avcodec.h"
> > +#include "bsf.h"
> > +#include "libavutil/intreadwrite.h"
> > +
> > +enum PGSSegmentType {
> > + PALETTE_SEGMENT = 0x14,
> > + OBJECT_SEGMENT = 0x15,
> > + PRESENTATION_SEGMENT = 0x16,
> > + WINDOW_SEGMENT = 0x17,
> > + DISPLAY_SEGMENT = 0x80,
> > +};
> > +
> > +typedef struct PGSMergeContext {
> > + AVPacket *buffer_pkt, *in;
> > + int presentation_found;
> > +} PGSMergeContext;
> > +
> > +static void frame_merge_flush(AVBSFContext *bsf)
> > +{
> > + PGSMergeContext *ctx = bsf->priv_data;
> > +
> > + av_packet_unref(ctx->in);
> > + av_packet_unref(ctx->buffer_pkt);
> > +}
> > +
> > +static int frame_merge_filter(AVBSFContext *bsf, AVPacket *out)
> > +{
> > + PGSMergeContext *ctx = bsf->priv_data;
> > + AVPacket *in = ctx->in, *pkt = ctx->buffer_pkt;
> > + int ret, i, size, pos, display = 0;
> > +
> > + if (!in->data) {
> > + ret = ff_bsf_get_packet_ref(bsf, in);
> > + if (ret < 0)
> > + return ret;
> > + }
> > + if (!in->size) {
> > + av_packet_unref(in);
> > + return AVERROR(EAGAIN);
> > + }
> > +
> > + // Validate packet data and find display_end segment
> > + size = in->size;
> > + i = 0;
> > + while (i + 3 <= in->size) {
> > + uint8_t segment_type;
> > + int segment_len;
> > +
> > + segment_type = in->data[i];
> > + segment_len = AV_RB16(in->data + i + 1) + 3;
> > + if (i + segment_len > in->size) // Invalid data
> > + break;
> > + if (segment_type == PRESENTATION_SEGMENT && !ctx-
> > > presentation_found) {
> > + int object_count;
> > + ctx->presentation_found = 1;
> > + ret = av_packet_copy_props(pkt, in);
> > + if (ret < 0)
> > + goto fail;
> > + object_count = in->data[i + 13];
> > + pkt->flags = !!object_count * AV_PKT_FLAG_KEY;
> > + }
> > + i += segment_len;
> > + if (segment_type == DISPLAY_SEGMENT) {
> > + size = display = i;
> > + break;
> > + }
> > + }
> > + if (display && pkt->size == 0 && size == in->size) { //
> > passthrough
> > + av_packet_move_ref(out, in);
> > + return 0;
> > + }
> > + if ((!display && i != in->size) || size > in->size) {
> > + av_log(bsf, AV_LOG_WARNING, "Failed to parse PGS
> > segments.\n");
> > + // force output what we have
> > + display = size = in->size;
> > + }
> > +
> > + pos = pkt->size;
> > + ret = av_grow_packet(pkt, size);
> > + if (ret < 0)
> > + goto fail;
> > + memcpy(pkt->data + pos, in->data, size);
> > +
> > + if (size == in->size)
> > + av_packet_unref(in);
> > + else {
> > + in->data += size;
> > + in->size -= size;
> > + }
> > +
> > + if (display) {
> > + ctx->presentation_found = 0;
> > + av_packet_move_ref(out, pkt);
> > + return 0;
> > + }
> > + return AVERROR(EAGAIN);
> > +
> > +fail:
> > + frame_merge_flush(bsf);
> > + return ret;
> > +}
> > +
> > +static int frame_merge_init(AVBSFContext *bsf)
> > +{
> > + PGSMergeContext *ctx = bsf->priv_data;
> > +
> > + ctx->in = av_packet_alloc();
> > + ctx->buffer_pkt = av_packet_alloc();
> > + if (!ctx->in || !ctx->buffer_pkt)
> > + return AVERROR(ENOMEM);
> > +
> > + return 0;
> > +}
> > +
> > +static void frame_merge_close(AVBSFContext *bsf)
> > +{
> > + PGSMergeContext *ctx = bsf->priv_data;
> > +
> > + av_packet_free(&ctx->in);
> > + av_packet_free(&ctx->buffer_pkt);
> > +}
> > +
> > +static const enum AVCodecID frame_merge_codec_ids[] = {
> > + AV_CODEC_ID_HDMV_PGS_SUBTITLE, AV_CODEC_ID_NONE,
> > +};
> > +
> > +const AVBitStreamFilter ff_pgs_frame_merge_bsf = {
> > + .name = "pgs_frame_merge",
> > + .priv_data_size = sizeof(PGSMergeContext),
> > + .init = frame_merge_init,
> > + .flush = frame_merge_flush,
> > + .close = frame_merge_close,
> > + .filter = frame_merge_filter,
> > + .codec_ids = frame_merge_codec_ids,
> > +};
More information about the ffmpeg-devel
mailing list