PeerStreamer

/*

 * Sorenson-3 (SVQ3/SV3V) payload for RTP

 * Copyright (c) 2010 Ronald S. Bultje

 *

 * 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

 */

/**

 * @file

 * @brief RTP support for the SV3V (SVQ3) payload

 * (http://wiki.multimedia.cx/index.php?title=Sorenson_Video_3#Packetization)

 * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>

 */

#include <string.h>

#include "libavutil/intreadwrite.h"

#include "rtp.h"

#include "rtpdec.h"

#include "rtpdec_formats.h"

struct PayloadContext {

    ByteIOContext *pktbuf;

    int64_t        timestamp;

    int            is_keyframe;

};

/** return 0 on packet, <0 on partial packet or error... */

static int svq3_parse_packet (AVFormatContext *s, PayloadContext *sv,

                              AVStream *st, AVPacket *pkt,

                              uint32_t *timestamp,

                              const uint8_t *buf, int len, int flags)

{

    int config_packet, start_packet, end_packet;

    if (len < 2)

        return AVERROR_INVALIDDATA;

    config_packet = buf[0] & 0x40;

    start_packet  = buf[0] & 0x20;

    end_packet    = buf[0] & 0x10;

    buf += 2;     // ignore buf[1]

    len -= 2;

    if (config_packet) {

        av_freep(&st->codec->extradata);

        st->codec->extradata_size = 0;

        if (len < 2 || !(st->codec->extradata =

                         av_malloc(len + 8 + FF_INPUT_BUFFER_PADDING_SIZE)))

            return AVERROR_INVALIDDATA;

        st->codec->extradata_size = len + 8;

        memcpy(st->codec->extradata, "SEQH", 4);

        AV_WB32(st->codec->extradata + 4, len);

        memcpy(st->codec->extradata + 8, buf, len);

        /* We set codec_id to CODEC_ID_NONE initially to

         * delay decoder initialization since extradata is

         * carried within the RTP stream, not SDP. Here,

         * by setting codec_id to CODEC_ID_SVQ3, we are signalling

         * to the decoder that it is OK to initialize. */

        st->codec->codec_id = CODEC_ID_SVQ3;

        return AVERROR(EAGAIN);

    }

    if (start_packet) {

        int res;

        if (sv->pktbuf) {

            uint8_t *tmp;

            url_close_dyn_buf(sv->pktbuf, &tmp);

            av_free(tmp);

        }

        if ((res = url_open_dyn_buf(&sv->pktbuf)) < 0)

            return res;

        sv->timestamp   = *timestamp;

        sv->is_keyframe = flags & RTP_FLAG_KEY;

    }

    if (!sv->pktbuf)

        return AVERROR_INVALIDDATA;

    put_buffer(sv->pktbuf, buf, len);

    if (end_packet) {

        av_init_packet(pkt);

        pkt->stream_index = st->index;

        *timestamp        = sv->timestamp;

        pkt->flags        = sv->is_keyframe ? AV_PKT_FLAG_KEY : 0;

        pkt->size         = url_close_dyn_buf(sv->pktbuf, &pkt->data);

        pkt->destruct     = av_destruct_packet;

        sv->pktbuf        = NULL;

        return 0;

    }

    return AVERROR(EAGAIN);

}

static PayloadContext *svq3_extradata_new(void)

{

    return av_mallocz(sizeof(PayloadContext));

}

static void svq3_extradata_free(PayloadContext *sv)

{

    if (sv->pktbuf) {

        uint8_t *buf;

        url_close_dyn_buf(sv->pktbuf, &buf);

        av_free(buf);

    }

    av_free(sv);

}

RTPDynamicProtocolHandler ff_svq3_dynamic_handler = {

    "X-SV3V-ES",

    AVMEDIA_TYPE_VIDEO,

    CODEC_ID_NONE,          // see if (config_packet) above

    NULL,                   // parse sdp line

    svq3_extradata_new,

    svq3_extradata_free,

    svq3_parse_packet,

};