/*

 * RTP parser for DV payload format (RFC 6469)

 * Copyright (c) 2015 Thomas Volkert <thomas@homer-conferencing.com>

 *

 * 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/avstring.h"

#include "avio_internal.h"

#include "rtpdec.h"

struct PayloadContext {

    AVIOContext *buf;

    uint32_t    timestamp;

    int         bundled_audio;

};

static av_cold void dv_close_context(PayloadContext *data)

{

    ffio_free_dyn_buf(&data->buf);

}

static av_cold int dv_sdp_parse_fmtp_config(AVFormatContext *s,

                                            AVStream *stream,

                                            PayloadContext *dv_data,

                                            const char *attr, const char *value)

{

    /* does the DV stream include audio? */

    if (!strcmp(attr, "audio") && !strcmp(value, "bundled"))

        dv_data->bundled_audio = 1;

    /* extract the DV profile */

    if (!strcmp(attr, "encode")) {

        /* SD-VCR/525-60 */

        /* SD-VCR/625-50 */

        /* HD-VCR/1125-60 */

        /* HD-VCR/1250-50 */

        /* SDL-VCR/525-60 */

        /* SDL-VCR/625-50 */

        /* 314M-25/525-60 */

        /* 314M-25/625-50 */

        /* 314M-50/525-60 */

        /* 314M-50/625-50 */

        /* 370M/1080-60i */

        /* 370M/1080-50i */

        /* 370M/720-60p */

        /* 370M/720-50p */

        /* 306M/525-60 (for backward compatibility) */

        /* 306M/625-50 (for backward compatibility) */

    }

    return 0;

}

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

                                     PayloadContext *dv_data, const char *line)

{

    AVStream *current_stream;

    const char *sdp_line_ptr = line;

    if (st_index < 0)

        return 0;

    current_stream = ctx->streams[st_index];

    if (av_strstart(sdp_line_ptr, "fmtp:", &sdp_line_ptr)) {

        return ff_parse_fmtp(ctx, current_stream, dv_data, sdp_line_ptr,

                             dv_sdp_parse_fmtp_config);

    }

    return 0;

}

static int dv_handle_packet(AVFormatContext *ctx, PayloadContext *rtp_dv_ctx,

                            AVStream *st, AVPacket *pkt, uint32_t *timestamp,

                            const uint8_t *buf, int len, uint16_t seq,

                            int flags)

{

    int res = 0;

    /* drop data of previous packets in case of non-continuous (lossy) packet stream */

    if (rtp_dv_ctx->buf && rtp_dv_ctx->timestamp != *timestamp) {

        ffio_free_dyn_buf(&rtp_dv_ctx->buf);

    }

    /* sanity check for size of input packet: 1 byte payload at least */

    if (len < 1) {

        av_log(ctx, AV_LOG_ERROR, "Too short RTP/DV packet, got %d bytes\n", len);

        return AVERROR_INVALIDDATA;

    }

    /* start frame buffering with new dynamic buffer */

    if (!rtp_dv_ctx->buf) {

        res = avio_open_dyn_buf(&rtp_dv_ctx->buf);

        if (res < 0)

            return res;

        /* update the timestamp in the frame packet with the one from the RTP packet */

        rtp_dv_ctx->timestamp = *timestamp;

    }

    /* write the fragment to the dyn. buffer */

    avio_write(rtp_dv_ctx->buf, buf, len);

    /* RTP marker bit means: last fragment of current frame was received;

       otherwise, an additional fragment is needed for the current frame */

    if (!(flags & RTP_FLAG_MARKER))

        return AVERROR(EAGAIN);

    /* close frame buffering and create resulting A/V packet */

    res = ff_rtp_finalize_packet(pkt, &rtp_dv_ctx->buf, st->index);

    if (res < 0)

        return res;

    return 0;

}

const RTPDynamicProtocolHandler ff_dv_dynamic_handler = {

    .enc_name         = "DV",

    .codec_type       = AVMEDIA_TYPE_VIDEO,

    .codec_id         = AV_CODEC_ID_DVVIDEO,

    .need_parsing     = AVSTREAM_PARSE_FULL,

    .parse_sdp_a_line = dv_parse_sdp_line,

    .priv_data_size   = sizeof(PayloadContext),

    .close             = dv_close_context,

    .parse_packet     = dv_handle_packet,

};