[FFmpeg-devel] [PATCH 13/18] lavc: Add mpeg2_metadata bitstream filter
Michael Niedermayer
michael at niedermayer.cc
Mon Aug 21 21:21:56 EEST 2017
On Sun, Aug 20, 2017 at 11:41:41PM +0100, Mark Thompson wrote:
> (cherry picked from commit b78c30d7ec26af67c00ce2002709a189f6a87a7e)
> ---
> configure | 1 +
> doc/bitstream_filters.texi | 36 ++++
> libavcodec/Makefile | 1 +
> libavcodec/bitstream_filters.c | 1 +
> libavcodec/mpeg2_metadata_bsf.c | 360 ++++++++++++++++++++++++++++++++++++++++
> 5 files changed, 399 insertions(+)
> create mode 100644 libavcodec/mpeg2_metadata_bsf.c
>
> diff --git a/configure b/configure
> index 7641bd98d4..1e99038dca 100755
> --- a/configure
> +++ b/configure
> @@ -2836,6 +2836,7 @@ h264_metadata_bsf_select="cbs_h264"
> h264_redundant_pps_bsf_select="cbs_h264"
> hevc_metadata_bsf_select="cbs_h265"
> mjpeg2jpeg_bsf_select="jpegtables"
> +mpeg2_metadata_bsf_select="cbs_mpeg2"
> trace_headers_bsf_select="cbs_h264 cbs_h265 cbs_mpeg2"
>
> # external libraries
> diff --git a/doc/bitstream_filters.texi b/doc/bitstream_filters.texi
> index 71c307f2e2..8a8756bdcc 100644
> --- a/doc/bitstream_filters.texi
> +++ b/doc/bitstream_filters.texi
> @@ -324,6 +324,42 @@ See also the @ref{text2movsub} filter.
>
> Decompress non-standard compressed MP3 audio headers.
>
> + at section mpeg2_metadata
> +
> +Modify metadata embedded in an MPEG-2 stream.
> +
> + at table @option
> + at item display_aspect_ratio
> +Set the display aspect ratio in the stream.
> +
> +The following fixed values are supported:
> + at table @option
> + at item 4/3
> + at item 16/9
> + at item 221/100
> + at end table
> +Any other value will result in square pixels being signalled instead
> +(see H.262 section 6.3.3 and table 6-3).
> +
> + at item frame_rate
> +Set the frame rate in the stream. This is constructed from a table
> +of known values combined with a small multiplier and divisor - if
> +the supplied value is not exactly representable, the nearest
> +representable value will be used instead (see H.262 section 6.3.3
> +and table 6-4).
> +
> + at item video_format
> +Set the video format in the stream (see H.262 section 6.3.6 and
> +table 6-6).
> +
> + at item colour_primaries
> + at item transfer_characteristics
> + at item matrix_coefficients
> +Set the colour description in the stream (see H.262 section 6.3.6
> +and tables 6-7, 6-8 and 6-9).
> +
> + at end table
> +
> @section mpeg4_unpack_bframes
>
> Unpack DivX-style packed B-frames.
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 72f2bb2a12..3da7b9b508 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -1002,6 +1002,7 @@ OBJS-$(CONFIG_MPEG4_UNPACK_BFRAMES_BSF) += mpeg4_unpack_bframes_bsf.o
> OBJS-$(CONFIG_MOV2TEXTSUB_BSF) += movsub_bsf.o
> OBJS-$(CONFIG_MP3_HEADER_DECOMPRESS_BSF) += mp3_header_decompress_bsf.o \
> mpegaudiodata.o
> +OBJS-$(CONFIG_MPEG2_METADATA_BSF) += mpeg2_metadata_bsf.o
> OBJS-$(CONFIG_NOISE_BSF) += noise_bsf.o
> OBJS-$(CONFIG_NULL_BSF) += null_bsf.o
> OBJS-$(CONFIG_REMOVE_EXTRADATA_BSF) += remove_extradata_bsf.o
> diff --git a/libavcodec/bitstream_filters.c b/libavcodec/bitstream_filters.c
> index 6e6b894e7f..7b0cb5032a 100644
> --- a/libavcodec/bitstream_filters.c
> +++ b/libavcodec/bitstream_filters.c
> @@ -38,6 +38,7 @@ extern const AVBitStreamFilter ff_imx_dump_header_bsf;
> extern const AVBitStreamFilter ff_mjpeg2jpeg_bsf;
> extern const AVBitStreamFilter ff_mjpega_dump_header_bsf;
> extern const AVBitStreamFilter ff_mp3_header_decompress_bsf;
> +extern const AVBitStreamFilter ff_mpeg2_metadata_bsf;
> extern const AVBitStreamFilter ff_mpeg4_unpack_bframes_bsf;
> extern const AVBitStreamFilter ff_mov2textsub_bsf;
> extern const AVBitStreamFilter ff_noise_bsf;
> diff --git a/libavcodec/mpeg2_metadata_bsf.c b/libavcodec/mpeg2_metadata_bsf.c
> new file mode 100644
> index 0000000000..b4449eac71
> --- /dev/null
> +++ b/libavcodec/mpeg2_metadata_bsf.c
> @@ -0,0 +1,360 @@
> +/*
> + * 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 "libavutil/avstring.h"
> +#include "libavutil/common.h"
> +#include "libavutil/opt.h"
> +
> +#include "bsf.h"
> +#include "cbs.h"
> +#include "cbs_mpeg2.h"
> +
> +typedef struct MPEG2MetadataContext {
> + const AVClass *class;
> +
> + CodedBitstreamContext cbc;
> + CodedBitstreamFragment fragment;
> +
> + MPEG2RawExtensionData sequence_display_extension;
> +
> + AVRational display_aspect_ratio;
> +
> + AVRational frame_rate;
> +
> + int video_format;
> + int colour_primaries;
> + int transfer_characteristics;
> + int matrix_coefficients;
> +
> + int mpeg1_warned;
> +} MPEG2MetadataContext;
> +
> +
> +static int mpeg2_metadata_update_fragment(AVBSFContext *bsf,
> + CodedBitstreamFragment *frag)
> +{
> + MPEG2MetadataContext *ctx = bsf->priv_data;
> + MPEG2RawSequenceHeader *sh = NULL;
> + MPEG2RawSequenceExtension *se = NULL;
> + MPEG2RawSequenceDisplayExtension *sde = NULL;
> + int i, se_pos, add_sde = 0;
> +
> + for (i = 0; i < frag->nb_units; i++) {
> + if (frag->units[i].type == MPEG2_START_SEQUENCE_HEADER) {
> + sh = frag->units[i].content;
> + } else if (frag->units[i].type == MPEG2_START_EXTENSION) {
> + MPEG2RawExtensionData *ext = frag->units[i].content;
> + if (ext->extension_start_code_identifier ==
> + MPEG2_EXTENSION_SEQUENCE) {
> + se = &ext->data.sequence;
> + se_pos = i;
> + } else if (ext->extension_start_code_identifier ==
> + MPEG2_EXTENSION_SEQUENCE_DISPLAY) {
> + sde = &ext->data.sequence_display;
> + }
> + }
> + }
> +
> + if (!sh || !se) {
> + // No sequence header and sequence extension: not an MPEG-2 video
> + // sequence.
> + if (sh && !ctx->mpeg1_warned) {
> + av_log(bsf, AV_LOG_WARNING, "Stream contains a sequence "
> + "header but not a sequence extension: maybe it's "
> + "actually MPEG-1?\n");
> + ctx->mpeg1_warned = 1;
> + }
> + return 0;
> + }
> +
> + if (ctx->display_aspect_ratio.num && ctx->display_aspect_ratio.den) {
> + int num, den;
> +
> + av_reduce(&num, &den, ctx->display_aspect_ratio.num,
> + ctx->display_aspect_ratio.den, 65535);
> +
> + if (num == 4 && den == 3)
> + sh->aspect_ratio_information = 2;
> + else if (num == 16 && den == 9)
> + sh->aspect_ratio_information = 3;
> + else if (num == 221 && den == 100)
> + sh->aspect_ratio_information = 4;
> + else
> + sh->aspect_ratio_information = 1;
> + }
> +
> + if (ctx->frame_rate.num && ctx->frame_rate.den) {
> + // Table 6-4.
> + static AVRational frame_rate_table[] = {
> + { 0, 0 },
> + { 24000, 1001 },
> + { 24, 1 },
> + { 25, 1 },
> + { 30000, 1001 },
> + { 30, 1 },
> + { 50, 1 },
> + { 60000, 1001 },
> + { 60, 1 },
> + };
This is a duplicate of ff_mpeg12_frame_rate_tab
also should be static const
[...]
> +#define OFFSET(x) offsetof(MPEG2MetadataContext, x)
> +static const AVOption mpeg2_metadata_options[] = {
> + { "display_aspect_ratio", "Set display aspect ratio (table 6-3)",
> + OFFSET(display_aspect_ratio), AV_OPT_TYPE_RATIONAL,
> + { .i64 = 0 }, 0, 65535 },
> +
> + { "frame_rate", "Set frame rate",
> + OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL,
> + { .i64 = 0 }, 0, UINT_MAX },
for AV_OPT_TYPE_RATIONAL the default is dbl not i64, also this affects
some of the other patches as well
[...]
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
The bravest are surely those who have the clearest vision
of what is before them, glory and danger alike, and yet
notwithstanding go out to meet it. -- Thucydides
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 181 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20170821/3c99428a/attachment.sig>
More information about the ffmpeg-devel
mailing list