PeerStreamer

/*

 * copyright (c) 2007 Luca Abeni

 *

 * 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 "libavutil/base64.h"

#include "avformat.h"

#include "internal.h"

#include "avc.h"

#include "rtp.h"

#if CONFIG_RTP_MUXER

#define MAX_EXTRADATA_SIZE ((INT_MAX - 10) / 2)

struct sdp_session_level {

    int sdp_version;      /**< protocol version (currently 0) */

    int id;               /**< session ID */

    int version;          /**< session version */

    int start_time;       /**< session start time (NTP time, in seconds),

                               or 0 in case of permanent session */

    int end_time;         /**< session end time (NTP time, in seconds),

                               or 0 if the session is not bounded */

    int ttl;              /**< TTL, in case of multicast stream */

    const char *user;     /**< username of the session's creator */

    const char *src_addr; /**< IP address of the machine from which the session was created */

    const char *dst_addr; /**< destination IP address (can be multicast) */

    const char *name;     /**< session name (can be an empty string) */

};

static void sdp_write_address(char *buff, int size, const char *dest_addr, int ttl)

{

    if (dest_addr) {

        if (ttl > 0) {

            av_strlcatf(buff, size, "c=IN IP4 %s/%d\r\n", dest_addr, ttl);

        } else {

            av_strlcatf(buff, size, "c=IN IP4 %s\r\n", dest_addr);

        }

    }

}

static void sdp_write_header(char *buff, int size, struct sdp_session_level *s)

{

    av_strlcatf(buff, size, "v=%d\r\n"

                            "o=- %d %d IN IP4 %s\r\n"

                            "t=%d %d\r\n"

                            "s=%s\r\n"

                            "a=tool:libavformat " AV_STRINGIFY(LIBAVFORMAT_VERSION) "\r\n",

                            s->sdp_version,

                            s->id, s->version, s->src_addr,

                            s->start_time, s->end_time,

                            s->name);

    sdp_write_address(buff, size, s->dst_addr, s->ttl);

}

static int sdp_get_address(char *dest_addr, int size, int *ttl, const char *url)

{

    int port;

    const char *p;

    url_split(NULL, 0, NULL, 0, dest_addr, size, &port, NULL, 0, url);

    *ttl = 0;

    p = strchr(url, '?');

    if (p) {

        char buff[64];

        int is_multicast = find_info_tag(buff, sizeof(buff), "multicast", p);

        if (is_multicast) {

            if (find_info_tag(buff, sizeof(buff), "ttl", p)) {

                *ttl = strtol(buff, NULL, 10);

            } else {

                *ttl = 5;

            }

        }

    }

    return port;

}

#define MAX_PSET_SIZE 1024

static char *extradata2psets(AVCodecContext *c)

{

    char *psets, *p;

    const uint8_t *r;

    const char *pset_string = "; sprop-parameter-sets=";

    if (c->extradata_size > MAX_EXTRADATA_SIZE) {

        av_log(c, AV_LOG_ERROR, "Too much extradata!\n");

        return NULL;

    }

    psets = av_mallocz(MAX_PSET_SIZE);

    if (psets == NULL) {

        av_log(c, AV_LOG_ERROR, "Cannot allocate memory for the parameter sets.\n");

        return NULL;

    }

    memcpy(psets, pset_string, strlen(pset_string));

    p = psets + strlen(pset_string);

    r = ff_avc_find_startcode(c->extradata, c->extradata + c->extradata_size);

    while (r < c->extradata + c->extradata_size) {

        const uint8_t *r1;

        uint8_t nal_type;

        while (!*(r++));

        nal_type = *r & 0x1f;

        r1 = ff_avc_find_startcode(r, c->extradata + c->extradata_size);

        if (nal_type != 7 && nal_type != 8) { /* Only output SPS and PPS */

            r = r1;

            continue;

        }

        if (p != (psets + strlen(pset_string))) {

            *p = ',';

            p++;

        }

        if (av_base64_encode(p, MAX_PSET_SIZE - (p - psets), r, r1 - r) == NULL) {

            av_log(c, AV_LOG_ERROR, "Cannot Base64-encode %td %td!\n", MAX_PSET_SIZE - (p - psets), r1 - r);

            av_free(psets);

            return NULL;

        }

        p += strlen(p);

        r = r1;

    }

    return psets;

}

static char *extradata2config(AVCodecContext *c)

{

    char *config;

    if (c->extradata_size > MAX_EXTRADATA_SIZE) {

        av_log(c, AV_LOG_ERROR, "Too much extradata!\n");

        return NULL;

    }

    config = av_malloc(10 + c->extradata_size * 2);

    if (config == NULL) {

        av_log(c, AV_LOG_ERROR, "Cannot allocate memory for the config info.\n");

        return NULL;

    }

    memcpy(config, "; config=", 9);

    ff_data_to_hex(config + 9, c->extradata, c->extradata_size);

    config[9 + c->extradata_size * 2] = 0;

    return config;

}

static char *sdp_write_media_attributes(char *buff, int size, AVCodecContext *c, int payload_type)

{

    char *config = NULL;

    switch (c->codec_id) {

        case CODEC_ID_H264:

            if (c->extradata_size) {

                config = extradata2psets(c);

            }

            av_strlcatf(buff, size, "a=rtpmap:%d H264/90000\r\n"

                                    "a=fmtp:%d packetization-mode=1%s\r\n",

                                     payload_type,

                                     payload_type, config ? config : "");

            break;

        case CODEC_ID_H263:

        case CODEC_ID_H263P:

            av_strlcatf(buff, size, "a=rtpmap:%d H263-2000/90000\r\n", payload_type);

            break;

        case CODEC_ID_MPEG4:

            if (c->extradata_size) {

                config = extradata2config(c);

            }

            av_strlcatf(buff, size, "a=rtpmap:%d MP4V-ES/90000\r\n"

                                    "a=fmtp:%d profile-level-id=1%s\r\n",

                                     payload_type,

                                     payload_type, config ? config : "");

            break;

        case CODEC_ID_AAC:

            if (c->extradata_size) {

                config = extradata2config(c);

            } else {

                /* FIXME: maybe we can forge config information based on the

                 *        codec parameters...

                 */

                av_log(c, AV_LOG_ERROR, "AAC with no global headers is currently not supported.\n");

                return NULL;

            }

            if (config == NULL) {

                return NULL;

            }

            av_strlcatf(buff, size, "a=rtpmap:%d MPEG4-GENERIC/%d/%d\r\n"

                                    "a=fmtp:%d profile-level-id=1;"

                                    "mode=AAC-hbr;sizelength=13;indexlength=3;"

                                    "indexdeltalength=3%s\r\n",

                                     payload_type, c->sample_rate, c->channels,

                                     payload_type, config);

            break;

        case CODEC_ID_PCM_S16BE:

            if (payload_type >= 96)

                av_strlcatf(buff, size, "a=rtpmap:%d L16/%d/%d\r\n",

                                         payload_type,

                                         c->sample_rate, c->channels);

            break;

        case CODEC_ID_PCM_MULAW:

            if (payload_type >= 96)

                av_strlcatf(buff, size, "a=rtpmap:%d PCMU/%d/%d\r\n",

                                         payload_type,

                                         c->sample_rate, c->channels);

            break;

        case CODEC_ID_PCM_ALAW:

            if (payload_type >= 96)

                av_strlcatf(buff, size, "a=rtpmap:%d PCMA/%d/%d\r\n",

                                         payload_type,

                                         c->sample_rate, c->channels);

            break;

        case CODEC_ID_AMR_NB:

            av_strlcatf(buff, size, "a=rtpmap:%d AMR/%d/%d\r\n"

                                    "a=fmtp:%d octet-align=1\r\n",

                                     payload_type, c->sample_rate, c->channels,

                                     payload_type);

            break;

        case CODEC_ID_AMR_WB:

            av_strlcatf(buff, size, "a=rtpmap:%d AMR-WB/%d/%d\r\n"

                                    "a=fmtp:%d octet-align=1\r\n",

                                     payload_type, c->sample_rate, c->channels,

                                     payload_type);

            break;

        default:

            /* Nothing special to do here... */

            break;

    }

    av_free(config);

    return buff;

}

static void sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, int port, int ttl)

{

    const char *type;

    int payload_type;

    payload_type = ff_rtp_get_payload_type(c);

    if (payload_type < 0) {

        payload_type = 96;  /* FIXME: how to assign a private pt? rtp.c is broken too */

    }

    switch (c->codec_type) {

        case CODEC_TYPE_VIDEO   : type = "video"      ; break;

        case CODEC_TYPE_AUDIO   : type = "audio"      ; break;

        case CODEC_TYPE_SUBTITLE: type = "text"       ; break;

        default                 : type = "application"; break;

    }

    av_strlcatf(buff, size, "m=%s %d RTP/AVP %d\r\n", type, port, payload_type);

    sdp_write_address(buff, size, dest_addr, ttl);

    if (c->bit_rate) {

        av_strlcatf(buff, size, "b=AS:%d\r\n", c->bit_rate / 1000);

    }

    sdp_write_media_attributes(buff, size, c, payload_type);

}

int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)

{

    AVMetadataTag *title = av_metadata_get(ac[0]->metadata, "title", NULL, 0);

    struct sdp_session_level s;

    int i, j, port, ttl;

    char dst[32];

    memset(buff, 0, size);

    memset(&s, 0, sizeof(struct sdp_session_level));

    s.user = "-";

    s.src_addr = "127.0.0.1";    /* FIXME: Properly set this */

    s.name = title ? title->value : "No Name";

    port = 0;

    ttl = 0;

    if (n_files == 1) {

        port = sdp_get_address(dst, sizeof(dst), &ttl, ac[0]->filename);

        if (port > 0) {

            s.dst_addr = dst;

            s.ttl = ttl;

        }

    }

    sdp_write_header(buff, size, &s);

    dst[0] = 0;

    for (i = 0; i < n_files; i++) {

        if (n_files != 1) {

            port = sdp_get_address(dst, sizeof(dst), &ttl, ac[i]->filename);

        }

        for (j = 0; j < ac[i]->nb_streams; j++) {

            sdp_write_media(buff, size,

                                  ac[i]->streams[j]->codec, dst[0] ? dst : NULL,

                                  (port > 0) ? port + j * 2 : 0, ttl);

            if (port <= 0) {

                av_strlcatf(buff, size,

                                   "a=control:streamid=%d\r\n", i + j);

            }

        }

    }

    return 0;

}

#else

int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)

{

    return AVERROR(ENOSYS);

}

#endif