nginx-mod-rtmp/ngx_rtmp_live_module.c

/*
 * Copyright (c) 2012 Roman Arutyunyan
 */


#include "ngx_rtmp_live_module.h"
#include "ngx_rtmp_cmd_module.h"
#include "ngx_rtmp_codec_module.h"


static ngx_rtmp_publish_pt              next_publish;
static ngx_rtmp_play_pt                 next_play;
static ngx_rtmp_close_stream_pt         next_close_stream;


static ngx_int_t ngx_rtmp_live_postconfiguration(ngx_conf_t *cf);
static void * ngx_rtmp_live_create_app_conf(ngx_conf_t *cf);
static char * ngx_rtmp_live_merge_app_conf(ngx_conf_t *cf, 
        void *parent, void *child);


#define NGX_RTMP_LIVE_TIME_ABSOLUTE     0x01
#define NGX_RTMP_LIVE_TIME_RELATIVE     0x02


static ngx_command_t  ngx_rtmp_live_commands[] = {

    { ngx_string("live"),
      NGX_RTMP_MAIN_CONF|NGX_RTMP_SRV_CONF|NGX_RTMP_APP_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_flag_slot,
      NGX_RTMP_APP_CONF_OFFSET,
      offsetof(ngx_rtmp_live_app_conf_t, live),
      NULL },

    { ngx_string("meta"),
      NGX_RTMP_MAIN_CONF|NGX_RTMP_SRV_CONF|NGX_RTMP_APP_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_flag_slot,
      NGX_RTMP_APP_CONF_OFFSET,
      offsetof(ngx_rtmp_live_app_conf_t, meta),
      NULL },

    { ngx_string("stream_buckets"),
      NGX_RTMP_MAIN_CONF|NGX_RTMP_SRV_CONF|NGX_RTMP_APP_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_RTMP_APP_CONF_OFFSET,
      offsetof(ngx_rtmp_live_app_conf_t, nbuckets),
      NULL },

    { ngx_string("buffer"),
      NGX_RTMP_MAIN_CONF|NGX_RTMP_SRV_CONF|NGX_RTMP_APP_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_RTMP_APP_CONF_OFFSET,
      offsetof(ngx_rtmp_live_app_conf_t, buflen),
      NULL },

    { ngx_string("sync"),
      NGX_RTMP_MAIN_CONF|NGX_RTMP_SRV_CONF|NGX_RTMP_APP_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_RTMP_APP_CONF_OFFSET,
      offsetof(ngx_rtmp_live_app_conf_t, sync),
      NULL },

    { ngx_string("atc"),
      NGX_RTMP_MAIN_CONF|NGX_RTMP_SRV_CONF|NGX_RTMP_APP_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_flag_slot,
      NGX_RTMP_APP_CONF_OFFSET,
      offsetof(ngx_rtmp_live_app_conf_t, atc),
      NULL },

    { ngx_string("interleave"),
      NGX_RTMP_MAIN_CONF|NGX_RTMP_SRV_CONF|NGX_RTMP_APP_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_flag_slot,
      NGX_RTMP_APP_CONF_OFFSET,
      offsetof(ngx_rtmp_live_app_conf_t, interleave),
      NULL },

    { ngx_string("wait_key"),
      NGX_RTMP_MAIN_CONF|NGX_RTMP_SRV_CONF|NGX_RTMP_APP_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_flag_slot,
      NGX_RTMP_APP_CONF_OFFSET,
      offsetof(ngx_rtmp_live_app_conf_t, wait_key),
      NULL },

      ngx_null_command
};


static ngx_rtmp_module_t  ngx_rtmp_live_module_ctx = {
    NULL,                                   /* preconfiguration */
    ngx_rtmp_live_postconfiguration,        /* postconfiguration */
    NULL,                                   /* create main configuration */
    NULL,                                   /* init main configuration */
    NULL,                                   /* create server configuration */
    NULL,                                   /* merge server configuration */
    ngx_rtmp_live_create_app_conf,          /* create app configuration */
    ngx_rtmp_live_merge_app_conf            /* merge app configuration */
};


ngx_module_t  ngx_rtmp_live_module = {
    NGX_MODULE_V1,
    &ngx_rtmp_live_module_ctx,              /* module context */
    ngx_rtmp_live_commands,                 /* module directives */
    NGX_RTMP_MODULE,                        /* module type */
    NULL,                                   /* init master */
    NULL,                                   /* init module */
    NULL,                                   /* init process */
    NULL,                                   /* init thread */
    NULL,                                   /* exit thread */
    NULL,                                   /* exit process */
    NULL,                                   /* exit master */
    NGX_MODULE_V1_PADDING
};


static void *
ngx_rtmp_live_create_app_conf(ngx_conf_t *cf)
{
    ngx_rtmp_live_app_conf_t      *lacf;

    lacf = ngx_pcalloc(cf->pool, sizeof(ngx_rtmp_live_app_conf_t));
    if (lacf == NULL) {
        return NULL;
    }

    lacf->live = NGX_CONF_UNSET;
    lacf->meta = NGX_CONF_UNSET;
    lacf->nbuckets = NGX_CONF_UNSET;
    lacf->buflen = NGX_CONF_UNSET;
    lacf->sync = NGX_CONF_UNSET;
    lacf->atc = NGX_CONF_UNSET;
    lacf->interleave = NGX_CONF_UNSET;
    lacf->wait_key = NGX_CONF_UNSET;

    return lacf;
}


static char *
ngx_rtmp_live_merge_app_conf(ngx_conf_t *cf, void *parent, void *child)
{
    ngx_rtmp_live_app_conf_t *prev = parent;
    ngx_rtmp_live_app_conf_t *conf = child;

    ngx_conf_merge_value(conf->live, prev->live, 0);
    ngx_conf_merge_value(conf->meta, prev->meta, 1);
    ngx_conf_merge_value(conf->nbuckets, prev->nbuckets, 1024);
    ngx_conf_merge_msec_value(conf->buflen, prev->buflen, 0);
    ngx_conf_merge_msec_value(conf->sync, prev->sync, 0);
    ngx_conf_merge_value(conf->atc, prev->atc, 0);
    ngx_conf_merge_value(conf->interleave, prev->interleave, 0);
    ngx_conf_merge_value(conf->wait_key, prev->wait_key, 0);

    conf->pool = ngx_create_pool(4096, &cf->cycle->new_log);
    if (conf->pool == NULL) {
        return NGX_CONF_ERROR;
    }

    conf->streams = ngx_pcalloc(cf->pool, 
            sizeof(ngx_rtmp_live_stream_t *) * conf->nbuckets);

    return NGX_CONF_OK;
}


static ngx_rtmp_live_stream_t **
ngx_rtmp_live_get_stream(ngx_rtmp_session_t *s, u_char *name, int create)
{
    ngx_rtmp_live_app_conf_t   *lacf;
    ngx_rtmp_live_stream_t    **stream;
    size_t                      len;

    lacf = ngx_rtmp_get_module_app_conf(s, ngx_rtmp_live_module);
    if (lacf == NULL) {
        return NULL;
    }

    len = ngx_strlen(name);
    stream = &lacf->streams[ngx_hash_key(name, len) % lacf->nbuckets];

    for (; *stream; stream = &(*stream)->next) {
        if (ngx_strcmp(name, (*stream)->name) == 0) {
            return stream;
        }
    }

    if (!create) {
        return NULL;
    }

    ngx_log_debug1(NGX_LOG_DEBUG_RTMP, s->connection->log, 0,
            "live: create stream '%s'", name);

    if (lacf->free_streams) {
        *stream = lacf->free_streams;
        lacf->free_streams = lacf->free_streams->next;
    } else {
        *stream = ngx_palloc(lacf->pool, sizeof(ngx_rtmp_live_stream_t));
    }
    ngx_memzero(*stream, sizeof(ngx_rtmp_live_stream_t));
    ngx_memcpy((*stream)->name, name, 
            ngx_min(sizeof((*stream)->name) - 1, len));
    (*stream)->epoch = ngx_current_msec;

    return stream;
}


static void
ngx_rtmp_live_join(ngx_rtmp_session_t *s, u_char *name,
        ngx_uint_t flags)
{
    ngx_rtmp_live_ctx_t            *ctx;
    ngx_rtmp_live_stream_t        **stream;
    ngx_rtmp_live_app_conf_t       *lacf;

    lacf = ngx_rtmp_get_module_app_conf(s, ngx_rtmp_live_module);
    if (lacf == NULL) {
        return;
    }

    ctx = ngx_rtmp_get_module_ctx(s, ngx_rtmp_live_module);
    if (ctx && ctx->stream) {
        ngx_log_debug0(NGX_LOG_DEBUG_RTMP, s->connection->log, 
                0, "live: already joined");
        return;
    }

    if (ctx == NULL) {
        ctx = ngx_palloc(s->connection->pool, sizeof(ngx_rtmp_live_ctx_t));
        ngx_rtmp_set_ctx(s, ctx, ngx_rtmp_live_module);
    }

    ngx_memzero(ctx, sizeof(*ctx));
    ctx->session = s;

    ngx_log_debug1(NGX_LOG_DEBUG_RTMP, s->connection->log, 0, 
            "live: join '%s'", name);

    stream = ngx_rtmp_live_get_stream(s, name, 1);
    if (stream == NULL) {
        return;
    }
    if (flags & NGX_RTMP_LIVE_PUBLISHING) {
        if ((*stream)->flags & NGX_RTMP_LIVE_PUBLISHING) {
            ngx_log_error(NGX_LOG_ERR, s->connection->log, 0,
                    "live: already publishing");
            return;
        }
        (*stream)->flags |= NGX_RTMP_LIVE_PUBLISHING;
    }
    ctx->stream = *stream;
    ctx->flags = flags;
    ctx->next = (*stream)->ctx;
    (*stream)->ctx = ctx;

    if (lacf->buflen) {
        s->out_buffer = 1;
    }

    ctx->cs[0].csid = NGX_RTMP_MSG_AUDIO;
    ctx->cs[1].csid = NGX_RTMP_MSG_VIDEO;
}


static ngx_int_t
ngx_rtmp_live_close_stream(ngx_rtmp_session_t *s, ngx_rtmp_close_stream_t *v)
{
    ngx_rtmp_live_ctx_t            *ctx, **cctx;
    ngx_rtmp_live_stream_t        **stream;
    ngx_rtmp_live_app_conf_t       *lacf;

    lacf = ngx_rtmp_get_module_app_conf(s, ngx_rtmp_live_module);
    if (lacf == NULL) {
        goto next;
    }

    ctx = ngx_rtmp_get_module_ctx(s, ngx_rtmp_live_module);
    if (ctx == NULL) {
        goto next;
    }

    if (ctx->stream == NULL) {
        ngx_log_debug0(NGX_LOG_DEBUG_RTMP, s->connection->log, 0,
                   "live: not joined ");
        goto next;
    }

    ngx_log_debug1(NGX_LOG_DEBUG_RTMP, s->connection->log, 0,
                   "live: leave '%s'", ctx->stream->name);

    if (ctx->stream->flags & NGX_RTMP_LIVE_PUBLISHING
            && ctx->flags & NGX_RTMP_LIVE_PUBLISHING)
    {
        ctx->stream->flags &= ~NGX_RTMP_LIVE_PUBLISHING;
    }

    for (cctx = &ctx->stream->ctx; *cctx; cctx = &(*cctx)->next) {
        if (*cctx == ctx) {
            *cctx = ctx->next;
            break;
        }
    }

    if (ctx->stream->ctx) {
        ctx->stream = NULL;
        goto next;
    }

    ngx_log_debug1(NGX_LOG_DEBUG_RTMP, s->connection->log, 0,
            "live: delete empty stream '%s'", ctx->stream->name);

    stream = ngx_rtmp_live_get_stream(s, ctx->stream->name, 0);
    if (stream == NULL) {
        return NGX_ERROR;
    }
    *stream = (*stream)->next;

    ctx->stream->next = lacf->free_streams;
    lacf->free_streams = ctx->stream;
    ctx->stream = NULL;

next:
    return next_close_stream(s, v);
}
                           

static ngx_int_t
ngx_rtmp_live_av(ngx_rtmp_session_t *s, ngx_rtmp_header_t *h, 
                 ngx_chain_t *in)
{
    ngx_rtmp_live_ctx_t            *ctx, *pctx;
    ngx_rtmp_codec_ctx_t           *codec_ctx;
    ngx_chain_t                    *header, *meta,
                                   *apkt, *rpkt,
                                   *aheader, *rheader;
    ngx_rtmp_core_srv_conf_t       *cscf;
    ngx_rtmp_live_app_conf_t       *lacf;
    ngx_rtmp_session_t             *ss;
    ngx_rtmp_header_t               ch, lh;
    ngx_int_t                       rc, sync;
    ngx_uint_t                      prio;
    ngx_uint_t                      peers;
    ngx_uint_t                      header_version, meta_version;
    ngx_uint_t                      csidx, hvidx;
    uint32_t                        timestamp, delta;
    ngx_rtmp_live_chunk_stream_t   *cs;
#ifdef NGX_DEBUG
    const char                     *type_s;

    type_s = (h->type == NGX_RTMP_MSG_VIDEO ? "video" : "audio");
#endif

    lacf = ngx_rtmp_get_module_app_conf(s, ngx_rtmp_live_module);
    if (lacf == NULL) {
        return NGX_ERROR;
    }

    if (!lacf->live || in == NULL  || in->buf == NULL) {
        return NGX_OK;
    }

    ctx = ngx_rtmp_get_module_ctx(s, ngx_rtmp_live_module);
    if (ctx == NULL || ctx->stream == NULL) {
        return NGX_OK;
    }

    if ((ctx->flags & NGX_RTMP_LIVE_PUBLISHING) == 0) {
        ngx_log_debug1(NGX_LOG_DEBUG_RTMP, s->connection->log, 0,
                       "live: %s from non-publisher", type_s);
        return NGX_OK;
    }

    ngx_log_debug3(NGX_LOG_DEBUG_RTMP, s->connection->log, 0,
                   "live: %s packet timestamp=%uD timeshift=%uD",
                   type_s, h->timestamp, h->timeshift);

    sync = 0;
    peers = 0;
    aheader = NULL;
    rheader = NULL;
    apkt = NULL;
    header = NULL;
    header_version = 0;
    meta = NULL;
    meta_version = 0;

    prio = (h->type == NGX_RTMP_MSG_VIDEO ?
            ngx_rtmp_get_video_frame_type(in) : 0);

    cscf = ngx_rtmp_get_module_srv_conf(s, ngx_rtmp_core_module);

    csidx = !(lacf->interleave || h->type == NGX_RTMP_MSG_VIDEO);

    hvidx = (h->type == NGX_RTMP_MSG_VIDEO);

    cs = &ctx->cs[csidx];

    ngx_memzero(&ch, sizeof(ch));

    timestamp = h->timestamp;
    if (lacf->atc == 0) {
        timestamp += h->timeshift;
    }

    ch.timestamp = timestamp;
    ch.msid = NGX_RTMP_MSID;
    ch.csid = cs->csid;
    ch.type = h->type;

    lh = ch;

    if (cs->active) {
        lh.timestamp = cs->timestamp;
    } else {
        sync = 1;
    }

    cs->active = 1;
    cs->timestamp = ch.timestamp;

    delta = ch.timestamp - lh.timestamp;

    rpkt = ngx_rtmp_append_shared_bufs(cscf, NULL, in);

    ngx_rtmp_prepare_message(s, &ch, &lh, rpkt);

    codec_ctx = ngx_rtmp_get_module_ctx(s, ngx_rtmp_codec_module);

    if (codec_ctx) {

        if (h->type == NGX_RTMP_MSG_AUDIO) {
            
            if (codec_ctx->aac_header) {
                header = codec_ctx->aac_header;
                header_version = codec_ctx->aac_version;
            }

        } else {

            if (codec_ctx->avc_header) {
                header = codec_ctx->avc_header;
                header_version = codec_ctx->avc_version;
            }
        }

        if (lacf->meta && codec_ctx->meta) {
            meta = codec_ctx->meta;
            meta_version = codec_ctx->meta_version;
        }
    }

    /* broadcast to all subscribers */

    for (pctx = ctx->stream->ctx; pctx; pctx = pctx->next) {
        if (pctx == ctx) {
            continue;
        }

        ss = pctx->session;
        cs = &pctx->cs[csidx];

        /* send metadata */

        if (meta && meta_version != pctx->meta_version) {
            ngx_log_debug0(NGX_LOG_DEBUG_RTMP, ss->connection->log, 0,
                           "live: meta");

            if (ngx_rtmp_send_message(ss, meta, 0) == NGX_OK) {
                pctx->meta_version = meta_version;
            }
        }

        /* sync stream */

        if (cs->active && (sync || (lacf->sync && cs->dropped > lacf->sync))) {
            ngx_log_debug2(NGX_LOG_DEBUG_RTMP, ss->connection->log, 0,
                           "live: sync %s dropped=%uD", type_s, cs->dropped);
            cs->active = 0;
            cs->dropped = 0;
        }

        /* absolute packet */

        if (!cs->active) {

            if (lacf->wait_key && prio != NGX_RTMP_VIDEO_KEY_FRAME &&
               (lacf->interleave || h->type == NGX_RTMP_MSG_VIDEO))
            {
                ngx_log_debug0(NGX_LOG_DEBUG_RTMP, ss->connection->log, 0,
                               "live: skip non-key");
                continue;

            }

            ch.timestamp = timestamp;
            if (lacf->atc == 0) {
                ch.timestamp -= (uint32_t) ss->epoch;
            }

            lh.timestamp = ch.timestamp - delta;

            /*
            if (ngx_rtmp_send_user_stream_eof(ss, NGX_RTMP_MSID) != NGX_OK) {
                continue;
            }

            if (ngx_rtmp_send_user_stream_begin(ss, NGX_RTMP_MSID) != NGX_OK) {
                continue;
            }*/

            if (header) {

                /* send absolute codec header */

                if (lacf->atc == 0 && (int32_t) lh.timestamp < 0) {
                    ngx_log_debug1(NGX_LOG_DEBUG_RTMP, ss->connection->log, 0,
                                   "live: abs %s header from the past", type_s);
                    continue;
                }

                ngx_log_debug2(NGX_LOG_DEBUG_RTMP, ss->connection->log, 0,
                               "live: abs %s header timestamp=%uD",
                               type_s, lh.timestamp);

                if (aheader == NULL) {
                    aheader = ngx_rtmp_append_shared_bufs(cscf, NULL, header);
                    ngx_rtmp_prepare_message(s, &lh, NULL, aheader);
                }

                rc = ngx_rtmp_send_message(ss, aheader, 0);

                if (!lacf->atc) {
                    ngx_rtmp_free_shared_chain(cscf, aheader);
                    aheader = NULL;
                }

                if (rc != NGX_OK) {
                    continue;
                }

                cs->timestamp = lh.timestamp;
                cs->active = 1;

                pctx->header_versions[hvidx] = header_version;

            } else {

                /* send absolute packet */

                if (lacf->atc == 0 && (int32_t) ch.timestamp < 0) {
                    ngx_log_debug1(NGX_LOG_DEBUG_RTMP, ss->connection->log, 0,
                                   "live: abs %s packet from the past", type_s);
                    continue;
                }

                ngx_log_debug2(NGX_LOG_DEBUG_RTMP, ss->connection->log, 0,
                               "live: abs %s packet timestamp=%uD",
                               type_s, ch.timestamp);

                if (apkt == NULL) {
                    apkt = ngx_rtmp_append_shared_bufs(cscf, NULL, in);
                    ngx_rtmp_prepare_message(s, &ch, NULL, apkt);
                }

                rc = ngx_rtmp_send_message(ss, apkt, prio);

                if (!lacf->atc) {
                    ngx_rtmp_free_shared_chain(cscf, apkt);
                    apkt = NULL;
                }

                if (rc != NGX_OK) {
                    continue;
                }

                cs->timestamp = ch.timestamp;
                cs->active = 1;

                ++peers;

                continue;
            }
        }

        /* send codec header if newer header has arrived  */

        if (header && pctx->header_versions[hvidx] != header_version) {
            ngx_log_debug1(NGX_LOG_DEBUG_RTMP, ss->connection->log, 0,
                           "live: new %s header", type_s);

            if (rheader == NULL) {
                rheader = ngx_rtmp_append_shared_bufs(cscf, NULL, header);
                ngx_rtmp_prepare_message(s, &ch, &ch, rheader);
            }

            if (ngx_rtmp_send_message(ss, rheader, 0) == NGX_OK) {
                pctx->header_versions[hvidx] = header_version;
            }
        }

        /* send relative packet */

        ngx_log_debug2(NGX_LOG_DEBUG_RTMP, ss->connection->log, 0,
                       "live: rel %s packet delta=%uD",
                       type_s, delta);

        if (ngx_rtmp_send_message(ss, rpkt, prio) != NGX_OK) {
            ++pctx->ndropped;
            cs->dropped += delta;
            continue;
        }

        cs->timestamp += delta;
        ++peers;
    }

    if (rpkt) {
        ngx_rtmp_free_shared_chain(cscf, rpkt);
    }

    if (apkt) {
        ngx_rtmp_free_shared_chain(cscf, apkt);
    }

    if (rheader) {
        ngx_rtmp_free_shared_chain(cscf, rheader);
    }

    if (aheader) {
        ngx_rtmp_free_shared_chain(cscf, aheader);
    }

    ngx_rtmp_update_bandwidth(&ctx->stream->bw_in, h->mlen);
    ngx_rtmp_update_bandwidth(&ctx->stream->bw_out, h->mlen * peers);

    return NGX_OK;
}


static ngx_int_t
ngx_rtmp_live_publish(ngx_rtmp_session_t *s, ngx_rtmp_publish_t *v)
{
    ngx_rtmp_live_app_conf_t       *lacf;

    lacf = ngx_rtmp_get_module_app_conf(s, ngx_rtmp_live_module);

    if (lacf == NULL || !lacf->live) {
        goto next;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_RTMP, s->connection->log, 0,
            "live: publish: name='%s' type='%s'",
            v->name, v->type);

    /* join stream as publisher */
    ngx_rtmp_live_join(s, v->name, NGX_RTMP_LIVE_PUBLISHING);

next:
    return next_publish(s, v);
}


static ngx_int_t
ngx_rtmp_live_play(ngx_rtmp_session_t *s, ngx_rtmp_play_t *v)
{
    ngx_rtmp_live_app_conf_t       *lacf;

    lacf = ngx_rtmp_get_module_app_conf(s, ngx_rtmp_live_module);

    if (lacf == NULL || !lacf->live) {
        goto next;
    }

    ngx_log_debug4(NGX_LOG_DEBUG_RTMP, s->connection->log, 0,
            "live: play: name='%s' start=%uD duration=%uD reset=%d",
            v->name, (uint32_t)v->start, 
            (uint32_t)v->duration, (uint32_t)v->reset);

    /* join stream as player */
    ngx_rtmp_live_join(s, v->name, 0);

next:
    return next_play(s, v);
}


static ngx_int_t
ngx_rtmp_live_postconfiguration(ngx_conf_t *cf)
{
    ngx_rtmp_core_main_conf_t          *cmcf;
    ngx_rtmp_handler_pt                *h;

    cmcf = ngx_rtmp_conf_get_module_main_conf(cf, ngx_rtmp_core_module);

    /* register raw event handlers */
    h = ngx_array_push(&cmcf->events[NGX_RTMP_MSG_AUDIO]);
    *h = ngx_rtmp_live_av;

    h = ngx_array_push(&cmcf->events[NGX_RTMP_MSG_VIDEO]);
    *h = ngx_rtmp_live_av;

    /* chain handlers */
    next_publish = ngx_rtmp_publish;
    ngx_rtmp_publish = ngx_rtmp_live_publish;

    next_play = ngx_rtmp_play;
    ngx_rtmp_play = ngx_rtmp_live_play;

    next_close_stream = ngx_rtmp_close_stream;
    ngx_rtmp_close_stream = ngx_rtmp_live_close_stream;

    return NGX_OK;
}