/*
  * RTP/mpegts muxer
  * Copyright (c) 2011 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 "libavutil/mathematics.h"
 #include "avformat.h"

 #include "avio_internal.h"

 
 struct MuxChain {
     AVFormatContext *mpegts_ctx;
     AVFormatContext *rtp_ctx;
 };
 
 static int rtp_mpegts_write_close(AVFormatContext *s)
 {
     struct MuxChain *chain = s->priv_data;
 
     if (chain->mpegts_ctx) {

         av_write_trailer(chain->mpegts_ctx);

         ffio_free_dyn_buf(&chain->mpegts_ctx->pb);

         avformat_free_context(chain->mpegts_ctx);
     }
     if (chain->rtp_ctx) {
         av_write_trailer(chain->rtp_ctx);
         avformat_free_context(chain->rtp_ctx);
     }
     return 0;
 }
 
 static int rtp_mpegts_write_header(AVFormatContext *s)
 {
     struct MuxChain *chain = s->priv_data;
     AVFormatContext *mpegts_ctx = NULL, *rtp_ctx = NULL;
     AVOutputFormat *mpegts_format = av_guess_format("mpegts", NULL, NULL);
     AVOutputFormat *rtp_format    = av_guess_format("rtp", NULL, NULL);
     int i, ret = AVERROR(ENOMEM);
     AVStream *st;
 
     if (!mpegts_format || !rtp_format)
         return AVERROR(ENOSYS);
     mpegts_ctx = avformat_alloc_context();
     if (!mpegts_ctx)
         return AVERROR(ENOMEM);
     mpegts_ctx->oformat   = mpegts_format;
     mpegts_ctx->max_delay = s->max_delay;
     for (i = 0; i < s->nb_streams; i++) {
         AVStream* st = avformat_new_stream(mpegts_ctx, NULL);
         if (!st)
             goto fail;
         st->time_base           = s->streams[i]->time_base;
         st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
         avcodec_copy_context(st->codec, s->streams[i]->codec);
     }
     if ((ret = avio_open_dyn_buf(&mpegts_ctx->pb)) < 0)
         goto fail;
     if ((ret = avformat_write_header(mpegts_ctx, NULL)) < 0)
         goto fail;
     for (i = 0; i < s->nb_streams; i++)
         s->streams[i]->time_base = mpegts_ctx->streams[i]->time_base;
 
     chain->mpegts_ctx = mpegts_ctx;
     mpegts_ctx = NULL;
 
     rtp_ctx = avformat_alloc_context();
     if (!rtp_ctx) {
         ret = AVERROR(ENOMEM);
         goto fail;
     }
     rtp_ctx->oformat = rtp_format;
     st = avformat_new_stream(rtp_ctx, NULL);
     st->time_base.num   = 1;
     st->time_base.den   = 90000;
     st->codec->codec_id = AV_CODEC_ID_MPEG2TS;
     rtp_ctx->pb = s->pb;
     if ((ret = avformat_write_header(rtp_ctx, NULL)) < 0)
         goto fail;

     chain->rtp_ctx = rtp_ctx;

 
     return 0;
 
 fail:
     if (mpegts_ctx) {

         ffio_free_dyn_buf(&mpegts_ctx->pb);

         avformat_free_context(mpegts_ctx);
     }
     if (rtp_ctx)
         avformat_free_context(rtp_ctx);
     rtp_mpegts_write_close(s);
     return ret;
 }
 
 static int rtp_mpegts_write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     struct MuxChain *chain = s->priv_data;
     int ret = 0, size;
     uint8_t *buf;
     AVPacket local_pkt;
 
     if (!chain->mpegts_ctx->pb) {
         if ((ret = avio_open_dyn_buf(&chain->mpegts_ctx->pb)) < 0)
             return ret;
     }
     if ((ret = av_write_frame(chain->mpegts_ctx, pkt)) < 0)
         return ret;
     size = avio_close_dyn_buf(chain->mpegts_ctx->pb, &buf);
     chain->mpegts_ctx->pb = NULL;
     if (size == 0) {
         av_free(buf);
         return 0;
     }
     av_init_packet(&local_pkt);
     local_pkt.data         = buf;
     local_pkt.size         = size;
     local_pkt.stream_index = 0;
     if (pkt->pts != AV_NOPTS_VALUE)
         local_pkt.pts = av_rescale_q(pkt->pts,
                                      s->streams[pkt->stream_index]->time_base,
                                      chain->rtp_ctx->streams[0]->time_base);
     if (pkt->dts != AV_NOPTS_VALUE)
         local_pkt.dts = av_rescale_q(pkt->dts,
                                      s->streams[pkt->stream_index]->time_base,
                                      chain->rtp_ctx->streams[0]->time_base);
     ret = av_write_frame(chain->rtp_ctx, &local_pkt);
     av_free(buf);
 
     return ret;
 }
 
 AVOutputFormat ff_rtp_mpegts_muxer = {
     .name              = "rtp_mpegts",
     .long_name         = NULL_IF_CONFIG_SMALL("RTP/mpegts output format"),
     .priv_data_size    = sizeof(struct MuxChain),
     .audio_codec       = AV_CODEC_ID_AAC,
     .video_codec       = AV_CODEC_ID_MPEG4,
     .write_header      = rtp_mpegts_write_header,
     .write_packet      = rtp_mpegts_write_packet,
     .write_trailer     = rtp_mpegts_write_close,
 };