[FFmpeg-devel] [PATCH v4] avformat/ifv: added support for ifv cctv files

Peter Ross pross at xvid.org
Sat May 25 16:01:24 EEST 2019


On Sat, May 25, 2019 at 01:59:44PM +0200, Paul B Mahol wrote:
> On 5/25/19, Swaraj Hota <swarajhota353 at gmail.com> wrote:
> > Fixes ticket #2956.
> >
> > Signed-off-by: Swaraj Hota <swarajhota353 at gmail.com>
> > ---
> > Changes made based on previous discussions.
> >
> > Now the demuxer is working pretty much as the original dvr player does.
> > Framerate is based on timestamps (hence correct). Seeking is working for
> > all files without any issue.

more comments below.

> > ---
> >  Changelog                |   1 +
> >  libavformat/Makefile     |   1 +
> >  libavformat/allformats.c |   1 +
> >  libavformat/ifv.c        | 318 +++++++++++++++++++++++++++++++++++++++
> >  libavformat/version.h    |   4 +-
> >  5 files changed, 323 insertions(+), 2 deletions(-)
> >  create mode 100644 libavformat/ifv.c
> >
> > diff --git a/Changelog b/Changelog
> > index e6b209ae0a..e0b27657d7 100644
> > --- a/Changelog
> > +++ b/Changelog
> > @@ -30,6 +30,7 @@ version <next>:
> >  - colorhold filter
> >  - xmedian filter
> >  - asr filter
> > +- IFV demuxer
> >
> >
> >  version 4.1:
> > diff --git a/libavformat/Makefile b/libavformat/Makefile
> > index df87c54a58..a434b005a4 100644
> > --- a/libavformat/Makefile
> > +++ b/libavformat/Makefile
> > @@ -231,6 +231,7 @@ OBJS-$(CONFIG_ICO_MUXER)                 += icoenc.o
> >  OBJS-$(CONFIG_IDCIN_DEMUXER)             += idcin.o
> >  OBJS-$(CONFIG_IDF_DEMUXER)               += bintext.o sauce.o
> >  OBJS-$(CONFIG_IFF_DEMUXER)               += iff.o
> > +OBJS-$(CONFIG_IFV_DEMUXER)               += ifv.o
> >  OBJS-$(CONFIG_ILBC_DEMUXER)              += ilbc.o
> >  OBJS-$(CONFIG_ILBC_MUXER)                += ilbc.o
> >  OBJS-$(CONFIG_IMAGE2_DEMUXER)            += img2dec.o img2.o
> > diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> > index d316a0529a..cd00834807 100644
> > --- a/libavformat/allformats.c
> > +++ b/libavformat/allformats.c
> > @@ -188,6 +188,7 @@ extern AVOutputFormat ff_ico_muxer;
> >  extern AVInputFormat  ff_idcin_demuxer;
> >  extern AVInputFormat  ff_idf_demuxer;
> >  extern AVInputFormat  ff_iff_demuxer;
> > +extern AVInputFormat  ff_ifv_demuxer;
> >  extern AVInputFormat  ff_ilbc_demuxer;
> >  extern AVOutputFormat ff_ilbc_muxer;
> >  extern AVInputFormat  ff_image2_demuxer;
> > diff --git a/libavformat/ifv.c b/libavformat/ifv.c
> > new file mode 100644
> > index 0000000000..517f0252f5
> > --- /dev/null
> > +++ b/libavformat/ifv.c
> > @@ -0,0 +1,318 @@
> > +/*
> > + * IFV demuxer
> > + *
> > + * Copyright (c) 2019 Swaraj Hota
> > + *
> > + * 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 "avformat.h"
> > +#include "internal.h"
> > +#include "avio_internal.h"
> > +
> > +
> > +typedef struct IFVContext {
> > +    uint32_t next_video_index;
> > +    uint32_t next_audio_index;
> > +    uint32_t total_vframes;
> > +    uint32_t total_aframes;
> > +
> > +    int width, height;
> > +    int is_audio_present;
> > +    int sample_rate;
> > +
> > +    int video_stream_index;
> > +    int audio_stream_index;
> > +} IFVContext;
> > +
> > +static int ifv_probe(const AVProbeData *p)
> > +{
> > +    static const uint8_t ifv_magic[] = {0x11, 0xd2, 0xd3, 0xab, 0xba, 0xa9,
> > +        0xcf, 0x11, 0x8e, 0xe6, 0x00, 0xc0, 0x0c, 0x20, 0x53, 0x65, 0x44};
> > +
> > +    if (!memcmp(p->buf, ifv_magic, sizeof(ifv_magic)))
> > +        return AVPROBE_SCORE_MAX;
> > +
> > +    return 0;
> > +}
> > +
> > +static int read_index(AVFormatContext *s,
> > +                      enum AVMediaType frame_type,
> > +                      uint32_t start_index)
> > +{
> > +    IFVContext *ifv = s->priv_data;
> > +    AVStream *st;
> > +    int64_t pos, size, timestamp;
> > +    uint32_t end_index, i;
> > +    int ret;
> > +
> > +    if (frame_type == AVMEDIA_TYPE_VIDEO) {
> > +        end_index = ifv->total_vframes;
> > +        st = s->streams[ifv->video_stream_index];
> > +    } else {
> > +        end_index = ifv->total_aframes;
> > +        st = s->streams[ifv->audio_stream_index];
> > +    }
> > +
> > +    for (i = start_index; i < end_index; i++) {
> > +        pos = avio_rl32(s->pb);
> > +        size = avio_rl32(s->pb);
> > +
> > +        avio_skip(s->pb, 8);
> > +        timestamp = avio_rl32(s->pb);
> > +
> > +        ret = av_add_index_entry(st, pos, timestamp, size, 0, 0);
> > +        if (ret < 0)
> > +            return ret;
> > +
> > +        avio_skip(s->pb, frame_type == AVMEDIA_TYPE_VIDEO? 8: 4);

add space between symobl and ?

> > +    }
> > +
> > +    return 0;
> > +}
> > +
> > +static int parse_header(AVFormatContext *s)
> > +{
> > +    IFVContext *ifv = s->priv_data;
> > +    uint32_t aud_magic;
> > +    uint32_t vid_magic;
> > +
> > +    avio_skip(s->pb, 0x5c);
> > +    ifv->width = avio_rl16(s->pb);
> > +    ifv->height = avio_rl16(s->pb);
> > +
> > +    avio_skip(s->pb, 0x8);
> > +    vid_magic = avio_rl32(s->pb);
> > +
> > +    if (vid_magic != MKTAG('H','2','6','4'))
> > +        avpriv_request_sample(s, "Unknown video codec %x\n", vid_magic);

avpriv_request_sample: no need for for \n newline

> > +
> > +    avio_skip(s->pb, 0x2c);
> > +    ifv->sample_rate = avio_rl32(s->pb);
> > +    aud_magic = avio_rl32(s->pb);
> > +
> > +    if (aud_magic == MKTAG('G','R','A','W')) {
> > +        ifv->is_audio_present = 1;
> > +    } else if (aud_magic == MKTAG('P','C','M','U')) {
> > +        ifv->is_audio_present = 0;
> > +    } else {
> > +        avpriv_request_sample(s, "Unknown audio codec %x\n", aud_magic);

same

> > +    }
> > +
> > +    avio_skip(s->pb, 0x44);
> > +    ifv->total_vframes = avio_rl32(s->pb);
> > +    ifv->total_aframes = avio_rl32(s->pb);
> > +
> > +    return 0;
> > +}
> > +
> > +static int ifv_read_header(AVFormatContext *s)
> > +{
> > +    IFVContext *ifv = s->priv_data;
> > +    AVStream *st;
> > +    int ret;
> > +
> > +    ret = parse_header(s);
> > +    if (ret < 0)
> > +        return ret;
> > +
> > +    st = avformat_new_stream(s, NULL);
> > +    if (!st)
> > +        return AVERROR(ENOMEM);
> > +
> > +    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
> > +    st->codecpar->codec_id = AV_CODEC_ID_H264;
> > +    st->codecpar->width = ifv->width;
> > +    st->codecpar->height = ifv->height;
> > +    st->start_time = 0;
> > +    ifv->video_stream_index = st->index;
> > +
> > +    avpriv_set_pts_info(st, 32, 1, 1000);
> > +
> > +    if (ifv->is_audio_present) {
> > +        st = avformat_new_stream(s, NULL);
> > +        if (!st)
> > +            return AVERROR(ENOMEM);
> > +
> > +        st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
> > +        st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE;
> > +        st->codecpar->channels = 1;
> > +        st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
> > +        st->codecpar->sample_rate = ifv->sample_rate;
> > +        ifv->audio_stream_index = st->index;
> > +
> > +        avpriv_set_pts_info(st, 32, 1, 1000);
> > +    }
> > +
> > +    /*read video index*/
> > +    avio_seek(s->pb, 0xf8, SEEK_SET);
> > +
> > +    ret = read_index(s, AVMEDIA_TYPE_VIDEO, 0);
> > +    if (ret < 0)
> > +        return ret;
> > +
> > +    if (ifv->is_audio_present) {
> > +        /*read audio index*/
> > +        avio_seek(s->pb, 0x14918, SEEK_SET);
> > +
> > +        ret = read_index(s, AVMEDIA_TYPE_AUDIO, 0);
> > +        if (ret < 0)
> > +            return ret;
> > +    }
> > +
> > +    ifv->next_video_index = 0;
> > +    ifv->next_audio_index = 0;
> > +
> > +    return 0;
> > +}
> > +
> > +static int ifv_read_packet(AVFormatContext *s, AVPacket *pkt)
> > +{
> > +    IFVContext *ifv = s->priv_data;
> > +    AVStream *st;
> > +    AVIndexEntry *ev, *ea, *e_next;
> > +    uint32_t nb_new_vframes, nb_new_aframes;
> > +    int ret;
> > +
> > +    ev = ea = e_next = NULL;
> > +
> > +    if (ifv->next_video_index < ifv->total_vframes) {
> > +        st = s->streams[ifv->video_stream_index];
> > +        if (ifv->next_video_index < st->nb_index_entries)
> > +            e_next = ev = &st->index_entries[ifv->next_video_index];
> > +    }
> > +
> > +    if (ifv->is_audio_present &&
> > +        ifv->next_audio_index < ifv->total_aframes) {
> > +        st = s->streams[ifv->audio_stream_index];
> > +        if (ifv->next_audio_index < st->nb_index_entries) {
> > +            ea = &st->index_entries[ifv->next_audio_index];
> > +            if (!ev || ea->timestamp < ev->timestamp)
> > +                e_next = ea;
> > +        }
> > +    }
> > +
> > +    if (!ev) {
> > +        if (ifv->is_audio_present && !ea) {
> > +            /*read new video and audio indexes*/
> > +
> > +            avio_skip(s->pb, 0x1c);
> > +            nb_new_vframes = avio_rl32(s->pb);
> > +            nb_new_aframes = avio_rl32(s->pb);
> > +            avio_skip(s->pb, 0xc);
> > +
> > +            if (avio_feof(s->pb))
> > +                return AVERROR_EOF;
> > +
> > +            ifv->next_video_index = ifv->total_vframes;
> > +            ifv->total_vframes += nb_new_vframes;
> > +
> > +            ret = read_index(s, AVMEDIA_TYPE_VIDEO, ifv->next_video_index);
> > +            if (ret < 0)
> > +                return ret;
> > +
> > +            ifv->next_audio_index = ifv->total_aframes;
> > +            ifv->total_aframes += nb_new_aframes;
> > +
> > +            ret = read_index(s, AVMEDIA_TYPE_AUDIO, ifv->next_audio_index);
> > +            if (ret < 0)
> > +                return ret;
> > +
> > +            return 0;
> > +
> > +        } else if (!ifv->is_audio_present) {
> > +            /*read new video index*/
> > +
> > +            avio_skip(s->pb, 0x1c);
> > +            nb_new_vframes = avio_rl32(s->pb);
> > +            avio_skip(s->pb, 0x10);
> > +
> > +            if (avio_feof(s->pb))
> > +                return AVERROR_EOF;
> > +
> > +            ifv->next_video_index = ifv->total_vframes;
> > +            ifv->total_vframes += nb_new_vframes;
> > +
> > +            ret = read_index(s, AVMEDIA_TYPE_VIDEO, ifv->next_video_index);
> > +            if (ret < 0)
> > +                return ret;
> > +
> > +            return 0;
> > +        }

the audio-present and no-audio-present cases are almost identical.
could easily be combined.

this perhaps a style issue, but why have nb_new_a/vframes. the bits can be read and incremented one line,

> > +    }
> > +
> > +    if (!e_next) return AVERROR_EOF;
> > +
> > +    avio_seek(s->pb, e_next->pos, SEEK_SET);
> > +    ret = av_get_packet(s->pb, pkt, e_next->size);
> > +    if (ret < 0)
> > +        return ret;
> > +
> > +    if (e_next == ev) {
> > +        ifv->next_video_index++;
> > +        pkt->stream_index = ifv->video_stream_index;
> > +    } else if (e_next == ea) {

the (e_next == ea) case always evaluates to true

> > +        ifv->next_audio_index++;
> > +        pkt->stream_index = ifv->audio_stream_index;
> > +    }
> > +
> > +    pkt->pts = e_next->timestamp;
> > +    pkt->pos = e_next->pos;
> > +
> > +    return ret;

here you just need to return 0;

> > +}
> > +
> > +static int ifv_read_seek(AVFormatContext *s, int stream_index, int64_t ts,
> > int flags)
> > +{
> > +    IFVContext *ifv = s->priv_data;
> > +    AVStream *st = s->streams[0];
> > +
> > +    int index = av_index_search_timestamp(st, ts, AVSEEK_FLAG_ANY);
> > +    if (index < 0) {
> > +        ifv->next_video_index = ifv->total_vframes - 1;
> > +        ifv->next_audio_index = ifv->total_aframes - 1;
> > +        return 0;
> > +    }
> > +
> > +    ifv->next_video_index = index;
> > +    ifv->next_audio_index = index;
> 
> I do not think this will work.
> The video and audio index are not guaranteed to be same
> for same timestamp.
> 
> > +
> > +    return 0;
> > +}
> > +
> > +static int ifv_read_close(AVFormatContext *s)
> > +{
> > +    AVStream *st;
> > +    unsigned int i;
> > +    for (i = 0; i < s->nb_streams; i++) {
> > +        st = s->streams[i];
> > +        av_freep(&st->index_entries);
> > +    }

freep is not required i think. avformat/utils does this automatically.

> > +    return 0;
> > +}
> > +
> > +AVInputFormat ff_ifv_demuxer = {
> > +    .name           = "ifv",
> > +    .long_name      = NULL_IF_CONFIG_SMALL("IFV CCTV DVR"),

if IFV has a meaning, please expand the acronym and put it in long_name.

> > +    .priv_data_size = sizeof(IFVContext),
> > +    .extensions     = "ifv",
> > +    .read_probe     = ifv_probe,
> > +    .read_header    = ifv_read_header,
> > +    .read_packet    = ifv_read_packet,
> > +    .read_seek      = ifv_read_seek,
> > +    .read_close     = ifv_read_close,
> > +};

cheers,

-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 195 bytes
Desc: not available
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20190525/6d6d1803/attachment.sig>


More information about the ffmpeg-devel mailing list