text: /*
   * Live HDS fragmenter
   * Copyright (c) 2013 Martin Storsjo
   *
   * 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 "config.h"
  #include <float.h>
  #if HAVE_UNISTD_H
  #include <unistd.h>
  #endif
  
  #include "avformat.h"
  #include "avio_internal.h"
  #include "internal.h"
  #include "os_support.h"
  
  #include "libavutil/avstring.h"
  #include "libavutil/base64.h"
  #include "libavutil/intreadwrite.h"
  #include "libavutil/mathematics.h"
  #include "libavutil/opt.h"
  
  typedef struct Fragment {
      char file[1024];
      int64_t start_time, duration;
      int n;
  } Fragment;
  
  typedef struct OutputStream {
      int bitrate;
      int first_stream;
      AVFormatContext *ctx;
      int ctx_inited;
      uint8_t iobuf[32768];
      char temp_filename[1024];
      int64_t frag_start_ts, last_ts;
      AVIOContext *out;
      int packets_written;
      int nb_fragments, fragments_size, fragment_index;
      Fragment **fragments;
  
      int has_audio, has_video;
  
      uint8_t *metadata;
      int metadata_size;
  
      uint8_t *extra_packets[2];
      int extra_packet_sizes[2];
      int nb_extra_packets;
  } OutputStream;
  
  typedef struct HDSContext {
      const AVClass *class;  /* Class for private options. */
      int window_size;
      int extra_window_size;
      int min_frag_duration;
      int remove_at_exit;
  
      OutputStream *streams;
      int nb_streams;
  } HDSContext;
  
  static int parse_header(OutputStream *os, const uint8_t *buf, int buf_size)
  {
      if (buf_size < 13)
          return AVERROR_INVALIDDATA;
      if (memcmp(buf, "FLV", 3))
          return AVERROR_INVALIDDATA;
      buf      += 13;
      buf_size -= 13;
      while (buf_size >= 11 + 4) {
          int type = buf[0];
          int size = AV_RB24(&buf[1]) + 11 + 4;
          if (size > buf_size)
              return AVERROR_INVALIDDATA;
          if (type == 8 || type == 9) {
              if (os->nb_extra_packets >= FF_ARRAY_ELEMS(os->extra_packets))
                  return AVERROR_INVALIDDATA;
              os->extra_packet_sizes[os->nb_extra_packets] = size;
              os->extra_packets[os->nb_extra_packets] = av_malloc(size);
              if (!os->extra_packets[os->nb_extra_packets])
                  return AVERROR(ENOMEM);
              memcpy(os->extra_packets[os->nb_extra_packets], buf, size);
              os->nb_extra_packets++;
          } else if (type == 0x12) {
              if (os->metadata)
                  return AVERROR_INVALIDDATA;
              os->metadata_size = size - 11 - 4;
              os->metadata      = av_malloc(os->metadata_size);
              if (!os->metadata)
                  return AVERROR(ENOMEM);
              memcpy(os->metadata, buf + 11, os->metadata_size);
          }
          buf      += size;
          buf_size -= size;
      }
      if (!os->metadata)
          return AVERROR_INVALIDDATA;
      return 0;
  }
  
  static int hds_write(void *opaque, uint8_t *buf, int buf_size)
  {
      OutputStream *os = opaque;
      if (os->out) {
          avio_write(os->out, buf, buf_size);
      } else {
          if (!os->metadata_size) {
              int ret;
              // Assuming the IO buffer is large enough to fit the
              // FLV header and all metadata and extradata packets
              if ((ret = parse_header(os, buf, buf_size)) < 0)
                  return ret;
          }
      }
      return buf_size;
  }
  
  static void hds_free(AVFormatContext *s)
  {
      HDSContext *c = s->priv_data;
      int i, j;
      if (!c->streams)
          return;
      for (i = 0; i < s->nb_streams; i++) {
          OutputStream *os = &c->streams[i];
          if (os->out)
              ff_format_io_close(s, &os->out);
          if (os->ctx && os->ctx_inited)
              av_write_trailer(os->ctx);
          if (os->ctx)
              avio_context_free(&os->ctx->pb);
          avformat_free_context(os->ctx);
          av_freep(&os->metadata);
          for (j = 0; j < os->nb_extra_packets; j++)
              av_freep(&os->extra_packets[j]);
          for (j = 0; j < os->nb_fragments; j++)
              av_freep(&os->fragments[j]);
          av_freep(&os->fragments);
      }
      av_freep(&c->streams);
  }
  
  static int write_manifest(AVFormatContext *s, int final)
  {
      HDSContext *c = s->priv_data;
      AVIOContext *out;
      char filename[1024], temp_filename[1024];
      int ret, i;
      double duration = 0;
  
      if (c->nb_streams > 0)
          duration = c->streams[0].last_ts * av_q2d(s->streams[0]->time_base);
  
      snprintf(filename, sizeof(filename), "%s/index.f4m", s->url);
      snprintf(temp_filename, sizeof(temp_filename), "%s/index.f4m.tmp", s->url);
      ret = s->io_open(s, &out, temp_filename, AVIO_FLAG_WRITE, NULL);
      if (ret < 0) {
          av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", temp_filename);
          return ret;
      }
      avio_printf(out, "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
      avio_printf(out, "<manifest xmlns=\"http://ns.adobe.com/f4m/1.0\">\n");
      avio_printf(out, "\t<id>%s</id>\n", av_basename(s->url));
      avio_printf(out, "\t<streamType>%s</streamType>\n",
                       final ? "recorded" : "live");
      avio_printf(out, "\t<deliveryType>streaming</deliveryType>\n");
      if (final)
          avio_printf(out, "\t<duration>%f</duration>\n", duration);
      for (i = 0; i < c->nb_streams; i++) {
          OutputStream *os = &c->streams[i];
          int b64_size = AV_BASE64_SIZE(os->metadata_size);
          char *base64 = av_malloc(b64_size);
          if (!base64) {
              ff_format_io_close(s, &out);
              return AVERROR(ENOMEM);
          }
          av_base64_encode(base64, b64_size, os->metadata, os->metadata_size);
  
          avio_printf(out, "\t<bootstrapInfo profile=\"named\" url=\"stream%d.abst\" id=\"bootstrap%d\" />\n", i, i);
          avio_printf(out, "\t<media bitrate=\"%d\" url=\"stream%d\" bootstrapInfoId=\"bootstrap%d\">\n", os->bitrate/1000, i, i);
          avio_printf(out, "\t\t<metadata>%s</metadata>\n", base64);
          avio_printf(out, "\t</media>\n");
          av_free(base64);
      }
      avio_printf(out, "</manifest>\n");
      avio_flush(out);
      ff_format_io_close(s, &out);
      return ff_rename(temp_filename, filename, s);
  }
  
  static void update_size(AVIOContext *out, int64_t pos)
  {
      int64_t end = avio_tell(out);
      avio_seek(out, pos, SEEK_SET);
      avio_wb32(out, end - pos);
      avio_seek(out, end, SEEK_SET);
  }
  
  /* Note, the .abst files need to be served with the "binary/octet"
   * mime type, otherwise at least the OSMF player can easily fail
   * with "stream not found" when polling for the next fragment. */
  static int write_abst(AVFormatContext *s, OutputStream *os, int final)
  {
      HDSContext *c = s->priv_data;
      AVIOContext *out;
      char filename[1024], temp_filename[1024];
      int i, ret;
      int64_t asrt_pos, afrt_pos;
      int start = 0, fragments;
      int index = s->streams[os->first_stream]->id;
      int64_t cur_media_time = 0;
      if (c->window_size)
          start = FFMAX(os->nb_fragments - c->window_size, 0);
      fragments = os->nb_fragments - start;
      if (final)
          cur_media_time = os->last_ts;
      else if (os->nb_fragments)
          cur_media_time = os->fragments[os->nb_fragments - 1]->start_time;
  
      snprintf(filename, sizeof(filename),
               "%s/stream%d.abst", s->url, index);
      snprintf(temp_filename, sizeof(temp_filename),
               "%s/stream%d.abst.tmp", s->url, index);
      ret = s->io_open(s, &out, temp_filename, AVIO_FLAG_WRITE, NULL);
      if (ret < 0) {
          av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", temp_filename);
          return ret;
      }
      avio_wb32(out, 0); // abst size
      avio_wl32(out, MKTAG('a','b','s','t'));
      avio_wb32(out, 0); // version + flags
      avio_wb32(out, os->fragment_index - 1); // BootstrapinfoVersion
      avio_w8(out, final ? 0 : 0x20); // profile, live, update
      avio_wb32(out, 1000); // timescale
      avio_wb64(out, cur_media_time);
      avio_wb64(out, 0); // SmpteTimeCodeOffset
      avio_w8(out, 0); // MovieIdentifer (null string)
      avio_w8(out, 0); // ServerEntryCount
      avio_w8(out, 0); // QualityEntryCount
      avio_w8(out, 0); // DrmData (null string)
      avio_w8(out, 0); // MetaData (null string)
      avio_w8(out, 1); // SegmentRunTableCount
      asrt_pos = avio_tell(out);
      avio_wb32(out, 0); // asrt size
      avio_wl32(out, MKTAG('a','s','r','t'));
      avio_wb32(out, 0); // version + flags
      avio_w8(out, 0); // QualityEntryCount
      avio_wb32(out, 1); // SegmentRunEntryCount
      avio_wb32(out, 1); // FirstSegment
      avio_wb32(out, final ? (os->fragment_index - 1) : 0xffffffff); // FragmentsPerSegment
      update_size(out, asrt_pos);
      avio_w8(out, 1); // FragmentRunTableCount
      afrt_pos = avio_tell(out);
      avio_wb32(out, 0); // afrt size
      avio_wl32(out, MKTAG('a','f','r','t'));
      avio_wb32(out, 0); // version + flags
      avio_wb32(out, 1000); // timescale
      avio_w8(out, 0); // QualityEntryCount
      avio_wb32(out, fragments); // FragmentRunEntryCount
      for (i = start; i < os->nb_fragments; i++) {
          avio_wb32(out, os->fragments[i]->n);
          avio_wb64(out, os->fragments[i]->start_time);
          avio_wb32(out, os->fragments[i]->duration);
      }
      update_size(out, afrt_pos);
      update_size(out, 0);
      ff_format_io_close(s, &out);
      return ff_rename(temp_filename, filename, s);
  }
  
  static int init_file(AVFormatContext *s, OutputStream *os, int64_t start_ts)
  {
      int ret, i;
      ret = s->io_open(s, &os->out, os->temp_filename, AVIO_FLAG_WRITE, NULL);
      if (ret < 0)
          return ret;
      avio_wb32(os->out, 0);
      avio_wl32(os->out, MKTAG('m','d','a','t'));
      for (i = 0; i < os->nb_extra_packets; i++) {
          AV_WB24(os->extra_packets[i] + 4, start_ts);
          os->extra_packets[i][7] = (start_ts >> 24) & 0x7f;
          avio_write(os->out, os->extra_packets[i], os->extra_packet_sizes[i]);
      }
      return 0;
  }
  
  static void close_file(AVFormatContext *s, OutputStream *os)
  {
      int64_t pos = avio_tell(os->out);
      avio_seek(os->out, 0, SEEK_SET);
      avio_wb32(os->out, pos);
      avio_flush(os->out);
      ff_format_io_close(s, &os->out);
  }
  
  static int hds_write_header(AVFormatContext *s)
  {
      HDSContext *c = s->priv_data;
      int ret = 0, i;
      ff_const59 AVOutputFormat *oformat;
  
      if (mkdir(s->url, 0777) == -1 && errno != EEXIST) {
          av_log(s, AV_LOG_ERROR , "Failed to create directory %s\n", s->url);
          return AVERROR(errno);
      }
  
      oformat = av_guess_format("flv", NULL, NULL);
      if (!oformat) {
          return AVERROR_MUXER_NOT_FOUND;
      }
  
      c->streams = av_mallocz_array(s->nb_streams, sizeof(*c->streams));
      if (!c->streams) {
          return AVERROR(ENOMEM);
      }
  
      for (i = 0; i < s->nb_streams; i++) {
          OutputStream *os = &c->streams[c->nb_streams];
          AVFormatContext *ctx;
          AVStream *st = s->streams[i];
  
          if (!st->codecpar->bit_rate) {
              av_log(s, AV_LOG_ERROR, "No bit rate set for stream %d\n", i);
              return AVERROR(EINVAL);
          }
          if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
              if (os->has_video) {
                  c->nb_streams++;
                  os++;
              }
              os->has_video = 1;
          } else if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
              if (os->has_audio) {
                  c->nb_streams++;
                  os++;
              }
              os->has_audio = 1;
          } else {
              av_log(s, AV_LOG_ERROR, "Unsupported stream type in stream %d\n", i);
              return AVERROR(EINVAL);
          }
          os->bitrate += s->streams[i]->codecpar->bit_rate;
  
          if (!os->ctx) {
              os->first_stream = i;
              ctx = avformat_alloc_context();
              if (!ctx) {
                  return AVERROR(ENOMEM);
              }
              os->ctx = ctx;
              ctx->oformat = oformat;
              ctx->interrupt_callback = s->interrupt_callback;
              ctx->flags = s->flags;
  
              ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf),
                                           AVIO_FLAG_WRITE, os,
                                           NULL, hds_write, NULL);
              if (!ctx->pb) {
                  return AVERROR(ENOMEM);
              }
          } else {
              ctx = os->ctx;
          }
          s->streams[i]->id = c->nb_streams;
  
          if (!(st = avformat_new_stream(ctx, NULL))) {
              return AVERROR(ENOMEM);
          }
          avcodec_parameters_copy(st->codecpar, s->streams[i]->codecpar);
          st->codecpar->codec_tag = 0;
          st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
          st->time_base = s->streams[i]->time_base;
      }
      if (c->streams[c->nb_streams].ctx)
          c->nb_streams++;
  
      for (i = 0; i < c->nb_streams; i++) {
          OutputStream *os = &c->streams[i];
          int j;
          if ((ret = avformat_write_header(os->ctx, NULL)) < 0) {
               return ret;
          }
          os->ctx_inited = 1;
          avio_flush(os->ctx->pb);
          for (j = 0; j < os->ctx->nb_streams; j++)
              s->streams[os->first_stream + j]->time_base = os->ctx->streams[j]->time_base;
  
          snprintf(os->temp_filename, sizeof(os->temp_filename),
                   "%s/stream%d_temp", s->url, i);
          ret = init_file(s, os, 0);
          if (ret < 0)
              return ret;
  
          if (!os->has_video && c->min_frag_duration <= 0) {
              av_log(s, AV_LOG_WARNING,
                     "No video stream in output stream %d and no min frag duration set\n", i);
          }
          os->fragment_index = 1;
          write_abst(s, os, 0);
      }
      ret = write_manifest(s, 0);
  
      return ret;
  }
  
  static int add_fragment(OutputStream *os, const char *file,
                          int64_t start_time, int64_t duration)
  {
      Fragment *frag;
      if (duration == 0)
          duration = 1;
      if (os->nb_fragments >= os->fragments_size) {
          int ret;
          os->fragments_size = (os->fragments_size + 1) * 2;
          if ((ret = av_reallocp_array(&os->fragments, os->fragments_size,
                                       sizeof(*os->fragments))) < 0) {
              os->fragments_size = 0;
              os->nb_fragments   = 0;
              return ret;
          }
      }
      frag = av_mallocz(sizeof(*frag));
      if (!frag)
          return AVERROR(ENOMEM);
      av_strlcpy(frag->file, file, sizeof(frag->file));
      frag->start_time = start_time;
      frag->duration   = duration;
      frag->n          = os->fragment_index;
      os->fragments[os->nb_fragments++] = frag;
      os->fragment_index++;
      return 0;
  }
  
  static int hds_flush(AVFormatContext *s, OutputStream *os, int final,
                       int64_t end_ts)
  {
      HDSContext *c = s->priv_data;
      int i, ret = 0;
      char target_filename[1024];
      int index = s->streams[os->first_stream]->id;
  
      if (!os->packets_written)
          return 0;
  
      avio_flush(os->ctx->pb);
      os->packets_written = 0;
      close_file(s, os);
  
      snprintf(target_filename, sizeof(target_filename),
               "%s/stream%dSeg1-Frag%d", s->url, index, os->fragment_index);
      ret = ff_rename(os->temp_filename, target_filename, s);
      if (ret < 0)
          return ret;
      add_fragment(os, target_filename, os->frag_start_ts, end_ts - os->frag_start_ts);
  
      if (!final) {
          ret = init_file(s, os, end_ts);
          if (ret < 0)
              return ret;
      }
  
      if (c->window_size || (final && c->remove_at_exit)) {
          int remove = os->nb_fragments - c->window_size - c->extra_window_size;
          if (final && c->remove_at_exit)
              remove = os->nb_fragments;
          if (remove > 0) {
              for (i = 0; i < remove; i++) {
                  unlink(os->fragments[i]->file);
                  av_freep(&os->fragments[i]);
              }
              os->nb_fragments -= remove;
              memmove(os->fragments, os->fragments + remove,
                      os->nb_fragments * sizeof(*os->fragments));
          }
      }
  
      if (ret >= 0)
          ret = write_abst(s, os, final);
      return ret;
  }
  
  static int hds_write_packet(AVFormatContext *s, AVPacket *pkt)
  {
      HDSContext *c = s->priv_data;
      AVStream *st = s->streams[pkt->stream_index];
      OutputStream *os = &c->streams[s->streams[pkt->stream_index]->id];
      int64_t end_dts = os->fragment_index * (int64_t)c->min_frag_duration;
      int ret;
  
      if (st->first_dts == AV_NOPTS_VALUE)
          st->first_dts = pkt->dts;
  
      if ((!os->has_video || st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) &&
          av_compare_ts(pkt->dts - st->first_dts, st->time_base,
                        end_dts, AV_TIME_BASE_Q) >= 0 &&
          pkt->flags & AV_PKT_FLAG_KEY && os->packets_written) {
  
          if ((ret = hds_flush(s, os, 0, pkt->dts)) < 0)
              return ret;
      }
  
      // Note, these fragment start timestamps, that represent a whole
      // OutputStream, assume all streams in it have the same time base.
      if (!os->packets_written)
          os->frag_start_ts = pkt->dts;
      os->last_ts = pkt->dts;
  
      os->packets_written++;
      return ff_write_chained(os->ctx, pkt->stream_index - os->first_stream, pkt, s, 0);
  }
  
  static int hds_write_trailer(AVFormatContext *s)
  {
      HDSContext *c = s->priv_data;
      int i;
  
      for (i = 0; i < c->nb_streams; i++)
          hds_flush(s, &c->streams[i], 1, c->streams[i].last_ts);
      write_manifest(s, 1);
  
      if (c->remove_at_exit) {
          char filename[1024];
          snprintf(filename, sizeof(filename), "%s/index.f4m", s->url);
          unlink(filename);
          for (i = 0; i < c->nb_streams; i++) {
              snprintf(filename, sizeof(filename), "%s/stream%d.abst", s->url, i);
              unlink(filename);
          }
          rmdir(s->url);
      }
  
      return 0;
  }
  
  #define OFFSET(x) offsetof(HDSContext, x)
  #define E AV_OPT_FLAG_ENCODING_PARAM
  static const AVOption options[] = {
      { "window_size", "number of fragments kept in the manifest", OFFSET(window_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, E },
      { "extra_window_size", "number of fragments kept outside of the manifest before removing from disk", OFFSET(extra_window_size), AV_OPT_TYPE_INT, { .i64 = 5 }, 0, INT_MAX, E },
      { "min_frag_duration", "minimum fragment duration (in microseconds)", OFFSET(min_frag_duration), AV_OPT_TYPE_INT64, { .i64 = 10000000 }, 0, INT_MAX, E },
      { "remove_at_exit", "remove all fragments when finished", OFFSET(remove_at_exit), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, E },
      { NULL },
  };
  
  static const AVClass hds_class = {
      .class_name = "HDS muxer",
      .item_name  = av_default_item_name,
      .option     = options,
      .version    = LIBAVUTIL_VERSION_INT,
  };
  
  AVOutputFormat ff_hds_muxer = {
      .name           = "hds",
      .long_name      = NULL_IF_CONFIG_SMALL("HDS Muxer"),
      .priv_data_size = sizeof(HDSContext),
      .audio_codec    = AV_CODEC_ID_AAC,
      .video_codec    = AV_CODEC_ID_H264,
      .flags          = AVFMT_GLOBALHEADER | AVFMT_NOFILE,
      .write_header   = hds_write_header,
      .write_packet   = hds_write_packet,
      .write_trailer  = hds_write_trailer,
      .deinit         = hds_free,
      .priv_class     = &hds_class,
  };
  