/*
  * RTP MPEG2TS depacketizer
  * Copyright (c) 2003 Fabrice Bellard
  *

  * 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/attributes.h"

 #include "mpegts.h"
 #include "rtpdec_formats.h"
 
 struct PayloadContext {
     struct MpegTSContext *ts;
     int read_buf_index;
     int read_buf_size;
     uint8_t buf[RTP_MAX_PACKET_LENGTH];
 };
 
 static PayloadContext *mpegts_new_context(void)
 {
     return av_mallocz(sizeof(PayloadContext));
 }
 
 static void mpegts_free_context(PayloadContext *data)
 {
     if (!data)
         return;
     if (data->ts)
         ff_mpegts_parse_close(data->ts);
     av_free(data);
 }
 

 static av_cold int mpegts_init(AVFormatContext *ctx, int st_index,
                                PayloadContext *data)

 {
     data->ts = ff_mpegts_parse_open(ctx);
     if (!data->ts)
         return AVERROR(ENOMEM);
     return 0;
 }
 
 static int mpegts_handle_packet(AVFormatContext *ctx, PayloadContext *data,
                                 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
                                 const uint8_t *buf, int len, uint16_t seq,
                                 int flags)
 {
     int ret;
 
     // We don't want to use the RTP timestamps at all. If the mpegts demuxer
     // doesn't set any pts/dts, the generic rtpdec code shouldn't try to
     // fill it in either, since the mpegts and RTP timestamps are in totally
     // different ranges.
     *timestamp = RTP_NOTS_VALUE;
 
     if (!data->ts)
         return AVERROR(EINVAL);
 
     if (!buf) {
         if (data->read_buf_index >= data->read_buf_size)
             return AVERROR(EAGAIN);
         ret = ff_mpegts_parse_packet(data->ts, pkt, data->buf + data->read_buf_index,
                                      data->read_buf_size - data->read_buf_index);
         if (ret < 0)
             return AVERROR(EAGAIN);
         data->read_buf_index += ret;
         if (data->read_buf_index < data->read_buf_size)
             return 1;
         else
             return 0;
     }
 
     ret = ff_mpegts_parse_packet(data->ts, pkt, buf, len);
     /* The only error that can be returned from ff_mpegts_parse_packet
      * is "no more data to return from the provided buffer", so return
      * AVERROR(EAGAIN) for all errors */
     if (ret < 0)
         return AVERROR(EAGAIN);
     if (ret < len) {
         data->read_buf_size = FFMIN(len - ret, sizeof(data->buf));
         memcpy(data->buf, buf + ret, data->read_buf_size);
         data->read_buf_index = 0;
         return 1;
     }
     return 0;
 }
 
 RTPDynamicProtocolHandler ff_mpegts_dynamic_handler = {
     .codec_type        = AVMEDIA_TYPE_DATA,
     .parse_packet      = mpegts_handle_packet,
     .alloc             = mpegts_new_context,
     .init              = mpegts_init,
     .free              = mpegts_free_context,
     .static_payload_id = 33,
 };