[FFmpeg-devel] [PATCH] avformat/libsrt: Change latency option to milliseconds

[pkv]

Hi

new patch for latency option following the comments from N. George.

=====

Updated protocol doc for srt to specify the unit of various latency options.
Furthermore the type of the latency options is changed to 
AV_OPT_TYPE_DURATION
(following comment from N. George).

The microsecond unit has caused confusion for both FFmpeg and obs-studio 
users:
- https://github.com/Haivision/srt/issues/1223

- https://obsproject.com/mantis/view.php?id=1617

=====

Regards

-------------- next part --------------
From 1dd49812553f44bc5f1ed60660a2365d6a036c97 Mon Sep 17 00:00:00 2001
From: pkv <pkv at obsproject.com>
Date: Tue, 7 Apr 2020 18:08:22 +0200
Subject: [PATCH] avformat/libsrt: Document latency options unit

Updated protocol doc for srt to specify the unit of various latency options.
Furthermore the type of the latency options is changed to AV_OPT_TYPE_DURATION
(following comment from N. George).

The microsecond unit has caused confusion for both FFmpeg and obs-studio users:
- https://github.com/Haivision/srt/issues/1223

- https://obsproject.com/mantis/view.php?id=1617
---
 doc/protocols.texi   | 6 +++---
 libavformat/libsrt.c | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/doc/protocols.texi b/doc/protocols.texi
index e510019f2d..ebf9dec529 100644
--- a/doc/protocols.texi
+++ b/doc/protocols.texi
@@ -1286,8 +1286,8 @@ IP Type of Service. Applies to sender only. Default value is 0xB8.
 @item ipttl=@var{ttl}
 IP Time To Live. Applies to sender only. Default value is 64.
 
- at item latency
-Timestamp-based Packet Delivery Delay.
+ at item latency=@var{microseconds}
+Timestamp-based Packet Delivery Delay in microseconds.
 Used to absorb bursts of missed packet retransmissions.
 This flag sets both @option{rcvlatency} and @option{peerlatency}
 to the same value. Note that prior to version 1.3.0
@@ -1389,7 +1389,7 @@ Not required on receiver (set to 0),
 key size obtained from sender in HaiCrypt handshake.
 Default value is 0.
 
- at item rcvlatency
+ at item rcvlatency at var{microseconds}
 The time that should elapse since the moment when the
 packet was sent and the moment when it's delivered to
 the receiver application in the receiving function.
diff --git a/libavformat/libsrt.c b/libavformat/libsrt.c
index 2d6fc4b7e7..5c61f9e0d7 100644
--- a/libavformat/libsrt.c
+++ b/libavformat/libsrt.c
@@ -118,10 +118,10 @@ static const AVOption libsrt_options[] = {
     { "iptos",          "IP Type of Service",                                                   OFFSET(iptos),            AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, 255,       .flags = D|E },
     { "inputbw",        "Estimated input stream rate",                                          OFFSET(inputbw),          AV_OPT_TYPE_INT64,    { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
     { "oheadbw",        "MaxBW ceiling based on % over input stream rate",                      OFFSET(oheadbw),          AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, 100,       .flags = D|E },
-    { "latency",        "receiver delay to absorb bursts of missed packet retransmissions",     OFFSET(latency),          AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
+    { "latency",        "receiver delay to absorb bursts of missed packet retransmissions",     OFFSET(latency),          AV_OPT_TYPE_DURATION, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
     { "tsbpddelay",     "deprecated, same effect as latency option",                            OFFSET(latency),          AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
-    { "rcvlatency",     "receive latency",                                                      OFFSET(rcvlatency),       AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
-    { "peerlatency",    "peer latency",                                                         OFFSET(peerlatency),      AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
+    { "rcvlatency",     "receive latency",                                                      OFFSET(rcvlatency),       AV_OPT_TYPE_DURATION, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
+    { "peerlatency",    "peer latency",                                                         OFFSET(peerlatency),      AV_OPT_TYPE_DURATION, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
     { "tlpktdrop",      "Enable receiver pkt drop",                                             OFFSET(tlpktdrop),        AV_OPT_TYPE_BOOL,     { .i64 = -1 }, -1, 1,         .flags = D|E },
     { "nakreport",      "Enable receiver to send periodic NAK reports",                         OFFSET(nakreport),        AV_OPT_TYPE_BOOL,     { .i64 = -1 }, -1, 1,         .flags = D|E },
     { "connect_timeout", "Connect timeout. Caller default: 3000, rendezvous (x 10)",            OFFSET(connect_timeout),  AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
-- 
2.24.1.windows.2