[FFmpeg-devel] [PATCH 5/5] avformat/libsrt: add snddropdelay parameter for srt

[lance.lmwang at gmail.com]

On Thu, Sep 30, 2021 at 09:14:00AM +0800, lance.lmwang at gmail.com wrote:
> From: Limin Wang <lance.lmwang at gmail.com>
> 
> Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> ---
>  doc/protocols.texi   | 10 ++++++++++
>  libavformat/libsrt.c |  7 +++++++
>  2 files changed, 17 insertions(+)
> 
> diff --git a/doc/protocols.texi b/doc/protocols.texi
> index 726e5f1..9c246f8 100644
> --- a/doc/protocols.texi
> +++ b/doc/protocols.texi
> @@ -1496,6 +1496,16 @@ when the old encryption key is decommissioned. Default is -1.
>  -1 means auto (0x1000 in srt library). The range for
>  this option is integers in the 0 - @code{INT_MAX}.
>  
> + at item snddropdelay=@var{microseconds}
> +The sender's delay before dropping packets. This delay is
> +added to the default drop delay time interval value.
> +Keep in mind that the longer the delay, the more probable it
> +becomes that packets would be retransmitted uselessly because
> +they will be dropped by the receiver anyway.
> +
> +Default is -1 means auto which typically means do not drop
> +packets on the sender at all.
> +
>  @item payload_size=@var{bytes}
>  Sets the maximum declared size of a packet transferred
>  during the single call to the sending function in Live
> diff --git a/libavformat/libsrt.c b/libavformat/libsrt.c
> index c6308d1..13697d2 100644
> --- a/libavformat/libsrt.c
> +++ b/libavformat/libsrt.c
> @@ -65,6 +65,7 @@ typedef struct SRTContext {
>      int enforced_encryption;
>      int kmrefreshrate;
>      int kmpreannounce;
> +    int64_t snddropdelay;
>  #endif
>      int mss;
>      int ffs;
> @@ -111,6 +112,7 @@ static const AVOption libsrt_options[] = {
>      { "enforced_encryption", "Enforces that both connection parties have the same passphrase set",                              OFFSET(enforced_encryption), AV_OPT_TYPE_BOOL,  { .i64 = -1 }, -1, 1,         .flags = D|E },
>      { "kmrefreshrate",       "The number of packets to be transmitted after which the encryption key is switched to a new key", OFFSET(kmrefreshrate),       AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },
>      { "kmpreannounce",       "The interval between when a new encryption key is sent and when switchover occurs",               OFFSET(kmpreannounce),       AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },
> +    { "snddropdelay",        "The sender's delay(in microseconds) before dropping packets",                                     OFFSET(snddropdelay),        AV_OPT_TYPE_INT64,   { .i64 = -1 }, -1, INT64_MAX,   .flags = D|E },
>  #endif
>      { "mss",            "The Maximum Segment Size",                                             OFFSET(mss),              AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, 1500,      .flags = D|E },
>      { "ffs",            "Flight flag size (window size) (in bytes)",                            OFFSET(ffs),              AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },
> @@ -318,6 +320,7 @@ static int libsrt_set_options_pre(URLContext *h, int fd)
>      int latency = s->latency / 1000;
>      int rcvlatency = s->rcvlatency / 1000;
>      int peerlatency = s->peerlatency / 1000;
> +    int snddropdelay = s->snddropdelay / 1000;
>      int connect_timeout = s->connect_timeout;
>  
>      if ((s->mode == SRT_MODE_RENDEZVOUS && libsrt_setsockopt(h, fd, SRTO_RENDEZVOUS, "SRTO_RENDEZVOUS", &yes, sizeof(yes)) < 0) ||
> @@ -334,6 +337,7 @@ static int libsrt_set_options_pre(URLContext *h, int fd)
>  #endif
>          (s->kmrefreshrate >= 0 && libsrt_setsockopt(h, fd, SRTO_KMREFRESHRATE, "SRTO_KMREFRESHRATE", &s->kmrefreshrate, sizeof(s->kmrefreshrate)) < 0) ||
>          (s->kmpreannounce >= 0 && libsrt_setsockopt(h, fd, SRTO_KMPREANNOUNCE, "SRTO_KMPREANNOUNCE", &s->kmpreannounce, sizeof(s->kmpreannounce)) < 0) ||
> +        (s->snddropdelay  >= 0 && libsrt_setsockopt(h, fd, SRTO_SNDDROPDELAY,  "SRTO_SNDDROPDELAY",  &snddropdelay, sizeof(snddropdelay)) < 0) ||
>  #endif
>          (s->mss >= 0 && libsrt_setsockopt(h, fd, SRTO_MSS, "SRTO_MSS", &s->mss, sizeof(s->mss)) < 0) ||
>          (s->ffs >= 0 && libsrt_setsockopt(h, fd, SRTO_FC, "SRTO_FC", &s->ffs, sizeof(s->ffs)) < 0) ||
> @@ -549,6 +553,9 @@ static int libsrt_open(URLContext *h, const char *uri, int flags)
>          if (av_find_info_tag(buf, sizeof(buf), "kmpreannounce", p)) {
>              s->kmpreannounce = strtol(buf, NULL, 10);
>          }
> +        if (av_find_info_tag(buf, sizeof(buf), "snddropdelay", p)) {
> +            s->snddropdelay = strtoll(buf, NULL, 10);
> +        }
>  #endif
>          if (av_find_info_tag(buf, sizeof(buf), "mss", p)) {
>              s->mss = strtol(buf, NULL, 10);

will apply patch set(3,4,5) in two day unless there are objections.


> -- 
> 1.8.3.1
> 

-- 
Thanks,
Limin Wang