On Fri, Jun 1, 2012 at 8:11 AM, David Girault <[email protected]> wrote:
>
> Added support for HDMV Interactive Graphics Stream in mpegts
>
> This new muxer/demuxer will allow to read/write menu stream
> from/to 'mnu' files. This will allow to extract menu from BDAV
> m2ts file to a elementary stream file suitable for Bluray
> authoring software (such as BDedit from domm9).
>
> Mpeg TS muxer/demuxer was also updated to recognize these IGS
> menu streams. More update required to allow muxing IGS menu
> inside an mpegts file.
>
> Signed-off-by: David Girault <[email protected]>
> ---
> libavformat/Makefile | 2 +
> libavformat/allformats.c | 1 +
> libavformat/avformat.h | 1 +
> libavformat/mnudec.c | 103
> ++++++++++++++++++++++++++++++++++++++++++++++
> libavformat/mnuenc.c | 64 ++++++++++++++++++++++++++++
> libavformat/mpegts.c | 1 +
> 6 files changed, 172 insertions(+)
> create mode 100644 libavformat/mnudec.c
> create mode 100644 libavformat/mnuenc.c
>
Seems pretty good overall but I have a few concerns about the probe.
> diff --git a/libavformat/Makefile b/libavformat/Makefile
[...]
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
[...]
> diff --git a/libavformat/avformat.h b/libavformat/avformat.h
[...]
> diff --git a/libavformat/mnudec.c b/libavformat/mnudec.c
> new file mode 100644
> index 0000000..857b0f1
> --- /dev/null
> +++ b/libavformat/mnudec.c
> @@ -0,0 +1,103 @@
> +/*
> + * MNU demuxer
> + * Copyright (c) 2012 David Girault
> + *
> + * This file is part of Libav.
> + *
> + * Libav 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.
> + *
> + * Libav 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 Libav; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
> 02110-1301 USA
> + */
> +
> +#include "libavutil/mathematics.h"
> +#include "libavcodec/bytestream.h"
> +#include "avformat.h"
> +#include "internal.h"
> +
> +typedef struct MNUContext{
> + uint8_t *buffer;
> +} MNUContext;
> +
> +static int probe(AVProbeData *p)
> +{
> + const char *header= "IG";
static const char header[]
> +
> + if(!memcmp(p->buf , header, strlen(header)))
do we guarantee p->buf_size is always >= 2?
> + return AVPROBE_SCORE_MAX;
Two bytes seems like very little for AVPROBE_SCORE_MAX? Can we score
lower for just one packet and increase if we see 2+?
> +
> + return 0;
> +}
> +
> +static int read_close(AVFormatContext *s)
> +{
> + MNUContext *mnu = s->priv_data;
> + av_freep(&mnu->buffer);
> + return 0;
> +}
> +
> +static int read_header(AVFormatContext *s)
> +{
> + AVStream *st = avformat_new_stream(s, NULL);
> + if (!st)
> + return -1;
return AVERROR(ENOMEM)
> + //avpriv_set_pts_info(st, 64, 1, 100);
> + avpriv_set_pts_info(st, 33, 1, 90000);
> + st->codec->codec_type = AVMEDIA_TYPE_OVERLAY;
> + st->codec->codec_id= CODEC_ID_HDMV_IGS_MENU;
> + return 0;
> +}
> +
> +static int read_packet(AVFormatContext *s, AVPacket *pkt)
> +{
> +// MNUContext *mnu = s->priv_data;
> + uint64_t pos = avio_tell(s->pb);
> + int res = AVERROR_EOF;
> +
> + char header[2];
> + uint32_t pts, dts;
> + uint8_t seg_type;
> + uint16_t seg_length;
> +
> + // "IG",PTS,DTS,SEG_TYPE,SEG_LENGTH
> + res = avio_read(s->pb, header, 2);
> + if (header[0]!='I'||header[1]!='G') return AVERROR_INVALIDDATA;
> + pts = avio_rb32(s->pb);
> + dts = avio_rb32(s->pb);
> + seg_type = avio_r8(s->pb);
> + seg_length = avio_rb16(s->pb);
> +
> + res = av_new_packet(pkt, seg_length+3);
> + if (!res) {
> + uint8_t *buf = pkt->data;
> + bytestream_put_byte(&buf, seg_type);
> + bytestream_put_be16(&buf, seg_length);
> + avio_read(s->pb, buf, seg_length);
> + pkt->flags |= AV_PKT_FLAG_KEY;
> + pkt->pos = pos;
> + pkt->pts = pts;
> + pkt->dts = dts;
> + av_dlog(s, "New IG packet @ 0x%lx: type %d, length %d\n",
> + pos, seg_type, seg_length);
> + }
> + return res;
> +}
> +
> +AVInputFormat ff_mnu_demuxer = {
> + .name = "mnu",
> + .long_name = NULL_IF_CONFIG_SMALL("HDMV Interactive Graphic
> menus format"),
> + .priv_data_size = sizeof(MNUContext),
> + .read_probe = probe,
> + .read_header = read_header,
> + .read_packet = read_packet,
> + .read_close = read_close,
> +};
> diff --git a/libavformat/mnuenc.c b/libavformat/mnuenc.c
> new file mode 100644
> index 0000000..15d0ff8
> --- /dev/null
> +++ b/libavformat/mnuenc.c
> @@ -0,0 +1,64 @@
> +/*
> + * MNU demuxer
> + * Copyright (c) 2012 David Girault
> + *
> + * This file is part of Libav.
> + *
> + * Libav 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.
> + *
> + * Libav 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 Libav; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
> 02110-1301 USA
> + */
> +
> +#include "libavutil/mathematics.h"
> +#include "libavcodec/bytestream.h"
> +#include "avformat.h"
> +#include "internal.h"
> +
> +static int mnu_write_header(AVFormatContext *s)
> +{
> + AVCodecContext *ctx;
> +
> + if (s->nb_streams != 1) {
> + av_log(s, AV_LOG_ERROR, "Format supports only exactly one overlay
> stream\n");
> + return AVERROR(EINVAL);
> + }
> + ctx = s->streams[0]->codec;
> + if (ctx->codec_type != AVMEDIA_TYPE_OVERLAY || ctx->codec_id !=
> CODEC_ID_HDMV_IGS_MENU) {
> + av_log(s, AV_LOG_ERROR, "Currently only HDMV IGS menu is
> supported!\n");
> + return AVERROR(EINVAL);
> + }
> + return 0;
> +}
> +
> +static int mnu_write_packet(AVFormatContext *s, AVPacket *pkt)
> +{
> + AVIOContext *pb = s->pb;
> + avio_write(pb, "IG", 2);
> + avio_wb32(pb, pkt->pts);
> + avio_wb32(pb, pkt->dts);
> + avio_write(pb, pkt->data, pkt->size);
> + avio_flush(pb);
> + return 0;
> +}
> +
> +AVOutputFormat ff_mnu_muxer = {
> + .name = "mnu",
> + .long_name = NULL_IF_CONFIG_SMALL("HDMV Interactive Graphic menus
> format"),
> + .extensions = "mnu",
> + .audio_codec = CODEC_ID_NONE,
> + .video_codec = CODEC_ID_NONE,
> + .subtitle_codec = CODEC_ID_NONE,
> + .overlay_codec = CODEC_ID_HDMV_IGS_MENU,
> + .write_header = mnu_write_header,
> + .write_packet = mnu_write_packet,
> +};
> diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
[...]
--Alex
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