/*

 * 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 void mpegts_close_context(PayloadContext *data)

{

    if (!data)

        return;

    if (data->ts)

        avpriv_mpegts_parse_close(data->ts);

}

static av_cold int mpegts_init(AVFormatContext *ctx, int st_index,

                               PayloadContext *data)

{

    data->ts = avpriv_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 (!buf) {

        if (data->read_buf_index >= data->read_buf_size)

            return AVERROR(EAGAIN);

        ret = avpriv_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 = avpriv_mpegts_parse_packet(data->ts, pkt, buf, len);

    /* The only error that can be returned from avpriv_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;

}

const RTPDynamicProtocolHandler ff_mpegts_dynamic_handler = {

    .codec_type        = AVMEDIA_TYPE_DATA,

    .priv_data_size    = sizeof(PayloadContext),

    .parse_packet      = mpegts_handle_packet,

    .init              = mpegts_init,

    .close             = mpegts_close_context,

    .static_payload_id = 33,

};