/*
  * Copyright (c) 2011, Luca Barbato
  *
  * 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
  */
 

 /**
  * @file generic segmenter

  * M3U8 specification can be find here:

  * @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}

  */
 

 /* #define DEBUG */
 

 #include <float.h>
 
 #include "avformat.h"
 #include "internal.h"
 

 #include "libavutil/avassert.h"

 #include "libavutil/log.h"
 #include "libavutil/opt.h"
 #include "libavutil/avstring.h"
 #include "libavutil/parseutils.h"
 #include "libavutil/mathematics.h"

 #include "libavutil/timestamp.h"

 typedef struct SegmentListEntry {
     int index;
     double start_time, end_time;

     int64_t start_pts;

     char filename[1024];
     struct SegmentListEntry *next;
 } SegmentListEntry;
 

 typedef enum {

     LIST_TYPE_UNDEFINED = -1,

     LIST_TYPE_FLAT = 0,

     LIST_TYPE_CSV,

     LIST_TYPE_M3U8,

     LIST_TYPE_EXT, ///< deprecated

     LIST_TYPE_FFCONCAT,

     LIST_TYPE_NB,
 } ListType;
 

 #define SEGMENT_LIST_FLAG_CACHE 1
 #define SEGMENT_LIST_FLAG_LIVE  2
 

 typedef struct {
     const AVClass *class;  /**< Class for private options. */

     int segment_idx;       ///< index of the segment file to write, starting from 0
     int segment_idx_wrap;  ///< number after which the index wraps
     int segment_count;     ///< number of segment files already written

     AVOutputFormat *oformat;

     AVFormatContext *avf;

     char *format;          ///< format to use for output segment files
     char *list;            ///< filename for the segment list file

     int   list_flags;      ///< flags affecting list generation

     int   list_size;       ///< number of entries for the segment list file

     ListType list_type;    ///< set the list type

     AVIOContext *list_pb;  ///< list file put-byte context

     char *time_str;        ///< segment duration specification string
     int64_t time;          ///< segment duration

     char *times_str;       ///< segment times specification string
     int64_t *times;        ///< list of segment interval specification
     int nb_times;          ///< number of elments in the times array

 
     char *frames_str;      ///< segment frame numbers specification string
     int *frames;           ///< list of frame number specification
     int nb_frames;         ///< number of elments in the frames array
     int frame_count;
 

     char *time_delta_str;  ///< approximation value duration used for the segment times
     int64_t time_delta;

     int  individual_header_trailer; /**< Set by a private option. */

     int  write_header_trailer; /**< Set by a private option. */

 
     int reset_timestamps;  ///< reset timestamps at the begin of each segment

     char *reference_stream_specifier; ///< reference stream specifier
     int   reference_stream_index;
 

     SegmentListEntry cur_entry;

     SegmentListEntry *segment_list_entries;
     SegmentListEntry *segment_list_entries_end;
 

     int is_first_pkt;      ///< tells if it is the first packet in the segment

 } SegmentContext;
 

 static void print_csv_escaped_str(AVIOContext *ctx, const char *str)
 {

     int needs_quoting = !!str[strcspn(str, "\",\n\r")];

     if (needs_quoting)

         avio_w8(ctx, '"');
 

     for (; *str; str++) {
         if (*str == '"')

             avio_w8(ctx, '"');

         avio_w8(ctx, *str);

     }

     if (needs_quoting)

         avio_w8(ctx, '"');
 }
 

 static int segment_mux_init(AVFormatContext *s)

 {

     SegmentContext *seg = s->priv_data;

     AVFormatContext *oc;
     int i;
 
     seg->avf = oc = avformat_alloc_context();
     if (!oc)
         return AVERROR(ENOMEM);
 
     oc->oformat            = seg->oformat;
     oc->interrupt_callback = s->interrupt_callback;

     av_dict_copy(&oc->metadata, s->metadata, 0);

 
     for (i = 0; i < s->nb_streams; i++) {
         AVStream *st;

         AVCodecContext *icodec, *ocodec;
 

         if (!(st = avformat_new_stream(oc, NULL)))
             return AVERROR(ENOMEM);

         icodec = s->streams[i]->codec;
         ocodec = st->codec;
         avcodec_copy_context(ocodec, icodec);
         if (!oc->oformat->codec_tag ||
             av_codec_get_id (oc->oformat->codec_tag, icodec->codec_tag) == ocodec->codec_id ||
             av_codec_get_tag(oc->oformat->codec_tag, icodec->codec_id) <= 0) {
             ocodec->codec_tag = icodec->codec_tag;
         } else {
             ocodec->codec_tag = 0;
         }

         st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
     }
 
     return 0;
 }
 

 static int set_segment_filename(AVFormatContext *s)
 {
     SegmentContext *seg = s->priv_data;
     AVFormatContext *oc = seg->avf;
 
     if (seg->segment_idx_wrap)
         seg->segment_idx %= seg->segment_idx_wrap;
     if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
                               s->filename, seg->segment_idx) < 0) {
         av_log(oc, AV_LOG_ERROR, "Invalid segment filename template '%s'\n", s->filename);
         return AVERROR(EINVAL);
     }

     av_strlcpy(seg->cur_entry.filename, oc->filename, sizeof(seg->cur_entry.filename));

     return 0;
 }
 

 static int segment_start(AVFormatContext *s, int write_header)

 {

     SegmentContext *seg = s->priv_data;
     AVFormatContext *oc = seg->avf;

     int err = 0;
 

     if (write_header) {
         avformat_free_context(oc);

         seg->avf = NULL;

         if ((err = segment_mux_init(s)) < 0)
             return err;

         oc = seg->avf;

     }

     seg->segment_idx++;

     if ((err = set_segment_filename(s)) < 0)
         return err;

     seg->segment_count++;

 
     if ((err = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
                           &s->interrupt_callback, NULL)) < 0)
         return err;
 

     if (oc->oformat->priv_class && oc->priv_data)

         av_opt_set(oc->priv_data, "resend_headers", "1", 0); /* mpegts specific */

     if (write_header) {
         if ((err = avformat_write_header(oc, NULL)) < 0)
             return err;
     }

     seg->is_first_pkt = 1;

     return 0;
 }
 

 static int segment_list_open(AVFormatContext *s)
 {
     SegmentContext *seg = s->priv_data;

     int ret;
 
     ret = avio_open2(&seg->list_pb, seg->list, AVIO_FLAG_WRITE,
                      &s->interrupt_callback, NULL);
     if (ret < 0)
         return ret;

     if (seg->list_type == LIST_TYPE_M3U8 && seg->segment_list_entries) {
         SegmentListEntry *entry;
         double max_duration = 0;
 

         avio_printf(seg->list_pb, "#EXTM3U\n");

         avio_printf(seg->list_pb, "#EXT-X-VERSION:3\n");

         avio_printf(seg->list_pb, "#EXT-X-MEDIA-SEQUENCE:%d\n", seg->segment_list_entries->index);

         avio_printf(seg->list_pb, "#EXT-X-ALLOW-CACHE:%s\n",
                     seg->list_flags & SEGMENT_LIST_FLAG_CACHE ? "YES" : "NO");

 
         for (entry = seg->segment_list_entries; entry; entry = entry->next)
             max_duration = FFMAX(max_duration, entry->end_time - entry->start_time);
         avio_printf(seg->list_pb, "#EXT-X-TARGETDURATION:%"PRId64"\n", (int64_t)ceil(max_duration));

     } else if (seg->list_type == LIST_TYPE_FFCONCAT) {
         avio_printf(seg->list_pb, "ffconcat version 1.0\n");

     }
 

     return ret;

 }
 

 static void segment_list_print_entry(AVIOContext      *list_ioctx,
                                      ListType          list_type,

                                      const SegmentListEntry *list_entry,
                                      void *log_ctx)

 {
     switch (list_type) {
     case LIST_TYPE_FLAT:
         avio_printf(list_ioctx, "%s\n", list_entry->filename);
         break;
     case LIST_TYPE_CSV:
     case LIST_TYPE_EXT:
         print_csv_escaped_str(list_ioctx, list_entry->filename);
         avio_printf(list_ioctx, ",%f,%f\n", list_entry->start_time, list_entry->end_time);
         break;
     case LIST_TYPE_M3U8:
         avio_printf(list_ioctx, "#EXTINF:%f,\n%s\n",
                     list_entry->end_time - list_entry->start_time, list_entry->filename);
         break;

     case LIST_TYPE_FFCONCAT:
     {
         char *buf;
         if (av_escape(&buf, list_entry->filename, NULL, AV_ESCAPE_MODE_AUTO, AV_ESCAPE_FLAG_WHITESPACE) < 0) {
             av_log(log_ctx, AV_LOG_WARNING,
                    "Error writing list entry '%s' in list file\n", list_entry->filename);
             return;
         }
         avio_printf(list_ioctx, "file %s\n", buf);
         av_free(buf);
         break;
     }

     default:
         av_assert0(!"Invalid list type");
     }
 }
 

 static int segment_end(AVFormatContext *s, int write_trailer, int is_last)

 {

     SegmentContext *seg = s->priv_data;
     AVFormatContext *oc = seg->avf;

     int ret = 0;
 

     av_write_frame(oc, NULL); /* Flush any buffered data (fragmented mp4) */

     if (write_trailer)

         ret = av_write_trailer(oc);

     if (ret < 0)

         av_log(s, AV_LOG_ERROR, "Failure occurred when ending segment '%s'\n",

                oc->filename);
 

     if (seg->list) {

         if (seg->list_size || seg->list_type == LIST_TYPE_M3U8) {
             SegmentListEntry *entry = av_mallocz(sizeof(*entry));
             if (!entry) {
                 ret = AVERROR(ENOMEM);
                 goto end;
             }
 
             /* append new element */
             memcpy(entry, &seg->cur_entry, sizeof(*entry));
             if (!seg->segment_list_entries)
                 seg->segment_list_entries = seg->segment_list_entries_end = entry;
             else
                 seg->segment_list_entries_end->next = entry;
             seg->segment_list_entries_end = entry;
 
             /* drop first item */
             if (seg->list_size && seg->segment_count > seg->list_size) {
                 entry = seg->segment_list_entries;
                 seg->segment_list_entries = seg->segment_list_entries->next;
                 av_freep(&entry);
             }
 

             avio_close(seg->list_pb);

             if ((ret = segment_list_open(s)) < 0)

                 goto end;

             for (entry = seg->segment_list_entries; entry; entry = entry->next)

                 segment_list_print_entry(seg->list_pb, seg->list_type, entry, s);

             if (seg->list_type == LIST_TYPE_M3U8 && is_last)

                 avio_printf(seg->list_pb, "#EXT-X-ENDLIST\n");
         } else {

             segment_list_print_entry(seg->list_pb, seg->list_type, &seg->cur_entry, s);

         }

         avio_flush(seg->list_pb);

     }
 
 end:

     avio_close(oc->pb);
 
     return ret;
 }
 

 static int parse_times(void *log_ctx, int64_t **times, int *nb_times,
                        const char *times_str)
 {
     char *p;
     int i, ret = 0;
     char *times_str1 = av_strdup(times_str);
     char *saveptr = NULL;
 
     if (!times_str1)
         return AVERROR(ENOMEM);
 
 #define FAIL(err) ret = err; goto end
 
     *nb_times = 1;
     for (p = times_str1; *p; p++)
         if (*p == ',')
             (*nb_times)++;
 
     *times = av_malloc(sizeof(**times) * *nb_times);
     if (!*times) {
         av_log(log_ctx, AV_LOG_ERROR, "Could not allocate forced times array\n");
         FAIL(AVERROR(ENOMEM));
     }
 
     p = times_str1;
     for (i = 0; i < *nb_times; i++) {
         int64_t t;
         char *tstr = av_strtok(p, ",", &saveptr);
         p = NULL;
 

         if (!tstr || !tstr[0]) {
             av_log(log_ctx, AV_LOG_ERROR, "Empty time specification in times list %s\n",
                    times_str);
             FAIL(AVERROR(EINVAL));
         }
 

         ret = av_parse_time(&t, tstr, 1);
         if (ret < 0) {
             av_log(log_ctx, AV_LOG_ERROR,

                    "Invalid time duration specification '%s' in times list %s\n", tstr, times_str);

             FAIL(AVERROR(EINVAL));
         }
         (*times)[i] = t;
 
         /* check on monotonicity */
         if (i && (*times)[i-1] > (*times)[i]) {
             av_log(log_ctx, AV_LOG_ERROR,
                    "Specified time %f is greater than the following time %f\n",
                    (float)((*times)[i])/1000000, (float)((*times)[i-1])/1000000);
             FAIL(AVERROR(EINVAL));
         }
     }
 
 end:
     av_free(times_str1);
     return ret;
 }
 

 static int parse_frames(void *log_ctx, int **frames, int *nb_frames,
                         const char *frames_str)
 {
     char *p;
     int i, ret = 0;
     char *frames_str1 = av_strdup(frames_str);
     char *saveptr = NULL;
 
     if (!frames_str1)
         return AVERROR(ENOMEM);
 
 #define FAIL(err) ret = err; goto end
 
     *nb_frames = 1;
     for (p = frames_str1; *p; p++)
         if (*p == ',')
             (*nb_frames)++;
 
     *frames = av_malloc(sizeof(**frames) * *nb_frames);
     if (!*frames) {
         av_log(log_ctx, AV_LOG_ERROR, "Could not allocate forced frames array\n");
         FAIL(AVERROR(ENOMEM));
     }
 
     p = frames_str1;
     for (i = 0; i < *nb_frames; i++) {
         long int f;
         char *tailptr;
         char *fstr = av_strtok(p, ",", &saveptr);
 
         p = NULL;
         if (!fstr) {
             av_log(log_ctx, AV_LOG_ERROR, "Empty frame specification in frame list %s\n",
                    frames_str);
             FAIL(AVERROR(EINVAL));
         }
         f = strtol(fstr, &tailptr, 10);
         if (*tailptr || f <= 0 || f >= INT_MAX) {
             av_log(log_ctx, AV_LOG_ERROR,
                    "Invalid argument '%s', must be a positive integer <= INT64_MAX\n",
                    fstr);
             FAIL(AVERROR(EINVAL));
         }
         (*frames)[i] = f;
 
         /* check on monotonicity */
         if (i && (*frames)[i-1] > (*frames)[i]) {
             av_log(log_ctx, AV_LOG_ERROR,
                    "Specified frame %d is greater than the following frame %d\n",
                    (*frames)[i], (*frames)[i-1]);
             FAIL(AVERROR(EINVAL));
         }
     }
 
 end:
     av_free(frames_str1);
     return ret;
 }
 

 static int open_null_ctx(AVIOContext **ctx)
 {
     int buf_size = 32768;
     uint8_t *buf = av_malloc(buf_size);
     if (!buf)
         return AVERROR(ENOMEM);
     *ctx = avio_alloc_context(buf, buf_size, AVIO_FLAG_WRITE, NULL, NULL, NULL, NULL);
     if (!*ctx) {
         av_free(buf);
         return AVERROR(ENOMEM);
     }
     return 0;
 }
 
 static void close_null_ctx(AVIOContext *pb)
 {
     av_free(pb->buffer);
     av_free(pb);
 }
 

 static int select_reference_stream(AVFormatContext *s)
 {
     SegmentContext *seg = s->priv_data;
     int ret, i;
 
     seg->reference_stream_index = -1;
     if (!strcmp(seg->reference_stream_specifier, "auto")) {
         /* select first index of type with highest priority */
         int type_index_map[AVMEDIA_TYPE_NB];
         static const enum AVMediaType type_priority_list[] = {
             AVMEDIA_TYPE_VIDEO,
             AVMEDIA_TYPE_AUDIO,
             AVMEDIA_TYPE_SUBTITLE,
             AVMEDIA_TYPE_DATA,
             AVMEDIA_TYPE_ATTACHMENT
         };
         enum AVMediaType type;
 
         for (i = 0; i < AVMEDIA_TYPE_NB; i++)
             type_index_map[i] = -1;
 
         /* select first index for each type */
         for (i = 0; i < s->nb_streams; i++) {
             type = s->streams[i]->codec->codec_type;

             if ((unsigned)type < AVMEDIA_TYPE_NB && type_index_map[type] == -1
                 /* ignore attached pictures/cover art streams */
                 && !(s->streams[i]->disposition & AV_DISPOSITION_ATTACHED_PIC))

                 type_index_map[type] = i;
         }
 
         for (i = 0; i < FF_ARRAY_ELEMS(type_priority_list); i++) {
             type = type_priority_list[i];
             if ((seg->reference_stream_index = type_index_map[type]) >= 0)
                 break;
         }
     } else {
         for (i = 0; i < s->nb_streams; i++) {
             ret = avformat_match_stream_specifier(s, s->streams[i],
                                                   seg->reference_stream_specifier);
             if (ret < 0)

                 return ret;

             if (ret > 0) {
                 seg->reference_stream_index = i;
                 break;
             }
         }
     }
 
     if (seg->reference_stream_index < 0) {
         av_log(s, AV_LOG_ERROR, "Could not select stream matching identifier '%s'\n",
                seg->reference_stream_specifier);
         return AVERROR(EINVAL);
     }
 
     return 0;
 }
 

 static int seg_write_header(AVFormatContext *s)
 {
     SegmentContext *seg = s->priv_data;

     AVFormatContext *oc = NULL;

     int ret;

     seg->segment_count = 0;

     if (!seg->write_header_trailer)
         seg->individual_header_trailer = 0;

     if (!!seg->time_str + !!seg->times_str + !!seg->frames_str > 1) {

         av_log(s, AV_LOG_ERROR,

                "segment_time, segment_times, and segment_frames options "
                "are mutually exclusive, select just one of them\n");

         return AVERROR(EINVAL);
     }
 
     if (seg->times_str) {
         if ((ret = parse_times(s, &seg->times, &seg->nb_times, seg->times_str)) < 0)
             return ret;

     } else if (seg->frames_str) {
         if ((ret = parse_frames(s, &seg->frames, &seg->nb_frames, seg->frames_str)) < 0)
             return ret;

     } else {
         /* set default value if not specified */
         if (!seg->time_str)
             seg->time_str = av_strdup("2");
         if ((ret = av_parse_time(&seg->time, seg->time_str, 1)) < 0) {
             av_log(s, AV_LOG_ERROR,
                    "Invalid time duration specification '%s' for segment_time option\n",
                    seg->time_str);
             return ret;
         }

     }

     if (seg->time_delta_str) {
         if ((ret = av_parse_time(&seg->time_delta, seg->time_delta_str, 1)) < 0) {
             av_log(s, AV_LOG_ERROR,
                    "Invalid time duration specification '%s' for delta option\n",
                    seg->time_delta_str);
             return ret;
         }
     }
 

     if (seg->list) {
         if (seg->list_type == LIST_TYPE_UNDEFINED) {

             if      (av_match_ext(seg->list, "csv" )) seg->list_type = LIST_TYPE_CSV;
             else if (av_match_ext(seg->list, "ext" )) seg->list_type = LIST_TYPE_EXT;

             else if (av_match_ext(seg->list, "m3u8")) seg->list_type = LIST_TYPE_M3U8;

             else if (av_match_ext(seg->list, "ffcat,ffconcat")) seg->list_type = LIST_TYPE_FFCONCAT;

             else                                      seg->list_type = LIST_TYPE_FLAT;
         }

         if ((ret = segment_list_open(s)) < 0)

             goto fail;

     }

     if (seg->list_type == LIST_TYPE_EXT)
         av_log(s, AV_LOG_WARNING, "'ext' list type option is deprecated in favor of 'csv'\n");

     if ((ret = select_reference_stream(s)) < 0)

         goto fail;
     av_log(s, AV_LOG_VERBOSE, "Selected stream id:%d type:%s\n",
            seg->reference_stream_index,
            av_get_media_type_string(s->streams[seg->reference_stream_index]->codec->codec_type));

     seg->oformat = av_guess_format(seg->format, s->filename, NULL);

     if (!seg->oformat) {

         ret = AVERROR_MUXER_NOT_FOUND;
         goto fail;
     }

     if (seg->oformat->flags & AVFMT_NOFILE) {

         av_log(s, AV_LOG_ERROR, "format %s not supported.\n",

                seg->oformat->name);

         ret = AVERROR(EINVAL);
         goto fail;
     }
 

     if ((ret = segment_mux_init(s)) < 0)
         goto fail;
     oc = seg->avf;

     if ((ret = set_segment_filename(s)) < 0)

         goto fail;

     seg->segment_count++;

     if (seg->write_header_trailer) {
         if ((ret = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
                               &s->interrupt_callback, NULL)) < 0)
             goto fail;
     } else {
         if ((ret = open_null_ctx(&oc->pb)) < 0)
             goto fail;
     }

 
     if ((ret = avformat_write_header(oc, NULL)) < 0) {
         avio_close(oc->pb);
         goto fail;
     }

     seg->is_first_pkt = 1;

     if (oc->avoid_negative_ts > 0 && s->avoid_negative_ts < 0)
         s->avoid_negative_ts = 1;
 

     if (!seg->write_header_trailer) {
         close_null_ctx(oc->pb);
         if ((ret = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
                               &s->interrupt_callback, NULL)) < 0)
             goto fail;
     }
 

 fail:
     if (ret) {
         if (seg->list)

             avio_close(seg->list_pb);

         if (seg->avf)
             avformat_free_context(seg->avf);

     }
     return ret;
 }
 
 static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     SegmentContext *seg = s->priv_data;
     AVFormatContext *oc = seg->avf;

     AVStream *st = s->streams[pkt->stream_index];

     int64_t end_pts = INT64_MAX;
     int start_frame = INT_MAX;

     int ret;
 

     if (seg->times) {

         end_pts = seg->segment_count <= seg->nb_times ?
             seg->times[seg->segment_count-1] : INT64_MAX;

     } else if (seg->frames) {
         start_frame = seg->segment_count <= seg->nb_frames ?
             seg->frames[seg->segment_count-1] : INT_MAX;

     } else {

         end_pts = seg->time * seg->segment_count;

     }
 

     av_dlog(s, "packet stream:%d pts:%s pts_time:%s is_key:%d frame:%d\n",
            pkt->stream_index, av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, &st->time_base),
            pkt->flags & AV_PKT_FLAG_KEY,
            pkt->stream_index == seg->reference_stream_index ? seg->frame_count : -1);
 

     if (pkt->stream_index == seg->reference_stream_index &&

         pkt->flags & AV_PKT_FLAG_KEY &&
         (seg->frame_count >= start_frame ||
          (pkt->pts != AV_NOPTS_VALUE &&
           av_compare_ts(pkt->pts, st->time_base,
                         end_pts-seg->time_delta, AV_TIME_BASE_Q) >= 0))) {

         ret = segment_end(s, seg->individual_header_trailer, 0);

 
         if (!ret)

             ret = segment_start(s, seg->individual_header_trailer);

 
         if (ret)
             goto fail;
 

         oc = seg->avf;
 

         seg->cur_entry.index = seg->segment_idx;
         seg->cur_entry.start_time = (double)pkt->pts * av_q2d(st->time_base);
         seg->cur_entry.start_pts = av_rescale_q(pkt->pts, st->time_base, AV_TIME_BASE_Q);

     } else if (pkt->pts != AV_NOPTS_VALUE) {

         seg->cur_entry.end_time =
             FFMAX(seg->cur_entry.end_time, (double)(pkt->pts + pkt->duration) * av_q2d(st->time_base));

     }
 

     if (seg->is_first_pkt) {

         av_log(s, AV_LOG_DEBUG, "segment:'%s' starts with packet stream:%d pts:%s pts_time:%s frame:%d\n",

                seg->avf->filename, pkt->stream_index,

                av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, &st->time_base), seg->frame_count);

         seg->is_first_pkt = 0;
     }
 

     if (seg->reset_timestamps) {

         av_log(s, AV_LOG_DEBUG, "stream:%d start_pts_time:%s pts:%s pts_time:%s dts:%s dts_time:%s",

                pkt->stream_index,
                av_ts2timestr(seg->cur_entry.start_pts, &AV_TIME_BASE_Q),
                av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, &st->time_base),
                av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, &st->time_base));

 
         /* compute new timestamps */
         if (pkt->pts != AV_NOPTS_VALUE)

             pkt->pts -= av_rescale_q(seg->cur_entry.start_pts, AV_TIME_BASE_Q, st->time_base);

         if (pkt->dts != AV_NOPTS_VALUE)

             pkt->dts -= av_rescale_q(seg->cur_entry.start_pts, AV_TIME_BASE_Q, st->time_base);

         av_log(s, AV_LOG_DEBUG, " -> pts:%s pts_time:%s dts:%s dts_time:%s\n",
                av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, &st->time_base),
                av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, &st->time_base));

     }
 

     ret = ff_write_chained(oc, pkt->stream_index, pkt, s);

 
 fail:

     if (pkt->stream_index == seg->reference_stream_index)
         seg->frame_count++;
 

     if (ret < 0) {
         if (seg->list)

             avio_close(seg->list_pb);

         avformat_free_context(oc);
     }
 
     return ret;
 }
 
 static int seg_write_trailer(struct AVFormatContext *s)
 {
     SegmentContext *seg = s->priv_data;
     AVFormatContext *oc = seg->avf;

     SegmentListEntry *cur, *next;
 

     int ret;
     if (!seg->write_header_trailer) {

         if ((ret = segment_end(s, 0, 1)) < 0)

             goto fail;

         open_null_ctx(&oc->pb);

         ret = av_write_trailer(oc);

         close_null_ctx(oc->pb);
     } else {

         ret = segment_end(s, 1, 1);

     }

 fail:

     if (seg->list)

         avio_close(seg->list_pb);

 
     av_opt_free(seg);

     av_freep(&seg->times);

     av_freep(&seg->frames);

     cur = seg->segment_list_entries;
     while (cur) {
         next = cur->next;
         av_free(cur);
         cur = next;
     }
 

     avformat_free_context(oc);
     return ret;
 }
 
 #define OFFSET(x) offsetof(SegmentContext, x)
 #define E AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {

     { "reference_stream",  "set reference stream", OFFSET(reference_stream_specifier), AV_OPT_TYPE_STRING, {.str = "auto"}, CHAR_MIN, CHAR_MAX, E },

     { "segment_format",    "set container format used for the segments", OFFSET(format),  AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E },
     { "segment_list",      "set the segment list filename",              OFFSET(list),    AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E },

 
     { "segment_list_flags","set flags affecting segment list generation", OFFSET(list_flags), AV_OPT_TYPE_FLAGS, {.i64 = SEGMENT_LIST_FLAG_CACHE }, 0, UINT_MAX, E, "list_flags"},
     { "cache",             "allow list caching",                                    0, AV_OPT_TYPE_CONST, {.i64 = SEGMENT_LIST_FLAG_CACHE }, INT_MIN, INT_MAX,   E, "list_flags"},
     { "live",              "enable live-friendly list generation (useful for HLS)", 0, AV_OPT_TYPE_CONST, {.i64 = SEGMENT_LIST_FLAG_LIVE }, INT_MIN, INT_MAX,    E, "list_flags"},
 

     { "segment_list_size", "set the maximum number of playlist entries", OFFSET(list_size), AV_OPT_TYPE_INT,  {.i64 = 0},     0, INT_MAX, E },

     { "segment_list_type", "set the segment list type",                  OFFSET(list_type), AV_OPT_TYPE_INT,  {.i64 = LIST_TYPE_UNDEFINED}, -1, LIST_TYPE_NB-1, E, "list_type" },

     { "flat", "flat format",     0, AV_OPT_TYPE_CONST, {.i64=LIST_TYPE_FLAT }, INT_MIN, INT_MAX, E, "list_type" },
     { "csv",  "csv format",      0, AV_OPT_TYPE_CONST, {.i64=LIST_TYPE_CSV  }, INT_MIN, INT_MAX, E, "list_type" },
     { "ext",  "extended format", 0, AV_OPT_TYPE_CONST, {.i64=LIST_TYPE_EXT  }, INT_MIN, INT_MAX, E, "list_type" },

     { "ffconcat", "ffconcat format", 0, AV_OPT_TYPE_CONST, {.i64=LIST_TYPE_FFCONCAT }, INT_MIN, INT_MAX, E, "list_type" },

     { "m3u8", "M3U8 format",     0, AV_OPT_TYPE_CONST, {.i64=LIST_TYPE_M3U8 }, INT_MIN, INT_MAX, E, "list_type" },
     { "hls", "Apple HTTP Live Streaming compatible", 0, AV_OPT_TYPE_CONST, {.i64=LIST_TYPE_M3U8 }, INT_MIN, INT_MAX, E, "list_type" },
 

     { "segment_time",      "set segment duration",                       OFFSET(time_str),AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E },

     { "segment_time_delta","set approximation value used for the segment times", OFFSET(time_delta_str), AV_OPT_TYPE_STRING, {.str = "0"}, 0, 0, E },

     { "segment_times",     "set segment split time points",              OFFSET(times_str),AV_OPT_TYPE_STRING,{.str = NULL},  0, 0,       E },

     { "segment_frames",    "set segment split frame numbers",            OFFSET(frames_str),AV_OPT_TYPE_STRING,{.str = NULL},  0, 0,       E },

     { "segment_wrap",      "set number after which the index wraps",     OFFSET(segment_idx_wrap), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E },

     { "segment_start_number", "set the sequence number of the first segment", OFFSET(segment_idx), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E },

     { "individual_header_trailer", "write header/trailer to each segment", OFFSET(individual_header_trailer), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, E },

     { "write_header_trailer", "write a header to the first segment and a trailer to the last one", OFFSET(write_header_trailer), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, E },

     { "reset_timestamps", "reset timestamps at the begin of each segment", OFFSET(reset_timestamps), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, E },

     { NULL },
 };
 
 static const AVClass seg_class = {
     .class_name = "segment muxer",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 AVOutputFormat ff_segment_muxer = {
     .name           = "segment",

     .long_name      = NULL_IF_CONFIG_SMALL("segment"),

     .priv_data_size = sizeof(SegmentContext),

     .flags          = AVFMT_NOFILE|AVFMT_GLOBALHEADER,

     .write_header   = seg_write_header,
     .write_packet   = seg_write_packet,
     .write_trailer  = seg_write_trailer,
     .priv_class     = &seg_class,
 };

 
 static const AVClass sseg_class = {
     .class_name = "stream_segment muxer",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 AVOutputFormat ff_stream_segment_muxer = {
     .name           = "stream_segment,ssegment",
     .long_name      = NULL_IF_CONFIG_SMALL("streaming segment muxer"),
     .priv_data_size = sizeof(SegmentContext),
     .flags          = AVFMT_NOFILE,
     .write_header   = seg_write_header,
     .write_packet   = seg_write_packet,
     .write_trailer  = seg_write_trailer,
     .priv_class     = &sseg_class,
 };