[FFmpeg-devel,v6] avformat/ifv: added support for ifv cctv files

diff --git a/Changelog b/Changelog
index 1facc1fc46..8490f02d9f 100644
--- a/Changelog
+++ b/Changelog
@@ -31,6 +31,7 @@  version <next>:
 - xmedian filter
 - asr filter
 - showspatial multimedia filter
+- IFV demuxer
 
 
 version 4.1:
diff --git a/doc/general.texi b/doc/general.texi
index ec437230e3..5143dc35c0 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -468,6 +468,8 @@  library:
 @item IEC61937 encapsulation @tab X @tab X
 @item IFF                       @tab   @tab X
     @tab Interchange File Format
+@item IFV                       @tab   @tab X
+    @tab A format used by some old CCTV DVRs.
 @item iLBC                      @tab X @tab X
 @item Interplay MVE             @tab   @tab X
     @tab Format used in various Interplay computer games.
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..03c682bb9d
--- /dev/null
+++ b/libavformat/ifv.c
@@ -0,0 +1,304 @@ 
+/*
+ * 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);
+    }
+
+    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", vid_magic);
+
+    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", aud_magic);
+    }
+
+    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;
+    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*/
+
+            ifv->next_video_index = ifv->total_vframes;
+            ifv->next_audio_index = ifv->total_aframes;
+
+            avio_skip(s->pb, 0x1c);
+            ifv->total_vframes += avio_rl32(s->pb);
+            ifv->total_aframes += avio_rl32(s->pb);
+            avio_skip(s->pb, 0xc);
+
+            if (avio_feof(s->pb))
+                return AVERROR_EOF;
+
+            ret = read_index(s, AVMEDIA_TYPE_VIDEO, ifv->next_video_index);
+            if (ret < 0)
+                return ret;
+
+            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*/
+
+            ifv->next_video_index = ifv->total_vframes;
+
+            avio_skip(s->pb, 0x1c);
+            ifv->total_vframes += avio_rl32(s->pb);
+            avio_skip(s->pb, 0x10);
+
+            if (avio_feof(s->pb))
+                return AVERROR_EOF;
+
+            ret = read_index(s, AVMEDIA_TYPE_VIDEO, ifv->next_video_index);
+            if (ret < 0)
+                return ret;
+
+            return 0;
+        }
+    }
+
+    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 {
+        ifv->next_audio_index++;
+        pkt->stream_index = ifv->audio_stream_index;
+    }
+
+    pkt->pts = e_next->timestamp;
+    pkt->pos = e_next->pos;
+
+    return 0;
+}
+
+static int ifv_read_seek(AVFormatContext *s, int stream_index, int64_t ts, int flags)
+{
+    IFVContext *ifv = s->priv_data;
+
+    for (unsigned i = 0; i < s->nb_streams; i++) {
+        int index = av_index_search_timestamp(s->streams[i], 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;
+        }
+
+        if (i == ifv->video_stream_index) {
+            ifv->next_video_index = index;
+        } else {
+            ifv->next_audio_index = index;
+        }
+    }
+
+    return 0;
+}
+
+AVInputFormat ff_ifv_demuxer = {
+    .name           = "ifv",
+    .long_name      = NULL_IF_CONFIG_SMALL("IFV CCTV DVR"),
+    .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,
+};
diff --git a/libavformat/version.h b/libavformat/version.h
index 150a72e27d..52dd95f5c6 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -32,8 +32,8 @@ 
 // Major bumping may affect Ticket5467, 5421, 5451(compatibility with Chromium)
 // Also please add any ticket numbers that you believe might be affected here
 #define LIBAVFORMAT_VERSION_MAJOR  58
-#define LIBAVFORMAT_VERSION_MINOR  27
-#define LIBAVFORMAT_VERSION_MICRO 103
+#define LIBAVFORMAT_VERSION_MINOR  28
+#define LIBAVFORMAT_VERSION_MICRO 100
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
                                                LIBAVFORMAT_VERSION_MINOR, \