| Message ID | 1686953578-18843-5-git-send-email-dheitmueller@ltnglobal.com |
|---|---|
| State | New |
| Headers | show |
| Series | Add passthrough support for SCTE-35 | expand |
| Context | Check | Description |
|---|---|---|
| yinshiyou/make_loongarch64 | success | Make finished |
| yinshiyou/make_fate_loongarch64 | success | Make fate finished |
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
Devin Heitmueller: > Because SCTE-35 messages are represented in TS streams as sections > rather than PES packets, we cannot rely on ffmpeg's standard > mechanisms to adjust PTS values if reclocking the stream. > This filter will leverage the SCTE-35 pts_adjust field to > compensate for any change in the PTS values in the stream. > > See SCTE-35 2019 Sec 9.6 for information about the use of > the pts_adjust field. > > This filter also tweaks the mpegtsenc mux to automatically > add it so the user doesn't have to include it manually. > > Signed-off-by: Devin Heitmueller <dheitmueller@ltnglobal.com> > --- > libavcodec/Makefile | 1 + > libavcodec/bitstream_filters.c | 1 + > libavcodec/scte35ptsadjust_bsf.c | 114 +++++++++++++++++++++++++++++++++++++++ > libavformat/mpegtsenc.c | 2 + > 4 files changed, 118 insertions(+) > create mode 100644 libavcodec/scte35ptsadjust_bsf.c > > diff --git a/libavcodec/Makefile b/libavcodec/Makefile > index 0ce8fe5..6944c82 100644 > --- a/libavcodec/Makefile > +++ b/libavcodec/Makefile > @@ -1250,6 +1250,7 @@ OBJS-$(CONFIG_PCM_RECHUNK_BSF) += pcm_rechunk_bsf.o > OBJS-$(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 av1_parse.o > +OBJS-$(CONFIG_SCTE35PTSADJUST_BSF) += scte35ptsadjust_bsf.o > OBJS-$(CONFIG_SETTS_BSF) += setts_bsf.o > OBJS-$(CONFIG_TEXT2MOVSUB_BSF) += movsub_bsf.o > OBJS-$(CONFIG_TRACE_HEADERS_BSF) += trace_headers_bsf.o > diff --git a/libavcodec/bitstream_filters.c b/libavcodec/bitstream_filters.c > index 7512fcc..d30dfbd 100644 > --- a/libavcodec/bitstream_filters.c > +++ b/libavcodec/bitstream_filters.c > @@ -57,6 +57,7 @@ extern const FFBitStreamFilter ff_pcm_rechunk_bsf; > extern const FFBitStreamFilter ff_pgs_frame_merge_bsf; > extern const FFBitStreamFilter ff_prores_metadata_bsf; > extern const FFBitStreamFilter ff_remove_extradata_bsf; > +extern const FFBitStreamFilter ff_scte35ptsadjust_bsf; > extern const FFBitStreamFilter ff_setts_bsf; > extern const FFBitStreamFilter ff_text2movsub_bsf; > extern const FFBitStreamFilter ff_trace_headers_bsf; > diff --git a/libavcodec/scte35ptsadjust_bsf.c b/libavcodec/scte35ptsadjust_bsf.c > new file mode 100644 > index 0000000..e6e9ec9 > --- /dev/null > +++ b/libavcodec/scte35ptsadjust_bsf.c > @@ -0,0 +1,114 @@ > +/* > + * SCTE-35 PTS fixup bitstream filter > + * Copyright (c) 2023 LTN Global Communications, Inc. > + * > + * Author: Devin Heitmueller <dheitmueller@ltnglobal.com> > + * > + * Because SCTE-35 messages are represented in TS streams as sections > + * rather than PES packets, we cannot rely on ffmpeg's standard > + * mechanisms to adjust PTS values if reclocking the stream. > + * This filter will leverage the SCTE-35 pts_adjust field to > + * compensate for any change in the PTS values in the stream. > + * > + * See SCTE-35 2019 Sec 9.6 for information about the use of > + * the pts_adjust field. > + * > + * 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 "avcodec.h" What is that for? The BSF API is separate from the AVCodecContext stuff. > +#include "bsf.h" > +#include "bsf_internal.h" > + > +static int scte35ptsadjust_filter(AVBSFContext *ctx, AVPacket *out) > +{ > + AVPacket *in; > + size_t size; av_packet_get_side_data() can work with NULL for the size pointer. > + const int64_t *orig_pts; > + int64_t cur_pts_adjust; > + int ret = 0; > + > + ret = ff_bsf_get_packet(ctx, &in); > + if (ret < 0) > + return ret; > + > + /* Retrieve the original PTS, which will be used to calculate the pts_adjust */ > + orig_pts = (int64_t *) av_packet_get_side_data(in, AV_PKT_DATA_ORIG_PTS, &size); > + if (orig_pts == NULL) { > + /* No original PTS specified, so just pass the packet through */ > + av_packet_move_ref(out, in); > + av_packet_free(&in); > + return 0; > + } > + > + av_log(ctx, AV_LOG_DEBUG, "%s pts=%" PRId64 " orig_pts=%" PRId64 "\n", __func__, > + in->pts, *orig_pts); > + > + /* The pts_adjust field is logically buf[4]-buf[8] of the payload */ > + if (in->size < 8) You are reading data[8], so size should be at least 9. > + goto fail; This will return 0 instead of indicating an error. (But this is irrelevant, see below.) > + > + /* Extract the current pts_adjust value from the packet */ > + cur_pts_adjust = ((int64_t) in->data[4] & (int64_t) 0x01 << 32) | > + ((int64_t) in->data[5] << 24) | > + ((int64_t) in->data[6] << 16) | > + ((int64_t) in->data[7] << 8) | > + ((int64_t) in->data[8] ); > + > + av_log(ctx, AV_LOG_DEBUG, "%s pts_adjust=%" PRId64 "\n", __func__, > + cur_pts_adjust); > + > + /* Compute the new PTS adjust value */ > + cur_pts_adjust -= *orig_pts; > + cur_pts_adjust += in->pts; > + cur_pts_adjust &= (int64_t) 0x1ffffffff; > + > + av_log(ctx, AV_LOG_DEBUG, "%s new pts_adjust=%" PRId64 "\n", __func__, > + cur_pts_adjust); We typically don't add __func__, because the actual information where the log comes from is contained in the logcontext. Furthermore, you could combine these two av_log(). > + > + /* Clone the incoming packet since we need to modify it */ > + ret = av_new_packet(out, in->size); > + if (ret < 0) > + goto fail; > + ret = av_packet_copy_props(out, in); > + if (ret < 0) > + goto fail; > + memcpy(out->data, in->data, in->size); Just use av_packet_make_writable() instead of this; use it in conjunction with ff_bsf_get_packet_ref(), avoiding the second packet. It also avoids allocations and copies in case the packet's data is already writable and avoids copying side-data etc. > + > + /* Insert the updated pts_adjust value */ > + out->data[4] &= 0xfe; /* Preserve top 7 unrelated bits */ > + out->data[4] |= cur_pts_adjust >> 32; > + out->data[5] = cur_pts_adjust >> 24; > + out->data[6] = cur_pts_adjust >> 16; > + out->data[7] = cur_pts_adjust >> 8; > + out->data[8] = cur_pts_adjust; The last four could be simplified to AV_WB32(out_data[5], (uint32_t)cur_pts_adjust); > + > +fail: > + av_packet_free(&in); > + > + return ret; > +} > + > +static const enum AVCodecID codec_ids[] = { > + AV_CODEC_ID_SCTE_35, AV_CODEC_ID_NONE, > +}; > + > +const FFBitStreamFilter ff_scte35ptsadjust_bsf = { > + .p.name = "scte35ptsadjust", > + .p.codec_ids = codec_ids, > + .filter = scte35ptsadjust_filter, > +}; > diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c > index c6cd1fd..48d7833 100644 > --- a/libavformat/mpegtsenc.c > +++ b/libavformat/mpegtsenc.c > @@ -2337,6 +2337,8 @@ static int mpegts_check_bitstream(AVFormatContext *s, AVStream *st, > (st->codecpar->extradata_size > 0 && > st->codecpar->extradata[0] == 1))) > ret = ff_stream_add_bitstream_filter(st, "hevc_mp4toannexb", NULL); > + } else if (st->codecpar->codec_id == AV_CODEC_ID_SCTE_35) { > + ret = ff_stream_add_bitstream_filter(st, "scte35ptsadjust", NULL); > } > > return ret;
On Fri, Jun 16, 2023 at 5:58 PM Andreas Rheinhardt <andreas.rheinhardt@outlook.com> wrote: > > Devin Heitmueller: > > Because SCTE-35 messages are represented in TS streams as sections > > rather than PES packets, we cannot rely on ffmpeg's standard > > mechanisms to adjust PTS values if reclocking the stream. > > This filter will leverage the SCTE-35 pts_adjust field to > > compensate for any change in the PTS values in the stream. > > > > See SCTE-35 2019 Sec 9.6 for information about the use of > > the pts_adjust field. > > > > This filter also tweaks the mpegtsenc mux to automatically > > add it so the user doesn't have to include it manually. > > > > Signed-off-by: Devin Heitmueller <dheitmueller@ltnglobal.com> > > --- > > libavcodec/Makefile | 1 + > > libavcodec/bitstream_filters.c | 1 + > > libavcodec/scte35ptsadjust_bsf.c | 114 +++++++++++++++++++++++++++++++++++++++ > > libavformat/mpegtsenc.c | 2 + > > 4 files changed, 118 insertions(+) > > create mode 100644 libavcodec/scte35ptsadjust_bsf.c > > > > diff --git a/libavcodec/Makefile b/libavcodec/Makefile > > index 0ce8fe5..6944c82 100644 > > --- a/libavcodec/Makefile > > +++ b/libavcodec/Makefile > > @@ -1250,6 +1250,7 @@ OBJS-$(CONFIG_PCM_RECHUNK_BSF) += pcm_rechunk_bsf.o > > OBJS-$(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 av1_parse.o > > +OBJS-$(CONFIG_SCTE35PTSADJUST_BSF) += scte35ptsadjust_bsf.o > > OBJS-$(CONFIG_SETTS_BSF) += setts_bsf.o > > OBJS-$(CONFIG_TEXT2MOVSUB_BSF) += movsub_bsf.o > > OBJS-$(CONFIG_TRACE_HEADERS_BSF) += trace_headers_bsf.o > > diff --git a/libavcodec/bitstream_filters.c b/libavcodec/bitstream_filters.c > > index 7512fcc..d30dfbd 100644 > > --- a/libavcodec/bitstream_filters.c > > +++ b/libavcodec/bitstream_filters.c > > @@ -57,6 +57,7 @@ extern const FFBitStreamFilter ff_pcm_rechunk_bsf; > > extern const FFBitStreamFilter ff_pgs_frame_merge_bsf; > > extern const FFBitStreamFilter ff_prores_metadata_bsf; > > extern const FFBitStreamFilter ff_remove_extradata_bsf; > > +extern const FFBitStreamFilter ff_scte35ptsadjust_bsf; > > extern const FFBitStreamFilter ff_setts_bsf; > > extern const FFBitStreamFilter ff_text2movsub_bsf; > > extern const FFBitStreamFilter ff_trace_headers_bsf; > > diff --git a/libavcodec/scte35ptsadjust_bsf.c b/libavcodec/scte35ptsadjust_bsf.c > > new file mode 100644 > > index 0000000..e6e9ec9 > > --- /dev/null > > +++ b/libavcodec/scte35ptsadjust_bsf.c > > @@ -0,0 +1,114 @@ > > +/* > > + * SCTE-35 PTS fixup bitstream filter > > + * Copyright (c) 2023 LTN Global Communications, Inc. > > + * > > + * Author: Devin Heitmueller <dheitmueller@ltnglobal.com> > > + * > > + * Because SCTE-35 messages are represented in TS streams as sections > > + * rather than PES packets, we cannot rely on ffmpeg's standard > > + * mechanisms to adjust PTS values if reclocking the stream. > > + * This filter will leverage the SCTE-35 pts_adjust field to > > + * compensate for any change in the PTS values in the stream. > > + * > > + * See SCTE-35 2019 Sec 9.6 for information about the use of > > + * the pts_adjust field. > > + * > > + * 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 "avcodec.h" > > What is that for? The BSF API is separate from the AVCodecContext stuff. > > > +#include "bsf.h" > > +#include "bsf_internal.h" > > + > > +static int scte35ptsadjust_filter(AVBSFContext *ctx, AVPacket *out) > > +{ > > + AVPacket *in; > > + size_t size; > > av_packet_get_side_data() can work with NULL for the size pointer. > > > + const int64_t *orig_pts; > > + int64_t cur_pts_adjust; > > + int ret = 0; > > + > > + ret = ff_bsf_get_packet(ctx, &in); > > + if (ret < 0) > > + return ret; > > + > > + /* Retrieve the original PTS, which will be used to calculate the pts_adjust */ > > + orig_pts = (int64_t *) av_packet_get_side_data(in, AV_PKT_DATA_ORIG_PTS, &size); > > + if (orig_pts == NULL) { > > + /* No original PTS specified, so just pass the packet through */ > > + av_packet_move_ref(out, in); > > + av_packet_free(&in); > > + return 0; > > + } > > + > > + av_log(ctx, AV_LOG_DEBUG, "%s pts=%" PRId64 " orig_pts=%" PRId64 "\n", __func__, > > + in->pts, *orig_pts); > > + > > + /* The pts_adjust field is logically buf[4]-buf[8] of the payload */ > > + if (in->size < 8) > > You are reading data[8], so size should be at least 9. > > > + goto fail; > > This will return 0 instead of indicating an error. > (But this is irrelevant, see below.) > > > + > > + /* Extract the current pts_adjust value from the packet */ > > + cur_pts_adjust = ((int64_t) in->data[4] & (int64_t) 0x01 << 32) | > > + ((int64_t) in->data[5] << 24) | > > + ((int64_t) in->data[6] << 16) | > > + ((int64_t) in->data[7] << 8) | > > + ((int64_t) in->data[8] ); > > + > > + av_log(ctx, AV_LOG_DEBUG, "%s pts_adjust=%" PRId64 "\n", __func__, > > + cur_pts_adjust); > > + > > + /* Compute the new PTS adjust value */ > > + cur_pts_adjust -= *orig_pts; > > + cur_pts_adjust += in->pts; > > + cur_pts_adjust &= (int64_t) 0x1ffffffff; > > + > > + av_log(ctx, AV_LOG_DEBUG, "%s new pts_adjust=%" PRId64 "\n", __func__, > > + cur_pts_adjust); > > We typically don't add __func__, because the actual information where > the log comes from is contained in the logcontext. Furthermore, you > could combine these two av_log(). > > > + > > + /* Clone the incoming packet since we need to modify it */ > > + ret = av_new_packet(out, in->size); > > + if (ret < 0) > > + goto fail; > > + ret = av_packet_copy_props(out, in); > > + if (ret < 0) > > + goto fail; > > + memcpy(out->data, in->data, in->size); > > Just use av_packet_make_writable() instead of this; use it in > conjunction with ff_bsf_get_packet_ref(), avoiding the second packet. It > also avoids allocations and copies in case the packet's data is already > writable and avoids copying side-data etc. > > > + > > + /* Insert the updated pts_adjust value */ > > + out->data[4] &= 0xfe; /* Preserve top 7 unrelated bits */ > > + out->data[4] |= cur_pts_adjust >> 32; > > + out->data[5] = cur_pts_adjust >> 24; > > + out->data[6] = cur_pts_adjust >> 16; > > + out->data[7] = cur_pts_adjust >> 8; > > + out->data[8] = cur_pts_adjust; > > The last four could be simplified to AV_WB32(out_data[5], > (uint32_t)cur_pts_adjust); > > > + > > +fail: > > + av_packet_free(&in); > > + > > + return ret; > > +} > > + > > +static const enum AVCodecID codec_ids[] = { > > + AV_CODEC_ID_SCTE_35, AV_CODEC_ID_NONE, > > +}; > > + > > +const FFBitStreamFilter ff_scte35ptsadjust_bsf = { > > + .p.name = "scte35ptsadjust", > > + .p.codec_ids = codec_ids, > > + .filter = scte35ptsadjust_filter, > > +}; > > diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c > > index c6cd1fd..48d7833 100644 > > --- a/libavformat/mpegtsenc.c > > +++ b/libavformat/mpegtsenc.c > > @@ -2337,6 +2337,8 @@ static int mpegts_check_bitstream(AVFormatContext *s, AVStream *st, > > (st->codecpar->extradata_size > 0 && > > st->codecpar->extradata[0] == 1))) > > ret = ff_stream_add_bitstream_filter(st, "hevc_mp4toannexb", NULL); > > + } else if (st->codecpar->codec_id == AV_CODEC_ID_SCTE_35) { > > + ret = ff_stream_add_bitstream_filter(st, "scte35ptsadjust", NULL); > > } > > > > return ret; > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe". Thanks for reviewing. These all seem like reasonable comments and I will incorporate them into the next patch series. Regards, Devin
diff --git a/libavcodec/Makefile b/libavcodec/Makefile index 0ce8fe5..6944c82 100644 --- a/libavcodec/Makefile +++ b/libavcodec/Makefile @@ -1250,6 +1250,7 @@ OBJS-$(CONFIG_PCM_RECHUNK_BSF) += pcm_rechunk_bsf.o OBJS-$(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 av1_parse.o +OBJS-$(CONFIG_SCTE35PTSADJUST_BSF) += scte35ptsadjust_bsf.o OBJS-$(CONFIG_SETTS_BSF) += setts_bsf.o OBJS-$(CONFIG_TEXT2MOVSUB_BSF) += movsub_bsf.o OBJS-$(CONFIG_TRACE_HEADERS_BSF) += trace_headers_bsf.o diff --git a/libavcodec/bitstream_filters.c b/libavcodec/bitstream_filters.c index 7512fcc..d30dfbd 100644 --- a/libavcodec/bitstream_filters.c +++ b/libavcodec/bitstream_filters.c @@ -57,6 +57,7 @@ extern const FFBitStreamFilter ff_pcm_rechunk_bsf; extern const FFBitStreamFilter ff_pgs_frame_merge_bsf; extern const FFBitStreamFilter ff_prores_metadata_bsf; extern const FFBitStreamFilter ff_remove_extradata_bsf; +extern const FFBitStreamFilter ff_scte35ptsadjust_bsf; extern const FFBitStreamFilter ff_setts_bsf; extern const FFBitStreamFilter ff_text2movsub_bsf; extern const FFBitStreamFilter ff_trace_headers_bsf; diff --git a/libavcodec/scte35ptsadjust_bsf.c b/libavcodec/scte35ptsadjust_bsf.c new file mode 100644 index 0000000..e6e9ec9 --- /dev/null +++ b/libavcodec/scte35ptsadjust_bsf.c @@ -0,0 +1,114 @@ +/* + * SCTE-35 PTS fixup bitstream filter + * Copyright (c) 2023 LTN Global Communications, Inc. + * + * Author: Devin Heitmueller <dheitmueller@ltnglobal.com> + * + * Because SCTE-35 messages are represented in TS streams as sections + * rather than PES packets, we cannot rely on ffmpeg's standard + * mechanisms to adjust PTS values if reclocking the stream. + * This filter will leverage the SCTE-35 pts_adjust field to + * compensate for any change in the PTS values in the stream. + * + * See SCTE-35 2019 Sec 9.6 for information about the use of + * the pts_adjust field. + * + * 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 "avcodec.h" +#include "bsf.h" +#include "bsf_internal.h" + +static int scte35ptsadjust_filter(AVBSFContext *ctx, AVPacket *out) +{ + AVPacket *in; + size_t size; + const int64_t *orig_pts; + int64_t cur_pts_adjust; + int ret = 0; + + ret = ff_bsf_get_packet(ctx, &in); + if (ret < 0) + return ret; + + /* Retrieve the original PTS, which will be used to calculate the pts_adjust */ + orig_pts = (int64_t *) av_packet_get_side_data(in, AV_PKT_DATA_ORIG_PTS, &size); + if (orig_pts == NULL) { + /* No original PTS specified, so just pass the packet through */ + av_packet_move_ref(out, in); + av_packet_free(&in); + return 0; + } + + av_log(ctx, AV_LOG_DEBUG, "%s pts=%" PRId64 " orig_pts=%" PRId64 "\n", __func__, + in->pts, *orig_pts); + + /* The pts_adjust field is logically buf[4]-buf[8] of the payload */ + if (in->size < 8) + goto fail; + + /* Extract the current pts_adjust value from the packet */ + cur_pts_adjust = ((int64_t) in->data[4] & (int64_t) 0x01 << 32) | + ((int64_t) in->data[5] << 24) | + ((int64_t) in->data[6] << 16) | + ((int64_t) in->data[7] << 8) | + ((int64_t) in->data[8] ); + + av_log(ctx, AV_LOG_DEBUG, "%s pts_adjust=%" PRId64 "\n", __func__, + cur_pts_adjust); + + /* Compute the new PTS adjust value */ + cur_pts_adjust -= *orig_pts; + cur_pts_adjust += in->pts; + cur_pts_adjust &= (int64_t) 0x1ffffffff; + + av_log(ctx, AV_LOG_DEBUG, "%s new pts_adjust=%" PRId64 "\n", __func__, + cur_pts_adjust); + + /* Clone the incoming packet since we need to modify it */ + ret = av_new_packet(out, in->size); + if (ret < 0) + goto fail; + ret = av_packet_copy_props(out, in); + if (ret < 0) + goto fail; + memcpy(out->data, in->data, in->size); + + /* Insert the updated pts_adjust value */ + out->data[4] &= 0xfe; /* Preserve top 7 unrelated bits */ + out->data[4] |= cur_pts_adjust >> 32; + out->data[5] = cur_pts_adjust >> 24; + out->data[6] = cur_pts_adjust >> 16; + out->data[7] = cur_pts_adjust >> 8; + out->data[8] = cur_pts_adjust; + +fail: + av_packet_free(&in); + + return ret; +} + +static const enum AVCodecID codec_ids[] = { + AV_CODEC_ID_SCTE_35, AV_CODEC_ID_NONE, +}; + +const FFBitStreamFilter ff_scte35ptsadjust_bsf = { + .p.name = "scte35ptsadjust", + .p.codec_ids = codec_ids, + .filter = scte35ptsadjust_filter, +}; diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c index c6cd1fd..48d7833 100644 --- a/libavformat/mpegtsenc.c +++ b/libavformat/mpegtsenc.c @@ -2337,6 +2337,8 @@ static int mpegts_check_bitstream(AVFormatContext *s, AVStream *st, (st->codecpar->extradata_size > 0 && st->codecpar->extradata[0] == 1))) ret = ff_stream_add_bitstream_filter(st, "hevc_mp4toannexb", NULL); + } else if (st->codecpar->codec_id == AV_CODEC_ID_SCTE_35) { + ret = ff_stream_add_bitstream_filter(st, "scte35ptsadjust", NULL); } return ret;
Because SCTE-35 messages are represented in TS streams as sections rather than PES packets, we cannot rely on ffmpeg's standard mechanisms to adjust PTS values if reclocking the stream. This filter will leverage the SCTE-35 pts_adjust field to compensate for any change in the PTS values in the stream. See SCTE-35 2019 Sec 9.6 for information about the use of the pts_adjust field. This filter also tweaks the mpegtsenc mux to automatically add it so the user doesn't have to include it manually. Signed-off-by: Devin Heitmueller <dheitmueller@ltnglobal.com> --- libavcodec/Makefile | 1 + libavcodec/bitstream_filters.c | 1 + libavcodec/scte35ptsadjust_bsf.c | 114 +++++++++++++++++++++++++++++++++++++++ libavformat/mpegtsenc.c | 2 + 4 files changed, 118 insertions(+) create mode 100644 libavcodec/scte35ptsadjust_bsf.c