[FFmpeg-devel] [PATCH 3/4] V8 - SCTE-35 support in hlsenc

Steven Liu lingjiujianke at gmail.com
Thu Sep 1 02:10:34 EEST 2016


2016-09-01 1:39 GMT+08:00 Carlos Fernandez Sanz <carlos at ccextractor.org>:

> From: Carlos Fernandez <carlos at ccextractor.org>
>
> Signed-off-by: Carlos Fernandez <carlos at ccextractor.org>
> ---
>  libavformat/Makefile  |   2 +-
>  libavformat/hlsenc.c  | 110 ++++++++---
>  libavformat/scte_35.c | 527 ++++++++++++++++++++++++++++++
> ++++++++++++++++++++
>  libavformat/scte_35.h |  86 ++++++++
>  4 files changed, 702 insertions(+), 23 deletions(-)
>  create mode 100644 libavformat/scte_35.c
>  create mode 100644 libavformat/scte_35.h
>
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index 5d827d31..9218606 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -205,7 +205,7 @@ OBJS-$(CONFIG_HDS_MUXER)                 += hdsenc.o
>  OBJS-$(CONFIG_HEVC_DEMUXER)              += hevcdec.o rawdec.o
>  OBJS-$(CONFIG_HEVC_MUXER)                += rawenc.o
>  OBJS-$(CONFIG_HLS_DEMUXER)               += hls.o
> -OBJS-$(CONFIG_HLS_MUXER)                 += hlsenc.o
> +OBJS-$(CONFIG_HLS_MUXER)                 += hlsenc.o scte_35.o
>  OBJS-$(CONFIG_HNM_DEMUXER)               += hnm.o
>  OBJS-$(CONFIG_ICO_DEMUXER)               += icodec.o
>  OBJS-$(CONFIG_ICO_MUXER)                 += icoenc.o
> diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
> index 81b7efa..25092f7 100644
> --- a/libavformat/hlsenc.c
> +++ b/libavformat/hlsenc.c
> @@ -1,4 +1,4 @@
> -/*
> + /*
>   * Apple HTTP Live Streaming segmenter
>   * Copyright (c) 2012, Luca Barbato
>   *
> @@ -38,6 +38,7 @@
>  #include "avio_internal.h"
>  #include "internal.h"
>  #include "os_support.h"
> +#include "scte_35.h"
>
>  #define KEYSIZE 16
>  #define LINE_BUFFER_SIZE 1024
> @@ -48,6 +49,10 @@ typedef struct HLSSegment {
>      double duration; /* in seconds */
>      int64_t pos;
>      int64_t size;
> +    struct scte_35_event *event;
> +    int out;
> +    int adv_count;
> +    int64_t start_pts;
>
>      char key_uri[LINE_BUFFER_SIZE + 1];
>      char iv_string[KEYSIZE*2 + 1];
> @@ -91,6 +96,8 @@ typedef struct HLSContext {
>      uint32_t flags;        // enum HLSFlags
>      uint32_t pl_type;      // enum PlaylistType
>      char *segment_filename;
> +    char *adv_filename;
> +    char *adv_subfilename;
>
>      int use_localtime;      ///< flag to expand filename with localtime
>      int use_localtime_mkdir;///< flag to mkdir dirname in timebased
> filename
> @@ -106,6 +113,8 @@ typedef struct HLSContext {
>      int nb_entries;
>      int discontinuity_set;
>
> +    int adv_count;
> +    struct scte_35_interface *scte_iface;
>      HLSSegment *segments;
>      HLSSegment *last_segment;
>      HLSSegment *old_segments;
> @@ -205,6 +214,8 @@ static int hls_delete_old_segments(HLSContext *hls) {
>          av_freep(&path);
>          previous_segment = segment;
>          segment = previous_segment->next;
> +        if (hls->scte_iface)
> +            hls->scte_iface->unref_scte35_event(&previous_segment->
> event);
>          av_free(previous_segment);
>      }
>
> @@ -324,8 +335,8 @@ static int hls_mux_init(AVFormatContext *s)
>  }
>
>  /* Create a new segment and append it to the segment list */
> -static int hls_append_segment(struct AVFormatContext *s, HLSContext *hls,
> double duration,
> -                              int64_t pos, int64_t size)
> +static int hls_append_segment(struct AVFormatContext *s, HLSContext *hls,
> double duration, int64_t pos,
> +                              int64_t start_pts, struct scte_35_event
> *event, int64_t size)
>  {
>      HLSSegment *en = av_malloc(sizeof(*en));
>      char *tmp, *p;
> @@ -361,9 +372,23 @@ static int hls_append_segment(struct AVFormatContext
> *s, HLSContext *hls, double
>
>      en->duration = duration;
>      en->pos      = pos;
> +    en->event    = event;
>      en->size     = size;
> +    en->start_pts  = start_pts;
>      en->next     = NULL;
>
> +    if (hls->scte_iface) {
> +        if (hls->scte_iface->event_state == EVENT_OUT_CONT) {
> +            en->adv_count = hls->adv_count;;
> +            hls->adv_count++;
> +            en->out = hls->scte_iface->event_state;
> +        } else {
> +            hls->adv_count = 0;
> +            en->out = hls->scte_iface->event_state;
> +        }
> +    }
> +
> +
>      if (hls->key_info_file) {
>          av_strlcpy(en->key_uri, hls->key_uri, sizeof(en->key_uri));
>          av_strlcpy(en->iv_string, hls->iv_string, sizeof(en->iv_string));
> @@ -434,7 +459,7 @@ static int parse_playlist(AVFormatContext *s, const
> char *url)
>                  new_start_pos = avio_tell(hls->avf->pb);
>                  hls->size = new_start_pos - hls->start_pos;
>                  av_strlcpy(hls->avf->filename, line, sizeof(line));
> -                ret = hls_append_segment(s, hls, hls->duration,
> hls->start_pos, hls->size);
> +                ret = hls_append_segment(s, hls, hls->duration,
> hls->start_pos, 0, NULL, hls->size);
>                  if (ret < 0)
>                      goto fail;
>                  hls->start_pos = new_start_pos;
> @@ -533,9 +558,23 @@ static int hls_window(AVFormatContext *s, int last)
>          if (hls->flags & HLS_SINGLE_FILE)
>               avio_printf(out, "#EXT-X-BYTERANGE:%"PRIi64"@%"PRIi64"\n",
>                           en->size, en->pos);
> -        if (hls->baseurl)
> -            avio_printf(out, "%s", hls->baseurl);
> -        avio_printf(out, "%s\n", en->filename);
> +        if (hls->scte_iface && (en->event || en->out) ) {
> +            char *str;
> +            char fname[1024] = "";
> +            if (hls->adv_filename) {
> +                str = hls->scte_iface->get_hls_string(hls->scte_iface,
> en->event, hls->adv_filename, en->out, en->adv_count, en->start_pts);
> +            } else {
> +                if (hls->baseurl)
> +                    strncat(fname, hls->baseurl, 1024);
> +                strncat(fname, en->filename, 1024);

Overflow here

> +                str = hls->scte_iface->get_hls_string(hls->scte_iface,
> en->event, fname, en->out, -1, en->start_pts);
> +            }
> +            avio_printf(out, "%s", str);
> +        } else {
> +            if (hls->baseurl)
> +                avio_printf(out, "%s", hls->baseurl);
> +            avio_printf(out, "%s\n", en->filename);
> +        }
>      }
>
>      if (last && (hls->flags & HLS_OMIT_ENDLIST)==0)
> @@ -560,9 +599,15 @@ static int hls_window(AVFormatContext *s, int last)
>              if (hls->flags & HLS_SINGLE_FILE)
>                   avio_printf(sub_out, "#EXT-X-BYTERANGE:%"PRIi64"@%"
> PRIi64"\n",
>                           en->size, en->pos);
> -            if (hls->baseurl)
> -                avio_printf(sub_out, "%s", hls->baseurl);
> -            avio_printf(sub_out, "%s\n", en->sub_filename);
> +            if (hls->scte_iface && (en->event || en->out) ) {
> +                char *str = hls->scte_iface->get_hls_string(hls->scte_iface,
> en->event, hls->adv_subfilename, en->out, en->adv_count, en->pos);
> +                avio_printf(out, "%s", str);
> +            } else {
> +                if (hls->baseurl)
> +                    avio_printf(out, "%s", hls->baseurl);
> +                avio_printf(sub_out, "%s\n", en->sub_filename);
> +            }
> +
>          }
>
>          if (last)
> @@ -705,6 +750,7 @@ static int hls_write_header(AVFormatContext *s)
>      AVDictionary *options = NULL;
>      int basename_size;
>      int vtt_basename_size;
> +    int ts_index = 0;
>
>      hls->sequence       = hls->start_sequence;
>      hls->recording_time = (hls->init_time ? hls->init_time : hls->time) *
> AV_TIME_BASE;
> @@ -831,19 +877,21 @@ static int hls_write_header(AVFormatContext *s)
>          goto fail;
>      }
>      //av_assert0(s->nb_streams == hls->avf->nb_streams);
> -    for (i = 0; i < s->nb_streams; i++) {
> +    for (ts_index = 0, i = 0; i < s->nb_streams; i++) {
>          AVStream *inner_st;
>          AVStream *outer_st = s->streams[i];
> -        if (outer_st->codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE)
> -            inner_st = hls->avf->streams[i];
> -        else if (hls->vtt_avf)
> +        if (hls->vtt_avf && outer_st->codecpar->codec_type ==
> AVMEDIA_TYPE_SUBTITLE) {
>              inner_st = hls->vtt_avf->streams[0];
> -        else {
> -            /* We have a subtitle stream, when the user does not want one
> */
> -            inner_st = NULL;
> +            avpriv_set_pts_info(outer_st, inner_st->pts_wrap_bits,
> inner_st->time_base.num, inner_st->time_base.den);
> +        } else if (outer_st->codecpar->codec_type == AVMEDIA_TYPE_DATA) {
> +            inner_st = hls->avf->streams[ts_index];
> +            hls->scte_iface = ff_alloc_scte35_parser(hls,
> outer_st->time_base);
>              continue;
> +        } else {
> +            inner_st = hls->avf->streams[ts_index];
> +            avpriv_set_pts_info(outer_st, inner_st->pts_wrap_bits,
> inner_st->time_base.num, inner_st->time_base.den);
> +            ts_index++;
>          }
> -        avpriv_set_pts_info(outer_st, inner_st->pts_wrap_bits,
> inner_st->time_base.num, inner_st->time_base.den);
>      }
>  fail:
>
> @@ -869,6 +917,12 @@ static int hls_write_packet(AVFormatContext *s,
> AVPacket *pkt)
>      int is_ref_pkt = 1;
>      int ret, can_split = 1;
>      int stream_index = 0;
> +    struct scte_35_event *event = NULL;
> +
> +    if (st->codecpar->codec_id == AV_CODEC_ID_SCTE_35) {
> +        ret = ff_parse_scte35_pkt(hls->scte_iface, pkt);
> +        return ret;
> +    }
>
>      if (hls->sequence - hls->nb_entries > hls->start_sequence &&
> hls->init_time > 0) {
>          /* reset end_pts, hls->recording_time at end of the init hls list
> */
> @@ -902,14 +956,24 @@ static int hls_write_packet(AVFormatContext *s,
> AVPacket *pkt)
>          hls->duration = (double)(pkt->pts - hls->end_pts)
>                                     * st->time_base.num /
> st->time_base.den;
>
> -    if (can_split && av_compare_ts(pkt->pts - hls->start_pts,
> st->time_base,
> -                                   end_pts, AV_TIME_BASE_Q) >= 0) {
> +    if (hls->scte_iface)
> +        hls->scte_iface->update_video_pts(hls->scte_iface, pkt->pts *
> st->time_base.num / st->time_base.den);
> +
> +
> +    if (can_split && (( av_compare_ts(pkt->pts - hls->start_pts,
> st->time_base,
> +                                   end_pts, AV_TIME_BASE_Q) >= 0) ||
> +         (hls->scte_iface && hls->scte_iface->event_state == EVENT_OUT))
> ) {
>          int64_t new_start_pos;
>          av_write_frame(oc, NULL); /* Flush any buffered data */
>
>          new_start_pos = avio_tell(hls->avf->pb);
>          hls->size = new_start_pos - hls->start_pos;
> -        ret = hls_append_segment(s, hls, hls->duration, hls->start_pos,
> hls->size);
> +        if (hls->scte_iface) {
> +            event = hls->scte_iface->update_event_state(hls->scte_iface);
> +            if (event)
> +                hls->scte_iface->ref_scte35_event(event);
> +        }
> +        ret = hls_append_segment(s, hls, hls->duration, hls->start_pos,
> pkt->pts, event, hls->size);
>          hls->start_pos = new_start_pos;
>          if (ret < 0)
>              return ret;
> @@ -956,7 +1020,7 @@ static int hls_write_trailer(struct AVFormatContext
> *s)
>      if (oc->pb) {
>          hls->size = avio_tell(hls->avf->pb) - hls->start_pos;
>          ff_format_io_close(s, &oc->pb);
> -        hls_append_segment(s, hls, hls->duration, hls->start_pos,
> hls->size);
> +        hls_append_segment(s, hls, hls->duration, hls->start_pos,
> hls->end_pts, NULL, hls->size);
>      }
>
>      if (vtt_oc) {
> @@ -977,6 +1041,7 @@ static int hls_write_trailer(struct AVFormatContext
> *s)
>      hls->avf = NULL;
>      hls_window(s, 1);
>
> +    ff_delete_scte35_parser(hls->scte_iface);
>      hls_free_segments(hls->segments);
>      hls_free_segments(hls->old_segments);
>      return 0;
> @@ -1031,6 +1096,7 @@ AVOutputFormat ff_hls_muxer = {
>      .audio_codec    = AV_CODEC_ID_AAC,
>      .video_codec    = AV_CODEC_ID_H264,
>      .subtitle_codec = AV_CODEC_ID_WEBVTT,
> +    .data_codec     = AV_CODEC_ID_SCTE_35,
>      .flags          = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,
>      .write_header   = hls_write_header,
>      .write_packet   = hls_write_packet,
> diff --git a/libavformat/scte_35.c b/libavformat/scte_35.c
> new file mode 100644
> index 0000000..64e5f67
> --- /dev/null
> +++ b/libavformat/scte_35.c
> @@ -0,0 +1,527 @@
> +/*
> + * SCTE 35 decoder
> + * Copyright (c) 2016 Carlos Fernandez
> + *
> + * 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
> + */
> +/*
> + * Refrence Material Used
> + *
> + * ANSI/SCTE 35 2013 ( Digital Program Insertion Cueing Message for Cable
> )
> + *
> + * SCTE 67 2014 (Recommended Practice for SCTE 35
> + *          Digital Program Insertion Cueing Message for Cable )
> + */
> +
> +
> +
> +#include "libavcodec/bytestream.h"
> +#include "libavcodec/avcodec.h"
> +#include "libavcodec/get_bits.h"
> +#include "libavutil/buffer_internal.h"
> +#include "libavutil/base64.h"
> +#include "scte_35.h"
> +
> +#define SCTE_CMD_NULL                  0x00
> +#define SCTE_CMD_SCHEDULE              0x04
> +#define SCTE_CMD_INSERT                0x05
> +#define SCTE_CMD_SIGNAL                0x06
> +#define SCTE_CMD_BANDWIDTH_RESERVATION 0x07
> +
> +
> +static char* get_hls_string(struct scte_35_interface *iface, struct
> scte_35_event *event,
> +                 const char *filename, int out_state, int seg_count,
> int64_t pos)
> +{
> +    int ret;
> +    av_bprint_clear(&iface->avbstr);
> +    if (out_state == EVENT_IN ) {
> +        av_bprintf(&iface->avbstr, "#EXT-OATCLS-SCTE35:%s\n",
> iface->pkt_base64);
> +        av_bprintf(&iface->avbstr, "#EXT-X-CUE-IN\n");
> +        av_bprintf(&iface->avbstr, "#EXT-X-DISCONTINUITY\n");
> +    } else if (out_state == EVENT_OUT) {
> +        if (event) {
> +            av_bprintf(&iface->avbstr, "#EXT-OATCLS-SCTE35:%s\n",
> iface->pkt_base64);
> +            if(event->duration != AV_NOPTS_VALUE) {
> +                int64_t dur = ceil(((double)event->duration *
> iface->timebase.num) /iface->timebase.den);
> +                av_bprintf(&iface->avbstr, "#EXT-X-CUE-OUT:%"PRIu64"\n",
> dur);
> +            } else {
> +                av_bprintf(&iface->avbstr, "#EXT-X-CUE-OUT\n");
> +            }
> +            av_bprintf(&iface->avbstr, "#EXT-X-DISCONTINUITY\n");
> +        }
> +    } else if (out_state == EVENT_OUT_CONT) {
> +        if(event && event->duration != AV_NOPTS_VALUE) {
> +            int64_t dur = ceil(((double)event->duration *
> iface->timebase.num) /iface->timebase.den);
> +            int64_t elapsed_time = ceil(((double)pos *
> iface->timebase.num) /iface->timebase.den) - event->out_pts;
> +            av_bprintf(&iface->avbstr, "#EXT-X-CUE-OUT-CONT:
> ElapsedTime=%"PRIu64",Duration=%"PRIu64",SCTE35=%s\n",
> +                elapsed_time,  dur, iface->pkt_base64);
> +        } else {
> +            av_bprintf(&iface->avbstr, "#EXT-X-CUE-OUT-CONT:SCTE35=%s\n",
> iface->pkt_base64);
> +        }
> +    }
> +    if (seg_count >= 0)
> +        av_bprintf(&iface->avbstr, filename, seg_count);
> +    else
> +        av_bprintf(&iface->avbstr, "%s", filename);
> +    av_bprintf(&iface->avbstr, "\n");
> +
> +    ret = av_bprint_is_complete(&iface->avbstr);
> +    if( ret == 0) {
> +        av_log(iface->parent, AV_LOG_DEBUG, "Out of Memory");
> +        return NULL;
> +    }
> +
> +    av_log(iface->parent, AV_LOG_DEBUG, "%s", iface->avbstr.str);
> +    return iface->avbstr.str;
> +}
> +
> +static struct scte_35_event* alloc_scte35_event(int id)
> +{
> +    struct scte_35_event* event = av_malloc(sizeof(struct scte_35_event));
> +    if (!event)
> +        return NULL;
> +
> +    event->id = id;
> +    event->in_pts = AV_NOPTS_VALUE;
> +    event->nearest_in_pts = AV_NOPTS_VALUE;
> +    event->out_pts = AV_NOPTS_VALUE;
> +    event->running = 0;
> +    event->next = NULL;
> +    event->prev = NULL;
> +    return event;
> +}
> +
> +static void ref_scte35_event(struct scte_35_event *event)
> +{
> +    event->ref_count++;
> +}
> +
> +static void unref_scte35_event(struct scte_35_event **event)
> +{
> +    if(!(*event))
> +        return;
> +    if(!(*event)->ref_count) {
> +        av_freep(event);
> +    } else {
> +        (*event)->ref_count--;
> +    }
> +}
> +
> +static void unlink_scte35_event(struct scte_35_interface *iface, struct
> scte_35_event *event)
> +{
> +    if (!event)
> +        return;
> +    if (!event->prev)
> +        iface->event_list = event->next;
> +    else
> +        event->prev->next = event->next;
> +    if(event->next)
> +        event->next->prev = event->prev;
> +    unref_scte35_event(&event);
> +}
> +
> +static struct scte_35_event* get_event_id(struct scte_35_interface
> *iface, int id)
> +{
> +    struct scte_35_event *event = iface->event_list;
> +    struct scte_35_event *pevent = NULL;
> +
> +    while(event) {
> +
> +        if(event->id == id)
> +            break;
> +        pevent = event;
> +        event = event->next;
> +    }
> +    if (!event) {
> +        event = alloc_scte35_event(id);
> +        if (pevent)
> +            pevent->next = event;
> +        else
> +            iface->event_list = event;
> +    }
> +
> +    return event;
> +}
> +
> +/**
> + * save the parsed time in ctx pts_time
> +   @return length of buffer consumed
> +*/
> +static int parse_splice_time(struct scte_35_interface *iface, const
> uint8_t *buf, uint64_t *pts, int64_t pts_adjust)
> +{
> +    GetBitContext gb;
> +    int ret;
> +    init_get_bits(&gb, buf, 40);
> +    /* is time specified */
> +    ret =  get_bits(&gb, 1);
> +    if(ret) {
> +        skip_bits(&gb, 6);
> +        *pts = get_bits64(&gb,33) + pts_adjust;
> +        return 5;
> +    } else {
> +        skip_bits(&gb, 7);
> +        return 1;
> +    }
> +}
> +
> +static int parse_schedule_cmd(struct scte_35_interface *iface, const
> uint8_t *buf)
> +{
> +    const uint8_t *sbuf = buf;
> +    av_log(iface->parent, AV_LOG_DEBUG, "Schedule cmd\n");
> +    return buf - sbuf;
> +}
> +/**
> +     @return length of buffer used
> + */
> +static int parse_insert_cmd(struct scte_35_interface *iface,
> +    const uint8_t *buf,const int len, int64_t pts_adjust, int64_t
> current_pts)
> +{
> +    GetBitContext gb;
> +    int ret;
> +    const uint8_t *sbuf = buf;
> +    int program_splice_flag;
> +    int duration_flag;
> +    int splice_immediate_flag;
> +    int component_tag;
> +    int auto_return;
> +    uint16_t u_program_id;
> +    uint8_t avail_num;
> +    uint8_t avail_expect;
> +    int inout;
> +    int event_id;
> +    struct scte_35_event *event;
> +    char buffer[128];
> +    int cancel;
> +
> +
> +    av_log(iface->parent, AV_LOG_DEBUG, "%s Insert cmd\n", buffer);
> +    event_id  = AV_RB32(buf);
> +    av_log(iface->parent, AV_LOG_DEBUG, "event_id  = %x\n", event_id);
> +    event = get_event_id(iface, event_id);
> +    buf +=4;
> +    cancel = *buf & 0x80;
> +    av_log(iface->parent, AV_LOG_DEBUG, "splice_event_cancel_indicator  =
> %d\n", cancel);
> +    buf++;
> +
> +    if (!cancel) {
> +        init_get_bits(&gb, buf, 8);
> +        inout =  get_bits(&gb, 1);
> +        program_splice_flag =  get_bits(&gb, 1);
> +        duration_flag =  get_bits(&gb, 1);
> +        splice_immediate_flag =  get_bits(&gb, 1);
> +        skip_bits(&gb, 4);
> +
> +    } else {
> +        /*   Delete event only if its not already started */
> +        if (!event->running) {
> +            unlink_scte35_event(iface, event);
> +        }
> +    }
> +    buf++;
> +
> +
> +    av_log(iface->parent, AV_LOG_DEBUG, "out_of_network_indicator  =
> %d\n", inout);
> +    av_log(iface->parent, AV_LOG_DEBUG, "program_splice_flag  = %d\n",
> program_splice_flag);
> +    av_log(iface->parent, AV_LOG_DEBUG, "duration_flag  = %d\n",
> duration_flag);
> +    av_log(iface->parent, AV_LOG_DEBUG, "splice_immediate_flag  = %d\n",
> splice_immediate_flag);
> +
> +    if (program_splice_flag &&  !splice_immediate_flag) {
> +        if(inout) {
> +            ret = parse_splice_time(iface, buf, &event->out_pts,
> pts_adjust);
> +            event->out_pts = event->out_pts * iface->timebase.num /
> iface->timebase.den;
> +        } else {
> +            ret = parse_splice_time(iface, buf, &event->in_pts,
> pts_adjust);
> +            event->in_pts = event->in_pts * iface->timebase.num /
> iface->timebase.den;
> +        }
> +
> +        buf += ret;
> +    } else if (program_splice_flag && splice_immediate_flag) {
> +        if(inout)
> +            event->out_pts = current_pts * iface->timebase.num /
> iface->timebase.den;
> +        else
> +            event->in_pts = current_pts * iface->timebase.num /
> iface->timebase.den;
> +    }
> +    if ( program_splice_flag == 0) {
> +        int comp_cnt = *buf++;
> +        int  i;
> +        av_log(iface->parent, AV_LOG_DEBUG, "component_count  = %d\n",
> comp_cnt);
> +        for ( i = 0; i < comp_cnt; i++) {
> +            component_tag = *buf++;
> +            av_log(iface->parent, AV_LOG_DEBUG, "component_tag  = %d\n",
> component_tag);
> +            if (splice_immediate_flag) {
> +                if(inout)
> +                    ret = parse_splice_time(iface, buf, &event->in_pts,
> pts_adjust);
> +                else
> +                    ret = parse_splice_time(iface, buf, &event->out_pts,
> pts_adjust);
> +                buf += ret;
> +            }
> +        }
> +    }
> +    if ( duration_flag ) {
> +        init_get_bits(&gb, buf, 40);
> +        auto_return =  get_bits(&gb, 1);
> +        av_log(iface->parent, AV_LOG_DEBUG, "autoreturn  = %d\n",
> auto_return);
> +        skip_bits(&gb, 6);
> +        event->duration = get_bits64(&gb,33) + pts_adjust;
> +        buf += 5;
> +    }
> +    u_program_id = AV_RB16(buf);
> +    av_log(iface->parent, AV_LOG_DEBUG, "u_program_id  = %hd\n",
> u_program_id);
> +    buf += 2;
> +    avail_num = *buf++;
> +    av_log(iface->parent, AV_LOG_DEBUG, "avail_num  = %hhd\n", avail_num);
> +    avail_expect = *buf++;
> +    av_log(iface->parent, AV_LOG_DEBUG, "avail_expect  = %hhd\n",
> avail_expect);
> +
> +    return buf - sbuf;
> +}
> +static int parse_time_signal_cmd(struct scte_35_interface *iface, const
> uint8_t *buf)
> +{
> +    const uint8_t *sbuf = buf;
> +    av_log(iface->parent, AV_LOG_DEBUG, "Time Signal cmd\n");
> +    return buf - sbuf;
> +}
> +static int parse_bandwidth_reservation_cmd(struct scte_35_interface
> *iface, const uint8_t *buf)
> +{
> +    const uint8_t *sbuf = buf;
> +    av_log(iface->parent, AV_LOG_DEBUG, "Band Width reservation cmd\n");
> +    return buf - sbuf;
> +}
> +
> +int ff_parse_scte35_pkt(struct scte_35_interface *iface, const AVPacket
> *avpkt)
> +{
> +    const uint8_t *buf = avpkt->data;
> +    int section_length;
> +    int cmd_length;
> +    uint8_t cmd_type;
> +    int16_t tier;
> +    GetBitContext gb;
> +    int ret;
> +    int64_t pts_adjust;
> +
> +    if (!buf)
> +        return AVERROR_EOF;
> +
> +
> +    /* check table id */
> +    if (*buf != 0xfc)
> +        av_log(iface->parent, AV_LOG_ERROR, "Invalid SCTE packet\n");
> +
> +
> +    init_get_bits(&gb, buf + 1, 104);
> +
> +    /* section_syntax_indicator should be 0 */
> +    ret = get_bits(&gb,1);
> +    if (ret)
> +        av_log(iface->parent, AV_LOG_DEBUG, "Section indicator should be
> 0, since MPEG short sections are to be used.\n");
> +
> +    /* private indicator */
> +    ret = get_bits(&gb,1);
> +    if (ret)
> +        av_log(iface->parent, AV_LOG_DEBUG, "corrupt packet\n");
> +
> +    skip_bits(&gb,2);
> +
> +    /* section length may be there */
> +    section_length = get_bits(&gb,12);
> +    if( section_length > 4093)
> +    if(ret) {
> +        av_log(iface->parent, AV_LOG_ERROR, "Invalid length of
> section\n");
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    av_base64_encode( iface->pkt_base64, AV_BASE64_SIZE(section_length +
> 3), buf, section_length + 3);
> +
> +    /* protocol version */
> +    skip_bits(&gb,8);
> +
> +    ret = get_bits(&gb,1);
> +    if(ret) {
> +        av_log(iface->parent, AV_LOG_ERROR, "Encrytion not yet
> supported\n");
> +        return AVERROR_PATCHWELCOME;
> +    }
> +    /* encryption algo */
> +    skip_bits(&gb,6);
> +
> +    pts_adjust =  get_bits64(&gb, 33);
> +
> +    /* cw_index: used in encryption */
> +    skip_bits(&gb,8);
> +
> +
> +    /* tier */
> +    tier = get_bits(&gb,12);
> +    if( (tier & 0xfff) == 0xfff)
> +        tier = -1;
> +
> +    cmd_length = get_bits(&gb,12);
> +    if(cmd_length == 0xfff ) {
> +        /* Setting max limit to  cmd_len so it does not cross memory
> barrier */
> +        cmd_length = section_length - 17;
> +    } else if ( cmd_length != 0xfff && ( cmd_length > (section_length -
> 17) ) ) {
> +        av_log(iface->parent, AV_LOG_ERROR, "Command length %d
> invalid\n", cmd_length);
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    cmd_type = get_bits(&gb,8);
> +    switch(cmd_type) {
> +    case SCTE_CMD_NULL:
> +        av_log(iface->parent, AV_LOG_DEBUG, "SCTE-35 Ping Recieved");
> +        break;
> +    case SCTE_CMD_SCHEDULE:
> +        ret = parse_schedule_cmd(iface, buf + 14);
> +        break;
> +    case SCTE_CMD_INSERT:
> +        ret = parse_insert_cmd(iface, buf + 14, cmd_length, pts_adjust,
> avpkt->pts);
> +        break;
> +    case SCTE_CMD_SIGNAL:
> +        ret = parse_time_signal_cmd(iface, buf + 14);
> +        break;
> +    case SCTE_CMD_BANDWIDTH_RESERVATION:
> +        ret = parse_bandwidth_reservation_cmd(iface, buf + 14);
> +        break;
> +    default:
> +        break;
> +    /* reserved yet */
> +    }
> +    if(ret < 0)
> +        goto fail;
> +    buf += ret;
> +
> +fail:
> +    return ret;
> +}
> +
> +/*
> + * return event, if there is any event whose starting time aka out_pts is
> less then
> + * current pts. This condition also means that event starting time has
> already been passed.
> + * This function will look for event in events list which resides inside
> iface.
> + */
> +static struct scte_35_event* get_event_ciel_out(struct scte_35_interface
> *iface, uint64_t pts)
> +{
> +    struct scte_35_event *event = iface->event_list;
> +    while(event) {
> +        if(!event->running && event->out_pts < pts) {
> +            iface->event_state = EVENT_OUT;
> +            break;
> +        }
> +        event = event->next;
> +    }
> +    return event;
> +}
> +
> +/*
> + * return event, if current event is in running state
> + * and check that in_pts is less then current pts.
> + * Event from this function specify commerial ends and
> + * mainstream should be coupled in.
> + * This event is generally last event to be consumed.
> + */
> +static struct scte_35_event* get_event_floor_in(struct scte_35_interface
> *iface, uint64_t pts)
> +{
> +    struct scte_35_event *event = iface->event_list;
> +    struct scte_35_event *sevent = NULL;
> +    while(event) {
> +        if(event->in_pts != AV_NOPTS_VALUE && event->in_pts < pts &&
> +          (event->nearest_in_pts == AV_NOPTS_VALUE || pts <=
> event->nearest_in_pts) ) {
> +            event->nearest_in_pts = pts;
> +            unlink_scte35_event(iface, event);
> +            /* send in_event only when that event was in running state */
> +            if (event->running) {
> +                iface->event_state = EVENT_IN;
> +                sevent = event;
> +            }
> +        }
> +        event = event->next;
> +    }
> +    return sevent;
> +}
> +
> +
> +/*
> + *  If there is no running event, then search for an event which have
> + *  the pts matching to current pts. otherwise only give event when
> + *  its time to end the commercial.
> + *  if we have some event to be presented at this video then cache it
> + *  for later use.
> + */
> +static void update_video_pts(struct scte_35_interface *iface, uint64_t
> pts)
> +{
> +    struct scte_35_event *event = NULL;
> +    if(iface->event_state == EVENT_NONE) {
> +        event = get_event_ciel_out(iface, pts);
> +        if(event)
> +            event->running = 1;
> +    } else {
> +        event = get_event_floor_in(iface, pts);
> +    }
> +    if (event)
> +        iface->current_event = event;
> +}
> +
> +/*
> + * update the state of scte-35 parser
> + * return current event
> + */
> +static struct scte_35_event* update_event_state(struct scte_35_interface
> *iface)
> +{
> +
> +    struct scte_35_event* event = iface->current_event;
> +    if (iface->prev_event_state == EVENT_IN)
> +        iface->event_state = EVENT_NONE;
> +    else if (iface->prev_event_state == EVENT_OUT)
> +        iface->event_state = EVENT_OUT_CONT;
> +
> +    if(iface->event_state == EVENT_NONE)
> +        iface->current_event = NULL;
> +
> +    iface->prev_event_state = iface->event_state;
> +    return event;
> +}
> +
> +
> +/*
> + * Allocate scte_35 parser
> + * using function pointer so that this module reveals least interface
> + * to API uses
> + */
> +struct scte_35_interface* ff_alloc_scte35_parser(void *parent, AVRational
> timebase)
> +{
> +    struct scte_35_interface* iface = av_mallocz(sizeof(struct
> scte_35_interface));
> +    if(!iface)
> +       return NULL;
> +
> +    iface->parent = parent;
> +    iface->timebase = timebase;
> +    iface->update_video_pts = update_video_pts;
> +    iface->update_event_state = update_event_state;
> +    av_bprint_init(&iface->avbstr, 0, AV_BPRINT_SIZE_UNLIMITED);
> +    iface->get_hls_string = get_hls_string;
> +    iface->unref_scte35_event = unref_scte35_event;
> +    iface->ref_scte35_event = ref_scte35_event;
> +    iface->event_state = EVENT_NONE;
> +    iface->prev_event_state = EVENT_NONE;
> +    return iface;
> +}
> +
> +void ff_delete_scte35_parser(struct scte_35_interface* iface)
> +{
> +    if(!iface)
> +        return;
> +    av_bprint_finalize(&iface->avbstr, NULL);
> +    av_freep(&iface);
> +}
> diff --git a/libavformat/scte_35.h b/libavformat/scte_35.h
> new file mode 100644
> index 0000000..cac49ea
> --- /dev/null
> +++ b/libavformat/scte_35.h
> @@ -0,0 +1,86 @@
> +/*
> + * SCTE-35 parser
> + * Copyright (c) 2016 Carlos Fernandez
> + *
> + * 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
> + */
> +#ifndef AVFORMAT_SCTE_35_H
> +#define AVFORMAT_SCTE_35_H
> +
> +#include "libavutil/bprint.h"
> +
> +struct scte_35_event {
> +    /* ID given for each seprate event */
> +    int32_t id;
> +    /* pts specify time when event starts */
> +    uint64_t in_pts;
> +    uint64_t nearest_in_pts;
> +    /* pts specify ehen events end */
> +    uint64_t out_pts;
> +    /* duration of the event */
> +    int64_t duration;
> +    int64_t start_pos;
> +    int running;
> +    int ref_count;
> +    /* to traverse the list of events */
> +    struct scte_35_event *next;
> +    struct scte_35_event *prev;
> +};
> +
> +enum event_state {
> +    /* NO event */
> +    EVENT_NONE,
> +    /* Commercials need to end */
> +    EVENT_IN,
> +    /* Commercials can start from here */
> +    EVENT_OUT,
> +    /* commercial can continue */
> +    EVENT_OUT_CONT,
> +};
> +
> +struct scte_35_interface {
> +    /* contain all  the events */
> +    struct scte_35_event *event_list;
> +    /* state of current event */
> +    enum event_state event_state;
> +    /* time base of pts used in parser */
> +    AVRational timebase;
> +    struct scte_35_event *current_event;
> +    /* saved previous state to correctly transition
> +        the event state */
> +    int prev_event_state;
> +    //TODO use AV_BASE64_SIZE to dynamically allocate the array
> +    char pkt_base64[1024];
> +    /* keep context of its parent for log */
> +    void *parent;
> +    /* general purpose str */
> +    AVBPrint avbstr;
> +
> +    void (*update_video_pts)(struct scte_35_interface *iface, uint64_t
> pts);
> +    struct scte_35_event* (*update_event_state)(struct scte_35_interface
> *iface);
> +    char* (*get_hls_string)(struct scte_35_interface *iface, struct
> scte_35_event *event,
> +               const char *adv_filename, int out_state, int seg_count,
> int64_t pos);
> +
> +    void (*unref_scte35_event)(struct scte_35_event **event);
> +    void (*ref_scte35_event)(struct scte_35_event *event);
> +};
> +
> +int ff_parse_scte35_pkt(struct scte_35_interface *iface, const AVPacket
> *avpkt);
> +
> +struct scte_35_interface* ff_alloc_scte35_parser(void *parent, AVRational
> timebase);
> +void ff_delete_scte35_parser(struct scte_35_interface* iface);
> +#endif
> --
> 2.7.4
>
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